Debt Algorand Standard Application

A standard for debt instruments tokenization on Algorand

The Debt Algorand Standard Application (D-ASA) is a standard for tokenizing debt instruments on the Algorand Virtual Machine.

It provides the interfaces for arranging the asset, configuring its role-based access control, issuing and distributing it on the primary market, executing cash flows, exchanging it on the secondary market, and querying information about the debt instrument.

The specification provides recommendations to conform, at the best effort¹, to the Algorithmic Contract Types Unified Standards (ACTUS).

The specification allows the tokenization of various debt instruments, such as bonds, loans, commercial papers, mortgages, etc. A reference implementation of some fixed income contract examples is provided.

This document is a technical specification, it is not to be intended as a legal or a financial document.

Contributing

The D-ASA is free and open source. The source code is released on the official GitHub repository. External contributions are welcome, the project relies on the community to improve and expand. Issues and features requests can be submitted on the GitHub issues page. If you would like to contribute, please consider submitting a pull request.

License

The D-ASA source and documentation are released under the AGPL-3.0 license.

Motivation

Debt instruments represent one of the biggest asset classes (along with equities, commodities, and real estate). Debt instruments are investment contracts between borrowers and lenders, used to raise capital with binding obligations between the parties, who agree on the payoff and the cash flows (payments schedule, interest rates, maturity, etc.).

The definition of a comprehensive specification for the tokenization of debt instruments benefits several players of the traditional value chain, such as issuers, arrangers, asset managers, risk managers, lenders, payment agents, transfer agents, etc.

The Debt Algorand Standard Application turns a traditional debt instrument into a deterministic financial contract, executed on the Algorand Virtual Machine (AVM). The machine-readable and executable contract removes existing frictions over the debt instruments lifecycle and reconciliation, enabling use cases such as truly atomic delivery-vs-payment (with instant finality and no counterparty risk), deterministic cash flows analysis (when, how much, to whom), and easier quantitative risk management.

Definitions

The keywords "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119.

The data types (like uint64, byte[], etc.) in this document are to be interpreted as specified in ARC-4.

Acronyms in square brackets like \([THIS]\) are to be interpreted as defined in the ACTUS dictionary.

Notes like this are non-normative

Non-normative sections mainly contextualize the specification for technical readers unfamiliar with the financial concepts described.

📎 EXAMPLE

Sections like this are examples aiming to clarify the specifications.

Sections like this are either pseudo-code or formal examples.

Overview

A Debt Algorand Standard Application (D-ASA) is a debt instrument issued as an Algorand Application, that conforms to this specification, and whose operations and cash flows are executed on the AVM.

This specification defines the actors of a D-ASA and the interfaces of the Algorand Application to:

• Arrange and configure the D-ASA (e.g. principal, interest, time events, etc.);
• Manage D-ASA accounts (e.g. opening and closing accounts, etc.);
• Distribute the D-ASA on the primary market (e.g. book building, auctions, etc.);
• Execute D-ASA cash flows (e.g coupon payments, principal repayment, etc.);
• Exchange the D-ASA on secondary markets (if any);
• Query D-ASA information (e.g. due coupons, next coupon due date, etc.).

This specification also provides the interfaces to comply with regulatory requirements, such as defining a role-based access control, suspending D-ASA operations completely or for specific accounts, managing default processes, etc.

The contents are structured on four functional layers:

1. Trust Model: this layer defines the application role-based access control model to manage the fixed income contract and comply with regulatory frameworks;
2. Contract: this layer provides the algorithmic definitions of the debt instrument (data model, attributes, and cash flows);
3. Ownership: this layer defines the tokenization of the contract;
4. Execution: this layer defines the execution of the contract, both the distribution, cash flows and transfers.

ACTUS compliance

ACTUS still presents some limitations with respect to blockchain-based implementations.

Therefore, ACTUS compliance is RECOMMENDED but not mandatory.

ACTUS limitations are usually marked with footnotes.

Roles

D-ASA defines custom roles and permissions for the entities involved in the debt instrument.

The D-ASA MUST define contract roles \([CNTRL]\).

The contract roles MUST be identified with a role ID (uint8).

The contract roles MUST be associated with Algorand Addresses through a role key of the form:

[R||<role ID>||#||<role address>]

Where || denotes concatenation.

📎 EXAMPLE

Let’s have a D-ASA role ID 42 associated with the Algorand Address XYZ. The corresponding role key is 42#XYZ.

Issuer (Borrower)

Issuers are individuals, companies, institutions, governments, or other entities who borrow capital by issuing a debt.

An Issuer \([CRID]\) is an entity that owes a debt issued as D-ASA.

The Issuer role MUST be identified with the reserved ID 1 \([RPL]\).

Arranger

Arrangers are legal entities authorized to arrange debt instruments on behalf of the issuers.

The Arranger owns an Algorand Address.

The Arranger role MUST be identified with the reserved ID 20.

The Arranger SHALL configure the D-ASA using the asset_config method.

The Arranger MAY configure the D-ASA role-based access control with the OPTIONAL assign_role and revoke_role methods.

Investor (Lender)

Investors are lenders providing capital to borrowers with the expectation of a financial return, defined by debt instruments.

Investors \([CPID]\) own D-ASA accounts, characterized by a pair of Algorand Addresses:

• Holding Address: address that owns D-ASA units with the right to future payments;
• Payment Address: address that receives D-ASA payments.

The Payment Address MAY be different from the Holding Address.

D-ASA units can be in custody with a third party or temporarily deposited on an order book (Holding Address). At the same time, payments are always executed towards the investor (on the Payment Address).

The right to open and close investor accounts can be granted to different entities, such as KYC providers or banks.

The Investor role MUST be identified with the reserved ID 30.

Debt instruments may have an order of repayment in the event of a sale or default of the issuer, based on investors' seniority.

Investors with the same seniority are treated equally.

The Investors MAY have different seniority \([SEN]\).

Open Account

The D-ASA accounts SHALL be opened using the open_account method.

The D-ASA accounts MUST NOT be opened if the D-ASA is suspended (see Suspension section).

The D-ASA accounts MUST NOT be opened if the D-ASA is in default (see Default section).

Close Account

The D-ASA accounts MAY be closed using the close_account method.

The D-ASA accounts MUST NOT be closed if the D-ASA is in default (see Default section).

Oracles

Debt instruments may rely on external data, such as interest rates, covenant breaches, etc., provided by trusted oracles.

An Oracle \([MOC]\) is an external entity that provides trusted data to the D-ASA.

A D-ASA MAY have multiple oracles.

The Oracle roles MUST be identified with the reserved IDs between 80 - 100.

Role-Based Access Control

D-ASA can define a custom role-based access control to comply with administrative and regulatory requirements.

A D-ASA role MAY be assigned using the OPTIONAL assign_role method.

A D-ASA role MAY be revoked using the OPTIONAL revoke_role method.

Suspension

Debt instruments are regulated under different legal frameworks and their jurisdictions.

The D-ASA ensures efficient execution of the debt instrument in the "best case scenarios", where it offers the highest improvements in cost and time efficiency if compared to the traditional, manual, and labor-intensive contracts.

The D-ASA provides methods to comply with regulatory obligations, allowing the management of the "worst case scenarios", in which the intervention of the authority or the regulator is necessary.

Debt instruments can be temporarily suspended due to regulations or operational reasons.

The D-ASA suspension authority MUST be restricted to specific contract roles.

Asset Suspension

The D-ASA MAY suspend all:

• Payments;
• D-ASA units transfers.

The asset suspension status MUST be set with the set_asset_suspension_status method.

Account Suspension

The D-ASA MAY suspend an account:

• Payments (skipped on due dates);
• D-ASA units transfers (from and to).

The account suspension status MUST be set with the set_account_suspension_status method.

Contract Type

Debt instruments such as bullet bonds, amortizing loans, mortgages, etc. differ based on their cash flow exchange patterns (e.g., principal and interest payment time schedules, fixed or variable interest rates, etc.).

The ACTUS taxonomy reduces the majority of all financial contracts to a defined set of 32 generalized cash flow exchange patterns, called contract types.

It is RECOMMENDED to classify the D-ASA with an ACTUS contract type \([CT]\) (uint8) (see the ACTUS taxonomy).

The contract type MUST have the following properties:

• family: Basic
• class: Fixed Income

The contract type MAY be set using the OPTIONAL set_asset_metadata method (see Metadata section).

It is RECOMMENDED to use the unique D-ASA ID as contract identifier \([CID]\).

Denomination

Debt instruments are denominated in a currency, in which principal and interests are calculated.

The D-ASA MUST be denominated either in an on-chain or off-chain denomination asset \([CUR]\)¹.

The denomination asset identifier (uint64) MUST be set using the asset_config method.

On-chain denomination

The denomination asset MUST be an Algorand Standard Asset (ASA), an Application asset (App), or the ALGO.

The denomination asset identifier MUST be the ASA ID, the App ID, or 0for ALGO.

Off-chain denomination

The denomination asset identifier MUST the ISO 4217 currency numeric code.

The denomination asset MUST use the decimal digits specified by the ISO 4217.

Principal

Debt instruments principal is the amount of capital borrowed and used as a base for calculating interest.

The D-ASA MAY define the principal \([NT]\) (uint64), expressed in the denomination asset.

If the D-ASA has a principal, it MUST define a minimum denomination (uint64), expressed in the denomination asset.

The minimum denomination MUST be a divisor of the principal.

The principal and the minimum denomination MUST be set using the asset_config method.

If the D-ASA has no defined principal, the principal and the minimum denomination MUST be set to 0.

Discount

Debt instruments principal may be placed at discount on issuance.

The D-ASA MAY define a discount rate \([PDIED]\) (uint16) in bps to apply to the principal on the issuance.

The discount MUST be set using the asset_config method.

📎 EXAMPLE

Let’s have a D-ASA denominated in EUR, with a principal of 1M EUR paid at maturity and a minimum denomination of 1,000 EUR. The D-ASA has a principal discount of 200 bps (2%) at the issuance. Each D-ASA unit is sold on the primary market at 980 EUR and will be redeemed for 1,000 EUR of principal at maturity.

Amortization

⚠️This section is still subject to major changes and reviews.

Debt instruments principal may be amortized until maturity, according to an amortization schedule.

If the debt instrument has principal amortization, the D-ASA MUST define the amortization rates as uint16[] array, where:

• The length of the array is N=K+1, with K equal to the fixed total coupons (see Coupons section);

• The first Kelements of the array are the amortizing rates associated with coupon payments;

• The last element of the array is the amortization rate associated with outstanding principal payment at maturity date;

• The elements of the array are expressed in basis points (bps);

• The sum of all the amortization rates is equal to 10,000 bps.

The amortization rates define the amount of principal \([PRNXT]\) paid at the next payment date.

📎 EXAMPLE

A D-ASA with 5 coupons and even principal amortizing rates has the following amortizing rates (bps):

uint64[] = [2000, 2000, 2000, 2000, 2000, 0]

📎 EXAMPLE

A D-ASA with 5 coupons and a single principal early repayment of 50% has the following amortizing rates (bps):

uint64[] = [0, 0, 5000, 0, 0, 5000]

📎 EXAMPLE

A D-ASA with 4 coupons and different principal amortizing rates (bps):

uint64[] = [1000, 2000, 3000, 4000, 0]

📎 EXAMPLE

The following are invalid amortizing rates, since their sum is not equal to 10,000 bps:

uint64[] = [1000, 2000, 3000, 4000, 5000]

The amortizing rates MUST be set using the OPTIONAL set_amortizing_rates method.

The amortizing rates MAY be updated with the OPTIONAL set_amortizing_rates method.

The updated amortizing rates MUST NOT modify past amortizing rates.

Interests

Debt instruments interest is calculated on a fixed or variable rate on the outstanding principal.

The interest rate is the nominal yield paid by the debt instrument on the principal, usually expressed as Annual Percentage Yield (APY).

The D-ASA interest rates MUST be defined in basis points (bps).

Interest Rate

The D-ASA MAY define a nominal interest rate \([IPNR]\) (uint16).

The interest rate MUST be set using the asset_config method.

Coupons

Debt instruments can pay interest in periodic installments, called coupons.

Coupons mature in a coupon period, according to a defined coupon schedule.

The D-ASA MUST define the number of total coupons K (uint64):

• K>0 if the D-ASA has a defined number of coupons;
• K=0 if the D-ASA has zero or undefined (perpetual) coupons.

Coupon Rates

Debt instruments can pay coupons with fixed or variable interest rates.

The D-ASA MAY define the coupon rates \([ARRATE]\) as uint16[] array, where:

• The length of the array MUST be K, equal to the total coupons;
• The K-elements of the array are the coupon rates, expressed in bps.

If the D-ASA has zero or undefined coupons (K=0), the coupon rates array MUST be empty and the interest rate MUST be used instead.

Coupon rates could be derived from the interest rate.

📎 EXAMPLE

D-ASA with 4 coupons with the following rates: 2,00%, 2,50%, 3,00%, and 3,50% would have the following coupon rates array (bps):

uint64[] = [200, 250, 300, 350]

📎 EXAMPLE

D-ASA with zero coupons would have the following coupon rates array (bps):

uint64[] = []

The coupon rates MUST be set using the asset_config method.

Accruing Interest

Debt instruments may accrue interest over time.

The D-ASA units MAY accrue interest \([IPAC]\), according to the day-count convention (see Day-Count Convention section).

If the D-ASA has coupons, the units accrued interest MUST be calculated with respect to the latest coupon due date.

📎 EXAMPLE

Let's have a D-ASA with 4 coupons. The 2nd coupon is due. The D-ASA units are accruing the interest of the 3rd coupon. The accrued interest is calculated according to the day-count convention, applied to the elapsed time with respect to the 2nd coupon due date.

If the D-ASA has coupons, the account units accrued interest calculation SHOULD fail if it has pending coupon payments.

📎 EXAMPLE

Let's have a D-ASA with 4 coupons. The 2nd coupon is due. The D-ASA units are accruing the interest of the 3rd coupon. Coupon payments are not executed synchronously for all the Investors. The 2nd coupon payment is executed for Investor A, while Investor B is still waiting for the payment settlement. The accrued interest calculation succeeds for Investor A and fails for Investor B until the 2nd coupon payment is settled.

Variable Rates

⚠️This section is still subject to major changes and reviews.

Debt instruments may have variable interest rates, based on external data oracles.

If the debt instrument has variable interest rates, the D-ASA MAY implement the OPTIONAL set_variable_interest method.

