Connect to MCP

Postsiva runs two Streamable HTTP MCP endpoints. Auth rules differ by host:

Audience	Endpoint	Auth (required)
Claude.ai	`https://mcp.postsiva.com/web/mcp`	OAuth only — API keys in the URL/headers will not work (Claude drops them on tool calls)
ChatGPT (MCP / UI connector)	`https://mcp.postsiva.com/web/mcp`	API key as query param (`?api-key=psk_live_…`) or OAuth
CLI (Cursor, Claude Code)	`https://mcp.postsiva.com/mcp`	API key as `X-API-Key` header + MCP URL

Stateless — no session between calls. Built-in host search is used instead of an MCP search tool.

Authentication cheat sheet

Client	Do this	Do not
Claude.ai	OAuth Connect → workspace	Put `?api-key=` on the connector URL
ChatGPT UI / MCP	`https://mcp.postsiva.com/web/mcp?api-key=psk_live_…`	Rely on header-only if the client ignores headers
Cursor / Claude Code	URL `…/mcp` + header `X-API-Key: psk_live_…`	Put the key only in the URL if you can use headers instead

The key must belong to a workspace on the Pro plan with MCP enabled.

Errors

Missing or invalid credentials → 401 / tool error (e.g. “API key required” or “Invalid or expired API key”). Wrong plan → upgrade message referencing postsiva.com.

Cursor (CLI)

Cursor Settings → MCP → Add server
Type: HTTP (Streamable HTTP)
URL: https://mcp.postsiva.com/mcp
Headers: X-API-Key = your psk_live_… key
Restart Cursor or reload MCP

{
  "mcpServers": {
    "Postsiva": {
      "url": "https://mcp.postsiva.com/mcp",
      "headers": {
        "X-API-Key": "psk_live_YOUR_KEY"
      }
    }
  }
}

Claude Code (CLI)

claude mcp add --transport http postsiva https://mcp.postsiva.com/mcp \
  --header "X-API-Key: psk_live_YOUR_KEY"

Claude.ai (web) — OAuth only

Settings → Connectors → Add connector → Add custom connector
Name: Postsiva
URL: https://mcp.postsiva.com/web/mcp — no query string, no API key
Optional (or leave blank for CIMD) — paste: OAuth Client ID (OAUTH_CLAUDE_CLIENT_ID):
WOX4Pa0RfLt0Xg4_tUEAMqsbLvtKMtE9
OAuth Client Secret (OAUTH_CLAUDE_CLIENT_SECRET):
2ynPWmCIcklu-BFrt_5TVZ6nToEL9mGPdOJ4kklSSAM
Click Connect and complete Postsiva OAuth (pick workspace)

Full walkthrough: Claude.

ChatGPT UI — API key query param

For ChatGPT connecting to the web MCP endpoint:

https://mcp.postsiva.com/web/mcp?api-key=psk_live_YOUR_KEY

Also accepted: ?apikey= / ?api_key= (same key). OAuth remains available for Custom GPT Actions (Connect to Postsiva).

Verify connection

Ask the agent:

What social accounts are connected to my workspace?

Media upload

MCP	Flow
Web `/web/mcp`	`upload_media` → iframe → Postsiva storage → `media_id` / `public_url` → `publish`
CLI `/mcp`	`upload_media(file_path=…)` → run `curl_command` → `media_id` / `public_url` → `publish`

Get started

Features

REST API

MCP

Platforms

Guides

Integrations

Errors

Reference

Authentication cheat sheet

Errors

Cursor (CLI)

Claude Code (CLI)

Claude.ai (web) — OAuth only

ChatGPT UI — API key query param

Verify connection

Media upload

Next

​Authentication cheat sheet

​Errors

​Cursor (CLI)

​Claude Code (CLI)

​Claude.ai (web) — OAuth only

​ChatGPT UI — API key query param

​Verify connection

​Media upload

​Next

Authentication cheat sheet

Errors

Cursor (CLI)

Claude Code (CLI)

Claude.ai (web) — OAuth only

ChatGPT UI — API key query param

Verify connection

Media upload

Next