Contract API Reference

This document tracks the current public contract surface in contract/src/lib.rs. For error codes, see ERROR-CODES.md, which contains the CONTRACT-34 table. For events, see EVENTS.md. For the propose/commit and propose/accept pattern shared by transfer_admin/accept_admin, propose_fee/commit_fee, propose_grace_period/commit_grace_period, and propose_upgrade/commit_upgrade, see architecture/two-step-auth.md.

Bounded API delta (Issue 110)
Data Types
Functions
Units & Conversions
Events Reference
Error Codes

Bounded API delta (Issue 110)

This revision documents only the following symbols against contract/src/lib.rs, contract/src/charge_exec.rs, contract/src/batch.rs, contract/src/fee.rs, contract/src/errors.rs, and contract/src/storage.rs. It is not a full API audit.

Related ops: EVENTS.md (paused, subscription_auto_resumed, charged, batch_charge_skips), KEEPER.md (batch_charge), MAINNET-DEPLOYMENT.md (fee bounds / health gates).

Data Types

`Subscription`

pub struct Subscription {
  pub merchant: Address,
  pub amount: i128,
  pub interval: u64,
  pub last_charged: u64,
  pub active: bool,
  pub paused: bool,
  pub token: Address,
  pub referrer: Option<Address>,
  pub label: Symbol,
  pub trial_duration: u64,
}

`ChargeResult`

Returned by live batch_charge and by get_batch_charge_estimate. Defined in contract/src/batch.rs (re-exported from lib.rs).

pub enum ChargeResult {
  Charged,                 // live: funds transferred; estimate: would charge (no transfer)
  Skipped,                 // interval has not elapsed
  NoSubscription,          // no subscription record
  Inactive,                // cancelled / inactive
  Paused,                  // still paused
  GracePeriodElapsed,      // past the grace window
  AllowanceInsufficient,   // SAC allowance < gross `sub.amount`; appended (discriminant 6)
  Charged,
  Skipped,
  NoSubscription,
  Inactive,
  Paused,
  GracePeriodElapsed,
  AllowanceInsufficient,
}

Variant	Meaning on `batch_charge`	Meaning on `get_batch_charge_estimate`
`Charged`	Transfer succeeded	Precheck passed (or auto-resume short-circuit; no transfer)
`Skipped`	Interval not elapsed	Same (via `precheck_charge`)
`NoSubscription`	No record	Same
`Inactive`	Cancelled / inactive	Same
`Paused`	Still paused	Same
`GracePeriodElapsed`	Past grace window	Same
New variants must be appended so off-chain parsers keep decoding 0–5. Do not confuse `AllowanceInsufficient` with `ChargeSimResult::InsufficientAllowance` or `ContractError::InsufficientAllowance` (8) — those are different symbols.

Variant	Meaning on `batch_charge`	Meaning on `get_batch_charge_estimate`
`Charged`	Transfer succeeded	Precheck + allowance passed (no transfer)
`Skipped`	Interval not elapsed	Same (via `precheck_charge`)
`NoSubscription`	No record	Same
`Inactive`	Cancelled / inactive	Same
`Paused`	Still paused	Same
`GracePeriodElapsed`	Past grace window	Same
`AllowanceInsufficient`	Gross allowance too low; rest of batch continues	Same check; no transfer
`AllowanceInsufficient`	Allowance below gross amount; no transfer	Same precheck path as live charge

This type is not the dry-run enum. Single-user simulation uses ChargeSimResult.

`ChargeSimResult`

Returned only by simulate_charge. Defined in contract/src/charge_exec.rs.

pub enum ChargeSimResult {
  WouldSucceed,
  NotDue,
  Inactive,
  InsufficientAllowance,
  GracePeriodElapsed,
  ContractPaused,
  SubscriptionPaused,
}

Variant	Meaning
`WouldSucceed`	Prechecks including SAC allowance would pass
`NotDue`	Ledger time is before next charge
`Inactive`	Missing subscription or inactive (no separate `NoSubscription`)
`InsufficientAllowance`	`allowance(user, contract) < amount`
`GracePeriodElapsed`	Past grace window
`ContractPaused`	Protocol paused (`storage::is_contract_paused`)
`SubscriptionPaused`	User pause, including unexpired `pause_until`

simulate_charge never panics with a ContractError for these outcomes; they are return values.

`PayPerUseSimResult`

Returned only by simulate_pay_per_use / simulate_pay_per_use_to. Defined in contract/src/charge_exec.rs.

pub enum PayPerUseSimResult {
  WouldSucceed,
  Inactive,
  InsufficientAllowance,
  ContractPaused,
  SubscriptionPaused,
  AmountMustBePositive,
  AmountExceedsMaximum,
  DailyLimitExceeded,
  InvalidRecipient,
  MerchantNotWhitelisted,
}

Variant	Meaning
`WouldSucceed`	Eligible: active, unpaused, within daily limit, allowance sufficient
`Inactive`	Missing subscription or inactive (no separate `NoSubscription`)
`InsufficientAllowance`	`allowance(user, contract) < amount`
`ContractPaused`	Protocol paused (`storage::is_contract_paused`)
`SubscriptionPaused`	Subscription is paused
`AmountMustBePositive`	`amount <= 0`
`AmountExceedsMaximum`	`amount > MAX_AMOUNT` (per-call cap)
`DailyLimitExceeded`	`daily_spent + amount > daily_limit`
`InvalidRecipient`	`pay_per_use_to` recipient is the contract's own address
`MerchantNotWhitelisted`	Whitelist enabled and `pay_per_use_to` recipient not whitelisted

simulate_pay_per_use never panics with a ContractError for these outcomes; they are return values.

`ProtocolStats`

pub struct ProtocolStats {
  pub active_count: u64,
  pub fee_bps: u32,
  pub fee_collector: Option<Address>,
  pub grace_period: u64,
  pub whitelist_enabled: bool,
  pub schema_version: u32,
  pub contract_paused: bool,
}

`HealthReport`

Returned by contract_health_check. There is no separate health-status enum: interpret is_healthy plus the component flags.

pub struct HealthReport {
  pub is_healthy: bool,
  pub contract_paused: bool,
  pub token_configured: bool,
  pub admin_configured: bool,
  pub instance_ttl_ledgers: u32,
  pub active_subscription_count: u64,
  pub schema_version: u32,
  pub fee_collector_set: bool,
  pub global_volume_utilization_pct: u32,
  pub pending_merchant_rev_count: u32,
}

Field	Type	Meaning
`is_healthy`	`bool`	`!contract_paused && token_configured && admin_configured && instance_ttl_ledgers > 17_280`
`contract_paused`	`bool`	Protocol pause flag
`token_configured`	`bool`	Instance token is set
`admin_configured`	`bool`	Admin is set
`instance_ttl_ledgers`	`u32`	On-chain: hardcoded `100_000` (Soroban does not expose `get_ttl()` outside tests). Test/testutils: real instance TTL. Do not treat the on-chain value as precise remaining TTL.
`active_subscription_count`	`u64`	Active subscription counter
`schema_version`	`u32`	Migration schema version
`fee_collector_set`	`bool`	Protocol fee collector is set
`global_volume_utilization_pct`	`u32`	`(accumulated * 100) / cap`, clamped to ≤ 100; `0` if cap is 0. Cap is `GlobalVolumeCapOverride` or `GLOBAL_MAX_VOLUME_PER_HOUR`.
`pending_merchant_rev_count`	`u32`	Merchants in `MerchantIndex` with unwithdrawn revenue `> 0`

How to interpret: treat is_healthy == false as “do not send production traffic” until pause, token, admin, or TTL flags are understood. fee_collector_set and volume utilization are informational and do not enter the is_healthy formula. global_volume_utilization_pct uses the stored cap override when present; charge-time enforcement still uses the compile-time constant (see MAINNET-DEPLOYMENT.md).

`DataKey`

pub enum DataKey {
  Subscription(Address),
  Token,
  Admin,
  GracePeriod,
  MerchantWhitelist(Address),
  WhitelistEnabled,
  MerchantFrozen(Address),
  FeeCollector,
  FeeBps,
  PendingFee,
  PendingAdmin,
  ActiveCount,
  MerchantRevenue(Address),
  MerchantRevenueDay(Address, u64),
  DailyLimit(Address),
  DailySpent(Address),
  Referral(Address),
  SchemaVersion,
  SubscriptionMeta(Address),
  ChargeHistory(Address),
  GlobalVolumeWindow,
  ContractPaused,
  MinInterval,
  MerchantRevenueHistory(Address),
  SubscriberIndex(u64),
  SubscriberIndexSize,
  MerchantSubCount(Address),
  PendingGracePeriod,
}

Functions

`initialize`

initialize(env: Env, token: Address, admin: Address)

Name	Type	Description
`token`	`Address`	SAC token used for subscription payments.
`admin`	`Address`	Initial contract admin.

Auth: none.

Returns: ().

Errors: ContractError::AlreadyInitialized.

CLI example:

soroban contract invoke --id <CONTRACT_ID> --source deployer --network testnet -- initialize --token <TOKEN_ADDRESS> --admin <ADMIN_ADDRESS>

`subscribe`

subscribe(env: Env, user: Address, merchant: Address, amount: i128, interval: u64, token: Address, trial_period: Option<u64>, referrer: Option<Address>)

Name	Type	Description
`user`	`Address`	Subscriber and transaction signer.
`merchant`	`Address`	Merchant receiving funds.
`amount`	`i128`	Recurring amount in stroops.
`interval`	`u64`	Billing interval in seconds.
`token`	`Address`	Token contract used for this subscription.
`trial_period`	`Option<u64>`	Optional delay before the first charge.
`referrer`	`Option<Address>`	Optional referrer address.

Auth: user.require_auth().

Returns: ().

Errors: ContractError::AmountMustBePositive, ContractError::IntervalMustBePositive, ContractError::MerchantNotWhitelisted, ContractError::ContractPausedError, ContractError::InvalidTokenAddress, ContractError::IntervalTooShort, ContractError::InsufficientAllowance.