Interest Update Dates

The D-ASA MUST define interest update dates of known \([RRF]\) or unknown \([RR]\) with respect to:

• time events if the D-ASA has fixed number of coupons (see Time Events section);

• time periods if the D-ASA has undefined number of coupons (see Time Periods section).

The first interest update date corresponds to \([RRANX]\).

Spread

Debt instruments typically define a spread (bps) with respect to an external index to update the interest rate.

The D-ASA MAY define a rate spread \([RRSP]\) (uint16) in bps to apply to the external interest data feed.

The rate spread MUST be set using the OPTIONAL set_variable_rate method.

If the debt instrument has no rate spread, then the D-ASA MUST set the rate spread to 0.

📎 EXAMPLE

A D-ASA has variable interest rates pegged to an off-chain index. Interest update is equal to the off-chain index plus the rate spread (bps).

Cap and Floor

Debt instruments may define limitations to the interest rate variability, either over the whole contract lifespan or over specific periods.

Life Caps

The D-ASA MAY define a life cap \([RRLC]\) (uint16) in bps to apply to the variable interest rate.

The D-ASA MAY define a life floor \([RRLF]\) (uint16) in bps to apply to the variable interest rate.

The life cap and the life floor MUST be set using the OPTIONAL set_variable_rate method.

If the debt instrument has no life cap, then the D-ASA MUST set the life cap to 0.

If the debt instrument has no life floor, then the D-ASA MUST set the life floor to 0.

Period Caps

The D-ASA MAY define a period cap \([RRPC]\) (uint16) in bps to apply to the variable interest rate.

The D-ASA MAY define a period floor \([RRPF]\) (uint16) in bps to apply to the variable interest rate.

The period cap and the period floor MUST be set using the OPTIONAL set_variable_rate method.

If the debt instrument has no period cap, then the D-ASA MUST set the period cap to 0.

If the debt instrument has no period floor, then the D-ASA MUST set the period floor to 0.

Fixing Period

Debt instruments usually schedule interest rate updates before the new rate applies (defined by the rate reset schedule).

The D-ASA MUST define a fixing period \([RRFIX]\) (uint64) that specifies a period of time before the coupon due date in which the interest can be updated.

The fixing period MUST be set using the OPTIONAL set_variable_rate method.

Rates Update

Debt instruments may have a fixed or undefined rate update schedule.

If the debt instrument has a fixed rate update schedule, then the D-ASA MUST use the coupon due dates (either time events or time periods) as anchors for the rate update events (see Time Schedule section).

The interest rate MAY be updated using the OPTIONAL update_interest_rate method.

If the D-ASA has coupons, the interest rate MUST NOT be updated if there is any due coupon still to be paid.

The coupon rates MAY be updated using the OPTIONAL update_coupon_rates method.

The coupon rates MUST NOT be updated if there is any due coupon still to be paid.

The updated coupon rates MUST NOT modify past coupon rates.

The interest rate and coupon rates updatability MUST be restricted to the interest oracle role (see Oracles section).

📎 EXAMPLE

A D-ASA has variable interest rates pegged to an off-chain index. Interest update permissions are granted to an external interest oracle.

📎 EXAMPLE

A D-ASA has variable interest rates based on covenant breaches. Interest update permissions are granted to a trustee in charge of verifying breaches.

Time Schedule

Debt instruments may have fixed or variable time schedule (e.g., variable coupon due date, etc.).

Debt instruments may have a limited or unlimited time schedule (e.g., a fixed coupon bond or a perpetual bond).

Time Measurement

The time on the Algorand Virtual Machine is defined by the block UNIX timestamp¹.

The Algorand protocol has dynamic block latency with instant finality. At the time of writing (Jan 2025), block finality is about 2.8 seconds².

The AVM time may present a drift with respect to external standard time references.

Events

The D-ASA events \([EVT]\) are defined by:

• time events \([TEV]\) (or "anchors");
• time periods (or "cycles").

Time Events

D-ASA time events are time on which contractual events are due or on which cyclic events begin or end.

Primary Distribution

Debt instruments can be distributed on the primary market during the primary distribution.

The opening and closure dates define the primary distribution duration.

The D-ASA MUST have a primary opening (uint64) and closure date (uint64).

Issuance

Debt instruments start accruing interest on the issuance date.

The D-ASA MUST have an issuance date \([IED]\) (uint64).

Maturity

Debt instruments may have a maturity date, on which the principal is repaid and the contract obligations expire.

Debt instruments may have a fixed or variable maturity date.

The D-ASA MAY have a maturity date \([MD]\) (uint64).

The maturity date MAY be updated in case of early repayment options (see Early Repayment Options section).

Time Events Array

The D-ASA MUST define time events \([TEV]\) as uint64[] array, where:

• The length of the array MUST be:

  • N=K+4, if the D-ASA has a maturity date;
  • N=K+3, if the D-ASA has not a maturity date;

  with K equal to the total coupons.

• The first element MUST be the primary distribution opening date (uint64): the time at which the D-ASA primary distribution opens;

• The second element MUST be the primary distribution closure date (uint64): the time at which the D-ASA primary distribution closes;

• The third element MUST be the issuance date (uint64): the time at which D-ASA starts to accrue interest on the principal;

• If the D-ASA has a fixed number of coupons, then the next K-elements MUST be the coupon due dates \([IP]\) (uint64[K]): times at which the coupons mature and the interest payment \([IPPNT]\) can be executed¹. The first coupon due date corresponds to \([IPANX]\).

• If the D-ASA has unlimited number of coupons, then K MUST be 0 and coupons due dates \([IP]\) are managed with time periods (see Time Periods section).

• If the D-ASA has a maturity date, the last element MUST be the maturity date (uint64).

The time events MUST be sorted in strictly ascending order.

The time events MUST be defined as UNIX time, in seconds.

In the case of non-continuous day-count conventions (ID<255, see Day-Count Conventions section), the time periods between subsequent events MUST be multiples of a day, in seconds (86400)².

The time events MUST be set using the asset_config method.

📎 EXAMPLE

The following are valid time events (UNIX times):

uint64[] = [1704067200, 1735603200, 1767139200, 1798675200, 1830211200]

📎 EXAMPLE

The following are invalid (respectively unsorted and not-strictly sorted) time events (UNIX times):

uint64[] = [1830211200, 1704067200, 1735603200, 1767139200, 1798675200]

uint64[] = [1704067200, 1735603200, 1767139200, 1798675200, 1830211200, 1830211200]

📎 EXAMPLE

A D-ASA with K total coupons and a defined maturity date, has the following time events:

uint64[] = [primary_distribution_opening_date, primary_distribution_closure_date, issuance_date, cupon_due_date_1, ..., coupon_due_date_K, maturity_date]

📎 EXAMPLE

A D-ASA whose primary distribution lasts from December 1st, 2023 00:00:00 GMT+0 to December 15th, 2023 00:00:00 GMT+0, is issued on January 1st, 2024 00:00:00 GMT+0 and matures on January 1st, 2028 00:00:00 GMT+0, with 4 annual coupons, each paid on December 31st 00:00:00 GMT+0, has the following time events array (UNIX times):

uint64[] = [1701388800, 1702598400, 1704067200, 1735603200, 1767139200, 1798675200, 1830211200, 1830297600]

📎 EXAMPLE

A D-ASA whose primary distribution lasts from December 1st, 2023 00:00:00 GMT+0 to December 15th, 2023 00:00:00 GMT+0, is issued on January 1st, 2024 00:00:00 GMT+0 and matures on January 1st, 2028 00:00:00 GMT+0, with zero coupons, has the following time events array (UNIX times):

uint64[] = [1701388800, 1702598400, 1704067200, 1830297600]

📎 EXAMPLE

A D-ASA whose primary distribution lasts from December 1st, 2023 00:00:00 GMT+0 to December 15th, 2023 00:00:00 GMT+0, is issued on January 1st, 2024 00:00:00 GMT+0 and no maturity, with perpetual coupons, has the following time events array (UNIX times):

uint64[] = [1701388800, 1702598400, 1704067200]

Time Periods

D-ASA time periods can be used to define recurring (or "cyclic") events.

D-ASA time periods start on (are "anchored" to) time events.

The D-ASA MAY define time periods \([CL]\) as (uint64,uint64)[] array, where:

• The first element of the tuple defines the time period duration (uint64). It MUST be strictly greater than 0;

• The second element of the tuple defines the time period repetitions (uint64). It MUST be 0 if repetitions are unlimited;

The time periods MUST be anchored \([ANX]\) to a time event (see Time Events section).

The time periods MUST be defined as UNIX time, in seconds.

In case of non-continuous day-count conventions (ID<255, see Day-Count Conventions section), the time periods MUST be multiples of a day, in seconds (86400).

The time periods MAY be set using the asset_config method.

If the D-ASA does not implement time periods, it MUST be set to [] in the asset_config method.

📎 EXAMPLE

The following are valid time periods (UNIX times) indicating:

• a daily time event with unlimited repetitions
• a monthly (30 days) time event with 12 repetitions

(uint64,uint64)[] = [(86400, 0), (2592000, 12)]

📎 EXAMPLE

The following are invalid time periods (UNIX times):

(uint64,uint64)[] = [(0, 0), (0, 12)]

The time periods MUST be chronologically consistent with respect to the time events.

📎 EXAMPLE

Let's have a D-ASA with an issuance date and a maturity date, defined as time events, and 4 coupons whose periods are defined by time periods.

The sum of the 4 coupon time period durations must be smaller than the time period between the issuance date and the maturity date.

Unlimited Time Schedule

If the D-ASA has an undefined number of coupons, then the coupon due dates \([IP]\) MUST be defined with a time period (uint64,uint64).

The first coupon due date \([IPANX]\) occurs on issuance date plus the time period duration \([IPCL]\) and the interest payment \([IPPNT]\) can be executed¹.

📎 EXAMPLE

A D-ASA whose primary distribution lasts from December 1st, 2023 00:00:00 GMT+0 to December 15th, 2023 00:00:00 GMT+0, is issued on January 1st, 2024 00:00:00 GMT+0 and no maturity, with perpetual coupons maturing every 365 days, has the following time events array (UNIX times):

uint64[] = [1701388800, 1702598400, 1704067200]

and the following time period:

(uint64, uint64) = [31536000, 0]

The fist coupon due date \(([IPANX]\)) is 1704067200 + 31536000 (UNIX time).

Variable Time Schedule

Debt instruments can have variable time schedule, based on different contract terms, such as covenants, etc.

Variable Time Events

The time events MAY be updated with the OPTIONAL update_time_events method.

The updated time events MUST NOT modify past events.

A reference implementation SHOULD restrict the time events updatability according to the optionalities of the agreement.

📎 EXAMPLE

Let's have a D-ASA with a maturity date and 4 coupons, defined by time events. The 2nd coupon is due.

The updated time events can no longer modify:

• the primary distribution opening date;
• the primary distribution closure date;
• the issuance date;
• the 1st and 2nd coupon due dates.

The updated time events can still modify:

• the 3rd and 4th coupon due dates;
• the maturity date.

Variable Time Periods

The time periods MAY be updated with the OPTIONAL update_time_periods method.

The updated time periods MUST preserve chronological consistency with respect to the time events.

A reference implementation SHOULD restrict the time periods updatability.

📎 EXAMPLE

Let's have a D-ASA with an issuance date and a maturity date, defined as time events, and 4 coupons whose periods are defined by time periods.

The sum of the 4 updated coupon time period durations must be smaller than the time period between the issuance date and the maturity date.

Day-Count Convention

Debt instruments use a day-count convention to calculate the amount of accrued interest when the next coupon payment is less than a full coupon period away.

The D-ASA MUST specify one day-count convention \([IPCD]\) (uint8).

The day-count convention MUST be identified with one of the following enumerated IDs (uint8):

The day-count convention defines the day-count factor as a fraction of:

• Numerator: elapsed time of the accrual period to date;
• Denominator: time of the full accrual period defined by the time schedule.

The day-count convention MUST be set using the asset_config method.

📎 EXAMPLE

Let’s have a D-ASA with the following coupon dates:

• date1: starting date for the current coupon’s interest accrual, defined by the time schedule;
• date2: date through which the interest is being accrued (“to” date), equals to the current block timestamp;
• date3: next coupon due date, defined by the time schedule.

The day-count factor is calculated as:

Continuous (255) convention:

(date2 - date1) / (date3 - date1)

Actual/Actual (0) convention:

days_in(date2 - date1) / days_in(date3 - date1)

Where days_in returns the actual number of days (equal to 86400 seconds) in the time interval.

Calendar

Calendars define the non-working days which may affect the dates of traditional debt instruments.

The AVM (so the D-ASA) time has no notion of calendars. Conversion of serial UNIX timestamps into a year/month/day triple¹ (and vice versa) can be performed by external Algorand Applications² or client side.

The D-ASA MAY specify a calendar \([CLDR]\).

The calendar MUST be identified with one of the following enumerated IDs (uint8):

The calendar MAY be set using the OPTIONAL set_asset_metadata method (see Metadata section).

A reference implementation SHOULD use the default calendar (0).

Business Day Convention

Debt instruments cash flows execution may be stopped on non-working days (according to a calendar).

The business day convention defines how D-ASA execution can be shifted to the next business day (following) or the previous on (preceding).

The D-ASA MAY specify a business day convention \([BDC]\).

It is RECOMMENDED to use an ACTUS business day convention.

The business day convention MAY be set using the OPTIONAL set_asset_metadata method (see Metadata section).

A reference implementation SHOULD NOT adopt a business day convention (as it has no defined calendar).

End of Month Convention

Debt instruments may define due dates as the last day of the month.

The end-of-month convention defines how D-ASA execution can be shifted according to the different number of days in months (31, 30, and 28) according to the calendar.

The D-ASA MAY specify a end-of-month convention \([EOMC]\).

It is RECOMMENDED to use an ACTUS end-of-month convention.

The end-of-month convention MAY be set using the OPTIONAL set_asset_metadata method (see Metadata section).

A reference implementation SHOULD NOT adopt an end-of-month day convention (as it has no defined calendar).

Early Repayment Options

Debt instruments could have early repayment options to repay the principal to investors (partially or totally) before maturity or to reduce the maturity date.

Debt instrument with defined maturity date may terminate earlier if the full principal redemption happens earlier than maturity.

If the debt instrument has early repayment options, the D-ASA MUST implement the OPTIONAL set_early_repayment_option method.

