eSigKit · v1
Developer documentation
Everything you need to build with the eSigKit signature-management API — endpoints, authentication, webhooks, and language SDKs. Always in sync with the live spec.
API reference
Every endpoint, request schema, and response shape — generated directly from the production OpenAPI spec.
ReadQuickstart
Authenticate, render your first signature, and embed it in Gmail in under five minutes.
ReadAuthentication
Cognito JWTs for browser apps, API keys for server-to-server. PKCE flow, token rotation, and the dashboard / admin client split.
ReadErrors
The full error envelope, status-code catalog, retry guidance per status, and the correlationId pattern for debugging.
ReadRate limits
100 RPS stage-wide with 200 burst, plus the 429 + Retry-After contract and exponential-backoff client recipe.
ReadIdempotency
Optimistic concurrency on every mutable resource — version-based 409 handling and the read-modify-write loop pattern.
ReadPagination
Cursor-based pagination on every list endpoint. Opaque base64 cursors, default + max page size, and the loop pattern.
ReadWebhooks
Stripe-event handling: HMAC signing scheme, 7-day dedup, retry semantics, and the event-type catalog.
ReadSDKs
Drop-in patterns for HTML email signatures, React hooks (useSignature), and Next.js server-component rendering.
ReadBase URLs
Three environments matching the SDLC. Use staging for integration tests; never run automated tests against production.
| Stage | Base URL | Notes |
|---|---|---|
| Production | https://api.esigkit.com/v1 | Live customer traffic. |
| Staging | https://api-test.esigkit.com/v1 | Pre-prod validation. |
| Development | https://api-dev.esigkit.com/v1 | Sandbox — may break at any time. |