CLI example:

soroban contract invoke --id <CONTRACT_ID> --source <USER_KEY> --network testnet -- subscribe --user <USER_ADDRESS> --merchant <MERCHANT_ADDRESS> --amount 50000000 --interval 2592000 --token <TOKEN_ADDRESS>

`subscribe_with_metadata`

subscribe_with_metadata(env: Env, user: Address, merchant: Address, amount: i128, interval: u64, token: Address, trial_period: Option<u64>, referrer: Option<Address>, label: String)

Name	Type	Description
`user`	`Address`	Subscriber and transaction signer.
`merchant`	`Address`	Merchant receiving funds.
`amount`	`i128`	Recurring amount in stroops.
`interval`	`u64`	Billing interval in seconds.
`token`	`Address`	Token contract used for this subscription.
`trial_period`	`Option<u64>`	Optional delay before the first charge.
`referrer`	`Option<Address>`	Optional referrer address.
`label`	`String`	Subscription label, max 64 bytes.

Auth: user.require_auth().

Returns: ().

Errors: same as subscribe(), plus ContractError::MetadataLabelTooLong.

CLI example:

soroban contract invoke --id <CONTRACT_ID> --source <USER_KEY> --network testnet -- subscribe_with_metadata --user <USER_ADDRESS> --merchant <MERCHANT_ADDRESS> --amount 50000000 --interval 2592000 --token <TOKEN_ADDRESS> --label pro

`charge`

charge(env: Env, user: Address)

Name	Type	Description
`user`	`Address`	Subscriber to charge.

Auth: none. This is permissionless for keeper use.

Returns: ().

Errors: ContractError::NoSubscriptionFound, ContractError::SubscriptionNotActive, ContractError::SubscriptionPaused, ContractError::IntervalNotElapsed, ContractError::GracePeriodElapsed, ContractError::NotInitialized.

CLI example:

soroban contract invoke --id <CONTRACT_ID> --source <KEEPER_KEY> --network testnet -- charge --user <USER_ADDRESS>

`simulate_charge`

Dry-run of a single charge() for user. No storage writes and no token transfer. Outcomes are ChargeSimResult variants, not panics.

simulate_charge(env: Env, user: Address) -> ChargeSimResult

Name	Type	Description
`user`	`Address`	Subscriber to simulate.

Auth: none.

Returns: ChargeSimResult.

Success behavior: evaluates contract pause, subscription presence, pause_until expiry (in memory only — does not persist auto-resume), due time, grace window, then SAC allowance(user, contract) vs amount. Returns WouldSucceed if all pass.

Error conditions: none as ContractError panics. Failure reasons are enum variants (ContractPaused, Inactive, SubscriptionPaused, NotDue, GracePeriodElapsed, InsufficientAllowance).

Distinguish from live charge and batch estimate:

	`charge` / `batch_charge`	`simulate_charge`	`get_batch_charge_estimate`
Transfers	Yes	No	No
Storage writes	Yes on success / auto-resume	No (auto-resume is memory-only)	Yes if `try_auto_resume` fires
Contract pause	Enforced (panic / skip)	`ContractPaused`	Ignored
Allowance	Required for success	Checked	Not checked
Return	void / `ChargeResult`	`ChargeSimResult`	`Vec<ChargeResult>`
Contract pause	`charge` and `batch_charge` panic `ContractPaused` (18)	`ContractPaused`	Ignored
Allowance	`charge` panics `InsufficientAllowance` (8); `batch_charge` returns `AllowanceInsufficient`	`InsufficientAllowance`	`ChargeResult::AllowanceInsufficient`
Return	void / `Vec<ChargeResult>`	`ChargeSimResult`	`Vec<ChargeResult>`

Keeper ops still use live batch_charge; see KEEPER.md. Events for a real charge are in EVENTS.md.

CLI example:

soroban contract invoke --id <CONTRACT_ID> --network testnet -- simulate_charge --user <USER_ADDRESS>

`simulate_pay_per_use`

Dry-run of a single pay_per_use() for user and amount. No storage writes and no token transfer. Outcomes are PayPerUseSimResult variants, not panics.

simulate_pay_per_use(env: Env, user: Address, amount: i128) -> PayPerUseSimResult

Name	Type	Description
`user`	`Address`	Subscriber to simulate.
`amount`	`i128`	One-time amount to simulate.

Auth: none.

Returns: PayPerUseSimResult.

Success behavior: evaluates contract pause, amount bounds, subscription presence, paused/inactive state, the daily spending limit (get_daily_limit / get_daily_spent), then SAC allowance(user, contract) vs amount. Returns WouldSucceed if all pass. Never writes spend tracking or other storage.

`simulate_pay_per_use_to`

Dry-run of a single pay_per_use_to() for user, amount, and an explicit recipient. Same checks as simulate_pay_per_use, plus recipient validation (InvalidRecipient if recipient is the contract's own address; MerchantNotWhitelisted if the whitelist is enabled and recipient is not whitelisted). No storage writes.

simulate_pay_per_use_to(env: Env, user: Address, amount: i128, recipient: Address) -> PayPerUseSimResult

Name	Type	Description
`user`	`Address`	Subscriber to simulate.
`amount`	`i128`	One-time amount to simulate.
`recipient`	`Address`	Recipient that would receive the net payment.

Auth: none.

Returns: PayPerUseSimResult.

CLI example:

soroban contract invoke --id <CONTRACT_ID> --network testnet -- simulate_pay_per_use --user <USER_ADDRESS> --amount 1000000

`extend_subscription_ttl`

extend_subscription_ttl(env: Env, user: Address)

Name	Type	Description
`user`	`Address`	Subscriber whose TTL should be refreshed.

Auth: none.

Returns: ().

Errors: none beyond storage access.

CLI example:

soroban contract invoke --id <CONTRACT_ID> --network testnet -- extend_subscription_ttl --user <USER_ADDRESS>

`pay_per_use`

pay_per_use(env: Env, user: Address, amount: i128)

Name	Type	Description
`user`	`Address`	Subscriber and signer.
`amount`	`i128`	One-time payment amount in stroops.

Auth: user.require_auth().

Returns: ().

Errors: ContractError::AmountMustBePositive, ContractError::AmountExceedsMaximum, ContractError::NoSubscriptionFound, ContractError::SubscriptionNotActive, ContractError::SubscriptionPaused.

CLI example:

soroban contract invoke --id <CONTRACT_ID> --source <USER_KEY> --network testnet -- pay_per_use --user <USER_ADDRESS> --amount 1000000

`cancel`

cancel(env: Env, user: Address)

Name	Type	Description
`user`	`Address`	Subscriber and signer.

Auth: user.require_auth().

Returns: ().

Errors: ContractError::NoSubscriptionFound.

CLI example:

soroban contract invoke --id <CONTRACT_ID> --source <USER_KEY> --network testnet -- cancel --user <USER_ADDRESS>

`pause`

pause(env: Env, user: Address)

Name	Type	Description
`user`	`Address`	Subscriber and signer.

Auth: user.require_auth().

Returns: ().

Errors: ContractError::NoSubscriptionFound, ContractError::SubscriptionNotActive.

CLI example:

soroban contract invoke --id <CONTRACT_ID> --source <USER_KEY> --network testnet -- pause --user <USER_ADDRESS>

`pause_until`

Bounded user pause. The subscription auto-resumes on a later charge or batch_charge when ledger time >= expiry. Unlike indefinite pause, this path sets paused = true and active = false.

pause_until(env: Env, user: Address, expiry: u64)

Name	Type	Description
`user`	`Address`	Subscriber and signer.
`expiry`	`u64`	Unix ledger timestamp; must be strictly greater than current ledger time.

Auth: user.require_auth().

Returns: ().

Success behavior: writes the subscription, stores pause expiry internally, emits paused (("paused", user)). See EVENTS.md.

Errors:

Condition	Code	Symbol
`expiry <= now`	27	`InvalidPauseExpiry`
No subscription	4	`NoSubscriptionFound`
`!sub.active`	16	`SubscriptionNotActive`

Pause-expiry read API: there is no public get_pause_expiry, get_pause, or paused_until contract method. Expiry is stored via internal storage::set_pause_expiry / storage::get_pause_expiry only.

CLI example:

soroban contract invoke --id <CONTRACT_ID> --source <USER_KEY> --network testnet -- pause_until --user <USER_ADDRESS> --expiry <UNIX_TIMESTAMP>

`resume`

resume(env: Env, user: Address)

Name	Type	Description
`user`	`Address`	Subscriber and signer.

Auth: user.require_auth().

Returns: ().

Errors: ContractError::NoSubscriptionFound, ContractError::SubscriptionNotActive.

CLI example:

soroban contract invoke --id <CONTRACT_ID> --source <USER_KEY> --network testnet -- resume --user <USER_ADDRESS>

`transfer_admin`

transfer_admin(env: Env, new_admin: Address)

Name	Type	Description
`new_admin`	`Address`	Proposed admin address.

Auth: current admin only.

Returns: ().

Errors: none beyond auth.

CLI example:

soroban contract invoke --id <CONTRACT_ID> --source <ADMIN_KEY> --network testnet -- transfer_admin --new_admin <NEW_ADMIN_ADDRESS>

`accept_admin`

accept_admin(env: Env)

Auth: proposed admin only.

Returns: ().

Errors: expect("no pending admin") if no proposal exists.

CLI example:

soroban contract invoke --id <CONTRACT_ID> --source <NEW_ADMIN_KEY> --network testnet -- accept_admin

`is_contract_paused`

is_contract_paused(env: Env) -> bool

Auth: none.

Returns: bool.

CLI example:

soroban contract invoke --id <CONTRACT_ID> --network testnet -- is_contract_paused

`get_admin`

get_admin(env: Env) -> Option<Address>

Auth: none.

Returns: Option<Address>.

CLI example:

soroban contract invoke --id <CONTRACT_ID> --network testnet -- get_admin

`get_token`

get_token(env: Env) -> Option<Address>

Auth: none.

Returns: Option<Address>.

CLI example:

soroban contract invoke --id <CONTRACT_ID> --network testnet -- get_token

`upgrade`

upgrade(env: Env, new_wasm_hash: BytesN<32>)

Name	Type	Description
`new_wasm_hash`	`BytesN<32>`	New contract WASM hash.