Early Repayment Schedule

If the D-ASA has early repayment options, it MUST define early repayment time events as uint64[] array, where:

• The length of the array MUST be N>=1;

• The first element MUST be the early repayment start date \([OPANX]\) (uint64): the time after which early repayment options could be executed;

• If the D-ASA has a maturity date, the last element MUST be the early repayment end date \([OPXED]\) (uint64): the time after which early repayment options cannot be executed.

The early repayment time events MUST be sorted in strictly ascending order.

The early repayment start date MUST NOT be earlier than the issuance date.

The early repayment end date MUST NOT be later than the maturity date.

The unscheduled prepayment events \([PP]\) MUST occur within the defined early repayment schedule.

In the case of non-continuous day-count conventions (ID<255, see Day-Count Conventions section), the time periods between subsequent events MUST be multiples of a day, in seconds (86400).

The early repayment time events MUST be set with the set_early_repayment_time_events method.

The early repayment time events MAY be updated with the set_early_repayment_time_events method.

The updated early repayment time events MUST NOT modify past events.

Prepayment Effects

An early repayment option could have different prepayment effects \([PPEF]\):

• It MAY repay the principal partially or totally, to all or some Investors before the maturity date (see Early Repayment section);

• It MAY reduce the maturity date (see Variable Time Schedule section).

The prepayment effect MUST be identified with one of the following enumerated IDs (uint8):

The prepayment effect MAY be set using the OPTIONAL set_asset_metadata method (see Metadata section).

The implementation SHOULD manage the accrued interest on early repayments.

Penalties

Debt instruments may have a penalty as a consequence of an early repayment option.

The D-ASA MAY define a penalty type \([PYTP]\) (uint8) for the early repayment options.

The penalty type MUST be identified with one of the following enumerated IDs:

The penalty type MAY be set using the OPTIONAL set_asset_metadata method (see Metadata section).

If the debt instrument has a penalty type with ID>0, the D-ASA MUST define a penalty rate \([PYRT]\) (uint64) for the amount of the penalty.

The penalty rate is either the absolute amount or the rate of the penalty.

The penalty rate MAY be set using the OPTIONAL set_early_repayment_option method (see Metadata section).

Performance

Debt instruments performances are exposed to credit risks.

The D-ASA performance \([PRF]\) MUST be identified with one of the following enumerated IDs (uint8):

Grace Period

Debt instruments may define a grace period as a time window after the payment due date during which payment may be retried without a penalty.

The D-ASA MAY define a grace period \([GRP]\) (uint64).

The grace period MUST be defined as UNIX time, in seconds.

In case of non-continuous day-count conventions (ID<255, see Day-Count Conventions section), the grace period MUST be multiples of a day, in seconds (86400).

The grace period MAY be set using the asset_config method as time period with:

• The time period duration (uint64) equal to the grace period duration;

• The time period repetitions (uint64) equal to 1.

• The grace period MUST be anchored \([ANX]\) to the time event of the first failed payment.

📎 EXAMPLE

Let's have a D-ASA with a grace period. A D-ASA coupon payment is triggered on due date, but there is not enough liquidity to pay all the investors. The D-ASA program starts counting the grace period, increments a failed payments counter, and waits 3 hours to retry. If the D-ASA payment retrial succeeds within the grace period, no penalty or fee is applied.

Delinquency Period

Debt instruments may define a delinquency period as a time window after the grace period. If payment happens after the delinquency period, then the counterparty is in technical default.

The D-ASA MAY define a delinquency period \([DQP]\) (uint64).

The delinquency period MUST be defined as UNIX time, in seconds.

In case of non-continuous day-count conventions (ID<255, see Day-Count Conventions section), the delinquency period MUST be multiples of a day, in seconds (86400).

The delinquency period MAY be set using the asset_config method as time period with:

• The time period duration (uint64) equal to the delinquency period duration;

• The time period repetitions (uint64) equal to 1.

• The delinquency period MUST be anchored \([ANX]\) to the time event of the first failed payment or at the end of the grace period (if any).

📎 EXAMPLE

Let's have a D-ASA with a delinquency period. A D-ASA coupon payment is triggered on due date, but there is not enough liquidity to pay all the investors. The D-ASA program starts counting the delinquency period, increments a failed payments counter, and waits 3 hours to retry. If the D-ASA payment retrial succeeds within the delinquency period, a penalty or fee is applied.

Default

Default is the ultimate failure to pay the lenders according to the payment obligations. When this happens, the creditors have the right to declare default to the debtors.

Default processes require the intervention of regulatory bodies and courts, therefore the D-ASA default status bridges the default process off-chain.

The D-ASA SHOULD enter default status if it cannot perform payments on due dates.

The D-ASA MAY disable all non-administrative methods on default status.

The D-ASA default can be called either automatically (based on program conditions) or manually (based on the decision of a trustee).

The default status MAY be set with the OPTIONAL set_default_status method.

📎 EXAMPLE

The D-ASA has no grace period and no delinquency period. A D-ASA coupon payment is triggered on due date, but there is not enough liquidity to pay all the investors. The D-ASA contract automatically enters in default immediately.

📎 EXAMPLE

The D-ASA has a grace period and a delinquency period. A D-ASA coupon payment is triggered on due date, but there is not enough liquidity to pay all the investors. The D-ASA program starts counting the grace period and delinquency period. If the delinquency period expires, then the contract enters in default.

📎 EXAMPLE

A D-ASA coupon payment is triggered on due date, but there is not enough liquidity to pay all the investors. The D-ASA contract relies on a trustee to call the default.

Metadata

Metadata can be used to inform optional properties that define the specific D-ASA implementation.

The D-ASA metadata MAY be set using the OPTIONAL set_asset_metadata method.

The D-ASA metadata MAY be updated using the OPTIONAL set_asset_metadata method.

Prospectus

Debt instruments are defined by their prospectus.

The D-ASA can notarize the debt instrument prospectus in the metadata.

The D-ASA prospectus hash (byte[32]) and prospectus URL (string) MAY be set using the OPTIONAL set_asset_metadata method.

The prospectus hash MUST be computed with SHA-512/256, as defined in NIST FIPS 180-4.

The digests are a single SHA-256 integrity metadata defined in the W3C subresource integrity specification. Details on generating those digests can be found on the MDN Web Docs (only SHA-256 is supported by this specification).

D-ASA units

D-ASA units represent the ownership of the tokenized debt instrument.

Supply

The D-ASA MUST define its total units (uint64).

If the D-ASA has a principal, its initials total units MUST be equal to the principal divided by the minimum denomination.

📎 EXAMPLE

Let’s have a D-ASA denominated in EUR, with a principal of 1M EUR and a minimum denomination of 1,000 EUR. The D-ASA has 1,000 initial total units.

The D-ASA total units MAY be updated with the OPTIONAL update_total_units method.

Value

The D-ASA unit’s value is always intended as nominal value (at redemption).

The D-ASA unit value (uint64) MUST be expressed in the denomination asset.

If the D-ASA has a principal, its initial unit value MUST be equal to the minimum denomination.

The D-ASA unit value MAY change over time.

The D-ASA unit’s value may change according to different conditions, such as an amortizing principal repayment schedule (see Amortizing Schedule section).

The D-ASA unit value MAY change globally or locally (per account).

The D-ASA unit’s value can be global or local (per-account). Global unit value should be used when the value of all the units can be updated at the same time. Local unit value should be used when the units' value is updated at different times per each account.

📎 EXAMPLE

Let’s have a D-ASA denominated in EUR, with an initial unit value of 1,000 EUR. The D-ASA accrues interest on a daily basis, paid at redemption. The unit value is updated globally (for all the units).

📎 EXAMPLE

Let’s have a D-ASA denominated in EUR, with an initial unit value of 1,000 EUR. The D-ASA has an amortizing principal repayment schedule. Repayments are executed per-account. The unit value is updated per-account (for the account’s units).

The D-ASA unit value MAY be globally updated with the OPTIONAL update_global_unit_value method.

Fungibility

D-ASA units' fungibility depends on:

• Units value (nominal);
• Executed payments.

The D-ASA fungible units MUST have the same value and executed payments.

📎 EXAMPLE

Let’s have a D-ASA with 4 coupons. Investors A and B are holding 10 D-ASA units each. The 1st coupon is due. Coupon payments might not be executed synchronously for all the Investors. The coupon payment is executed for Investor A, while Investor B is still waiting for the payment settlement. Investor A units are temporarily non-fungible with Investor B units until the 1st coupon is paid for both.

Primary Market

Debt instruments can be distributed on the primary market in different ways, such as book building, auctions, etc.

The D-ASA units MUST be distributed to D-ASA accounts, at most up to total units, using the primary_distribution method.

The primary distribution of D-ASA units SHALL be completed between the primary distribution opening and closing dates, according to the primary market.

The primary_distribution method MUST be called by an authorized primary distribution entity.

📎 EXAMPLE

The primary market is performed as an auction on a dedicated Algorand Application. The implementation requires the primary_distribution method to be called exclusively by the primary market Application, which defines the auction’s outcome.

📎 EXAMPLE

The primary market is performed as a book building by an authorized Book-builder Address. The implementation requires the primary_distribution method to be called exclusively by the authorized Book-builder.

Payment Agent

Debt instruments' cash flows usually involve:

• Principal repayment
• Early repayments
• Coupon payments

D-ASA cash flows might not be executed synchronously for all the Investors. The execution of a given cash flow could last a few blocks¹, depending on the number of payees.

Although a single block proposer could order transactions in a block, in a healthy network block proposers are selected randomly by the Algorand consensus. Therefore, order of payments in a block is random and unbiased, with no systematic advantage or precedence of a payee with respect to others.

D-ASA supports both on-chain and off-chain payment agents, depending on the settlement asset (see Settlement section).

For reference implementations using on-chain payment agents, the AVM fees (ALGO) for the cash flows execution SHOULD be paid by who triggers the cash flows.

A reference implementation of an on-chain payment agent SHOULD NOT require extra fees for the cash flows execution.

The D-ASA payment methods MAY provide additional information about the payment.

The payment information could be used, for example, for:

• Adding unique identifiers or external context to the payments;
• Enabling external payment system integration in the case of off-chain settlement;
• Providing information about the settled amount and conversion rate used with respect to the denomination asset.

Settlement

Debt instruments cash flows may be settled in a currency different from the denomination.

The D-ASA MUST define either an on-chain or off-chain settlement asset \([CURS]\)¹ to regulate the cash flows.

The settlement asset identifier (uint64) MUST be set using the asset_config method.

If the D-ASA defines a settlement asset different from the denomination asset, then the respective denomination/settlement conversion rate is applied at settlement time.

The denomination/settlement conversion rate can be provided by different oracles, depending on if the denomination/settlement assets are on-chain or off-chain.

If the D-ASA does not define a different settlement asset, then the cash flows MUST be settled in the denomination asset and the settlement asset identifier MUST be equal to the denomination asset identifier.

On-chain settlement

The settlement asset MUST be an Algorand Standard Asset (ASA), an Application asset (App), or the ALGO.

The settlement asset identifier MUST be the ASA ID, the App ID, or 0for ALGO.

On-chain settlement is possible even if the denomination asset is a traditional off-chain currency.

Off-chain denomination

The settlement asset identifier MUST the ISO 4217 currency numeric code.

The settlement asset MUST use the decimal digits specified by the ISO 4217.

In the case of an off-chain settlement, the D-ASA state machine:

• Regulates payments’ approval conditions (e.g. a coupon is due);
• Notarizes the amounts and timestamps of payments settled off-chain.

Principal Repayment

Debt instruments repay the principal according to the repayment schedule.

The principal MUST be repaid according to a principal repayment schedule.

In the case of an on-chain payment agent, the D-ASA MUST repay the principal to the Investor’s Payment Addresses.

Bullet Schedule

If the debt instrument has a bullet principal repayment schedule, the principal MUST be paid entirely at the maturity date using the pay_principal method.

If the D-ASA has coupons, the principal MUST NOT be paid if there is any due coupon still to be paid.

Amortizing Schedule

If the debt instrument has an amortizing principal repayment schedule, the principal MUST be repaid along with the fixed number of coupons, according to the principal amortization (see Amortization section), using the pay_coupon method.

The first coupon due date corresponds to \([PRANX]\).

The D-ASA unit value MUST be updated according to the outstanding principal.

It is RECOMMENDED to use an ACTUS interest calculation base \([IPCB]\).

A reference implementation SHOULD calculate interest on the outstanding principal.

A reference implementation SHOULD restrict the amortizing rates updatability.

📎 EXAMPLE

Let’s have a D-ASA denominated in EUR, with a principal of 1M EUR and a minimum denomination of 1,000 EUR, 5 coupons, and an even amortizing schedule (20% amortizing rate). The D-ASA has 1,000 total units. The D-ASA initial unit value is 1,000 EUR. The 1st coupon pays both the interest (according to the coupon rates) and 20% of the principal (according to amortizing rates). The D-ASA outstanding principal is 800k EUR. The D-ASA unit value is 800 EUR.

📎 EXAMPLE

Let’s have a D-ASA denominated in EUR, with a principal of 1M EUR and a minimum denomination of 1,000 EUR. The D-ASA originally had 1,000 total units (worth 1,000 EUR each) in circulation. A partial repayment of 500k EUR (50% of the original principal) must be executed pro-rata to all investors. A single amortizing rate of 5,000 bps is used. After the partial repayment, the D-ASA still has 1000 circulating units (worth 500 EUR each).

Early Repayment

If the early repayment options repays the principal amount before maturity (prepayment effect 1, see Prepayment Effects section), the D-ASA MUST implement the OPTIONAL early_repayment method.

In the case of an on-chain payment agent, the D-ASA MUST repay the principal to the Investor Payment Addresses.

The D-ASA units associated with the early repaid principal MUST be removed from Investors’ Accounts and from circulation.

📎 EXAMPLE

Let’s have a D-ASA denominated in EUR, with a principal of 1M EUR and a minimum denomination of 1,000 EUR. The D-ASA originally had 1,000 total units in circulation. An early repayment of 500k EUR (equal to 500 units) is executed for some Investors. The D-ASA now has 500 circulating units (worth 1,000 EUR each), while 500 early repaid units are removed from circulation.

Coupons Payment

If the D-ASA has coupons, it MUST pay due coupons, according to the time schedule, with the OPTIONAL pay_coupon method.

The D-ASA MUST pay due coupons, once, to the Investors.

