Developer documentation

REST API for the Abundera Sign e-signature service. Create envelopes, manage signers, verify documents, capture cryptographic evidence.

API specification

The Abundera Sign API follows OpenAPI 3.0 (converted from 3.1 source for broad tooling compatibility). Browse the interactive reference, download the spec, or import it into your preferred API client.

Interactive API reference →

Every endpoint with request and response schemas, parameters, and try-it-now in your browser. Powered by Scalar.

OpenAPI 3.0 (YAML)

Full specification with schemas, descriptions, and examples.

OpenAPI 3.0 (JSON)

Same specification in JSON. Best for programmatic consumption.

Postman collection

Import directly into Postman for interactive testing.

curl examples

Copy-paste curl commands for the most commonly used endpoints.

Integration guide

Long-form prose covering authentication, errors, rate limits, webhooks, embedded signing, and the MCP server.

Official SDKs (10 languages)

Typed clients for TypeScript, Python, Go, Ruby, Java, C#, Rust, PHP, Kotlin, and Swift.

Authentication

The Sign API supports two authentication methods:

JWT Bearer tokens · obtained from the Abundera auth service, verified against the hub JWKS at https://abundera.ai/v1/auth/jwks.
API keys · product-scoped, prefix abnd_sign_, managed at abundera.ai/account/api-keys. Validated server-side against abundera.ai/v1/auth/validate-key with a 60-second KV cache.

Authorization: Bearer abnd_sign_…

Base URL and format

Base URL: https://sign.abundera.ai/api/v1

Request format: JSON (Content-Type: application/json).

Response format: JSON (application/json; charset=utf-8).

Quick example

curl -X POST https://sign.abundera.ai/api/v1/envelopes \
  -H "Authorization: Bearer abnd_sign_…" \
  -H "Content-Type: application/json" \
  -d '{"template_id":"nda-simple","signers":[{"email":"jane@contoso.com","name":"Jane Doe","role":"recipient"}]}'

Official SDKs

Typed clients in ten languages, each a thin wrapper over the same v1 surface: they unwrap the { ok, data, error, request_id } envelope for you, retry on 429 with Retry-After, and verify Standard Webhooks signatures. Source lives on GitHub (not yet on the public package registries). The shared contract is documented per repo.

TypeScript · @abundera/sign

npm install github:abundera/sign-typescript

Python · abundera-sign

pip install "git+https://github.com/abundera/sign-python.git"

Go · github.com/abundera/sign-go

go get github.com/abundera/sign-go

Ruby · abundera-sign

gem "abundera-sign", git: "https://github.com/abundera/sign-ruby.git"

Java · ai.abundera:abundera-sign

JitPack: com.github.abundera:sign-java:main-SNAPSHOT

C# / .NET · Abundera.Sign

Clone, then dotnet add reference Abundera.Sign.csproj