Auth: none in the current implementation.

Returns: ().

Errors: none beyond host/deployer failures.

CLI example:

soroban contract invoke --id <CONTRACT_ID> --network testnet -- upgrade --new_wasm_hash <WASM_HASH>

`propose_upgrade`

propose_upgrade(env: Env, new_wasm_hash: BytesN<32>)

Queues a WASM hash for the two-step upgrade flow. Auth: admin. The pending proposal is stored temporarily and refreshed to a 17,280-ledger TTL.

`cancel_pending_upgrade`

cancel_pending_upgrade(env: Env)

Clears the pending upgrade proposal. Auth: admin.

`commit_upgrade`

commit_upgrade(env: Env)

Commits the pending WASM hash and clears the proposal. Auth: admin. Panics with NoPendingProposal when the proposal was cancelled or expired.

`get_pending_upgrade`

get_pending_upgrade(env: Env) -> Option<BytesN<32>>

Returns the pending upgrade hash, or None when no proposal exists. Auth: none.

`get_subscription`

get_subscription(env: Env, user: Address) -> Option<Subscription>

Name	Type	Description
`user`	`Address`	Subscriber address to look up.

Auth: none.

Returns: Option<Subscription>.

CLI example:

soroban contract invoke --id <CONTRACT_ID> --network testnet -- get_subscription --user <USER_ADDRESS>

`next_charge_at`

Read-only view. Returns the Unix timestamp of the next scheduled charge for a user.

next_charge_at(env: Env, user: Address) -> Option<u64>

Parameters

Name	Type	Description
`user`	`Address`	The subscriber address to query.

Auth: None.

Returns: Option<u64> — Some(last_charged + interval) if the subscription is active and not paused. Returns None when:

No subscription exists for user
The subscription is inactive (cancelled, active == false)
The subscription is paused (paused == true)

The returned timestamp does not change between charges; it reflects the scheduled billing time regardless of whether the charge has been triggered yet.

Storage read: DataKey::Subscription(user) in persistent storage.

See also: is_charge_due to test whether the charge window is open right now; get_subscription to inspect the full record.

CLI example

soroban contract invoke \
  --id <CONTRACT_ID> \
  --network testnet \
  -- next_charge_at \
  --user <USER_ADDRESS>

`is_charge_due`

Read-only predicate. Returns true when a subscriber has a charge due at the current ledger timestamp — that is, when calling charge(user) right now would succeed rather than panic.

is_charge_due(env: Env, user: Address) -> bool

Parameters

Name	Type	Description
`user`	`Address`	The subscriber address to test.

Auth: None.

Returns: bool — true when all of the following conditions hold simultaneously:

A subscription exists for user
The subscription is active (active == true) and not paused (paused == false)
now >= next_charge_at — the billing interval has elapsed
now <= next_charge_at + grace_period — the charge is still within the grace window (this condition is skipped when grace_period == 0)

Returns false for any absent subscription, inactive or paused subscription, interval not yet elapsed, or expired grace window.

Storage read: DataKey::Subscription(user) in persistent storage; DataKey::GracePeriod in instance storage.

Usage for keepers: Poll is_charge_due for each subscriber before deciding whether to submit a charge() transaction, saving gas on calls that would revert.

See also: next_charge_at for the exact scheduled timestamp; get_grace_period for the contract-wide grace window; charge for the write operation.

CLI example

soroban contract invoke \
  --id <CONTRACT_ID> \
  --network testnet \
  -- is_charge_due \
  --user <USER_ADDRESS>

`get_trial_end`

Read-only view. Returns the Unix timestamp when a subscriber's trial period ends, or None if the subscriber is not currently in a trial or has no subscription.

get_trial_end(env: Env, user: Address) -> Option<u64>

Parameters

Name	Type	Description
`user`	`Address`	The subscriber address to query.

Auth: None.

Returns: Option<u64> — Unix timestamp (seconds) of trial expiry when last_charged > now, otherwise None.

How trials work: When subscribe() is called with a trial_period of N seconds, the contract sets last_charged = now + N instead of now. This pushes the first eligible charge forward by the trial duration. get_trial_end returns Some(last_charged) while that timestamp is still in the future, indicating the subscriber is actively in a trial. Once the trial expires — that is, once last_charged <= now — this function returns None because the first charge window has opened. No separate storage key is used; the trial end is encoded directly in last_charged.

Returns None if no subscription exists for user.

Storage read: DataKey::Subscription(user) in persistent storage (reads last_charged field).

See also: subscribe for the trial_period parameter; next_charge_at which returns Some(last_charged + interval) once the trial ends.

CLI example

soroban contract invoke \
  --id <CONTRACT_ID> \
  --network testnet \
  -- get_trial_end \
  --user <USER_ADDRESS>

`propose_grace_period`

propose_grace_period(env: Env, seconds: u64)

Name	Type	Description
`seconds`	`u64`	Proposed grace period in seconds.

Auth: admin only.

Returns: ().

Errors: ContractError::NoPendingProposal is not used here; seconds is validated in the helper.

CLI example:

soroban contract invoke --id <CONTRACT_ID> --source <ADMIN_KEY> --network testnet -- propose_grace_period --seconds 86400

`commit_grace_period`

commit_grace_period(env: Env)

Auth: admin only.

Returns: ().

Errors: ContractError::NoPendingProposal.

CLI example:

soroban contract invoke --id <CONTRACT_ID> --source <ADMIN_KEY> --network testnet -- commit_grace_period

`get_grace_period`

Read-only view. Returns the current contract-wide grace period in seconds.

get_grace_period(env: Env) -> u64

Auth: None.

Returns: u64 — grace period in seconds. Returns 0 when no grace period has been configured, which means charges must arrive exactly at or after next_charge_at with no tolerance window.

What the grace period means: After a billing interval elapses, keepers have a window of grace_period seconds in which to submit charge(). Concretely, charge() accepts a call only while now falls within [next_charge_at, next_charge_at + grace_period]. Calls that arrive after this window panic with "grace period elapsed". In batch_charge, users whose grace window has closed are returned as ChargeResult::GracePeriodElapsed without aborting the batch.

Storage read: DataKey::GracePeriod in instance storage. Defaults to 0 when the key is absent.

See also: propose_grace_period and commit_grace_period to change this value (admin, two-step); is_charge_due which incorporates the grace window into its result.

CLI example

soroban contract invoke \
  --id <CONTRACT_ID> \
  --network testnet \
  -- get_grace_period

`set_subscription_amount`

set_subscription_amount(env: Env, user: Address, new_amount: i128)

Auth: admin only.

Returns: ().

Errors: ContractError::NoSubscriptionFound, ContractError::AmountMustBePositive, ContractError::AmountExceedsMaximum, ContractError::ContractPausedError.

CLI example:

soroban contract invoke --id <CONTRACT_ID> --source <ADMIN_KEY> --network testnet -- set_subscription_amount --user <USER_ADDRESS> --new_amount 50000000

`set_subscription_interval`

set_subscription_interval(env: Env, user: Address, new_interval: u64)

Auth: admin only.

Returns: ().

Errors: ContractError::NoSubscriptionFound, ContractError::IntervalTooShort, ContractError::ContractPausedError.

CLI example:

soroban contract invoke --id <CONTRACT_ID> --source <ADMIN_KEY> --network testnet -- set_subscription_interval --user <USER_ADDRESS> --new_interval 604800

`set_min_interval`

set_min_interval(env: Env, seconds: u64)

Auth: admin only.

Returns: ().

Errors: panics if seconds == 0.

CLI example:

soroban contract invoke --id <CONTRACT_ID> --source <ADMIN_KEY> --network testnet -- set_min_interval --seconds 3600

`get_min_interval`

Read-only view. Returns the minimum allowed subscription interval in seconds.

get_min_interval(env: Env) -> u64

Auth: None.

Returns: u64 — minimum interval in seconds. Default: 3600 (1 hour) when set_min_interval has never been called.

What this controls: When subscribe() or set_subscription_interval() is called, the requested interval is validated against this floor. Any attempt to create or update a subscription with interval < get_min_interval() will panic with ContractError::IntervalTooShort. The floor prevents subscriptions from being charged too frequently (e.g. every second), protecting both users and the network from spam.

Storage read: DataKey::MinInterval in instance storage. Falls back to the compile-time constant DEFAULT_MIN_INTERVAL = 3600 when the key is absent.

See also: set_min_interval to change this value (admin only); subscribe and set_subscription_interval which enforce it.

CLI example

soroban contract invoke \
  --id <CONTRACT_ID> \
  --network testnet \
  -- get_min_interval

`add_merchant`

add_merchant(env: Env, merchant: Address)

Auth: admin only.

Returns: ().

CLI example:

soroban contract invoke --id <CONTRACT_ID> --source <ADMIN_KEY> --network testnet -- add_merchant --merchant <MERCHANT_ADDRESS>

See also: Merchant Integration Cookbook — Getting Started for whitelist request flow.

`remove_merchant`

remove_merchant(env: Env, merchant: Address)

Auth: admin only.

Returns: ().

CLI example:

soroban contract invoke --id <CONTRACT_ID> --source <ADMIN_KEY> --network testnet -- remove_merchant --merchant <MERCHANT_ADDRESS>

`set_whitelist_enabled`

set_whitelist_enabled(env: Env, enabled: bool)

Auth: admin only.

Returns: ().

CLI example:

soroban contract invoke --id <CONTRACT_ID> --source <ADMIN_KEY> --network testnet -- set_whitelist_enabled --enabled true

`get_whitelist_enabled`

get_whitelist_enabled(env: Env) -> bool

Auth: none.

Returns: bool (true by default if not set).

CLI example:

soroban contract invoke --id <CONTRACT_ID> --network testnet -- get_whitelist_enabled

`is_whitelist_enabled`

is_whitelist_enabled(env: Env) -> bool

Auth: none.

Returns: bool (true by default if not set).