The D-ASA MUST NOT pay coupons before coupon due dates.

In the case of an on-chain payment agent, the D-ASA MUST pay the coupons to the Investor Payment Addresses.

Transfer Agent

Debt instruments can be transferable among investors.

D-ASA supports both on-chain and off-chain transfer agents.

The Transfer Agent SHALL authorize the D-ASA transfers according to the transferability policy.

The transferred D-ASA units MUST be fungible (see D-ASA Units fungibility section).

The transferred D-ASA units MUST record D-ASA unit value and paid coupons.

D-ASA units SHALL NOT be transferred if the sender has pending due coupon payments.

The D-ASA transferability policy may involve and integrate KYC/AML processes, secondary market restrictions, etc.

If the debt instrument is transferable, the D-ASA MUST implement the OPTIONAL asset_transfer methods.

The asset_transfer method MAY be restricted to an authorized Transfer Agent.

Secondary Market

Debt instruments can be traded on secondary markets.

If the debt instrument can be traded on secondary markets, the D-ASA MUST be transferable and implement the OPTIONAL set_secondary_time_events.

The D-ASA MUST define secondary market time events as uint64[] array, where:

• The length of the array MUST be N>=1;

• The first element MUST be the secondary market opening date (uint64): the time at which the secondary market opens;

• If the secondary market has a closure date, the last element MUST be the secondary market closure date (uint64): the time at which the secondary market closes.

The secondary market time events MUST be sorted in strictly ascending order.

The secondary market opening date MUST NOT be earlier than the issuance date.

The secondary market closure date MUST NOT be later than the maturity date.

In case of non-continuous day-count conventions (ID<255, see Day-Count Conventions section), the time periods between subsequent events MUST be multiples of a day, in seconds (86400).

The secondary market time events MUST be set using the set_secondary_time_events method.

The secondary market time events MAY be updated with the set_secondary_time_events method.

The updated secondary market time events MUST NOT modify past events.

The asset_transfer method MUST fail if the secondary market is closed.

Asset Config

{
  "name": "asset_config",
  "desc": "Configure the Debt Algorand Standard Application",
  "readonly": false,
  "args": [
    {
      "type": "uint64",
      "name": "denomination_asset_id",
      "desc": "Denomination asset identifier"
    },
    {
      "type": "uint64",
      "name": "settlement_asset_id",
      "desc": "Settlement asset identifier"
    },
    {
      "type": "uint64",
      "name": "principal",
      "desc": "Principal, expressed in denomination asset"
    },
    {
      "type": "uint16",
      "name": "principal_discount",
      "desc": "Discount on principal in bps"
    },
    {
      "type": "uint64",
      "name": "minimum_denomination",
      "desc": "Minimum denomination, expressed in denomination asset"
    },
    {
      "type": "uint8",
      "name": "day_count_convention_id",
      "desc": "Day-count convention for interests calculation"
    },
    {
      "type": "uint16",
      "name": "interest_rate",
      "desc": "Interest rates in bps"
    },
    {
      "type": "uint16[]",
      "name": "coupon_rates",
      "desc": "Coupon interest rates in bps"
    },
    {
      "type": "uint64[]",
      "name": "time_events",
      "desc": "Time events (strictly ascending order)"
    },
    {
      "type": "(uint64,uint64)[]",
      "name": "time_periods",
      "desc": "Time periods of recurring time events"
    }
  ],
  "returns": {
    "type": "void"
  },
  "errors": [
    {
      "code": "UNAUTHORIZED",
      "message": "Not authorized"
    },
    {
      "code": "ALREADY_CONFIGURED",
      "message": "D-ASA already configured"
    },
    {
      "code": "INVALID_MINIMUM_DENOMINATION",
      "message": "Minimum denomination is not a divisor of principal"
    },
    {
      "code": "INVALID_DAY_COUNT_CONVENTION",
      "message": "Invalid day-count convention ID"
    },
    {
      "code": "INVALID_TIME_EVENTS_LENGTH",
      "message": "Time events length is invalid"
    },
    {
      "code": "INVALID_TIME",
      "message": "Time events must be set in the future"
    },
    {
      "code": "INVALID_SORTING",
      "message": "Time events are not sorted correctly"
    },
    {
      "code": "INVALID_TIME_PERIOD_DURATION",
      "message": "Time period durations must be greater than zero"
    },
    {
      "code": "INVALID_SETTLEMENT_ASSET",
      "message": "Different settlement asset not supported, must be equal to denomination asset"
    },
    {
      "code": "INVALID_TIME_PERIODS",
      "message": "Time periods not properly set"
    },
    {
      "code": "INVALID_TIME_PERIOD_REPETITIONS",
      "message": "Time period repetitions not properly set"
    },
    {
      "code": "INVALID_COUPON_RATES",
      "message": "Coupon rates not properly set"
    }
  ]
}

The call MUST fail with the UNAUTHORIZED error code if not called by an authorized caller.

The call MUST fail with the ALREADY_CONFIGURED error code if the D-ASA has been already configured.

The call MUST fail with the INVALID_DENOMINATION error code if the denomination asset is not properly set for the specific implementation.

The call MUST fail with the INVALID_MINIMUM_DENOMINATION error code if the minimum denomination is not a divisor of the principal.

The call MUST fail with the INVALID_DAY_COUNT_CONVENTION error code if the day-count convention ID is invalid.

The call MUST fail with the INVALID_INTEREST_RATE error code if the interest rate is not properly set for the specific implementation.

The call MUST fail with the INVALID_TIME_EVENTS_LENGTH error code if the length of the time events is not greater than or equal to:

• total coupons + 3, if the D-ASA has not a defined maturity date;
• total coupons + 4, if the D-ASA has a defined maturity date.

The call MUST fail with the INVALID_TIME error code if the first time event is earlier than the latest timestamp (or block height).

The call MUST fail with the INVALID_SORTING error code if the time events are not sorted in strictly ascending order.

The call MUST fail with the INVALID_TIME_PERIOD_DURATION error code if the time period durations are not strictly greater than zero.

The call MAY fail with the INVALID_SETTLEMENT_ASSET error code if a settlement asset different from the denomination asset is not supported by the specific implementation.

The call MAY fail with the INVALID_TIME_PERIODS error code if the time periods are not properly set for the specific implementation.

The call MAY fail with the INVALID_TIME_PERIOD_REPETITIONS error code if the time period repetitions are not properly set for the specific implementation.

The call MAY fail with the INVALID_COUPON_RATES error code if the coupon rates are not properly set for the specific implementation.

Assign Role

{
  "name": "assign_role",
  "desc": "Assign a role to an address",
  "readonly": false,
  "args": [
    {
      "type": "address",
      "name": "role_address",
      "desc": "Account Role Address"
    },
    {
      "type": "uint8",
      "name": "role",
      "desc": "Role identifier"
    },
    {
      "type": "bytes[]",
      "name": "config",
      "desc": "Role configuration (Optional)"
    }
  ],
  "returns": {
    "type": "uint64",
    "desc": "Timestamp of the role assignment"
  },
  "errors": [
    {
      "code": "UNAUTHORIZED",
      "message": "Not authorized"
    },
    {
      "code": "DEFAULTED",
      "message": "Defaulted"
    },
    {
      "code": "INVALID_ROLE",
      "message": "Invalid role identifier"
    },
    {
      "code": "INVALID_ROLE_ADDRESS",
      "message": "Invalid account role address"
    }
  ]
}

The call MUST fail with the UNAUTHORIZED error code if not called by an authorized.

The call MUST fail with the DEFAULTED error code if the asset is defaulted.

The call MUST fail with the INVALID_ROLE error code if the role identifier is invalid.

The call MUST fail with the INVALID_ROLE_ADDRESS error code if the role address has been already assigned to the role.

Revoke Role

{
  "name": "revoke_role",
  "desc": "Revoke a role from an address",
  "readonly": false,
  "args": [
    {
      "type": "address",
      "name": "role_address",
      "desc": "Account Role Address"
    },
    {
      "type": "uint8",
      "name": "role",
      "desc": "Role identifier"
    }
  ],
  "returns": {
    "type": "uint64",
    "desc": "Timestamp of the role revocation"
  },
  "errors": [
    {
      "code": "UNAUTHORIZED",
      "message": "Not authorized"
    },
    {
      "code": "DEFAULTED",
      "message": "Defaulted"
    },
    {
      "code": "INVALID_ROLE",
      "message": "Invalid role identifier"
    },
    {
      "code": "INVALID_ROLE_ADDRESS",
      "message": "Invalid account role address"
    }
  ]
}

The call MUST fail with the UNAUTHORIZED error code if not called by an authorized caller or if the operation is not authorized.

The call MUST fail with the DEFAULTED error code if the asset is defaulted.

The call MUST fail with the INVALID_ROLE error code if the role identifier is invalid.

The call MUST fail with the INVALID_ROLE_ADDRESS error code if the Account Role Address is invalid.

Open Account

{
  "name": "open_account",
  "desc": "Open D-ASA account",
  "readonly": false,
  "args": [
    {
      "type": "address",
      "name": "holding_address",
      "desc": "Account Holding Address"
    },
    {
      "type": "address",
      "name": "payment_address",
      "desc": "Account Payment Address"
    }
  ],
  "returns": {
    "type": "uint64",
    "desc": "Timestamp of the account opening"
  },
  "errors": [
    {
      "code": "UNAUTHORIZED",
      "message": "Not authorized"
    },
    {
      "code": "DEFAULTED",
      "message": "Defaulted"
    },
    {
      "code": "SUSPENDED",
      "message": "Suspended operations"
    },
    {
      "code": "INVALID_HOLDING_ADDRESS",
      "message": "Invalid account holding address"
    }
  ]
}

The call MUST fail with the UNAUTHORIZED error code if not called by an authorized caller or if the operation is not authorized.

The call MUST fail with the DEFAULTED error code if the asset is defaulted.

The call MAY fail with the SUSPENDED error code if the asset operations are suspended.

The call MUST fail with the INVALID_HOLDING_ADDRESS error code if the Account already exists.

Close Account

{
  "name": "close_account",
  "desc": "Close D-ASA account",
  "readonly": false,
  "args": [
    {
      "type": "address",
      "name": "holding_address",
      "desc": "Account Holding Address"
    }
  ],
  "returns": {
    "type": "(uint64,uint64)",
    "desc": "Closed units, Timestamp of the account closing"
  },
  "errors": [
    {
      "code": "UNAUTHORIZED",
      "message": "Not authorized"
    },
    {
      "code": "DEFAULTED",
      "message": "Defaulted"
    },
    {
      "code": "INVALID_HOLDING_ADDRESS",
      "message": "Invalid account holding address"
    }
  ]
}

The call MUST fail with the UNAUTHORIZED error code if not called by an authorized caller or if the operation is not authorized.

The call MUST fail with the DEFAULTED error code if the asset is defaulted.

The call MUST fail with the INVALID_HOLDING_ADDRESS error code if the Account does not exist.

Set Asset Metadata

{
  "name": "set_asset_metadata",
  "desc": "Set D-ASA metadata",
  "readonly": false,
  "args": [
    {
      "type": "uint8",
      "name": "contract_type",
      "desc": "Contract type"
    },
    {
      "type": "uint8",
      "name": "calendar",
      "desc": "Calendar [default 0]"
    },
    {
      "type": "uint8",
      "name": "business_day_convention",
      "desc": "Business day convention [default 0]"
    },
    {
      "type": "uint8",
      "name": "end_of_month_convention",
      "desc": "End of month convention [default 0]"
    },
    {
      "type": "uint8",
      "name": "prepayment_effect",
      "desc": "Early repayment effect [default 0]"
    },
    {
      "type": "uint8",
      "name": "penalty_type",
      "desc": "Early repayment penalty type [default 0]"
    },
    {
      "type": "byte[32]",
      "name": "prospectus_hash",
      "desc": "Prospectus hash"
    },
    {
      "type": "string",
      "name": "prospectus_url",
      "desc": "Prospectus URL"
    }
  ],
  "returns": {
    "type": "uint64",
    "desc": "Timestamp of the set metadata"
  },
  "errors": [
    {
      "code": "UNAUTHORIZED",
      "message": "Not authorized"
    },
    {
      "code": "DEFAULTED",
      "message": "Defaulted"
    },
    {
      "code": "SUSPENDED",
      "message": "Asset operations are suspended"
    }
  ]
}

The call MUST fail with the UNAUTHORIZED error code if not called by an authorized caller.

The call MUST fail with the DEFAULTED error code if the asset is defaulted.

The call MAY fail with the SUSPENDED error code if the asset is suspended.

Set Asset Suspension Status

{
  "name": "set_asset_suspension_status",
  "desc": "Set asset suspension status",
  "readonly": false,
  "args": [
    {
      "type": "bool",
      "name": "suspended",
      "desc": "Suspension status"
    }
  ],
  "returns": {
    "type": "uint64",
    "desc": "Timestamp of the set asset suspension status"
  },
  "errors": [
    {
      "code": "UNAUTHORIZED",
      "message": "Not authorized"
    }
  ]
}

The call MUST fail with the UNAUTHORIZED error code if not called by an authorized caller.

Set Account Suspension Status

{
  "name": "set_account_suspension_status",
  "desc": "Set account suspension status",
  "readonly": false,
  "args": [
    {
      "type": "address",
      "name": "holding_address",
      "desc": "Account Holding Address"
    },
    {
      "type": "bool",
      "name": "suspended",
      "desc": "Suspension status"
    }
  ],
  "returns": {
    "type": "uint64",
    "desc": "Timestamp of the set account suspension status"
  },
  "errors": [
    {
      "code": "UNAUTHORIZED",
      "message": "Not authorized"
    },
    {
      "code": "INVALID_HOLDING_ADDRESS",
      "message": "Invalid account holding address"
    }
  ]
}

The call MUST fail with the UNAUTHORIZED error code if not called by an authorized caller.

The call MUST fail with the INVALID_HOLDING_ADDRESS error code if the Account does not exist.

Set Default Status

{
  "name": "set_default_status",
  "desc": "Set D-ASA default status",
  "readonly": false,
  "args": [
    {
      "type": "bool",
      "name": "defaulted",
      "desc": "Default status"
    }
  ],
  "returns": {
    "type": "uint64",
    "desc": "Timestamp of the set status"
  },
  "errors": [
    {
      "code": "UNAUTHORIZED",
      "message": "Not authorized"
    }
  ]
}

The call MUST fail with the UNAUTHORIZED error code if not called by an authorized caller.

