> ## Documentation Index > Fetch the complete documentation index at: https://docs.antonpayments.com/llms.txt > Use this file to discover all available pages before exploring further. # Update a Webhook Subscription > Partial update: any of `url`, `events`, `metadata`. Absent fields are left unchanged; a body carrying none of the three is rejected with `400 missing_required_field`. - `url` — validated with the same HTTPS/SSRF rules as creation. - `events` — must be non-empty when present; every entry must be a known event type or the `"*"` wildcard (unknown types fail with `422`, keyed by position). - `metadata` — replaces the whole map (`{}` clears it); no per-key merge. `status` and the signing secret are not patchable — unknown fields are rejected with `400 unknown_field`. Use `POST /v1/webhooks/{id}/deactivate` and `POST /v1/webhooks/{id}/secret/rotate` instead. Requires an `Idempotency-Key` header. ## OpenAPI ````yaml PATCH /v1/webhooks/{id} openapi: 3.1.0 info: title: Anton Payments API version: 1.0.0 summary: Cross-border payout infrastructure. Fiat, stablecoin, and crypto. description: > The Anton Payments merchant API. Versioned, idempotent, cursor-paginated. - **Authentication**: OAuth 2.0 client_credentials with DPoP proof-of-possession (RFC 6749 §4.4 + RFC 9449). Programmatic clients exchange `(client_id, client_secret)` for a short-lived access token at `POST /oauth/token`, then send each request with `Authorization: DPoP ` plus a per-request `DPoP: ` header. Static API keys are not accepted on v1. - Base URLs: `https://api.antonpayments.com` (production), `https://api.antonpayments.dev` (sandbox). - Monetary amounts are decimal strings. Never floats. - Timestamps are RFC 3339 UTC. - All mutating endpoints support the `Idempotency-Key` header. - Anton's OAuth public signing key is published at `GET /.well-known/jwks.json` (5-minute cache; RFC 8615). **Capabilities and scopes.** Every account carries a capability set (`payouts`, `intelligence`) and every credential carries a scope set validated against it at creation. AI-compliance-only accounts hold only `intelligence` — all payout-surface endpoints return `403 capability_required` for them. A credential minted without a scope returns `403 insufficient_scope` on that surface. Effective access is `scopes ∩ capabilities`. Access tokens embed the grants as a space-delimited `scope` claim, echoed in the token response. **What machine credentials can never do.** Approval decisions (payout approve/reject — maker-checker requires a human identity) and detokenized PII readback (beneficiary PII, verification name reveal, captured-document viewing) are dashboard-only: those operations require a signed-in portal user with the right role, and every access is audit-logged. Machine credentials can deposit and replace PII — your system is its source — but can never read it back, so a leaked credential cannot harvest identities. See the Cross-Cutting section of the docs for idempotency, pagination, rate limits, errors, webhook events, and webhook signing. contact: name: Anton Payments Support url: https://help.antonpayments.com license: name: Proprietary url: https://www.antonpayments.com servers: - url: https://api.antonpayments.com description: Production - url: https://api.antonpayments.dev description: Sandbox security: - oauthDPoP: [] dpopHeader: [] tags: - name: Authentication description: >- OAuth 2.0 token endpoint and JWKS publication. See the API description for the full DPoP-bound flow. - name: OAuth Clients description: >- Manage OAuth credentials (programmatic access). Portal-only — JWT auth required. - name: Reference Data description: Currencies, countries, and supported payment methods. - name: Beneficiaries description: Create and manage the people and businesses you pay. - name: Instruments description: >- Payment instruments attached to beneficiaries — bank accounts, wallets, cards. - name: Payouts description: Initiate and track payouts. - name: Batches description: CSV-driven bulk payout processing. - name: Balances description: Merchant balance by currency. - name: Accounts description: Virtual accounts for merchant funding. - name: Webhooks description: Subscribe to event notifications. - name: Documents description: Upload and manage KYB and supporting documents. - name: RFIs description: Respond to Requests for Information raised during review. - name: Pricing description: Read merchant pricing plans and quote fees. - name: FX description: Quote, lock, and execute currency exchanges between balances. - name: Corridors description: Active cross-border corridors for your merchant. - name: Balance Alerts description: >- Per-currency low-balance thresholds that drive the `balance.low` webhook event. - name: Sandbox description: Reset and seed your sandbox environment. - name: Merchant description: Merchant profile, branding, preferences, and security posture. - name: API Keys description: Issue, list, and revoke API keys. - name: Users description: Self-service profile, MFA, and team management. - name: Notifications description: Per-user notification channels and preferences. - name: Velocity description: Merchant-scoped risk rules and what-if simulation. - name: Engine description: Glass-box view of Anton's risk intelligence. - name: Intelligence description: >- Normalized payee, instrument, payout, and merchant risk intelligence evaluations. - name: Verifications description: >- KYC/KYB-as-a-service — verify the identity of your customers and their businesses through Anton-hosted flows, with sanctions screening built in. - name: Onboarding description: Authenticated KYB onboarding draft and submission. - name: Public Onboarding description: >- Session-authenticated hosted onboarding flow. Not intended for SDK consumption. paths: /v1/webhooks/{id}: parameters: - name: id in: path required: true schema: type: string pattern: ^whk_[a-zA-Z0-9]+$ patch: tags: - Webhooks summary: Update a webhook subscription description: | Partial update: any of `url`, `events`, `metadata`. Absent fields are left unchanged; a body carrying none of the three is rejected with `400 missing_required_field`. - `url` — validated with the same HTTPS/SSRF rules as creation. - `events` — must be non-empty when present; every entry must be a known event type or the `"*"` wildcard (unknown types fail with `422`, keyed by position). - `metadata` — replaces the whole map (`{}` clears it); no per-key merge. `status` and the signing secret are not patchable — unknown fields are rejected with `400 unknown_field`. Use `POST /v1/webhooks/{id}/deactivate` and `POST /v1/webhooks/{id}/secret/rotate` instead. Requires an `Idempotency-Key` header. operationId: updateWebhookSubscription parameters: - $ref: '#/components/parameters/IdempotencyKey' requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/WebhookSubscriptionUpdateRequest' responses: '200': description: >- The updated subscription (same shape as GET; the secret is never included). content: application/json: schema: type: object required: - data properties: data: $ref: '#/components/schemas/WebhookSubscription' '400': description: >- No patchable field present (`missing_required_field`), an unknown field such as `status` or `secret` (`unknown_field`), or an invalid URL. content: application/json: schema: $ref: '#/components/schemas/ErrorEnvelope' '401': $ref: '#/components/responses/Unauthorized' '404': $ref: '#/components/responses/NotFound' '409': $ref: '#/components/responses/IdempotencyConflict' '422': $ref: '#/components/responses/ValidationFailed' '429': $ref: '#/components/responses/RateLimited' components: parameters: IdempotencyKey: name: Idempotency-Key in: header description: > Unique key identifying this operation. Sending the same key twice returns the original response instead of creating a duplicate. Keys are retained for 24 hours. required: true schema: type: string maxLength: 255 schemas: WebhookSubscriptionUpdateRequest: type: object description: | Partial update for `PATCH /v1/webhooks/{id}`. Include at least one field. `metadata` replaces the entire map. Status changes and secret rotation go through their dedicated endpoints. properties: url: type: string format: uri description: New HTTPS delivery URL. Same validation rules as creation. events: type: array description: Full replacement event filter. Must be non-empty when present. items: $ref: '#/components/schemas/WebhookEventType' metadata: type: object additionalProperties: type: string WebhookSubscription: type: object description: A registered webhook endpoint and its event filter. required: - id - merchant_id - url - events - status - version - created_at - updated_at properties: id: type: string pattern: ^whk_[a-zA-Z0-9]+$ example: whk_01HX8Z9K0M2N3P4Q5R6S7T8UW merchant_id: type: string pattern: ^mer_[a-zA-Z0-9]+$ url: type: string format: uri events: type: array items: $ref: '#/components/schemas/WebhookEventType' status: type: string enum: - active - inactive version: type: string description: API version this subscription pins to. example: '2024-01-01' metadata: type: object additionalProperties: type: string created_at: $ref: '#/components/schemas/Timestamp' updated_at: $ref: '#/components/schemas/Timestamp' ErrorEnvelope: type: object required: - error properties: error: type: object required: - message properties: message: type: string description: Human-readable description of what went wrong. code: type: string description: Machine-readable error code. Branch on this, not on `message`. example: insufficient_balance example: error: message: insufficient funds for this payout code: insufficient_balance WebhookEventType: type: string description: | See [Webhook Events](/api-reference/webhook-events) for the full catalog and payload shapes. Some reserved event types (`balance.low` on some paths) may be defined but not yet dispatched — subscribing to them is safe but no deliveries arrive until they're wired up. enum: - payout.created - payout.approved - payout.processing - payout.sent - payout.completed - payout.failed - payout.cancelled - payout.returned - payout.screening_failed - payout.velocity_blocked - payout.engine_blocked - beneficiary.created - beneficiary.updated - beneficiary.deleted - beneficiary.blocked - instrument.created - instrument.updated - instrument.deleted - batch.uploaded - batch.completed - batch.failed - fx.quote.created - fx.exchange.created - fx.exchange.completed - fx.exchange.failed - funding.credit - screening.hit - intelligence.evaluation.completed - intelligence.evaluation.failed - balance.low - test Timestamp: type: string format: date-time description: RFC 3339 / ISO 8601 timestamp in UTC. example: '2026-04-15T14:30:00Z' ValidationErrorEnvelope: type: object required: - error properties: error: type: object required: - message - code properties: message: type: string example: request failed validation code: type: string enum: - validation_error details: type: array description: Field-level validation errors. items: type: object required: - field - message properties: field: type: string description: Dotted JSON path to the offending field. example: individual.date_of_birth message: type: string example: must be in YYYY-MM-DD format example: error: message: request failed validation code: validation_error details: - field: individual.first_name message: is required - field: country message: must be a valid ISO-3166 alpha-2 country code responses: Unauthorized: description: Missing or invalid API key, or key used against the wrong environment. content: application/json: schema: $ref: '#/components/schemas/ErrorEnvelope' examples: missing_key: summary: Missing bearer token value: error: code: unauthorized message: missing or invalid credentials wrong_environment: summary: Test key used against production value: error: code: key_environment_mismatch message: this API key is not valid for this environment NotFound: description: The resource does not exist, or belongs to a different merchant. content: application/json: schema: $ref: '#/components/schemas/ErrorEnvelope' IdempotencyConflict: description: >- The same `Idempotency-Key` was previously used with a different request body. content: application/json: schema: $ref: '#/components/schemas/ErrorEnvelope' ValidationFailed: description: The request body failed validation. content: application/json: schema: $ref: '#/components/schemas/ValidationErrorEnvelope' RateLimited: description: >- Rate limit exceeded. See `Retry-After`. The `X-RateLimit-*` headers are present on every API response, not only on 429s — they are documented here because this is where clients act on them. headers: Retry-After: $ref: '#/components/headers/Retry-After' X-RateLimit-Limit: $ref: '#/components/headers/X-RateLimit-Limit' X-RateLimit-Remaining: $ref: '#/components/headers/X-RateLimit-Remaining' X-RateLimit-Reset: $ref: '#/components/headers/X-RateLimit-Reset' content: application/json: schema: $ref: '#/components/schemas/ErrorEnvelope' examples: rate_limit_exceeded: summary: Retry after the limiter resets value: error: code: rate_limit_exceeded message: rate limit exceeded, retry after 60 seconds headers: Retry-After: description: Seconds to wait before retrying. Included on 429 responses. schema: type: integer X-RateLimit-Limit: description: Maximum requests permitted in the current window. schema: type: integer X-RateLimit-Remaining: description: Requests remaining in the current window. schema: type: integer X-RateLimit-Reset: description: Unix timestamp when the current window resets. schema: type: integer securitySchemes: oauthDPoP: type: http scheme: DPoP description: > OAuth 2.0 client_credentials grant (RFC 6749 §4.4) bound to a DPoP keypair (RFC 9449). **Flow** (every authenticated `/v1` call requires both an access token AND a fresh per-request DPoP proof): 1. Register a credential via the merchant portal. Anton issues a `client_id` (`ant_oc__<32hex>`) and a `client_secret` (`ant_ocs__<48hex>`, shown ONCE). The portal generates an ES256 or Ed25519 DPoP keypair in your browser; you store the private half. 2. Mint an access token: `POST /oauth/token` with `Authorization: Basic ` and `Content-Type: application/x-www-form-urlencoded`. Body: `grant_type=client_credentials`. A `DPoP` header carrying a proof signed for the token endpoint is required (no `ath` claim on this proof). 3. Use the token: send `Authorization: DPoP ` plus a fresh `DPoP: ` header on every `/v1` request. The proof JWT MUST carry `htm` (request method), `htu` (request URL, no query/fragment), `iat` (within ±60s), `jti` (unique within 5 min), and `ath` (SHA-256 of the access token, base64url). Tokens expire in **1 hour** in production / staging and **8 hours** in sandbox. There are no refresh tokens — call `/oauth/token` again with your secret. Anton's public signing key is published at `/.well-known/jwks.json`. **Scopes** (requested at `POST /oauth/token`, returned in the `scope` response field): | Scope | Grants | |---|---| | `payouts` | Money movement — payouts, batches, beneficiaries, instruments, balances, funding, FX. | | `intelligence` | Anton Intelligence — screening evaluations and evidence. | This scheme is declared as `http`/`DPoP` rather than `oauth2` so that generated examples show the correct `Authorization: DPoP ` header. Sending `Authorization: Bearer ` returns `401 unauthorized` — the token is sender-constrained and the scheme is not interchangeable. dpopHeader: type: apiKey in: header name: DPoP description: > Per-request DPoP proof JWT (RFC 9449). MUST accompany the `Authorization: DPoP ` header on every protected operation. The proof is signed by the merchant's private DPoP key and carries `htm`, `htu`, `iat`, `jti`, and `ath` claims. ````