CLI example:

soroban contract invoke --id <CONTRACT_ID> --network testnet -- is_whitelist_enabled

`is_merchant_whitelisted`

is_merchant_whitelisted(env: Env, merchant: Address) -> bool

Auth: none.

Returns: bool.

CLI example:

soroban contract invoke --id <CONTRACT_ID> --network testnet -- is_merchant_whitelisted --merchant <MERCHANT_ADDRESS>

`get_top_merchants_by_subs`

get_top_merchants_by_subs(env: Env, limit: u32) -> Vec<(Address, u32)>

Auth: none.

Returns: Vec<(Address, u32)> (top N merchants ranked by active subscriber count in descending order).

Panics: ContractError::BatchTooLarge if limit > 20.

CLI example:

soroban contract invoke --id <CONTRACT_ID> --network testnet -- get_top_merchants_by_subs --limit 10

`freeze_merchant`

freeze_merchant(env: Env, merchant: Address)

Auth: admin only.

Returns: ().

CLI example:

soroban contract invoke --id <CONTRACT_ID> --source <ADMIN_KEY> --network testnet -- freeze_merchant --merchant <MERCHANT_ADDRESS>

`unfreeze_merchant`

unfreeze_merchant(env: Env, merchant: Address)

Auth: admin only.

Returns: ().

CLI example:

soroban contract invoke --id <CONTRACT_ID> --source <ADMIN_KEY> --network testnet -- unfreeze_merchant --merchant <MERCHANT_ADDRESS>

`bump_merchant_revenue_day`

bump_merchant_revenue_day(env: Env, merchant: Address, day: u64)

Auth: none.

Returns: ().

CLI example:

soroban contract invoke --id <CONTRACT_ID> --network testnet -- bump_merchant_revenue_day --merchant <MERCHANT_ADDRESS> --day 20000

`prune_merchant_revenue_days`

prune_merchant_revenue_days(env: Env, merchant: Address, days: Vec<u64>)

Auth: none in the wrapper.

Returns: ().

CLI example:

soroban contract invoke --id <CONTRACT_ID> --network testnet -- prune_merchant_revenue_days --merchant <MERCHANT_ADDRESS> --days '[20000,20001]'

`get_merchant_revenue_day`

get_merchant_revenue_day(env: Env, merchant: Address, day: u64) -> i128

Auth: none.

Returns: i128.

CLI example:

soroban contract invoke --id <CONTRACT_ID> --network testnet -- get_merchant_revenue_day --merchant <MERCHANT_ADDRESS> --day 20000

`is_merchant_frozen`

is_merchant_frozen(env: Env, merchant: Address) -> bool

Auth: none.

Returns: bool.

CLI example:

soroban contract invoke --id <CONTRACT_ID> --network testnet -- is_merchant_frozen --merchant <MERCHANT_ADDRESS>

`get_fee`

get_fee(env: Env) -> Option<(Address, u32)>

Auth: none.

Returns: Option<(Address, u32)>.

CLI example:

soroban contract invoke --id <CONTRACT_ID> --network testnet -- get_fee

`propose_fee`

propose_fee(env: Env, collector: Address, bps: u32)

Auth: admin only.

Returns: ().

Errors: ContractError::InvalidFeeBps.

CLI example:

soroban contract invoke --id <CONTRACT_ID> --source <ADMIN_KEY> --network testnet -- propose_fee --collector <COLLECTOR_ADDRESS> --bps 100

`commit_fee`

commit_fee(env: Env)

Auth: admin only.

Returns: ().

Errors: ContractError::NoPendingProposal (23), ContractError::FeeOutOfBoundsAtCommit (35) if pending bps is outside get_fee_bounds.

CLI example:

soroban contract invoke --id <CONTRACT_ID> --source <ADMIN_KEY> --network testnet -- commit_fee

`set_fee_bounds`

Admin-only guardrails for future fee commits. Stored on instance as DataKey::MinFeeBps / DataKey::MaxFeeBps.

set_fee_bounds(env: Env, min_bps: u32, max_bps: u32)

Name	Type	Description
`min_bps`	`u32`	Inclusive minimum bps for a pending fee at commit.
`max_bps`	`u32`	Inclusive maximum bps; must be `<= 10_000`.

Auth: admin (admin::require_admin).

Returns: ().

Bounds semantics: propose_fee does not apply these bounds (it only rejects bps > 10_000 and an invalid collector). commit_fee rejects pending bps outside [min_bps, max_bps] with FeeOutOfBoundsAtCommit (35).

Errors: ContractError::InvalidFeeBounds (34) if min_bps > max_bps or max_bps > 10_000. Unauthorized callers fail admin auth.

CLI example:

soroban contract invoke --id <CONTRACT_ID> --source <ADMIN_KEY> --network testnet -- set_fee_bounds --min_bps 0 --max_bps 500

`get_fee_bounds`

get_fee_bounds(env: Env) -> (u32, u32)

Auth: none.

Returns: (min_bps, max_bps). Defaults to (0, 10000) when governance has not set explicit bounds.

Errors: none.

CLI example:

soroban contract invoke --id <CONTRACT_ID> --network testnet -- get_fee_bounds

Operational gate: MAINNET-DEPLOYMENT.md.

`batch_charge`

batch_charge(env: Env, users: Vec<Address>) -> Vec<ChargeResult>

Auth: none.

Returns: Vec<ChargeResult> — one entry per input address, in order.

A non-Charged result for one user never aborts the rest of the batch. Insufficient SAC allowance is ChargeResult::AllowanceInsufficient (not a transaction panic). When the batch includes at least one interesting non-success (NoSubscription, Inactive, Paused, GracePeriodElapsed, AllowanceInsufficient), the contract emits batch_charge_skips. All-charged or all-not-due (Skipped) batches emit no summary.

The public wrapper calls ensure_contract_not_paused first: a paused protocol panics ContractPaused (18) for the whole invoke (not a per-user result).

Errors: ContractError::BatchTooLarge (20) if users.len() exceeds get_max_batch_size (default 50). Ordinary per-user outcomes are enum values.

Keeper ops: KEEPER.md.

CLI example:

soroban contract invoke --id <CONTRACT_ID> --source <KEEPER_KEY> --network testnet -- batch_charge --users '["<USER_A>","<USER_B>"]'

`get_batch_charge_estimate`

Batch estimate (not a transfer). Returns Vec<ChargeResult> — the live batch enum — not ChargeSimResult.

get_batch_charge_estimate(env: Env, users: Vec<Address>) -> Vec<ChargeResult>

Name	Type	Description
`users`	`Vec<Address>`	Addresses to estimate.

Auth: none.

Returns: one ChargeResult per input address, in order.

Success behavior: for each user, missing sub → NoSubscription. If paused, try_auto_resume may persist an auto-resume. Then precheck_charge runs. If that returns Ok, the estimate reads SAC allowance(user, contract) against gross sub.amount and returns Charged or AllowanceInsufficient.

Errors: ContractError::BatchTooLarge (20) if users.len() > 200 (hardcoded; not get_max_batch_size). Ordinary per-user outcomes are enum values, not panics.

Operational caveats (from lib.rs):

Calls real try_auto_resume, which writes the subscription, clears pause expiry, and emits subscription_auto_resumed — not a pure view.
Does not check protocol pause (is_contract_paused). simulate_charge returns ContractPaused instead.
Allowance is checked (same gross-amount test as live batch_charge). A keeper file-header comment that says otherwise is stale.
Cap 200 vs live batch max (default 50 via MaxBatchSize).

Use simulate_charge when you need a no-write, pause-aware single-user dry-run. Keepers that charge should still call batch_charge (KEEPER.md). Auto-resume event: EVENTS.md.

CLI example:

soroban contract invoke --id <CONTRACT_ID> --network testnet -- get_batch_charge_estimate --users '["<USER_A>","<USER_B>"]'

`get_active_count`

get_active_count(env: Env) -> u64

Auth: none.

Returns: u64.

CLI example:

soroban contract invoke --id <CONTRACT_ID> --network testnet -- get_active_count

`get_subscriber_count`

get_subscriber_count(env: Env) -> u64

Auth: none.

Returns: u64.

CLI example:

soroban contract invoke --id <CONTRACT_ID> --network testnet -- get_subscriber_count

`get_subscriber_at`

get_subscriber_at(env: Env, index: u64) -> Option<Address>

Auth: none.

Returns: Option<Address>.

CLI example:

soroban contract invoke --id <CONTRACT_ID> --network testnet -- get_subscriber_at --index 0

`get_subscriber_page`

get_subscriber_page(env: Env, offset: u64, limit: u32) -> Vec<Address>

Auth: none.

Returns: Vec<Address>.

CLI example:

soroban contract invoke --id <CONTRACT_ID> --network testnet -- get_subscriber_page --offset 0 --limit 10

`get_active_subscriber_page`

View of active subscriber addresses from the append-only SubscriberIndex. Sibling get_subscriber_page does not filter on sub.active.

get_active_subscriber_page(env: Env, offset: u64, limit: u32) -> Vec<Address>

Name	Type	Description
`offset`	`u64`	Index-slot cursor into `SubscriberIndex`, not “Nth active subscriber”.
`limit`	`u32`	Requested page size. Silently clamped to 50. `0` returns empty.

Auth: none.

Returns: Vec<Address>. Empty when offset >= index_size or cap == 0. Length may be less than limit when many slots are missing or inactive; the scan continues until result.len() == cap or the index ends.

Pagination: increment offset by the number of index slots consumed, not by result.len(), if you need to walk the whole index. The implementation walks i from offset upward and pushes only addresses whose Subscription exists and sub.active is true.

Errors: none.

Related: ChargeResult / keeper paging still typically use batch_charge with an operator-supplied address list (KEEPER.md).

CLI example:

soroban contract invoke --id <CONTRACT_ID> --network testnet -- get_active_subscriber_page --offset 0 --limit 50

`clear_subscriber_index_entry`

Admin repair for a single stale subscriber-index slot. Looks up the occupant of index, refuses if that subscriber currently has an active subscription, then tombstones the slot so keepers skip it. Does not garbage-collect the rest of the index.

clear_subscriber_index_entry(env: Env, index: u64)

Name	Type	Description
`index`	`u64`	Slot in the append-only `SubscriberIndex`.

