> ## Documentation Index > Fetch the complete documentation index at: https://docs.pay.aptahq.com/llms.txt > Use this file to discover all available pages before exploring further. # Provider ingress (NOT for tenants) > **Where the PROVIDER tells the gateway a payment's outcome changed.** Documented for completeness — **a tenant never calls this.** You do not implement it, you do not send to it; the provider does, and the gateway turns what arrives into the canonical webhook you receive at YOUR callback URL, signed by us. See `docs/TENANT_INTEGRATION.md` for the one you actually handle. Listed here so the surface is honest about what exists and how it is protected. One path per provider, because sniffing the body to guess the sender is the ambiguity to avoid when two providers are live at once. Gated by the PROVIDER's own signature over the raw bytes, not by tenant auth. Exempt from rate limiting (a provider retrying into a 429 turns one notification into hours of retries) but never from the signature check, and capped at 64 KB. You receive the canonical version of these events at YOUR callback URL, signed by us — see `docs/TENANT_INTEGRATION.md`. ## OpenAPI ````yaml /openapi.json post /v1/webhooks/{provider} openapi: 3.0.3 info: title: AptaPay Gateway version: 1.0.0 description: > One provider-neutral payment API owned by many apps: collections, payouts, bank resolution and FX, with signed webhooks back. ## Authentication Every `/v1/*` request carries four headers. **A plain API key is not enough** — a key in a proxy log or an error report would be immediately usable, whereas a signature binds the request to a body and a moment. | Header | Value | | --- | --- | | `X-AptaPay-Key` | `{app_id}.{key_id}.{api_key}` | | `X-AptaPay-Timestamp` | unix seconds | | `X-AptaPay-Nonce` | 16-64 chars, `[A-Za-z0-9_-]`, unique per request | | `X-AptaPay-Signature` | `v1={hex HMAC-SHA256}` | The signature is HMAC-SHA256, with your **inbound** signing secret, over exactly these ten fields joined by `\n`: ``` v1 {APP_ID} {KEY_ID} {HOST} lowercased {METHOD} uppercased {PATH} no query, NOT url-decoded {CANONICAL_QUERY} sorted, RFC3986-encoded, "" when absent {TIMESTAMP} {NONCE} {SHA256_HEX(RAW_BODY)} sha256("") for GET/DELETE ``` Every field earns its place. `CANONICAL_QUERY` is in there because without it `?limit=1` and `?limit=100000` sign identically, so a captured read signature could be replayed to dump everything. `HOST` stops a signature captured against one deployment replaying into another. The timestamp window is **asymmetric**: `-120s <= now - ts <= +30s`. A symmetric window is a ten-minute replay window, and there is no legitimate reason to sign in the future beyond small clock skew. A working reference implementation is in `docs/TENANT_INTEGRATION.md`, and `scripts/sign_request.mjs` signs a request from the terminal. ## Idempotency `Idempotency-Key` is **required** on every money-moving POST. A missing key is a 400 — the server never invents one, because a server-generated key is unique per request and protects nothing, which is worse than none because it looks like protection. - Replaying a completed key returns the **original response verbatim**, with its original status code. No second provider call. - The same key with **different parameters** is a 422, never a replay. - A concurrent duplicate is a 409 `request_in_progress`. ## Errors Branch on `error.code` and the three booleans, never on the HTTP status: `terminal` (reverse and tell the user), `retriable` (retry with the same key), `ambiguous` (**do not reverse** — poll instead). ## Amounts Integer minor units, with a per-currency exponent. **UGX, RWF, XAF and XOF are zero-decimal**: 2000 UGX is `2000`. Getting this wrong is a 100x error. ## Test mode is NOT a sandbox **Every request reaches a real provider. There is no sandbox, and no test host.** AptaPay routes to a single upstream provider, and that provider publishes exactly one API host for live and test traffic alike. No sandbox base URL exists anywhere in its reference documentation. So "test mode" here does not mean what it means on Stripe. It is a **second, real provider account** holding a small real balance, reached over the same wire as production. A test-mode payout moves real money out of a real wallet to a real phone number. It cannot be reversed, because the provider exposes no refund endpoint. | | What you might expect | What actually happens | | --- | --- | --- | | Host | a separate sandbox host | the one production host, always | | Money | simulated | real, in a real wallet | | Recipients | fake numbers accepted | real MSISDNs, really credited | | Undo | reverse the test charge | none — no refund endpoint exists | Two guardrails stand in for the sandbox, and they are permanent, not temporary scaffolding: - **A hard amount ceiling on every test-mode transaction**, enforced by this gateway *before* any provider call. Over it, you get a `422` and no request ever leaves. - **`is_test_mode` stamped on every transaction record**, so a test transaction is identifiable forever after the fact. Mode is a property of **which credentials you hold**, never of a request field — there is no `test: true` to send, and no header that switches it. A live key transacts live; that is the only thing that decides it. See `GET /healthz` for which mode a deployment is running. ## CORS There isn't any, deliberately. This is a server-to-server API and browsers must never call it: signing from client-side JS would put your secret in view-source. Cross-origin browser requests are denied. servers: - url: https://api.pay.aptahq.com description: >- Production. There is no sandbox host, because the upstream provider has none — see "Test mode is NOT a sandbox". Sign the host you dial: the host is part of the canonical string, so a request dialled here must claim `api.pay.aptahq.com`. security: - AptaPaySignature: [] tags: - name: Collections description: Money in. - name: Payouts description: Money out. - name: Refunds description: Reversals — 501 where the routed provider has no refund endpoint. - name: Transactions description: The gateway's own ledger of what it was asked to do. - name: Beneficiaries description: Saved recipients. Stored masked, names re-resolved at payout time. - name: Reference description: Corridors, banks, countries, balances, capability matrix. - name: Float description: Your own claim on the shared wallet pool — what you can actually pay out. - name: FX description: Exchange between your own wallets. Quote is free; exchange moves money. - name: Webhooks description: Provider ingress. Documented for completeness; tenants never call it. - name: Ops description: Health. paths: /v1/webhooks/{provider}: post: tags: - Webhooks summary: Provider ingress (NOT for tenants) description: > **Where the PROVIDER tells the gateway a payment's outcome changed.** Documented for completeness — **a tenant never calls this.** You do not implement it, you do not send to it; the provider does, and the gateway turns what arrives into the canonical webhook you receive at YOUR callback URL, signed by us. See `docs/TENANT_INTEGRATION.md` for the one you actually handle. Listed here so the surface is honest about what exists and how it is protected. One path per provider, because sniffing the body to guess the sender is the ambiguity to avoid when two providers are live at once. Gated by the PROVIDER's own signature over the raw bytes, not by tenant auth. Exempt from rate limiting (a provider retrying into a 429 turns one notification into hours of retries) but never from the signature check, and capped at 64 KB. You receive the canonical version of these events at YOUR callback URL, signed by us — see `docs/TENANT_INTEGRATION.md`. operationId: providerWebhook parameters: - name: provider in: path required: true schema: type: string enum: - eversend - flutterwave - stripe responses: '200': description: > Accepted, ignored as a replay, or unmatched. A 200 here means "received", not "applied". '401': description: Signature verification failed. security: [] components: securitySchemes: AptaPaySignature: type: apiKey in: header name: X-AptaPay-Signature description: > `v1={hex HMAC-SHA256}` over the ten-field canonical string. Sent alongside `X-AptaPay-Key`, `X-AptaPay-Timestamp` and `X-AptaPay-Nonce` — all four are required. OpenAPI can only model one header per scheme, so the other three are described in the Authentication section above. ````