GPT Actions

GPT Actions let a ChatGPT Custom GPT call Postsiva tools directly. Each tool is a POST endpoint with a JSON body matching the MCP tool schema. OpenAPI schema: GET https://backend.postsiva.com/openapi/chatgpt-actions.json

Requirements

Pro plan with gpt_app_enabled
Connected social accounts in the target workspace
Either ChatGPT OAuth (Connect to Postsiva) or a workspace API key

GPT Actions omit web_search_duckduckgo and clear_workspace_chat_history. Everything else matches the MCP tool catalog.

Authentication

Two supported methods:

Method	When to use	Header
OAuth (recommended)	End users in ChatGPT	`Authorization: Bearer <JWT from Connect to Postsiva>`
API key	Internal/testing Custom GPTs	`X-API-Key: psk_live_YOUR_KEY` or `Authorization: Bearer psk_live_YOUR_KEY`

OAuth flow:

User clicks Connect to Postsiva in ChatGPT
Signs in at https://backend.postsiva.com/auth/oauth/login
Selects a workspace
ChatGPT receives a Bearer JWT scoped to that workspace

Discovery endpoint: GET /.well-known/oauth-protected-resource

Call a tool

`POST /unified/gpt-actions/{tool_name}`

Replace {tool_name} with the exact MCP tool name (snake_case). Base URL

https://backend.postsiva.com

Headers

Content-Type: application/json
Authorization: Bearer YOUR_TOKEN_OR_PSK

Example — list accounts

curl -X POST "https://backend.postsiva.com/unified/gpt-actions/get_accounts" \
  -H "Content-Type: application/json" \
  -H "X-API-Key: psk_live_YOUR_KEY" \
  -d '{}'

const res = await fetch("https://backend.postsiva.com/unified/gpt-actions/get_accounts", {
  method: "POST",
  headers: {
    "Content-Type": "application/json",
    "Authorization": "Bearer psk_live_YOUR_KEY",
  },
  body: JSON.stringify({}),
});

import requests

r = requests.post(
    "https://backend.postsiva.com/unified/gpt-actions/get_accounts",
    headers={
        "Content-Type": "application/json",
        "X-API-Key": "psk_live_YOUR_KEY",
    },
    json={},
)
print(r.json())

Response example

{
  "success": true,
  "platforms": ["linkedin", "instagram"],
  "profiles": {
    "linkedin": { "name": "Jane Doe", "handle": "jane-doe" },
    "instagram": { "username": "janedoesocial" }
  }
}

Example — idea to content

curl -X POST "https://backend.postsiva.com/unified/gpt-actions/idea_to_content" \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer YOUR_OAUTH_JWT" \
  -d '{
    "platforms": ["linkedin", "threads"],
    "idea": "Why async standups beat daily video calls",
    "user_requirements": "Include one stat placeholder"
  }'

Example — publish

curl -X POST "https://backend.postsiva.com/unified/gpt-actions/publish" \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer YOUR_OAUTH_JWT" \
  -d '{
    "post_type": "text",
    "platforms": ["linkedin"],
    "default_text": "Async standups save 30 minutes per week per engineer.",
    "draft": false
  }'

Available tools

Tool	Description
`get_accounts`	List connected platforms or one profile
`get_queued_posts`	Scheduled posts and drafts
`get_user_posts`	Recent posts per platform
`get_unified_analytics`	Stored cross-platform analytics
`get_comments`	Comments on recent posts
`reply_to_comment`	Reply to a comment
`manage_platform_connection`	OAuth connect URL or disconnect
`idea_to_content`	Topic → per-platform copy
`content_to_image`	Copy → generated images
`media_to_content`	Image/video URL → captions
`analyze_media`	Describe image or video URL
`publish`	Publish, draft, or schedule
`disconnect_gpt_connector`	Revoke ChatGPT OAuth session

Tool bodies match MCP arguments exactly. Import the OpenAPI schema for full JSON Schema per operation.