Auth: Contract admin only (require_admin).

Errors: ContractError::NoSubscriptionFound if index is out of range, empty, or already tombstoned. ContractError::CannotClearActiveSubscriber if the occupant still has an active subscription.

Event emitted

Event name	Topic	Data
`subscriber_index_cleared`	`("subscriber_index_cleared", user_address)`	`index: u64`

CLI example:

soroban contract invoke --id <CONTRACT_ID> --network testnet --source-account <ADMIN> -- clear_subscriber_index_entry --index 0

`get_merchant_revenue`

get_merchant_revenue(env: Env, merchant: Address) -> i128

Auth: none.

Returns: i128.

CLI example:

soroban contract invoke --id <CONTRACT_ID> --network testnet -- get_merchant_revenue --merchant <MERCHANT_ADDRESS>

`get_merchant_revenue_history`

get_merchant_revenue_history(env: Env, merchant: Address, days: u32) -> Vec<i128>

Auth: none.

Returns: Vec<i128>.

CLI example:

soroban contract invoke --id <CONTRACT_ID> --network testnet -- get_merchant_revenue_history --merchant <MERCHANT_ADDRESS> --days 7

`clear_merchant_revenue_history`

clear_merchant_revenue_history(env: Env, merchant: Address)

Auth: admin only.

Returns: ().

CLI example:

soroban contract invoke --id <CONTRACT_ID> --source <ADMIN_KEY> --network testnet -- clear_merchant_revenue_history --merchant <MERCHANT_ADDRESS>

`get_merchant_subscriber_count`

get_merchant_subscriber_count(env: Env, merchant: Address) -> u64

Auth: none.

Returns: u64.

CLI example:

soroban contract invoke --id <CONTRACT_ID> --network testnet -- get_merchant_subscriber_count --merchant <MERCHANT_ADDRESS>

`get_merchant_sub_count`

get_merchant_sub_count(env: Env, merchant: Address) -> u32

Auth: none.

Returns: u32 — active subscriber count for merchant (same MerchantSubCount storage as get_merchant_subscriber_count, narrowed to u32).

CLI example:

soroban contract invoke --id <CONTRACT_ID> --network testnet -- get_merchant_sub_count --merchant <MERCHANT_ADDRESS>

`reset_merchant_revenue`

reset_merchant_revenue(env: Env, merchant: Address)

Auth: admin only.

Returns: ().

CLI example:

soroban contract invoke --id <CONTRACT_ID> --source <ADMIN_KEY> --network testnet -- reset_merchant_revenue --merchant <MERCHANT_ADDRESS>

`withdraw_merchant_revenue`

withdraw_merchant_revenue(env: Env, merchant: Address)

Name	Type	Description
`merchant`	`Address`	Merchant withdrawing accrued revenue.

Auth: merchant.require_auth().

Returns: ().

Errors: ContractError::NotInitialized, ContractError::ZeroBalanceAvailable.

CLI example:

soroban contract invoke --id <CONTRACT_ID> --source <MERCHANT_KEY> --network testnet -- withdraw_merchant_revenue --merchant <MERCHANT_ADDRESS>

See also: Merchant Integration Cookbook for the full merchant onboarding → revenue → withdraw path.

`set_daily_limit`

set_daily_limit(env: Env, user: Address, limit: i128)

Auth: user.require_auth().

Returns: ().

Errors: ContractError::AmountMustBePositive.

CLI example: See also: Daily Spending Limits Guide for a conceptual overview of the pay_per_use spending cap. For a complete list of all error codes returned by the contract, see ERROR-CODES.md.

soroban contract invoke --id <CONTRACT_ID> --source <USER_KEY> --network testnet -- set_daily_limit --user <USER_ADDRESS> --limit 50000000

`remove_daily_limit`

remove_daily_limit(env: Env, user: Address)

Auth: user.require_auth().

Returns: ().

CLI example:

soroban contract invoke --id <CONTRACT_ID> --source <USER_KEY> --network testnet -- remove_daily_limit --user <USER_ADDRESS>

`get_daily_spent`

See the full reference entry below.

`get_day_start`

get_day_start(env: Env, user: Address) -> bool

Auth: none.

Returns: bool — true if DataKey::DayStart(user) exists (current ~24h spend window is active), false otherwise. This is a presence marker, not a wall-clock timestamp.

CLI example: See also: Daily Spending Limits Deep-Dive.

soroban contract invoke --id <CONTRACT_ID> --network testnet -- get_day_start --user <USER_ADDRESS>

`get_referrer`

get_referrer(env: Env, user: Address) -> Option<Address>

Auth: none.

Returns: Option<Address>.

CLI example:

soroban contract invoke --id <CONTRACT_ID> --network testnet -- get_referrer --user <USER_ADDRESS>

`migrate`

migrate(env: Env, users: Vec<Address>)

Auth: none.

Returns: ().

CLI example:

soroban contract invoke --id <CONTRACT_ID> --network testnet -- migrate --users '["<USER_ADDRESS>"]'

`get_schema_version`

See the full reference entry below.

`set_metadata`

set_metadata(env: Env, user: Address, label: String)

Auth: user.require_auth().

Returns: ().

Errors: ContractError::MetadataLabelTooLong.

CLI example:

soroban contract invoke --id <CONTRACT_ID> --source <USER_KEY> --network testnet -- set_metadata --user <USER_ADDRESS> --label pro

`get_metadata`

get_metadata(env: Env, user: Address) -> Option<String>

Auth: none.

Returns: Option<String>.

CLI example:

soroban contract invoke --id <CONTRACT_ID> --network testnet -- get_metadata --user <USER_ADDRESS>

`get_subscription_label`

get_subscription_label(env: Env, user: Address) -> Option<String>

Auth: none.

Returns: Option<String>.

CLI example:

soroban contract invoke --id <CONTRACT_ID> --network testnet -- get_subscription_label --user <USER_ADDRESS>

`clear_metadata`

clear_metadata(env: Env, user: Address)

Auth: user.require_auth().

Returns: ().

CLI example:

soroban contract invoke --id <CONTRACT_ID> --source <USER_KEY> --network testnet -- clear_metadata --user <USER_ADDRESS>

`get_charge_history`

get_charge_history(env: Env, user: Address) -> Vec<u64>

Auth: none.

Returns: Vec<u64>.

CLI example:

soroban contract invoke --id <CONTRACT_ID> --network testnet -- get_charge_history --user <USER_ADDRESS>

`get_protocol_stats`

get_protocol_stats(env: Env) -> ProtocolStats

Auth: none.

Returns: ProtocolStats.

CLI example:

soroban contract invoke --id <CONTRACT_ID> --network testnet -- get_protocol_stats

`pause_contract`

pause_contract(env: Env)

Auth: admin only.

Returns: ().

CLI example:

soroban contract invoke --id <CONTRACT_ID> --source <ADMIN_KEY> --network testnet -- pause_contract

`unpause_contract`

unpause_contract(env: Env)

Auth: admin only.

Returns: ().

CLI example:

soroban contract invoke --id <CONTRACT_ID> --source <ADMIN_KEY> --network testnet -- unpause_contract

`set_initial_admin`

set_initial_admin(env: Env, admin: Address)

Auth: none.

Returns: ().

Errors: panics if the admin is already set.

CLI example:

soroban contract invoke --id <CONTRACT_ID> --network testnet -- set_initial_admin --admin <ADMIN_ADDRESS>

`contract_health_check`

Read-only snapshot of protocol health. Safe at any time: no auth, no storage writes. There is no health_check or get_health export.

contract_health_check(env: Env) -> HealthReport

Auth: none.

Returns: HealthReport.

Success behavior: builds the struct; does not panic on the normal path. is_healthy is true only when the contract is not paused, token and admin are set, and instance_ttl_ledgers > 17_280.

Errors: none defined.

Operational notes: on-chain instance_ttl_ledgers is a hardcoded 100_000. Off-chain scripts/health-check.ts is a shallow RPC simulation of get_schema_version and get_active_count only — it does not call this method. See MAINNET-DEPLOYMENT.md.

CLI example:

soroban contract invoke --id <CONTRACT_ID> --network testnet -- contract_health_check

`clear_charge_history`

clear_charge_history(env: Env, user: Address)

Auth: user.require_auth().

Returns: ().

CLI example:

soroban contract invoke --id <CONTRACT_ID> --source <USER_KEY> --network testnet -- clear_charge_history --user <USER_ADDRESS>

`get_charge_history_page`

get_charge_history_page(env: Env, user: Address, offset: u32, limit: u32, ascending: bool) -> Vec<u64>

Auth: none.

Returns: Vec<u64>.

CLI example:

soroban contract invoke --id <CONTRACT_ID> --network testnet -- get_charge_history_page --user <USER_ADDRESS> --offset 0 --limit 12 --ascending false

Pagination Guide

ChargeHistory(user) is a Vec<u64> of up to 12 charge timestamps, stored oldest → newest. Every successful charge() appends a timestamp; once the vector holds 12 entries, the next append drops entry 0 (the oldest) before pushing the new one. In other words, storage itself is the ring buffer — get_charge_history_page slices whatever is currently in it (in ascending or descending order). There is no separate "total charge count" stored anywhere; the longest history you can ever page through is 12 entries, because older charges are physically gone.

Slicing algorithm (from subscription_history.rs):

ordered_history = if ascending { history } else { history.reversed() }
effective_limit = min(limit, 12)
if offset >= ordered_history.len() { return [] }   // empty, not an error
end = min(offset + effective_limit, ordered_history.len())
return ordered_history[offset..end]

limit is silently capped at 12 — passing limit: 100 is safe and simply returns everything available. offset is never validated against the history length beyond the empty-result check above; there is no IndexOutOfBounds-style error anywhere in this path.

ascending parameter. Passing ascending = true returns records in oldest-to-newest order. Passing ascending = false returns records in newest-to-oldest order (most recent first).