Set Amortizing Rates

{
  "name": "set_amortizing_rates",
  "desc": "Set principal amortizing rates",
  "readonly": false,
  "args": [
    {
      "type": "uint64[]",
      "name": "amortizing_rates",
      "desc": "Principal amortizing rates in bps"
    }
  ],
  "returns": {
    "type": "uint64",
    "desc": "Timestamp of the set rates"
  },
  "errors": [
    {
      "code": "UNAUTHORIZED",
      "message": "Not authorized"
    },
    {
      "code": "DEFAULTED",
      "message": "Defaulted"
    },
    {
      "code": "SUSPENDED",
      "message": "Suspended operations"
    },
    {
      "code": "INVALID_AMORTIZING_RATES_LENGTH",
      "message": "Amortizing rates length is invalid"
    },
    {
      "code": "INVALID_RATES",
      "message": "Sum of amortizing rates must be equal to 10000 bps"
    },
    {
      "code": "INVALID_PAST_RATE",
      "message": "Past amortizing rates can not be modified"
    }
  ]
}

The call MUST fail with the UNAUTHORIZED error code if not called by an authorized caller.

The call MUST fail with the DEFAULTED error code if the asset is defaulted.

The call MAY fail with the SUSPENDED error code if the asset operations are suspended.

The call MUST fail with the INVALID_AMORTIZING_RATES_LENGTH error code if the length of the amortizing rates is not equal to total_coupons plus 1.

The call MUST fail with the INVALID_RATES error code if the sum of amortizing rates is not equal to 10,000 bps.

The call MUST fail with the INVALID_PAST_RATE error code if a past amortizing rate is modified.

Set Secondary Time Events

{
  "name": "set_secondary_time_events",
  "desc": "Set secondary market time schedule",
  "readonly": false,
  "args": [
    {
      "type": "uint64[]",
      "name": "secondary_market_time_events",
      "desc": "Secondary market time events (strictly ascending order)"
    }
  ],
  "returns": {
    "type": "(uint64, uint64)",
    "desc": "Secondary market opening date, Secondary market closure date"
  },
  "errors": [
    {
      "code": "UNAUTHORIZED",
      "message": "Not authorized"
    },
    {
      "code": "DEFAULTED",
      "message": "Defaulted"
    },
    {
      "code": "SUSPENDED",
      "message": "Suspended operations"
    },
    {
      "code": "INVALID_TIME_EVENTS_LENGTH",
      "message": "Time events length is invalid"
    },
    {
      "code": "INVALID_SORTING",
      "message": "Time events are not sorted correctly"
    },
    {
      "code": "INVALID_SECONDARY_OPENING_DATE",
      "message": "Invalid secondary market opening date"
    },
    {
      "code": "INVALID_SECONDARY_CLOSURE_DATE",
      "message": "Invalid secondary market closure date"
    },
    {
      "code": "INVALID_PAST_EVENT",
      "message": "Past time events can not be modified"
    }
  ]
}

The call MUST fail with the UNAUTHORIZED error code if not called by an authorized caller.

The call MUST fail with the DEFAULTED error code if the asset is defaulted.

The call MAY fail with the SUSPENDED error code if the asset operations are suspended.

The call MUST fail with the INVALID_TIME_EVENTS_LENGTH error code if the length of the time events is not greater than or equal to 1.

The call MUST fail with the INVALID_SORTING error code if the time events are not sorted in strictly ascending order.

The call MUST fail with the INVALID_SECONDARY_OPENING_DATE error code if the secondary market opening date is earlier than the issuance date.

The call MUST fail with the INVALID_SECONDARY_CLOSURE_DATE error code if the secondary market closure date is earlier than the secondary market opening date or later than the maturity date.

The call MUST fail with the INVALID_PAST_EVENT error code if a past event is modified.

Set Early Repayment Option

{
  "name": "set_early_repayment_option",
  "desc": "Set early repayment schedule and eventual penalty rate",
  "readonly": false,
  "args": [
    {
      "type": "uint64[]",
      "name": "time_events",
      "desc": "Early repayment time events (strictly ascending order)"
    },
    {
      "type": "uint64",
      "name": "penalty_rate",
      "desc": "Early repayment penalty rate (absolute or relative), if any"
    }
  ],
  "returns": {
    "type": "(uint64, uint64)",
    "desc": "Early repayments start date, Early repayments end date"
  },
  "errors": [
    {
      "code": "UNAUTHORIZED",
      "message": "Not authorized"
    },
    {
      "code": "DEFAULTED",
      "message": "Defaulted"
    },
    {
      "code": "SUSPENDED",
      "message": "Suspended operations"
    },
    {
      "code": "INVALID_TIME_EVENTS_LENGTH",
      "message": "Time events length is invalid"
    },
    {
      "code": "INVALID_SORTING",
      "message": "Time events are not sorted correctly"
    },
    {
      "code": "INVALID_EARLY_REPAYMENT_START_DATE",
      "message": "Invalid early repayment start date"
    },
    {
      "code": "INVALID_EARLY_REPAYMENT_END_DATE",
      "message": "Invalid early repayment end date"
    },
    {
      "code": "INVALID_PAST_EVENT",
      "message": "Past time events can not be modified"
    }
  ]
}

The call MUST fail with the UNAUTHORIZED error code if not called by an authorized caller.

The call MUST fail with the DEFAULTED error code if the asset is defaulted.

The call MAY fail with the SUSPENDED error code if the asset operations are suspended.

The call MUST fail with the INVALID_TIME_EVENTS_LENGTH error code if the length of the time events is not greater than or equal to 2.

The call MUST fail with the INVALID_SORTING error code if the time events are not sorted in strictly ascending order.

The call MUST fail with the INVALID_EARLY_REPAYMENT_START_DATE error code if the early repayment start date is earlier than the issuance date.

The call MUST fail with the INVALID_EARLY_REPAYMENT_END_DATE error code if the early repayment end date is later than the maturity date.

The call MUST fail with the INVALID_PAST_EVENT error code if a past event is modified.

Set Variable Rate

{
  "name": "set_variable_interest_rate",
  "desc": "Set D-ASA variable interest rate",
  "readonly": false,
  "args": [
    {
      "type": "uint16",
      "name": "spread",
      "desc": "Spread in bps"
    },
    {
      "type": "uint16",
      "name": "life_cap",
      "desc": "Rate life cap in bps"
    },
    {
      "type": "uint16",
      "name": "life_floor",
      "desc": "Rate life floor in bps"
    },
    {
      "type": "uint16",
      "name": "period_cap",
      "desc": "Rate period cap in bps"
    },
    {
      "type": "uint16",
      "name": "period_floor",
      "desc": "Rate period floor in bps"
    },
    {
      "type": "uint64",
      "name": "fixing_period",
      "desc": "Rate fixing period (UNIX time)"
    }
  ],
  "returns": {
    "type": "void"
  },
  "errors": [
    {
      "code": "UNAUTHORIZED",
      "message": "Not authorized"
    },
    {
      "code": "DEFAULTED",
      "message": "Defaulted"
    },
    {
      "code": "SUSPENDED",
      "message": "Asset operations are suspended"
    }
  ]
}

Primary Distribution

{
  "name": "primary_distribution",
  "desc": "Distribute D-ASA units to accounts according the primary market",
  "readonly": false,
  "args": [
    {
      "type": "address",
      "name": "holding_address",
      "desc": "Account Holding Address"
    },
    {
      "type": "uint64",
      "name": "units",
      "desc": "Amount of D-ASA units to distribute"
    }
  ],
  "returns": {
    "type": "uint64",
    "desc": "Remaining D-ASA units to be distributed"
  },
  "errors": [
    {
      "code": "UNAUTHORIZED",
      "message": "Not authorized"
    },
    {
      "code": "DEFAULTED",
      "message": "Defaulted"
    },
    {
      "code": "SUSPENDED",
      "message": "Suspended operations"
    },
    {
      "code": "INVALID_HOLDING_ADDRESS",
      "message": "Invalid account holding address"
    },
    {
      "code": "ZERO_UNITS",
      "message": "Cannot distribute zero units"
    },
    {
      "code": "OVER_DISTRIBUTION",
      "message": "Insufficient remaining D-ASA units"
    },
    {
      "code": "PRIMARY_DISTRIBUTION_CLOSED",
      "message": "Primary distribution is closed"
    }
  ]
}

The call MUST fail with the UNAUTHORIZED error code if not called by the authorized primary market entity.

The call MUST fail with the INVALID_HOLDING_ADDRESS error code if the Account associated with the holding address does not exist.

The call MUST fail with the DEFAULTED error code if the asset is defaulted.

The call MAY fail with the SUSPENDED error code if the asset operations are suspended.

The call MUST fail with the ZERO_UNITS error code if the distributing units are null.

The call MUST fail with the OVER_DISTRIBUTION error code if there are no sufficient remaining D-ASA units for the primary distribution.

The call MUST fail with the PRIMARY_DISTRIBUTION_CLOSED error code if the primary distribution is closed.

Pay Principal

{
  "name": "pay_principal",
  "desc": "Pay the outstanding principal to an account",
  "readonly": false,
  "args": [
    {
      "type": "address",
      "name": "holding_address",
      "desc": "Account Holding Address"
    },
    {
      "type": "byte[]",
      "name": "payment_info",
      "desc": "Additional payment information (Optional)"
    }
  ],
  "returns": {
    "type": "(uint64, uint64, byte[])",
    "desc": "Paid principal amount in denomination asset, Payment timestamp, Payment context"
  },
  "errors": [
    {
      "code": "UNAUTHORIZED",
      "message": "Not authorized"
    },
    {
      "code": "DEFAULTED",
      "message": "Defaulted"
    },
    {
      "code": "SUSPENDED",
      "message": "Suspended operations"
    },
    {
      "code": "INVALID_HOLDING_ADDRESS",
      "message": "Invalid account holding address"
    },
    {
      "code": "NO_UNITS",
      "message": "No D-ASA units"
    },
    {
      "code": "NOT_MATURE",
      "message": "Not mature"
    },
    {
      "code": "PENDING_COUPON_PAYMENT",
      "message": "Pending due coupon payment"
    }
  ]
}

A reference implementation SHOULD NOT require an authorized caller.

The call MUST remove D-ASA units from the Account Holding Address and from circulation.

If the call requires authorization, it MUST fail with the UNAUTHORIZED error code if not called by an authorized caller.

The call MUST fail with the DEFAULTED error code if the asset is defaulted.

The call MUST fail with the SUSPENDED error code if the asset operations are suspended.

The call MUST fail with the INVALID_HOLDING_ADDRESS error code if the Account does not exist.

The call MUST fail with the NO_UNTIS error code if the Account has no D-ASA units.

The call MUST fail with the NOT_MATURE error code if the principal is not mature.

The call MUST fail with the PENDING_COUPON_PAYMENT error code if there is any due coupon still to be paid.

If the D-ASA has on-chain payment agent, the call MUST fail with the NOT_ENOUGH_FUNDS error code if funds are not enough for the payment.

Pay Coupon

{
  "name": "pay_coupon",
  "desc": "Pay due coupon to an account",
  "readonly": false,
  "args": [
    {
      "type": "address",
      "name": "holding_address",
      "desc": "Account Holding Address"
    },
    {
      "type": "byte[]",
      "name": "payment_info",
      "desc": "Additional payment information (Optional)"
    }
  ],
  "returns": {
    "type": "(uint64, uint64, byte[])",
    "desc": "Paid coupon amount in denomination asset, Payment timestamp, Payment context"
  },
  "errors": [
    {
      "code": "UNAUTHORIZED",
      "message": "Not authorized"
    },
    {
      "code": "DEFAULTED",
      "message": "Defaulted"
    },
    {
      "code": "SUSPENDED",
      "message": "Suspended operations"
    },
    {
      "code": "INVALID_HOLDING_ADDRESS",
      "message": "Invalid account holding address"
    },
    {
      "code": "NO_UNITS",
      "message": "No D-ASA units"
    },
    {
      "code": "NO_DUE_COUPON",
      "message": "No due coupon to pay"
    },
    {
      "code": "PENDING_COUPON_PAYMENT",
      "message": "Pending due coupon payment"
    }
  ]
}

A reference implementation SHOULD NOT require an authorized caller.

If the D-ASA has an amortizing principal payment schedule, the call MUST update the Account's unit value.

If the call requires authorization, it MUST fail with the UNAUTHORIZED error code if not called by an authorized caller.

The call MUST fail with the DEFAULTED error code if the asset is defaulted.

The call MUST fail with the SUSPENDED error code if the asset operations are suspended.

The call MUST fail with the INVALID_HOLDING_ADDRESS error code if the Account does not exist.

The call MUST fail with the NO_UNTIS error code if the Account has no D-ASA units.

The call MUST fail with the NO_DUE_COUPON error code if there is no due coupon left to pay for the Account.

The call MUST fail with the PENDING_COUPON_PAYMENT error code if there is an old due coupon still to be paid to any account.

If the D-ASA has on-chain payment agent, the call MUST fail with the NOT_ENOUGH_FUNDS error code if funds are not enough for the payment.

Early Repayment

{
  "name": "early_repayment",
  "desc": "Pay the principal to an account before maturity",
  "readonly": false,
  "args": [
    {
      "type": "address",
      "name": "holding_address",
      "desc": "Account Holding Address"
    },
    {
      "type": "uint64",
      "name": "units",
      "desc": "Amount of D-ASA units to repay"
    },
    {
      "type": "byte[]",
      "name": "payment_info",
      "desc": "Additional payment information (Optional)"
    }
  ],
  "returns": {
    "type": "(uint64, uint64, byte[])",
    "desc": "Paid principal amount in denomination asset, Payment timestamp, Payment information"
  },
  "errors": [
    {
      "code": "UNAUTHORIZED",
      "message": "Not authorized"
    },
    {
      "code": "DEFAULTED",
      "message": "Defaulted"
    },
    {
      "code": "SUSPENDED",
      "message": "Suspended operations"
    },
    {
      "code": "INVALID_HOLDING_ADDRESS",
      "message": "Invalid account holding address"
    },
    {
      "code": "NO_UNITS",
      "message": "No D-ASA units"
    },
    {
      "code": "PENDING_COUPON_PAYMENT",
      "message": "Pending due coupon payment for the account"
    },
    {
      "code": "ZERO_UNITS",
      "message": "Can not repay zero units"
    },
    {
      "code": "OVER_REPAYMENT",
      "message": "Insufficient units to repay for the account"
    },
    {
      "code": "ALREADY_MATURE",
      "message": "Already mature"
    }
  ]
}

The call MUST remove D-ASA early rapid units from the Account Holding Address and from circulation.

