Postscript · OpenAPI Overlay 1.0.0

API Evangelist enhancements for Postscript Messages API

4 actions 4 updates update extends openapi/postscript-messages-api-openapi.yml

Derived by API Evangelist Built from the contracts Postscript publishes. Postscript did not publish this file.

View Overlay File View on GitHub Overlay Specification

What the actions change

x-apievangelist-providerx-apievangelist-harvestx-apievangelist-artifactsx-apievangelist-rate-limitx-apievangelist-notex-apievangelist-error-envelope

Targets 3

$.info

$.components.securitySchemes['sec0']

$.paths.*.*

OpenAPI Overlay

overlay: 1.0.0
info:
  title: API Evangelist enhancements for Postscript Messages API
  version: 1.0.0
extends: openapi/postscript-messages-api-openapi.yml
x-generated: '2026-08-13'
x-method: generated
x-source: apis.yml + repo artifacts; enhancements only, never applied to the harvested spec
actions:
- target: $.info
  update:
    x-apievangelist-provider: postscript
    x-apievangelist-harvest: Assembled from the per-operation OpenAPI 3.1.0 blocks Postscript publishes on developers.postscript.io/reference.
      Postscript publishes no single assembled document.
    x-apievangelist-artifacts:
      authentication: authentication/postscript-authentication.yml
      conventions: conventions/postscript-conventions.yml
      errors: errors/postscript-error-codes.yml
      rate_limits: rate-limits/postscript-rate-limits.yml
      lifecycle: lifecycle/postscript-lifecycle.yml
      data_model: data-model/postscript-data-model.yml
      webhooks: asyncapi/postscript-webhooks.yml
- target: $.info
  update:
    x-apievangelist-rate-limit: 15 requests per second per token; 429 with {"error_code":3002}; no rate-limit response
      headers published
- target: $.components.securitySchemes['sec0']
  update:
    x-apievangelist-note: Private API key as a bearer token. Partners additionally send the target shop key in X-Postscript-Shop-Token,
      which Postscript declares as a plain header parameter rather than a securityScheme.
- target: $.paths.*.*
  update:
    x-apievangelist-error-envelope: '{"error_code": <int>, "error_message": <string>, "success": false}'

Work with this as data

Every overlay here is available over the APIs.io API and to AI agents over MCP.

MCP server

One button, every client — Claude, Cursor, VS Code and the rest.

https://apis.io/mcp

Tools for openapi overlays

4 MCP tools reach this

find_overlaysBrowse and filter every overlay in the catalog.
apis_io_searchSTART HERE — APIs, providers and tags for one query, each with its total.
resolveTurn a domain, URL or GitHub org into the provider it belongs to.
find_cohortsEvery scored population of providers in the catalog.

All 92 tools →

Call it yourself

curl for this page

This overlay

curl "https://apis.io/api/v1/overlays/postscript-messages-api-overlay"

All openapi overlays

curl "https://apis.io/api/v1/overlays?limit=25"

Calls without X-API-Key need no key. Calls with it need a paid plan — get a key.

Get an API key

Free tier, no form to fill in. Signing in shares your email address with us — we store it to create your key and to recognise you if you sign in with another provider. See our Privacy Policy and Terms.

GitHub Google LinkedIn

A second provider on the same verified email joins the account you already have.