Ring buffer diagram — a subscriber with 14 total lifetime charges (c1..c14). Only the last 12 survive:

 lifetime charges:  c1  c2  c3 [c4  c5  c6  c7  c8  c9  c10 c11 c12 c13 c14]
                     ↑   ↑   ↑   └──────────────── retained (12 slots) ────────────────┘
                  evicted (FIFO, oldest dropped first as new charges arrive)

 ChargeHistory(user) in storage (index 0 = oldest):

   index:   0    1    2    3    4    5    6    7    8    9    10   11
   value:  [c4,  c5,  c6,  c7,  c8,  c9, c10, c11, c12, c13, c14]  (len = 11 here, one slot short of the cap)

 get_charge_history_page(user, offset=8, limit=3)
                                    │
                     slices index [8..11) ─┐
                                            ▼
                                        [c12, c13, c14]

Worked examples

Example 1 — fetch everything (offset=0, limit=12):

soroban contract invoke --id <CONTRACT_ID> --network testnet -- \
  get_charge_history_page --user <USER_ADDRESS> --offset 0 --limit 12

With a history of [c4..c14] (11 entries), this returns all 11 entries, oldest to newest. If the subscriber has fewer than 12 charges total, one call is always enough — you never need a second page.

Example 2 — most recent 5 records (no ascending param, so compute the offset):

const all = await getChargeHistoryPage(user, 0, 12); // at most 12 entries ever exist
const mostRecent5 = all.slice(-5); // last 5 = newest 5, since storage is oldest → newest

Equivalently, on-chain: offset = max(0, total - 5), limit = 5. If total = 11, call get_charge_history_page(user, 6, 5) to get entries [6..11).

Example 3 — offset beyond the record count (returns empty, not an error):

soroban contract invoke --id <CONTRACT_ID> --network testnet -- \
  get_charge_history_page --user <USER_ADDRESS> --offset 5 --limit 2

For a subscriber with only 1 recorded charge, offset=5 >= len(1) so this returns []. This mirrors the covering test test_get_charge_history_page_offset_beyond_length.

Offset / limit reference table (history has 11 entries, c4..c14, oldest → newest):

`offset`	`limit`	Result	Notes
`0`	`12`	`[c4..c14]` (11 items)	`limit` capped at 12, but history only has 11
`0`	`5`	`[c4, c5, c6, c7, c8]`	oldest 5
`6`	`5`	`[c10, c11, c12, c13, c14]`	newest 5 (see Example 2)
`11`	`5`	`[]`	`offset == len`, empty result
`20`	`5`	`[]`	`offset > len`, empty result, no error
`9`	`100`	`[c13, c14]`	`limit` capped then clamped to remaining length

"Load all history" with a pagination loop (TypeScript)

Because storage never holds more than 12 entries, a single call with limit: 12 already returns everything. The loop below is still useful as the general-purpose pattern for infinite-scroll style UIs, and keeps working unmodified if the on-chain cap is ever raised. It calls the contract the same way getSubscription does — build, simulate, decode:

import {
  Contract,
  TransactionBuilder,
  BASE_FEE,
  nativeToScVal,
  Address,
  xdr,
} from "@stellar/stellar-sdk";
import { server, CONTRACT_ID, NETWORK_PASSPHRASE } from "./stellar";
import { ScValDecoder } from "./services/scval";

function addressVal(addr: string): xdr.ScVal {
  return nativeToScVal(Address.fromString(addr), { type: "address" });
}

/** Fetches one page of charge timestamps via get_charge_history_page. */
async function getChargeHistoryPage(
  user: string,
  offset: number,
  limit: number,
): Promise<number[]> {
  const contract = new Contract(CONTRACT_ID);
  const account = await server.getAccount(user);

  const tx = new TransactionBuilder(account, {
    fee: BASE_FEE,
    networkPassphrase: NETWORK_PASSPHRASE,
  })
    .addOperation(
      contract.call(
        "get_charge_history_page",
        addressVal(user),
        nativeToScVal(offset, { type: "u32" }),
        nativeToScVal(limit, { type: "u32" }),
      ),
    )
    .setTimeout(30)
    .build();

  const result = await server.simulateTransaction(tx);
  if ("error" in result) throw new Error((result as { error: string }).error);

  const retval = (result as { result?: { retval?: xdr.ScVal } }).result?.retval;
  if (!retval) return [];

  return retval.vec()?.map((v) => Number(ScValDecoder.decodeU64(v))) ?? [];
}

/**
 * Loads the subscriber's full charge history by paging until an empty
 * (or short) page comes back. Safe to call even though today's 12-record
 * cap means it will always resolve after a single request.
 */
async function loadAllChargeHistory(user: string): Promise<number[]> {
  const PAGE_SIZE = 12; // matches the contract's MAX_HISTORY cap
  const all: number[] = [];
  let offset = 0;

  while (true) {
    const page = await getChargeHistoryPage(user, offset, PAGE_SIZE);
    all.push(...page);

    if (page.length < PAGE_SIZE) break; // short page = no more records
    offset += page.length;
  }

  return all;
}

See INTEGRATION-GUIDE.md § 8 — Paginating Charge History for the same pattern in a full integration walkthrough.

`transfer_subscription`

transfer_subscription(env: Env, user: Address, new_user: Address)

Auth: user.require_auth().

Returns: ().

Errors: ContractError::ContractPausedError, ContractError::NoSubscriptionFound, ContractError::SubscriptionAlreadyActive.

CLI example:

soroban contract invoke --id <CONTRACT_ID> --source <USER_KEY> --network testnet -- transfer_subscription --user <USER_ADDRESS> --new_user <NEW_USER_ADDRESS>

Units & Conversions

All amounts are in stroops. 1 XLM = 10,000,000 stroops. Intervals are

Events Reference

See EVENTS.md for the complete event schema reference. For building keepers, analytics, notifications, or reconciliation jobs on top of those events, see EVENT-DRIVEN-GUIDE.md.

Parameters

Name	Type	Description
`user`	`Address`	The payer. Must match the transaction signer.
`amount`	`i128`	Stroops to transfer. Must be > 0.

Auth: user.require_auth().

What it does:

Loads the subscription for user
Asserts active == true
Calls transfer_from(contract, user, merchant, amount) on the token contract

Events emitted

topic:  ("pay_per_use", user)
data:   (merchant, amount)

Errors

Condition	Panic message
`amount <= 0`	`"amount must be positive"`
No subscription exists	`"no subscription found"`
Subscription is cancelled	`"subscription is not active"`
Subscription is paused	`"subscription is paused"`
Insufficient allowance	Host error from token contract

CLI example

soroban contract invoke \
  --id <CONTRACT_ID> \
  --source <USER_KEY> \
  --network testnet \
  -- pay_per_use \
  --user <USER_ADDRESS> \
  --amount 1000000

`pause`

Temporarily halts charges for a subscription. The subscription record is preserved and can be resumed at any time. Both charge() and pay_per_use() will panic while paused.

pause(env: Env, user: Address)

Parameters

Name	Type	Description
`user`	`Address`	The subscriber. Must match the transaction signer.

Auth: user.require_auth().

Events emitted

topic:  ("paused", user)
data:   ()

Errors

Condition	Panic message
No subscription exists	`"no subscription found"`
Subscription is cancelled	`"subscription is not active"`
Subscription already paused	`"subscription is already paused"`

CLI example

soroban contract invoke \
  --id <CONTRACT_ID> \
  --source <USER_KEY> \
  --network testnet \
  -- pause \
  --user <USER_ADDRESS>

`resume`

Resumes a paused subscription, re-enabling charge() and pay_per_use().

resume(env: Env, user: Address)

Parameters

Name	Type	Description
`user`	`Address`	The subscriber. Must match the transaction signer.

Auth: user.require_auth().

Events emitted

topic:  ("resumed", user)
data:   ()

Errors

Condition	Panic message
No subscription exists	`"no subscription found"`
Subscription is cancelled	`"subscription is not active"`
Subscription is not paused	`"subscription is not paused"`

CLI example

soroban contract invoke \
  --id <CONTRACT_ID> \
  --source <USER_KEY> \
  --network testnet \
  -- resume \
  --user <USER_ADDRESS>

`cancel`

Deactivates a subscription. The subscription record remains in storage with active = false. No further charges can be made.

cancel(env: Env, user: Address)

Parameters

Name	Type	Description
`user`	`Address`	The subscriber. Must match the transaction signer.

Auth: user.require_auth().

Events emitted

topic:  ("cancelled", user)
data:   ()

Errors

Condition	Panic message
No subscription exists	`"no subscription found"`

CLI example

soroban contract invoke \
  --id <CONTRACT_ID> \
  --source <USER_KEY> \
  --network testnet \
  -- cancel \
  --user <USER_ADDRESS>

`get_subscription`

Read-only view function. Returns the subscription for a given user, or None if none exists.

get_subscription(env: Env, user: Address) -> Option<Subscription>

Parameters

Name	Type	Description
`user`	`Address`	The subscriber address to look up.

Auth: None.

Returns: Option<Subscription> — None if no subscription exists for this address.

CLI example

soroban contract invoke \
  --id <CONTRACT_ID> \
  --network testnet \
  -- get_subscription \
  --user <USER_ADDRESS>

`next_charge_at`

See the full reference entry above.

`batch_charge`

Charges multiple subscribers in a single transaction. Individual failures do not abort the batch — every address is processed and its outcome is returned.

batch_charge(env: Env, users: Vec<Address>) -> Vec<ChargeResult>

Parameters

Name	Type	Description
`users`	`Vec<Address>`	List of subscriber addresses to attempt charging.

Auth: None. Same permissionless model as charge().

Returns: Vec<ChargeResult> — one entry per input address, in order.

pub enum ChargeResult {
    Charged,            // funds transferred successfully
    Skipped,            // interval has not elapsed yet
    NoSubscription,     // no subscription found for this address
    Inactive,           // subscription is cancelled
    Paused,             // subscription is paused
    GracePeriodElapsed, // charge window has closed
}

Storage written: DataKey::Subscription(user) updated for each Charged result. DataKey::MerchantRevenue(merchant) incremented for each Charged result.

Events emitted: ("charged", user) for each successfully charged user.