The call MUST fail with the UNAUTHORIZED error code if not called by an authorized caller.

The call MUST fail with the DEFAULTED error code if the asset is defaulted.

The call MUST fail with the SUSPENDED error code if the asset operations or any account involved in the transfers are suspended.

The call MUST fail with the INVALID_HOLDING_ADDRESS error code if the Sender or Receiver Holding Address is invalid.

The call MUST fail with the NO_UNTIS error code if the Account has no D-ASA units.

The call MUST fail with the PENDING_COUPON_PAYMENT error code if there is a due coupon still to be paid for the Account.

The call MUST fail with the ZERO_UNITS error code if the distributing units are null.

The call MUST fail with the OVER_REPAYMENT error code if there are no sufficient remaining D-ASA units to repay.

The call MUST fail with the ALREADY_MATURE error code if the principal is mature.

If the D-ASA has on-chain payment agent, the call MUST fail with the NOT_ENOUGH_FUNDS error code if funds are not enough for the payment.

Asset Transfer

{
  "name": "asset_transfer",
  "desc": "Transfer D-ASA units between accounts",
  "readonly": false,
  "args": [
    {
      "type": "address",
      "name": "sender_holding_address",
      "desc": "Sender Account Holding Address"
    },
    {
      "type": "address",
      "name": "receiver_holding_address",
      "desc": "Receiver Account Holding Address"
    },
    {
      "type": "uint64",
      "name": "units",
      "desc": "Amount of D-ASA units to transfer"
    }
  ],
  "returns": {
    "type": "uint64",
    "desc": "Transferred actualized value in denomination asset"
  },
  "errors": [
    {
      "code": "UNAUTHORIZED",
      "message": "Not authorized"
    },
    {
      "code": "DEFAULTED",
      "message": "Defaulted"
    },
    {
      "code": "SUSPENDED",
      "message": "Suspended operations"
    },
    {
      "code": "INVALID_HOLDING_ADDRESS",
      "message": "Invalid account holding address"
    },
    {
      "code": "SECONDARY_MARKET_CLOSED",
      "message": "Secondary market is closed"
    },
    {
      "code": "OVER_TRANSFER",
      "message": "Insufficient sender units to transfer"
    },
    {
      "code": "NON_FUNGIBLE_UNITS",
      "message": "Sender and receiver units are not fungible"
    },
    {
      "code": "PENDING_COUPON_PAYMENT",
      "message": "Pending due coupon payment"
    }
  ]
}

The call MUST transfer D-ASA units from the Sender Account Holding Address (removing D-ASA units) to the Receiver Account Holding Address (adding D-ASA units).

The call MUST fail with the UNAUTHORIZED error code if not called by an authorized caller.

The call MUST fail with the DEFAULTED error code if the asset is defaulted.

The call MUST fail with the SUSPENDED error code if the asset operations or any account involved in the transfers are suspended.

The call MUST fail with the INVALID_HOLDING_ADDRESS error code if the Sender or Receiver Holding Address is invalid.

The call MUST fail with the SECONDARY_MARKET_CLOSED error code if the secondary market is closed.

The call MUST fail with the OVER_TRANSFER error code if the Sender Account Holding Address has insufficient D-ASA units to transfer.

The call MUST fail with the NON_FUNGIBLE_UNITS error code if the Sender and Receiver units are not fungible (e.g. different paid coupons, see D-ASA units fungibility section).

The call MUST fail with the PENDING_COUPON_PAYMENT error code if there is a due coupon still to be paid to the Sender Holding Address.

Update Total Units

{
  "name": "update_total_units",
  "desc": "Update D-ASA total_units",
  "readonly": false,
  "args": [
    {
      "type": "uint64",
      "name": "total_units",
      "desc": "D-ASA total units"
    }
  ],
  "returns": {
    "type": "uint64",
    "desc": "Timestamp of the update"
  },
  "errors": [
    {
      "code": "UNAUTHORIZED",
      "message": "Not authorized"
    },
    {
      "code": "DEFAULTED",
      "message": "Defaulted"
    },
    {
      "code": "SUSPENDED",
      "message": "Asset operations are suspended"
    },
    {
      "code": "PENDING_COUPON_PAYMENT",
      "message": "Pending due coupon payment"
    }
  ]
}

The call MUST fail with the UNAUTHORIZED error code if not called by an authorized caller.

The call MUST fail with the DEFAULTED error code if the asset is defaulted.

The call MAY fail with the SUSPENDED error code if the asset is suspended.

The call MUST fail with the PENDING_COUPON_PAYMENT error code if there is any due coupon still to be paid.

Update Global Unit Value

{
  "name": "update_global_unit_value",
  "desc": "Update D-ASA nominal unit value globally",
  "readonly": false,
  "args": [
    {
      "type": "uint64",
      "name": "unit_value",
      "desc": "D-ASA nominal unit value, expressed in denomination asset"
    }
  ],
  "returns": {
    "type": "uint64",
    "desc": "Timestamp of the update"
  },
  "errors": [
    {
      "code": "UNAUTHORIZED",
      "message": "Not authorized"
    },
    {
      "code": "DEFAULTED",
      "message": "Defaulted"
    },
    {
      "code": "SUSPENDED",
      "message": "Asset operations are suspended"
    },
    {
      "code": "PENDING_COUPON_PAYMENT",
      "message": "Pending due coupon payment"
    }
  ]
}

The call MUST fail with the UNAUTHORIZED error code if not called by an authorized caller.

The call MUST fail with the DEFAULTED error code if the asset is defaulted.

The call MAY fail with the SUSPENDED error code if the asset is suspended.

The call MUST fail with the PENDING_COUPON_PAYMENT error code if there is any due coupon still to be paid.

Update Interest Rate

{
  "name": "update_interest_rate",
  "desc": "Update variable interest rates in bps",
  "readonly": false,
  "args": [
    {
      "type": "uint16",
      "name": "interest_rate",
      "desc": "Interest rate in bps"
    }
  ],
  "returns": {
    "type": "uint64",
    "desc": "Timestamp of the update"
  },
  "errors": [
    {
      "code": "UNAUTHORIZED",
      "message": "Not authorized"
    },
    {
      "code": "DEFAULTED",
      "message": "Defaulted"
    },
    {
      "code": "SUSPENDED",
      "message": "Asset operations are suspended"
    },
    {
      "code": "PENDING_COUPON_PAYMENT",
      "message": "Pending due coupon payment"
    }
  ]
}

The call MUST fail with the UNAUTHORIZED error code if not called by an authorized caller.

The call MUST fail with the DEFAULTED error code if the asset is defaulted.

The call MAY fail with the SUSPENDED error code if the asset is suspended.

The call MUST fail with the PENDING_COUPON_PAYMENT error code if there is any due coupon still to be paid.

Update Coupon Rates

{
  "name": "update_coupon_rates",
  "desc": "Update variable coupon interest rates in bps",
  "readonly": false,
  "args": [
    {
      "type": "uint64[]",
      "name": "coupon_rates",
      "desc": "Coupon interest rates in bps"
    }
  ],
  "returns": {
    "type": "uint64",
    "desc": "Timestamp of the update"
  },
  "errors": [
    {
      "code": "UNAUTHORIZED",
      "message": "Not authorized"
    },
    {
      "code": "DEFAULTED",
      "message": "Defaulted"
    },
    {
      "code": "SUSPENDED",
      "message": "Asset operations are suspended"
    },
    {
      "code": "INVALID_COUPON_RATES_LENGTH",
      "message": "Coupon rates length is not equal to total coupons"
    },
    {
      "code": "INVALID_PAST_RATE",
      "message": "Due coupon rates can not be modified"
    },
    {
      "code": "PENDING_COUPON_PAYMENT",
      "message": "Pending due coupon payment"
    }
  ]
}

The call MUST fail with the UNAUTHORIZED error code if not called by an authorized caller.

The call MUST fail with the DEFAULTED error code if the asset is defaulted.

The call MAY fail with the SUSPENDED error code if the asset is suspended.

The call MUST fail with the INVALID_COUPON_RATES_LENGTH error code if the length of the coupon rates is not equal to total_coupons.

The call MUST fail with the INVALID_PAST_RATE error code if a due coupon rate is modified.

The call MUST fail with the PENDING_COUPON_PAYMENT error code if there is any due coupon still to be paid.

Update Time Events

{
  "name": "update_time_events",
  "desc": "Update D-ASA variable time schedule",
  "readonly": false,
  "args": [
    {
      "type": "uint64[]",
      "name": "time_events",
      "desc": "D-ASA time events (strictly ascending order)"
    }
  ],
  "returns": {
    "type": "(uint64, uint64, uint64, uint64, uint64)",
    "desc": "Primary distribution opening date, Primary distribution closure date, Issuance date, Maturity date, Timestamp of the update"
  },
  "errors": [
    {
      "code": "UNAUTHORIZED",
      "message": "Not authorized"
    },
    {
      "code": "DEFAULTED",
      "message": "Defaulted"
    },
    {
      "code": "SUSPENDED",
      "message": "Suspended operations"
    },
    {
      "code": "INVALID_TIME_EVENTS_LENGTH",
      "message": "Time events length is invalid"
    },
    {
      "code": "INVALID_TIME",
      "message": "Time events must be set in the future"
    },
    {
      "code": "INVALID_SORTING",
      "message": "Time events are not sorted correctly"
    },
    {
      "code": "INVALID_PAST_EVENT",
      "message": "Past time events can not be modified"
    },
    {
      "code": "PENDING_COUPON_PAYMENT",
      "message": "Pending due coupon payment"
    }
  ]
}

The call MUST fail with the UNAUTHORIZED error code if not called by an authorized caller.

The call MUST fail with the DEFAULTED error code if the asset is defaulted.

The call MAY fail with the SUSPENDED error code if the asset is suspended.

The call MUST fail with the INVALID_TIME_EVENTS_LENGTH error code if the length of the time events is not equal to total_coupons plus 4.

The call MUST fail with the INVALID_TIME error code if the first time event is earlier than the latest timestamp (or block height).

The call MUST fail with the INVALID_SORTING error code if the time events are not sorted in strictly ascending order.

The call MUST fail with the INVALID_PAST_EVENT error code if a past event is modified.

The call MUST fail with the PENDING_COUPON_PAYMENT error code if there is any due coupon still to be paid.

Update Time Periods

{
  "name": "update_time_periods",
  "desc": "Update D-ASA variable time periods",
  "readonly": false,
  "args": [
    {
      "type": "(uint64,uint64)[]",
      "name": "time_periods",
      "desc": "D-ASA time periods"
    }
  ],
  "returns": {
    "type": "uint64",
    "desc": "Timestamp of the update"
  },
  "errors": [
    {
      "code": "UNAUTHORIZED",
      "message": "Not authorized"
    },
    {
      "code": "DEFAULTED",
      "message": "Defaulted"
    },
    {
      "code": "SUSPENDED",
      "message": "Suspended operations"
    },
    {
      "code": "INVALID_TIME_PERIOD",
      "message": "Time period durations must be greater than zero"
    },
    {
      "code": "PENDING_COUPON_PAYMENT",
      "message": "Pending due coupon payment"
    }
  ]
}

The call MUST fail with the UNAUTHORIZED error code if not called by an authorized caller.

The call MUST fail with the DEFAULTED error code if the asset is defaulted.

The call MAY fail with the SUSPENDED error code if the asset is suspended.

The call MUST fail with the INVALID_TIME_PERIOD error code if the time period durations are not strictly greater than zero.

The call MUST fail with the PENDING_COUPON_PAYMENT error code if there is any due coupon still to be paid.

Get Asset Info

{
  "name": "get_asset_info",
  "desc": "Get D-ASA info",
  "readonly": true,
  "args": [],
  "returns": {
    "type": "(uint64,uint64,uint64,uint64,uint8,uint16,uint16,uint64,uint64,uint64, uint64,uint64,uint64,bool,uint8)",
    "desc": "Denomination asset ID, Settlement asset ID, Outstanding principal, Unit nominal value, Day-count convention, Principal discount, Interest rate, Total supply, Circulating supply, Primary distribution opening date, Primary distribution closure date, Issuance date, Maturity date, Suspended, Performance"
  }
}

Get Asset Metadata

{
  "name": "get_asset_metadata",
  "desc": "Get D-ASA metadata",
  "readonly": true,
  "args": [],
  "returns": {
    "type": "(uint8,uint8,uint8,uint8,uint8,uint8,byte[32],string)",
    "desc": "Contract type, Calendar, Business day convention, End of month convention, Early repayment effect, Early repayment penalty type, Prospectus hash, Prospectus URL"
  }
}

Get Account Info

{
  "name": "get_account_info",
  "desc": "Get account account info",
  "readonly": true,
  "args": [
    {
      "type": "address",
      "name": "holding_address",
      "desc": "Account Holding Address"
    }
  ],
  "returns": {
    "type": "(address,uint64,uint64,uint64,bool)",
    "desc": "Payment Address, D-ASA units, Unit nominal value in denomination asset, Paid coupons, Suspended"
  },
  "errors": [
    {
      "code": "INVALID_HOLDING_ADDRESS",
      "message": "Invalid Holding Address"
    }
  ]
}

The call MUST fail with the INVALID_HOLDING_ADDRESS error code if the Sender or Receiver Holding Address is invalid.

Get Account Units Value

{
  "name": "get_account_units_value",
  "desc": "Get account's units nominal value",
  "readonly": true,
  "args": [
    {
      "type": "address",
      "name": "holding_address",
      "desc": "Account Holding Address"
    },
    {
      "type": "uint64",
      "name": "units",
      "desc": "Account's units for the nominal value calculation"
    }
  ],
  "returns": {
    "type": "uint64",
    "desc": "Units nominal value in denomination asset"
  },
  "errors": [
    {
      "code": "NO_PRIMARY_DISTRIBUTION",
      "message": "Primary distribution not yet executed"
    },
    {
      "code": "INVALID_HOLDING_ADDRESS",
      "message": "Invalid Holding Address"
    },
    {
      "code": "INVALID_UNITS",
      "message": "Invalid amount of units for the account"
    }
  ]
}

The call MUST fail with the NO_PRIMARY_DISTRIBUTION error code if the method is called before the primary distribution opening date.

