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Signkoi
Developer docs

API reference

Every endpoint of the Signkoi API v1: parameters, request bodies, response objects, errors and code samples in curl, Node, Python and PHP.

On this page

Base URL and versioning

All endpoints live under https://signkoi.com/api/v1, take JSON and return JSON, and are authenticated with an API key. Every response carries the API version and a request id:

Response headers
HTTP/1.1 200 OK
Content-Type: application/json
Signkoi-Version: 2026-11-14
X-Request-Id: 0f6c8f5e-2b1d-4c3a-9e7f-5a8b1c2d3e4f
X-RateLimit-Limit: 300
X-RateLimit-Remaining: 299
Cache-Control: no-store

The current version is v1 (2026-11-14). Within v1 we only make additive changes — new endpoints, new optional parameters, new fields, new event types and error codes — so ignore fields you don’t recognise. Anything that would break an integration ships as a new version, announced in the changelog.

OpenAPI specification

The whole API is described in an OpenAPI 3.1.0 document — the same file this reference is generated from. Import it into Postman, Insomnia or Bruno, or generate a client with your favourite OpenAPI code generator.

Download OpenAPI (JSON)

Shell
curl -O https://signkoi.com/developers/openapi.json

All endpoints

Account

Who the API key belongs to, its scopes, plan and usage.

Envelopes

An envelope is one or more PDFs sent to recipients for signature. Create, update, send, remind, void and track them.

Recipients

Manage the people on an envelope, resend invitations and create signing URLs for embedded signing.

Files

Download the original PDF, the signed PDF and the certificate of completion.

Templates

Reusable documents with roles and fields. Create an envelope from a template by filling its roles.

Webhooks

Get notified when envelopes and recipients change. Deliveries are signed with your endpoint secret.