CLI example

soroban contract invoke \
  --id <CONTRACT_ID> \
  --source <KEEPER_KEY> \
  --network testnet \
  -- batch_charge \
  --users '["<USER_A>","<USER_B>","<USER_C>"]'

`get_active_count`

Returns the current number of active subscriptions. Incremented by subscribe(), decremented by cancel().

get_active_count(env: Env) -> u64

Auth: None.

Returns: u64 — total active subscriptions.

Storage read: DataKey::ActiveCount in instance storage.

CLI example

soroban contract invoke \
  --id <CONTRACT_ID> \
  --network testnet \
  -- get_active_count

`get_merchant_revenue`

Returns the cumulative amount charged to a merchant's subscribers across all charge() and pay_per_use() calls.

get_merchant_revenue(env: Env, merchant: Address) -> i128

Parameters

Name	Type	Description
`merchant`	`Address`	The merchant address to query.

Auth: None.

Returns: i128 — total stroops received by this merchant. Returns 0 if no charges have occurred.

Storage read: DataKey::MerchantRevenue(merchant) in persistent storage.

CLI example

soroban contract invoke \
  --id <CONTRACT_ID> \
  --network testnet \
  -- get_merchant_revenue \
  --merchant <MERCHANT_ADDRESS>

`set_daily_limit`

Sets a daily spending cap for pay_per_use() for the calling user. The limit is stored in temporary storage and resets automatically after approximately one day (~17,280 ledgers at 5 s/ledger).

For a detailed conceptual guide on how limits and TTL expirations work, see Daily Spending Limits.

set_daily_limit(env: Env, user: Address, limit: i128)

Parameters

Name	Type	Description
`user`	`Address`	The subscriber. Must match the transaction signer.
`limit`	`i128`	Maximum stroops spendable via `pay_per_use()` per day. Must be > 0.

Auth: user.require_auth().

Storage written: DataKey::DailyLimit(user) in temporary storage with TTL of ~1 day.

Enforcement: Every pay_per_use() call checks DailySpent(user) + amount <= DailyLimit(user) before transferring. The running total is tracked in DataKey::DailySpent(user) (also temporary, same TTL).

Errors

Condition	Panic message
`limit <= 0`	`"limit must be positive"`
Spend would exceed limit	`"daily spending limit exceeded"`

CLI example

soroban contract invoke \
  --id <CONTRACT_ID> \
  --source <USER_KEY> \
  --network testnet \
  -- set_daily_limit \
  --user <USER_ADDRESS> \
  --limit 50000000

`get_daily_limit`

Read-only view. Returns the current daily spending cap for a user's pay_per_use() calls, or None if no cap has been set.

get_daily_limit(env: Env, user: Address) -> Option<i128>

Parameters

Name	Type	Description
`user`	`Address`	The subscriber address to query.

Auth: None.

Returns: Option<i128> — the daily limit in stroops, or None if no limit has been set for this user. A None result means pay_per_use() is uncapped for this user.

Storage read: DataKey::DailyLimit(user) in temporary storage (TTL ≈ 1 day, ~17,280 ledgers at 5 s/ledger). Returns None automatically once the TTL expires, which resets the cap each day without manual intervention.

See also: set_daily_limit to configure the cap; remove_daily_limit to clear it; get_daily_spent to check how much has been consumed today.

CLI example

soroban contract invoke \
  --id <CONTRACT_ID> \
  --network testnet \
  -- get_daily_limit \
  --user <USER_ADDRESS>

`get_daily_spent`

Read-only view. Returns the total amount spent today by a user via pay_per_use() calls.

get_daily_spent(env: Env, user: Address) -> i128

Parameters

Name	Type	Description
`user`	`Address`	The subscriber address to query.

Auth: None.

Returns: i128 — stroops spent today via pay_per_use(). Returns 0 when no spend has been recorded in the current window or when the daily tracking TTL has expired.

How the window works: The first pay_per_use() call of the day anchors a DataKey::DayStart(user) marker in temporary storage with a TTL of ~17,280 ledgers (≈1 day). get_daily_spent returns 0 whenever that marker is absent — either because the user has never called pay_per_use(), or because the 24-hour window has expired and both DayStart and DailySpent have been automatically pruned.

Storage read: DataKey::DayStart(user) presence check first; then DataKey::DailySpent(user) — both in temporary storage.

See also: set_daily_limit to configure the daily cap; get_daily_limit to read the configured cap; pay_per_use which increments this counter on each call.

CLI example

soroban contract invoke \
  --id <CONTRACT_ID> \
  --network testnet \
  -- get_daily_spent \
  --user <USER_ADDRESS>

`extend_subscription_ttl`

Extends the TTL of a user's subscription record in persistent storage.

extend_subscription_ttl(env: Env, user: Address)

Parameters

Name	Type	Description
`user`	`Address`	The subscriber address to extend TTL for.

Auth: None.

Storage written: Extends TTL of DataKey::Subscription(user) in persistent storage.

CLI example

soroban contract invoke \
  --id <CONTRACT_ID> \
  --network testnet \
  -- extend_subscription_ttl \
  --user <USER_ADDRESS>

`get_trial_end`

See the full reference entry above.

Adds a merchant to the whitelist. Only the contract admin can call this.

add_merchant(env: Env, merchant: Address)

Parameters

Name	Type	Description
`merchant`	`Address`	The merchant address to whitelist.

Auth: Admin only.

Storage written: DataKey::MerchantWhitelist(merchant) in persistent storage.

CLI example

soroban contract invoke \
  --id <CONTRACT_ID> \
  --source <ADMIN_KEY> \
  --network testnet \
  -- add_merchant \
  --merchant <MERCHANT_ADDRESS>

`remove_merchant`

Removes a merchant from the whitelist. Only the contract admin can call this.

remove_merchant(env: Env, merchant: Address)

Parameters

Name	Type	Description
`merchant`	`Address`	The merchant address to remove from the whitelist.

Auth: Admin only.

Storage written: Removes DataKey::MerchantWhitelist(merchant) from persistent storage.

CLI example

soroban contract invoke \
  --id <CONTRACT_ID> \
  --source <ADMIN_KEY> \
  --network testnet \
  -- remove_merchant \
  --merchant <MERCHANT_ADDRESS>

`set_whitelist_enabled`

Enables or disables the merchant whitelist. Only the contract admin can call this.

set_whitelist_enabled(env: Env, enabled: bool)

Parameters

Name	Type	Description
`enabled`	`bool`	True to enable the whitelist, false to disable.

Auth: Admin only.

Storage written: DataKey::WhitelistEnabled in instance storage.

CLI example

soroban contract invoke \
  --id <CONTRACT_ID> \
  --source <ADMIN_KEY> \
  --network testnet \
  -- set_whitelist_enabled \
  --enabled true

`get_merchant_revenue_history`

Returns per-day revenue for the given merchant for the last days days, oldest to newest.

get_merchant_revenue_history(env: Env, merchant: Address, days: u32) -> Vec<i128>

Parameters

Name	Type	Description
`merchant`	`Address`	The merchant address to query.
`days`	`u32`	The number of days of history to retrieve.

Auth: None.

Returns: Vec<i128> — Daily revenue in stroops, ordered oldest to newest.

Storage read: DataKey::MerchantRevenueDay(merchant, day) in persistent storage.

CLI example

soroban contract invoke \
  --id <CONTRACT_ID> \
  --network testnet \
  -- get_merchant_revenue_history \
  --merchant <MERCHANT_ADDRESS> \
  --days 7

`get_referrer`

Returns the referrer address recorded for a subscriber.

get_referrer(env: Env, user: Address) -> Option<Address>

Parameters

Name	Type	Description
`user`	`Address`	The subscriber address to query.

Auth: None.

Returns: Option<Address> — None if no referrer was recorded.

Storage read: DataKey::Referral(user) in persistent storage.

CLI example

soroban contract invoke \
  --id <CONTRACT_ID> \
  --network testnet \
  -- get_referrer \
  --user <USER_ADDRESS>

`migrate`

Upgrades contract storage to the latest schema version. Safe to call multiple times.

migrate(env: Env)

Auth: None (admin restriction can be added in future versions).

Storage written: DataKey::SchemaVersion in instance storage.

CLI example

soroban contract invoke \
  --id <CONTRACT_ID> \
  --network testnet \
  -- migrate

`get_schema_version`

Read-only view. Returns the current storage schema version of the contract.

get_schema_version(env: Env) -> u32

Auth: None.

Returns: u32 — the schema version stored in instance storage. Default: 1 when DataKey::SchemaVersion has never been written (i.e. before the first migrate() call or on freshly deployed contracts).

What schema versions mean:

Version	Description
`1`	Initial schema. `Subscription` struct does not include the `paused` field.
`2`	Current schema. `Subscription` includes `paused: bool`. Set by `migrate()`.

When to call this: Use get_schema_version to verify a deployment is on the current schema before running migrate(), and to confirm a migration completed successfully. A keeper or admin script can check this before submitting migrate(users) to avoid redundant transactions — migrate() is a no-op when already at version 2, but reading the version first avoids the gas cost entirely.

Storage read: DataKey::SchemaVersion in instance storage. Falls back to 1u32 when absent.

See also: migrate which bumps this value from 1 → 2; the Deployment — State Migration guide for the full migration history and CLI steps.

CLI example

soroban contract invoke \
  --id <CONTRACT_ID> \
  --network testnet \
  -- get_schema_version

`set_metadata`

Attaches a short label string (e.g. plan name) to the caller's subscription.

set_metadata(env: Env, user: Address, label: String)

Parameters

Name	Type	Description
`user`	`Address`	The subscriber. Must match the transaction signer.
`label`	`String`	Short display label (e.g. `"pro"`, `"basic"`).

Auth: user.require_auth().

Storage written: DataKey::SubscriptionMeta(user) in persistent storage.

CLI example

soroban contract invoke \
  --id <CONTRACT_ID> \
  --source <USER_KEY> \
  --network testnet \
  -- set_metadata \
  --user <USER_ADDRESS> \
  --label pro

`get_metadata`

Returns the metadata label for a subscriber.

get_metadata(env: Env, user: Address) -> Option<String>

Parameters

Name	Type	Description
`user`	`Address`	The subscriber address to query.