The call MUST fail with the INVALID_HOLDING_ADDRESS error code if the Sender or Receiver Holding Address is invalid.

The call MUST fail with the INVALID_UNTIS error code if the unit value is greater than Account D-ASA units.

Get Account Units Current Value

{
  "name": "get_account_units_current_value",
  "desc": "Get account's current units value and accrued interest",
  "readonly": true,
  "args": [
    {
      "type": "address",
      "name": "holding_address",
      "desc": "Account Holding Address"
    },
    {
      "type": "uint64",
      "name": "units",
      "desc": "Account's units for the current value calculation"
    }
  ],
  "returns": {
    "type": "(uint64,uint64,(uint64,uint64))",
    "desc": "Units current value in denomination asset, Accrued interest in denomination asset, (Day count factor numerator, Day count factor denominator)"
  },
  "errors": [
    {
      "code": "NO_PRIMARY_DISTRIBUTION",
      "message": "Primary distribution not yet executed"
    },
    {
      "code": "INVALID_HOLDING_ADDRESS",
      "message": "Invalid Holding Address"
    },
    {
      "code": "INVALID_UNITS",
      "message": "Invalid amount of units for the account"
    },
    {
      "code": "PENDING_COUPON_PAYMENT",
      "message": "Pending due coupon payment for the account"
    }
  ]
}

The call MUST fail with the NO_PRIMARY_DISTRIBUTION error code if the method is called before the primary distribution opening date.

The call MUST fail with the INVALID_HOLDING_ADDRESS error code if the Sender or Receiver Holding Address is invalid.

The call MUST fail with the INVALID_UNTIS error code if the unit value is greater than Account D-ASA units.

If the D-ASA has coupons, the call MUST fail with the PENDING_COUPON_PAYMENT error code if there is an old due coupon still to be paid to any account.

The accrued interest MUST 0 if the method is called before the issuance date.

If the D-ASA has fixed coupons, the accrued interest MUST be 0 after all coupons are due.

If the D-ASA has zero coupons, the accrued interest MUST be 0 after the maturity date.

Get Roles

{
  "name": "get_roles",
  "desc": "Get role identifiers",
  "readonly": true,
  "args": [],
  "returns": {
    "type": "uint8[]",
    "desc": "Role identifiers"
  }
}

Get Role Config

{
  "name": "get_role_config",
  "desc": "Get role configuration",
  "readonly": true,
  "args": [
    {
      "type": "address",
      "name": "role_address",
      "desc": "Account Role Address"
    },
    {
      "type": "uint8",
      "name": "role",
      "desc": "Role identifier"
    }
  ],
  "returns": {
    "type": "bytes[]",
    "desc": "Role configuration"
  },
  "errors": [
    {
      "code": "INVALID_ROLE",
      "message": "Invalid role identifier"
    },
    {
      "code": "INVALID_ROLE_ADDRESS",
      "message": "Invalid account role address"
    }
  ]
}

Get Time Events

{
  "name": "get_time_events",
  "desc": "Get D-ASA time events",
  "readonly": true,
  "args": [],
  "returns": {
    "type": "uint64[]",
    "desc": "Time events"
  }
}

Get Time Periods

{
  "name": "get_time_periods",
  "desc": "Get D-ASA time periods",
  "readonly": true,
  "args": [],
  "returns": {
    "type": "(uint64,uint64)[]",
    "desc": "Time periods"
  }
}

Get Payment Amount

{
  "name": "get_payment_amount",
  "desc": "Get the next payment amount",
  "readonly": true,
  "args": [
    {
      "type": "address",
      "name": "holding_address",
      "desc": "Account Holding Address"
    }
  ],
  "returns": {
    "type": "(uint64,uint64)",
    "desc": "Interest amount in denomination asset, Principal amount in denomination asset"
  },
  "errors": [
    {
      "code": "INVALID_HOLDING_ADDRESS",
      "message": "Invalid Holding Address"
    }
  ]
}

The getter MUST return the next payment amount for the account or 0 if there is no payment to execute for the account.

The getter MUST return the interest and the principal components separately.

📎 EXAMPLE

Let's have a D-ASA with 4 coupons. The account already received 2 coupon payments. The getter returns the interest amount of the 3rd coupon.

📎 EXAMPLE

Let's have a D-ASA with 4 coupons and a principal amortizing schedule. The account already received 2 coupon payments. The getter returns the interest amount of the 3rd coupon and the amortized principal.

📎 EXAMPLE

Let's have a D-ASA with 4 coupons and principal at maturity. The account already received 4 coupon payments. The getter returns the amount of the principal repayment.

📎 EXAMPLE

Let's have a D-ASA with zero coupons and principal at maturity. The principal is not yet mature. The getter returns the amount of the principal repayment.

📎 EXAMPLE

Let's have a D-ASA with perpetual coupons and no callable principal. The account already received N coupon payments. The getter returns the interest amount of the N+1 coupon.

Get Coupon Rates

{
  "name": "get_coupons_rates",
  "desc": "Get D-ASA coupon rates",
  "readonly": true,
  "args": [],
  "returns": {
    "type": "uint16[]",
    "desc": "Coupon rates"
  }
}

Get Coupons Status

{
  "name": "get_coupons_status",
  "desc": "Get D-ASA coupons status",
  "readonly": true,
  "args": [],
  "returns": {
    "type": "(uint64,uint64,uint64,(uint64,uint64),bool)",
    "desc": "Total coupons, Due coupons, Next coupon due date, (Day count factor numerator, Day count factor denominator) , All coupons due paid"
  }
}

The next coupon due date value MUST be 0 if all coupons are due.

The day count factor values MUST 0 if the method is called before the issuance date or if all coupons are due.

Get Amortizing Rates

{
  "name": "get_amortizing_rates",
  "desc": "Get D-ASA principal amortizing rates",
  "readonly": true,
  "args": [],
  "returns": {
    "type": "uint64[]",
    "desc": "Principal amortizing rates"
  }
}

Get Secondary Market Schedule

{
  "name": "get_secondary_market_schedule",
  "desc": "Get secondary market schedule",
  "readonly": true,
  "args": [],
  "returns": {
    "type": "uint64[]",
    "desc": "Secondary market schedule"
  }
}

Get Early Repayment Schedule

{
  "name": "get_early_repayment_schedule",
  "desc": "Get early repayment schedule",
  "readonly": true,
  "args": [],
  "returns": {
    "type": "uint64[]",
    "desc": "Early repayment schedule"
  }
}

Rationale

This standard has been designed to support different types of debt instruments and their payoffs, with cash-flows executed both on-chain and off-chain.

The standard fosters modularity, with high degree of flexibility with respect to the integration of external components (Applications), such as KYC, auctions, order-books, off-chain transfer agents, etc.

The specification makes sure that the trust model and RBAC of D-ASA implementations can range from trustless versions (e.g., payments triggered automatically if the conditions are met, default called automatically on payment failure) to trusted ones (e.g., payments triggered only by authorized entities, default called manually by a trustee).

The implementation of the specified interfaces is left to the use-cases, which may cherry-pick a subset of methods and getters based on their requirements.

Reference Implementation

⚠️The reference implementations have not been audited. Do not use this code for real products. The author declines all responsibility.

⚠️The reference implementation does not guarantee compliance with ACTUS reference implementation.

The reference implementation provides the following features:

• RBAC:

  • Arranger: creates, configures and updates the D-ASA
  • Account Manager: opens and closes accounts (proxy a KYC process)
  • Primary Dealer: performs the primary distribution on the primary market
  • Trustee: can call a default
  • Authority: can suspend accounts or the whole asset
  • Interest Oracle: can update the interest rate in case of variable rates

• Types:

  • Zero Coupon Bond
  • Fixed Coupon Bond
  • Perpetual Bond

• Denomination:

  • On-chain (ASA)
  • Off-chain

• Payment Agent (Settlement):

  • On-chain (ASA)

• Day-count conventions:

  • Actual/Actual (time periods must be in days, i.e., multiples of 86400 seconds)
  • Continuous

• Transfer Agent:

  • On-chain
  • Direct (i.e., from investor to investor)

• Secondary market

• Notarize metadata (e.g., prospectus, etc.)

• Updatable program (restricted to the Arranger)

Deployments

D-ASA examples deployed on TestNet:

1. Download the App Spec JSON file;
2. Navigate to the Lora App Lab;
3. Create the App Interface using the existing App ID and App Spec JSON;
4. Explore the D-ASA interface.

Zero Coupon Bond

Contract Data Model

Contract Events

Contract Execution

Payment Agent

Payments are trustless (i.e., can be triggered by anyone), as long as payments' conditions are met (e.g., the payment is due).

AVM fees (ALGO) for the execution of the cash flows are paid by who triggers the cash flow.

Performance

No grace period. No delinquency period. Default called manually by the trustee.

Fixed Coupon Bond

Contract Data Model

Contract Events

Contract Execution

Payment Agent

Payments are trustless (i.e., can be triggered by anyone), as long as payments' conditions are met (e.g., the payment is due).

AVM fees (ALGO) for the execution of the cash flows are paid by who triggers the cash flow.

A coupon payment cannot be executed until all the previous due coupons (if any) have been paid to all the investors.

Transfer Agent

D-ASA units cannot be transferred until all the pending due coupon payments for the sender and receiver (if any) have been executed.

Performance

No grace period. No delinquency period. Default called manually by the trustee.

Perpetual Bond

Contract Data Model

Contract Events

Contract Execution

Payment Agent

Payments are trustless (i.e., can be triggered by anyone), as long as payments' conditions are met (e.g., the payment is due).

AVM fees (ALGO) for the execution of the cash flows are paid by who triggers the cash flow.

A coupon payment cannot be executed until all the previous due coupons (if any) have been paid to all the investors.

Transfer Agent

D-ASA units cannot be transferred until all the pending due coupon payments for the sender and receiver (if any) have been executed.

Interest Rate

Updated by the interest oracle.

Interest rate cannot be updated until all the previous due coupons (if any) have been paid to all the investors.

Performance

No grace period. No delinquency period. Default called manually by the trustee.

Tests

The D-ASA project is developed with AlgoKit.

• Install AlgoKit
• Setup your virtual environment (managed with Poetry)

algokit bootstrap all

• Start your Algorand LocalNet (requires Docker)

algokit localnet start

• Run tests (managed with PyTest)

algokit project run test

or, for verbose results:

poetry run pytest -s -v tests/<contract_name>/<test_case>.py

Contributors

• Cosimo Bassi (@cusma)
• Altynbek Orumbayev (@aorumbayev)

License

                    GNU AFFERO GENERAL PUBLIC LICENSE
                       Version 3, 19 November 2007

 Copyright (C) 2007 Free Software Foundation, Inc. <https://fsf.org/>
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the conditions stated below.  Sublicensing is not allowed; section 10
makes it unnecessary.

  3. Protecting Users' Legal Rights From Anti-Circumvention Law.

  No covered work shall be deemed part of an effective technological
measure under any applicable law fulfilling obligations under article
11 of the WIPO copyright treaty adopted on 20 December 1996, or
similar laws prohibiting or restricting circumvention of such
measures.

  When you convey a covered work, you waive any legal power to forbid
circumvention of technological measures to the extent such circumvention
is effected by exercising rights under this License with respect to
the covered work, and you disclaim any intention to limit operation or
modification of the work as a means of enforcing, against the work's
users, your or third parties' legal rights to forbid circumvention of
technological measures.

  4. Conveying Verbatim Copies.

  You may convey verbatim copies of the Program's source code as you
receive it, in any medium, provided that you conspicuously and
appropriately publish on each copy an appropriate copyright notice;
keep intact all notices stating that this License and any
non-permissive terms added in accord with section 7 apply to the code;
keep intact all notices of the absence of any warranty; and give all
recipients a copy of this License along with the Program.

  You may charge any price or no price for each copy that you convey,
and you may offer support or warranty protection for a fee.

  5. Conveying Modified Source Versions.

  You may convey a work based on the Program, or the modifications to
produce it from the Program, in the form of source code under the
terms of section 4, provided that you also meet all of these conditions:

    a) The work must carry prominent notices stating that you modified
    it, and giving a relevant date.

    b) The work must carry prominent notices stating that it is
    released under this License and any conditions added under section
    7.  This requirement modifies the requirement in section 4 to
    "keep intact all notices".

    c) You must license the entire work, as a whole, under this
    License to anyone who comes into possession of a copy.  This
    License will therefore apply, along with any applicable section 7
    additional terms, to the whole of the work, and all its parts,
    regardless of how they are packaged.  This License gives no
    permission to license the work in any other way, but it does not
    invalidate such permission if you have separately received it.

    d) If the work has interactive user interfaces, each must display
    Appropriate Legal Notices; however, if the Program has interactive
    interfaces that do not display Appropriate Legal Notices, your
    work need not make them do so.

  A compilation of a covered work with other separate and independent
works, which are not by their nature extensions of the covered work,
and which are not combined with it such as to form a larger program,
in or on a volume of a storage or distribution medium, is called an
"aggregate" if the compilation and its resulting copyright are not
used to limit the access or legal rights of the compilation's users
beyond what the individual works permit.  Inclusion of a covered work
in an aggregate does not cause this License to apply to the other
parts of the aggregate.

  6. Conveying Non-Source Forms.

  You may convey a covered work in object code form under the terms
of sections 4 and 5, provided that you also convey the
machine-readable Corresponding Source under the terms of this License,
in one of these ways:

    a) Convey the object code in, or embodied in, a physical product
    (including a physical distribution medium), accompanied by the
    Corresponding Source fixed on a durable physical medium
    customarily used for software interchange.

    b) Convey the object code in, or embodied in, a physical product
    (including a physical distribution medium), accompanied by a
    written offer, valid for at least three years and valid for as
    long as you offer spare parts or customer support for that product
    model, to give anyone who possesses the object code either (1) a
    copy of the Corresponding Source for all the software in the
    product that is covered by this License, on a durable physical
    medium customarily used for software interchange, for a price no
    more than your reasonable cost of physically performing this
    conveying of source, or (2) access to copy the
    Corresponding Source from a network server at no charge.

    c) Convey individual copies of the object code with a copy of the
    written offer to provide the Corresponding Source.  This
    alternative is allowed only occasionally and noncommercially, and
    only if you received the object code with such an offer, in accord
    with subsection 6b.

    d) Convey the object code by offering access from a designated
    place (gratis or for a charge), and offer equivalent access to the
    Corresponding Source in the same way through the same place at no
    further charge.  You need not require recipients to copy the
    Corresponding Source along with the object code.  If the place to
    copy the object code is a network server, the Corresponding Source
    may be on a different server (operated by you or a third party)
    that supports equivalent copying facilities, provided you maintain
    clear directions next to the object code saying where to find the
    Corresponding Source.  Regardless of what server hosts the
    Corresponding Source, you remain obligated to ensure that it is
    available for as long as needed to satisfy these requirements.

    e) Convey the object code using peer-to-peer transmission, provided
    you inform other peers where the object code and Corresponding
    Source of the work are being offered to the general public at no
    charge under subsection 6d.

