SignEnvoy developer docs

The REST API for sending, tracking, and downloading sealed signature requests. API version 1.3.0-m4.

Base URL and authentication

All endpoints live under https://signenvoystaging.fly.dev/v1. Authenticate every request with an API key in the Authorization header:

Authorization: Bearer senv_live_...

Keys come in two modes. senv_live_ keys send real email and count toward your allowance; senv_test_ keys never count. Create and revoke keys under Settings, API keys, or with the /v1/keys endpoints. API access is part of the Pro plan; a Personal workspace's requests answer plan-no-api.

Errors

Every error is an application/problem+json document (RFC 9457) with a stable type of the form /problems/<slug> and a docs_url member that links the page for that slug. Switch on type, never on title or detail, which are human-readable and may change. The error reference lists every slug.

Headers on every response

`X-SignEnvoy-Envelopes-Remaining`	Signature requests left in the current monthly allowance. Test keys report the live figure without consuming it.
`X-RateLimit-Limit`, `X-RateLimit-Remaining`, `X-RateLimit-Reset`	Fair-use rate limit state. A `429` carries `Retry-After`.
`X-SignEnvoy-Warning`	Present while a subscription is past due: the request succeeded, but billing needs attention.
`Idempotency-Key` (request)	Send one on any `POST` to make retries safe for 24 hours. A replay returns the stored response with `Idempotency-Replayed: true`.

Where to go

Quickstart: seven curl commands from a key to a sealed PDF.
API reference: every operation and schema, rendered from the OpenAPI document.
Webhook events and verifying signatures.
Event stream: tail events live over SSE while you develop a handler.
Device-flow sign-in: how a terminal obtains an API key a person approves.
Templates: roles and fields placed once, prefills by field name, versions, and templates as code.
Folders and search: organize documents without touching them, and find them by title, recipient, or template.
Recipient authentication: the signing link alone, or the link plus a one-time code; what the certificate records.
Bulk send: one template, many rows, validated whole and tracked per row.
Customer portals: one page under your name where recipients sign what is waiting and download what they signed.
The CLI: install senv and every command it offers.
Error reference: every problem type, with what to do about each.

The specification

The API is described by an OpenAPI 3.1 document served at https://signenvoystaging.fly.dev/v1/openapi.json and mirrored at /openapi.json. It is the contract: the official clients are generated from it, and its operation set is pinned by a test in the app repository so it cannot drift.