OpenAPI schema

`GET /openapi/chatgpt-actions.json`

Public, no auth required. Import this URL when creating a Custom GPT:

https://backend.postsiva.com/openapi/chatgpt-actions.json

The schema includes:

OpenAPI 3.1.0
One POST path per tool under /unified/gpt-actions/{operationId}
Request body schemas from Pydantic tool inputs
BearerAuth security scheme (OAuth JWT or psk_live_ key)
x-openai-action-timeout: 120 (seconds)

curl "https://backend.postsiva.com/openapi/chatgpt-actions.json"

Disconnect ChatGPT connector

`POST /unified/gpt-actions/disconnect_gpt_connector`

Revokes the ChatGPT OAuth Bearer token so the next Action call returns 401 until the user reconnects.

Does not unlink social platforms (use manage_platform_connection with action=disconnect for that)
No-op success when authenticated with an API key (nothing to revoke)

Request body: {} (empty JSON object)

curl -X POST "https://backend.postsiva.com/unified/gpt-actions/disconnect_gpt_connector" \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer YOUR_OAUTH_JWT" \
  -d '{}'

Response example (OAuth revoked)

{
  "success": true,
  "revoked_oauth_token": true,
  "detail": "Connector session revoked. Reconnect to Postsiva in ChatGPT on your next request."
}

Response example (API key auth)

{
  "success": true,
  "revoked_oauth_token": false,
  "detail": "No OAuth Bearer token was revoked (e.g. you use an API key, or token was invalid). Social accounts in Postsiva are unchanged; use disconnect_social_platform to unlink a network."
}

REST vs MCP vs GPT Actions

Feature	MCP	GPT Actions
Transport	Streamable HTTP MCP	OpenAPI REST
Web search	Yes (`web_search_duckduckgo`)	No
Clear chat history	No	No
Auth	API key only	OAuth or API key
Timeout	Client-defined	120s (OpenAPI hint)

Errors

Status	Meaning
`401`	Missing auth or revoked OAuth — user must reconnect in ChatGPT
`402` / plan message	`gpt_app_enabled` not on current plan
`422`	Invalid JSON body or schema validation failure
`200` with `success: false`	Tool-level error inside JSON payload

Setup guide

See ChatGPT Custom GPT setup for step-by-step Custom GPT configuration, OAuth URLs, and privacy instructions.

ChatGPT setup

Custom GPT walkthrough

MCP tools

Full tool reference

Plans

Pro plan requirements

Get started

Features

REST API

MCP

Platforms

Guides

Integrations

Errors

Reference

Requirements

Authentication

Call a tool

`POST /unified/gpt-actions/{tool_name}`

Example — list accounts

Example — idea to content

Example — publish

Available tools

OpenAPI schema

`GET /openapi/chatgpt-actions.json`

Disconnect ChatGPT connector

`POST /unified/gpt-actions/disconnect_gpt_connector`

REST vs MCP vs GPT Actions

Errors

Setup guide

Next

ChatGPT setup

MCP tools

Plans

​Requirements

​Authentication

​Call a tool

​POST /unified/gpt-actions/{tool_name}

​Example — list accounts

​Example — idea to content

​Example — publish

​Available tools

​OpenAPI schema

​GET /openapi/chatgpt-actions.json

​Disconnect ChatGPT connector

​POST /unified/gpt-actions/disconnect_gpt_connector

​REST vs MCP vs GPT Actions

​Errors

​Setup guide

​Next

ChatGPT setup

MCP tools

Plans

Requirements

Authentication

Call a tool

`POST /unified/gpt-actions/{tool_name}`

Example — list accounts

Example — idea to content

Example — publish

Available tools

OpenAPI schema

`GET /openapi/chatgpt-actions.json`

Disconnect ChatGPT connector

`POST /unified/gpt-actions/disconnect_gpt_connector`

REST vs MCP vs GPT Actions

Errors

Setup guide

Next