  A separable portion of the object code, whose source code is excluded
from the Corresponding Source as a System Library, need not be
included in conveying the object code work.

  A "User Product" is either (1) a "consumer product", which means any
tangible personal property which is normally used for personal, family,
or household purposes, or (2) anything designed or sold for incorporation
into a dwelling.  In determining whether a product is a consumer product,
doubtful cases shall be resolved in favor of coverage.  For a particular
product received by a particular user, "normally used" refers to a
typical or common use of that class of product, regardless of the status
of the particular user or of the way in which the particular user
actually uses, or expects or is expected to use, the product.  A product
is a consumer product regardless of whether the product has substantial
commercial, industrial or non-consumer uses, unless such uses represent
the only significant mode of use of the product.

  "Installation Information" for a User Product means any methods,
procedures, authorization keys, or other information required to install
and execute modified versions of a covered work in that User Product from
a modified version of its Corresponding Source.  The information must
suffice to ensure that the continued functioning of the modified object
code is in no case prevented or interfered with solely because
modification has been made.

  If you convey an object code work under this section in, or with, or
specifically for use in, a User Product, and the conveying occurs as
part of a transaction in which the right of possession and use of the
User Product is transferred to the recipient in perpetuity or for a
fixed term (regardless of how the transaction is characterized), the
Corresponding Source conveyed under this section must be accompanied
by the Installation Information.  But this requirement does not apply
if neither you nor any third party retains the ability to install
modified object code on the User Product (for example, the work has
been installed in ROM).

  The requirement to provide Installation Information does not include a
requirement to continue to provide support service, warranty, or updates
for a work that has been modified or installed by the recipient, or for
the User Product in which it has been modified or installed.  Access to a
network may be denied when the modification itself materially and
adversely affects the operation of the network or violates the rules and
protocols for communication across the network.

  Corresponding Source conveyed, and Installation Information provided,
in accord with this section must be in a format that is publicly
documented (and with an implementation available to the public in
source code form), and must require no special password or key for
unpacking, reading or copying.

  7. Additional Terms.

  "Additional permissions" are terms that supplement the terms of this
License by making exceptions from one or more of its conditions.
Additional permissions that are applicable to the entire Program shall
be treated as though they were included in this License, to the extent
that they are valid under applicable law.  If additional permissions
apply only to part of the Program, that part may be used separately
under those permissions, but the entire Program remains governed by
this License without regard to the additional permissions.

  When you convey a copy of a covered work, you may at your option
remove any additional permissions from that copy, or from any part of
it.  (Additional permissions may be written to require their own
removal in certain cases when you modify the work.)  You may place
additional permissions on material, added by you to a covered work,
for which you have or can give appropriate copyright permission.

  Notwithstanding any other provision of this License, for material you
add to a covered work, you may (if authorized by the copyright holders of
that material) supplement the terms of this License with terms:

    a) Disclaiming warranty or limiting liability differently from the
    terms of sections 15 and 16 of this License; or

    b) Requiring preservation of specified reasonable legal notices or
    author attributions in that material or in the Appropriate Legal
    Notices displayed by works containing it; or

    c) Prohibiting misrepresentation of the origin of that material, or
    requiring that modified versions of such material be marked in
    reasonable ways as different from the original version; or

    d) Limiting the use for publicity purposes of names of licensors or
    authors of the material; or

    e) Declining to grant rights under trademark law for use of some
    trade names, trademarks, or service marks; or

    f) Requiring indemnification of licensors and authors of that
    material by anyone who conveys the material (or modified versions of
    it) with contractual assumptions of liability to the recipient, for
    any liability that these contractual assumptions directly impose on
    those licensors and authors.

  All other non-permissive additional terms are considered "further
restrictions" within the meaning of section 10.  If the Program as you
received it, or any part of it, contains a notice stating that it is
governed by this License along with a term that is a further
restriction, you may remove that term.  If a license document contains
a further restriction but permits relicensing or conveying under this
License, you may add to a covered work material governed by the terms
of that license document, provided that the further restriction does
not survive such relicensing or conveying.

  If you add terms to a covered work in accord with this section, you
must place, in the relevant source files, a statement of the
additional terms that apply to those files, or a notice indicating
where to find the applicable terms.

  Additional terms, permissive or non-permissive, may be stated in the
form of a separately written license, or stated as exceptions;
the above requirements apply either way.

  8. Termination.

  You may not propagate or modify a covered work except as expressly
provided under this License.  Any attempt otherwise to propagate or
modify it is void, and will automatically terminate your rights under
this License (including any patent licenses granted under the third
paragraph of section 11).

  However, if you cease all violation of this License, then your
license from a particular copyright holder is reinstated (a)
provisionally, unless and until the copyright holder explicitly and
finally terminates your license, and (b) permanently, if the copyright
holder fails to notify you of the violation by some reasonable means
prior to 60 days after the cessation.

  Moreover, your license from a particular copyright holder is
reinstated permanently if the copyright holder notifies you of the
violation by some reasonable means, this is the first time you have
received notice of violation of this License (for any work) from that
copyright holder, and you cure the violation prior to 30 days after
your receipt of the notice.

  Termination of your rights under this section does not terminate the
licenses of parties who have received copies or rights from you under
this License.  If your rights have been terminated and not permanently
reinstated, you do not qualify to receive new licenses for the same
material under section 10.

  9. Acceptance Not Required for Having Copies.

  You are not required to accept this License in order to receive or
run a copy of the Program.  Ancillary propagation of a covered work
occurring solely as a consequence of using peer-to-peer transmission
to receive a copy likewise does not require acceptance.  However,
nothing other than this License grants you permission to propagate or
modify any covered work.  These actions infringe copyright if you do
not accept this License.  Therefore, by modifying or propagating a
covered work, you indicate your acceptance of this License to do so.

  10. Automatic Licensing of Downstream Recipients.

  Each time you convey a covered work, the recipient automatically
receives a license from the original licensors, to run, modify and
propagate that work, subject to this License.  You are not responsible
for enforcing compliance by third parties with this License.

  An "entity transaction" is a transaction transferring control of an
organization, or substantially all assets of one, or subdividing an
organization, or merging organizations.  If propagation of a covered
work results from an entity transaction, each party to that
transaction who receives a copy of the work also receives whatever
licenses to the work the party's predecessor in interest had or could
give under the previous paragraph, plus a right to possession of the
Corresponding Source of the work from the predecessor in interest, if
the predecessor has it or can get it with reasonable efforts.

  You may not impose any further restrictions on the exercise of the
rights granted or affirmed under this License.  For example, you may
not impose a license fee, royalty, or other charge for exercise of
rights granted under this License, and you may not initiate litigation
(including a cross-claim or counterclaim in a lawsuit) alleging that
any patent claim is infringed by making, using, selling, offering for
sale, or importing the Program or any portion of it.

  11. Patents.

  A "contributor" is a copyright holder who authorizes use under this
License of the Program or a work on which the Program is based.  The
work thus licensed is called the contributor's "contributor version".

  A contributor's "essential patent claims" are all patent claims
owned or controlled by the contributor, whether already acquired or
hereafter acquired, that would be infringed by some manner, permitted
by this License, of making, using, or selling its contributor version,
but do not include claims that would be infringed only as a
consequence of further modification of the contributor version.  For
purposes of this definition, "control" includes the right to grant
patent sublicenses in a manner consistent with the requirements of
this License.

  Each contributor grants you a non-exclusive, worldwide, royalty-free
patent license under the contributor's essential patent claims, to
make, use, sell, offer for sale, import and otherwise run, modify and
propagate the contents of its contributor version.

  In the following three paragraphs, a "patent license" is any express
agreement or commitment, however denominated, not to enforce a patent
(such as an express permission to practice a patent or covenant not to
sue for patent infringement).  To "grant" such a patent license to a
party means to make such an agreement or commitment not to enforce a
patent against the party.

  If you convey a covered work, knowingly relying on a patent license,
and the Corresponding Source of the work is not available for anyone
to copy, free of charge and under the terms of this License, through a
publicly available network server or other readily accessible means,
then you must either (1) cause the Corresponding Source to be so
available, or (2) arrange to deprive yourself of the benefit of the
patent license for this particular work, or (3) arrange, in a manner
consistent with the requirements of this License, to extend the patent
license to downstream recipients.  "Knowingly relying" means you have
actual knowledge that, but for the patent license, your conveying the
covered work in a country, or your recipient's use of the covered work
in a country, would infringe one or more identifiable patents in that
country that you have reason to believe are valid.

  If, pursuant to or in connection with a single transaction or
arrangement, you convey, or propagate by procuring conveyance of, a
covered work, and grant a patent license to some of the parties
receiving the covered work authorizing them to use, propagate, modify
or convey a specific copy of the covered work, then the patent license
you grant is automatically extended to all recipients of the covered
work and works based on it.

  A patent license is "discriminatory" if it does not include within
the scope of its coverage, prohibits the exercise of, or is
conditioned on the non-exercise of one or more of the rights that are
specifically granted under this License.  You may not convey a covered
work if you are a party to an arrangement with a third party that is
in the business of distributing software, under which you make payment
to the third party based on the extent of your activity of conveying
the work, and under which the third party grants, to any of the
parties who would receive the covered work from you, a discriminatory
patent license (a) in connection with copies of the covered work
conveyed by you (or copies made from those copies), or (b) primarily
for and in connection with specific products or compilations that
contain the covered work, unless you entered into that arrangement,
or that patent license was granted, prior to 28 March 2007.

  Nothing in this License shall be construed as excluding or limiting
any implied license or other defenses to infringement that may
otherwise be available to you under applicable patent law.

  12. No Surrender of Others' Freedom.

  If conditions are imposed on you (whether by court order, agreement or
otherwise) that contradict the conditions of this License, they do not
excuse you from the conditions of this License.  If you cannot convey a
covered work so as to satisfy simultaneously your obligations under this
License and any other pertinent obligations, then as a consequence you may
not convey it at all.  For example, if you agree to terms that obligate you
to collect a royalty for further conveying from those to whom you convey
the Program, the only way you could satisfy both those terms and this
License would be to refrain entirely from conveying the Program.

  13. Remote Network Interaction; Use with the GNU General Public License.

  Notwithstanding any other provision of this License, if you modify the
Program, your modified version must prominently offer all users
interacting with it remotely through a computer network (if your version
supports such interaction) an opportunity to receive the Corresponding
Source of your version by providing access to the Corresponding Source
from a network server at no charge, through some standard or customary
means of facilitating copying of software.  This Corresponding Source
shall include the Corresponding Source for any work covered by version 3
of the GNU General Public License that is incorporated pursuant to the
following paragraph.

  Notwithstanding any other provision of this License, you have
permission to link or combine any covered work with a work licensed
under version 3 of the GNU General Public License into a single
combined work, and to convey the resulting work.  The terms of this
License will continue to apply to the part which is the covered work,
but the work with which it is combined will remain governed by version
3 of the GNU General Public License.

  14. Revised Versions of this License.

  The Free Software Foundation may publish revised and/or new versions of
the GNU Affero General Public License from time to time.  Such new versions
will be similar in spirit to the present version, but may differ in detail to
address new problems or concerns.

  Each version is given a distinguishing version number.  If the
Program specifies that a certain numbered version of the GNU Affero General
Public License "or any later version" applies to it, you have the
option of following the terms and conditions either of that numbered
version or of any later version published by the Free Software
Foundation.  If the Program does not specify a version number of the
GNU Affero General Public License, you may choose any version ever published
by the Free Software Foundation.

  If the Program specifies that a proxy can decide which future
versions of the GNU Affero General Public License can be used, that proxy's
public statement of acceptance of a version permanently authorizes you
to choose that version for the Program.

  Later license versions may give you additional or different
permissions.  However, no additional obligations are imposed on any
author or copyright holder as a result of your choosing to follow a
later version.

  15. Disclaimer of Warranty.

  THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY
APPLICABLE LAW.  EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT
HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY
OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO,
THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
PURPOSE.  THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM
IS WITH YOU.  SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF
ALL NECESSARY SERVICING, REPAIR OR CORRECTION.

  16. Limitation of Liability.

  IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES AND/OR CONVEYS
THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY
GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE
USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF
DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD
PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS),
EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF
SUCH DAMAGES.

  17. Interpretation of Sections 15 and 16.

  If the disclaimer of warranty and limitation of liability provided
above cannot be given local legal effect according to their terms,
reviewing courts shall apply local law that most closely approximates
an absolute waiver of all civil liability in connection with the
Program, unless a warranty or assumption of liability accompanies a
copy of the Program in return for a fee.

                     END OF TERMS AND CONDITIONS

            How to Apply These Terms to Your New Programs

  If you develop a new program, and you want it to be of the greatest
possible use to the public, the best way to achieve this is to make it
free software which everyone can redistribute and change under these terms.

  To do so, attach the following notices to the program.  It is safest
to attach them to the start of each source file to most effectively
state the exclusion of warranty; and each file should have at least
the "copyright" line and a pointer to where the full notice is found.

    <one line to give the program's name and a brief idea of what it does.>
    Copyright (C) <year>  <name of author>

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU Affero General Public License as published
    by the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU Affero General Public License for more details.

    You should have received a copy of the GNU Affero General Public License
    along with this program.  If not, see <https://www.gnu.org/licenses/>.

Also add information on how to contact you by electronic and paper mail.

  If your software can interact with users remotely through a computer
network, you should also make sure that it provides a way for users to
get its source.  For example, if your program is a web application, its
interface could display a "Source" link that leads users to an archive
of the code.  There are many ways you could offer source, and different
solutions will be better for different programs; see section 13 for the
specific requirements.

  You should also get your employer (if you work as a programmer) or school,
if any, to sign a "copyright disclaimer" for the program, if necessary.
For more information on this, and how to apply and follow the GNU AGPL, see
<https://www.gnu.org/licenses/>.