Auth: None.

Returns: Option<String> — None if no label has been set.

CLI example

soroban contract invoke \
  --id <CONTRACT_ID> \
  --network testnet \
  -- get_metadata \
  --user <USER_ADDRESS>

`get_charge_history`

Returns the last (up to 12) charge timestamps for a subscriber, ordered oldest → newest.

get_charge_history(env: Env, user: Address) -> Vec<u64>

Parameters

Name	Type	Description
`user`	`Address`	The subscriber address to query.

Auth: None.

Returns: Vec<u64> — UNIX timestamps of successful charge() calls. Empty if no charges have occurred.

Storage read: DataKey::ChargeHistory(user) in persistent storage.

CLI example

soroban contract invoke \
  --id <CONTRACT_ID> \
  --network testnet \
  -- get_charge_history \
  --user <USER_ADDRESS>

Subscription Integrity Diagnostics

Administrative utilities for detecting and repairing corrupted subscription records after migrations or contract upgrades.

`validate_subscription`

Read-only integrity check for a subscriber address.

validate_subscription(env: Env, user: Address) -> SubscriptionValidationReport

Returns SubscriptionValidationReport

Field	Type	Description
`is_valid`	`bool`	`true` when no inconsistencies are detected
`violations`	`Vec<String>`	General integrity violations
`missing_records`	`Vec<String>`	Missing auxiliary records (history, metadata, etc.)
`invalid_state_transitions`	`Vec<String>`	Illegal active/paused/cancelled state combinations
`corrupted_references`	`Vec<String>`	Broken merchant/token/referrer references

Auth: None (read-only simulation).

Frontend: Exposed in the Admin Dashboard → Subscription Repair panel.

`repair_subscription`

Repairs detected subscription inconsistencies for a user.

repair_subscription(env: Env, user: Address) -> u32

Auth: Contract admin only (require_admin).

Returns: Count of fixed inconsistencies (also emitted in the subscription_repaired event).

Event emitted

Event name	Topic	Data
`subscription_repaired`	`("subscription_repaired", user_address)`	`fixed_inconsistencies: u32`

Frontend authorization: The repair button is enabled only when the connected Freighter wallet matches the on-chain admin returned by get_admin.

Units & Conversions

All amounts are in stroops — the smallest unit of a Stellar token.

Amount	Stroops
1 XLM	10,000,000
0.5 XLM	5,000,000
0.0000001 XLM	1

All intervals are in seconds.

Interval	Seconds
1 day	86,400
1 week	604,800
30 days	2,592,000

Events Reference

All events can be indexed by listening to the Stellar RPC event stream for the FlowPay contract ID.

For a complete reference of all events with detailed schemas and examples, see EVENTS.md. For consumption patterns (polling, deduplication, reaction, reliability), see EVENT-DRIVEN-GUIDE.md.

Event name	Topic	Data
`subscribed`	`("subscribed", user_address)`	`(merchant, amount, interval)`
`charged`	`("charged", user_address)`	`(merchant, amount, timestamp)`
`pay_per_use`	`("pay_per_use", user_address)`	`(merchant, amount)`
`cancelled`	`("cancelled", user_address)`	`()`
`paused`	`("paused", user_address)`	`()`
`resumed`	`("resumed", user_address)`	`()`
`referred`	`("referred", user_address)`	`referrer_address`
`subscription_transferred`	`("subscription_transferred", from_address, to_address)`	`(merchant, amount, interval, token)`
`subscription_repaired`	`("subscription_repaired", user_address)`	`fixed_inconsistencies: u32`
`subscription_repaired`	`("subscription_repaired", user_address)`	`fixed_inconsistencies: u32`
`subscriber_index_cleared`	`("subscriber_index_cleared", user_address)`	`index: u64`

Error Codes

All error conditions are returned as ContractError values. Client SDKs can decode these programmatically. Each variant is identified by its u32 discriminant.

Code	Variant	Description
1	`AlreadyInitialized`	`initialize()` was called on an already-initialized contract.
2	`AmountMustBePositive`	A payment or subscription amount was zero or negative.
3	`IntervalMustBePositive`	A subscription interval was zero.
4	`NoSubscriptionFound`	No subscription record exists for the given user.
5	`SubscriptionInactive`	The subscription exists but is cancelled or paused.
6	`IntervalNotElapsed`	`charge()` was called before the billing interval elapsed.
7	`NotInitialized`	A contract function was called before `initialize()`.
8	`InsufficientAllowance`	The user's token allowance is below the subscription amount.
9	`GracePeriodElapsed`	The charge grace period has passed; the subscription cannot be charged.
10	`MerchantNotWhitelisted`	The merchant is not on the whitelist (when whitelist is enabled).
11	`ContractPaused`	The contract is paused; all user-facing write operations are blocked.
24	`DailyLimitExceeded`	A `pay_per_use()` call would exceed the user's configured daily spending limit.
33	`InvalidVolumeCap`	`set_global_volume_cap` was called with a non-positive cap.
34	`InvalidFeeBounds`	`set_fee_bounds` min/max is inconsistent or `max_bps > 10000`.
35	`FeeOutOfBoundsAtCommit`	`commit_fee` pending bps is outside current fee bounds.
Code	Variant	Description
---	---	---
1	`AlreadyInitialized`	`initialize()` was called on an already-initialized contract.
2	`AmountMustBePositive`	A payment or subscription amount was zero or negative.
3	`IntervalMustBePositive`	A subscription interval was zero.
4	`NoSubscriptionFound`	No subscription record exists for the given user.
5	`SubscriptionInactive`	The subscription exists but is cancelled or paused.
6	`IntervalNotElapsed`	`charge()` was called before the billing interval elapsed.
7	`NotInitialized`	A contract function was called before `initialize()`.
8	`InsufficientAllowance`	The user's token allowance is below the subscription amount.
9	`GracePeriodElapsed`	The charge grace period has passed; the subscription cannot be charged.
10	`MerchantNotWhitelisted`	The merchant is not on the whitelist (when whitelist is enabled).
11	`ContractPaused`	The contract is paused; all user-facing write operations are blocked.
24	`DailyLimitExceeded`	A `pay_per_use()` call would exceed the user's configured daily spending limit.
33	`InvalidVolumeCap`	`set_global_volume_cap` was called with a non-positive cap.
34	`InvalidFeeBounds`	`set_fee_bounds` min/max is inconsistent or `max_bps > 10000`.
35	`FeeOutOfBoundsAtCommit`	`commit_fee` pending bps is outside current fee bounds.
41	`CannotClearActiveSubscriber`	`clear_subscriber_index_entry` refused because the slot occupant is still active.

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Contract API Reference

Table of Contents

Bounded API delta (Issue 110)

Data Types

Subscription

ChargeResult

ChargeSimResult

PayPerUseSimResult

ProtocolStats

HealthReport

DataKey

Functions

initialize

subscribe

subscribe_with_metadata

charge

simulate_charge

simulate_pay_per_use

simulate_pay_per_use_to

extend_subscription_ttl

pay_per_use

cancel

pause

pause_until

resume

transfer_admin

accept_admin

is_contract_paused

get_admin

get_token

upgrade

propose_upgrade

cancel_pending_upgrade

commit_upgrade

get_pending_upgrade

get_subscription

next_charge_at

is_charge_due

get_trial_end

propose_grace_period

commit_grace_period

get_grace_period

set_subscription_amount

set_subscription_interval

set_min_interval

get_min_interval

add_merchant

remove_merchant

set_whitelist_enabled

get_whitelist_enabled

is_whitelist_enabled

is_merchant_whitelisted

get_top_merchants_by_subs

freeze_merchant

unfreeze_merchant

bump_merchant_revenue_day

prune_merchant_revenue_days

get_merchant_revenue_day

is_merchant_frozen

get_fee

propose_fee

commit_fee

set_fee_bounds

get_fee_bounds

batch_charge

get_batch_charge_estimate

get_active_count

get_subscriber_count

get_subscriber_at

get_subscriber_page

get_active_subscriber_page

clear_subscriber_index_entry

get_merchant_revenue

`Subscription`

`ChargeResult`

`ChargeSimResult`

`PayPerUseSimResult`

`ProtocolStats`

`HealthReport`

`DataKey`

`initialize`

`subscribe`

`subscribe_with_metadata`

`charge`

`simulate_charge`

`simulate_pay_per_use`

`simulate_pay_per_use_to`

`extend_subscription_ttl`

`pay_per_use`

`cancel`

`pause`

`pause_until`

`resume`

`transfer_admin`

`accept_admin`

`is_contract_paused`

`get_admin`

`get_token`

`upgrade`

`propose_upgrade`

`cancel_pending_upgrade`

`commit_upgrade`

`get_pending_upgrade`

`get_subscription`

`next_charge_at`

`is_charge_due`

`get_trial_end`

`propose_grace_period`

`commit_grace_period`

`get_grace_period`

`set_subscription_amount`

`set_subscription_interval`

`set_min_interval`

`get_min_interval`

`add_merchant`

`remove_merchant`

`set_whitelist_enabled`

`get_whitelist_enabled`

`is_whitelist_enabled`

`is_merchant_whitelisted`

`get_top_merchants_by_subs`

`freeze_merchant`

`unfreeze_merchant`

`bump_merchant_revenue_day`

`prune_merchant_revenue_days`

`get_merchant_revenue_day`

`is_merchant_frozen`

`get_fee`

`propose_fee`

`commit_fee`

`set_fee_bounds`

`get_fee_bounds`

`batch_charge`

`get_batch_charge_estimate`

`get_active_count`

`get_subscriber_count`

`get_subscriber_at`

`get_subscriber_page`

`get_active_subscriber_page`

`clear_subscriber_index_entry`

`get_merchant_revenue`

`get_merchant_revenue_history`

`clear_merchant_revenue_history`

`get_merchant_subscriber_count`

`get_merchant_sub_count`

`reset_merchant_revenue`

`withdraw_merchant_revenue`

`set_daily_limit`

`remove_daily_limit`

`get_daily_spent`

`get_day_start`

`get_referrer`

`migrate`