Skip to content
Postgram

Postgram OAuth Connectors For Claude And Eligible ChatGPT Accounts

June 16, 2026

Postgram now supports the OAuth flow expected by native remote MCP clients. That means a self-hosted Postgram instance can be connected from Claude’s Connectors UI and from ChatGPT only when custom-connector or developer-mode access is available, using Postgram’s normal MCP endpoint:

https://<your-postgram-host>/mcp

The important bit: do not paste a Postgram API key into ChatGPT or Claude connector settings. The connector uses OAuth discovery, Dynamic Client Registration, authorization-code flow, and PKCE. Postgram shows its own authorization page, and that page asks for an existing Postgram API key.

What Changed

Section titled “What Changed”

Postgram PR #72 added opt-in OAuth support for native remote MCP connectors:

  • OAuth authorization-code flow with PKCE.
  • Dynamic Client Registration for clients such as ChatGPT and Claude.
  • OAuth metadata and protected-resource metadata routes.
  • DB-backed OAuth clients, authorization codes, access tokens, and refresh tokens.
  • OAuth bearer tokens that resolve into the same Postgram auth context as API keys.
  • Existing static clients still work with Authorization: Bearer <api-key> and /mcp?apiKey=....

OAuth grants inherit the source API key’s scopes, client ID, allowed entity types, and allowed visibility. If that API key is revoked, OAuth tokens derived from it stop working.

Server Setup

Section titled “Server Setup”

Deploy a current Postgram build with OAuth enabled, then configure the server:

Terminal window
OAUTH_ENABLED=true
PUBLIC_BASE_URL=https://<your-postgram-host>

PUBLIC_BASE_URL must be the public HTTPS origin for the Postgram server. Do not include /mcp in this value.

The connector URL remains:

https://<your-postgram-host>/mcp

For Docker Compose deployments, set the values in your environment file and make sure the mcp-server service receives them:

services:
  mcp-server:
    environment:
      OAUTH_ENABLED: ${OAUTH_ENABLED:-false}
      PUBLIC_BASE_URL: ${PUBLIC_BASE_URL:-}

Remote connectors are called from provider cloud infrastructure. If Postgram is only available on localhost, behind a VPN, or behind a firewall that blocks provider traffic, ChatGPT and Claude will not be able to connect. Use a public HTTPS endpoint, a tunnel, or explicit allowlisting.

Quick metadata checks:

Terminal window
curl https://<your-postgram-host>/.well-known/oauth-protected-resource/mcp
curl https://<your-postgram-host>/.well-known/oauth-authorization-server

Claude Desktop Setup

Section titled “Claude Desktop Setup”

Claude custom connectors use remote MCP. Even in Claude Desktop, remote connector traffic is brokered through the Claude account and originates from Anthropic infrastructure, not the local computer.

  1. Open Claude and go to Customize > Connectors.
  2. Click + and choose Add custom connector.
  3. Name the connector Postgram.
  4. Set the connector URL to https://<your-postgram-host>/mcp.
  5. Leave OAuth Client ID and OAuth Client Secret blank unless your deployment intentionally requires static OAuth client credentials. Postgram’s normal connector flow supports Dynamic Client Registration.
  6. Click Add.
  7. Click Connect, complete the Postgram authorization page, and enter your Postgram API key there.
  8. In a chat, use the + button near the composer, open Connectors, and enable Postgram for that conversation.

For Team or Enterprise plans, an Owner or Primary Owner may need to add the custom connector at the organization level first. Individual users then connect and authorize it for their own account.

ChatGPT Setup

Section titled “ChatGPT Setup”

ChatGPT can connect to a remote MCP server as a custom app/connector when the account or workspace has access to apps, MCP connectors, and developer mode. Availability and admin controls vary by plan and workspace policy.

  1. In ChatGPT web, open Settings > Apps & Connectors > Advanced settings.
  2. Enable Developer mode if the account or workspace allows it.
  3. Go to Settings > Connectors or Apps & Connectors and choose Create.
  4. Name the connector Postgram.
  5. Use a description such as: Search, store, and recall knowledge from a self-hosted Postgram memory server.
  6. Set the connector URL to https://<your-postgram-host>/mcp.
  7. Choose the OAuth or server-provided authentication option if prompted.
  8. Create or scan the connector. If ChatGPT opens an authorization prompt, complete the Postgram authorization page and enter your Postgram API key there.
  9. Open a new ChatGPT conversation, click the + button near the composer, choose More or the available tools/apps list, and add Postgram to the conversation.
  10. Test with a prompt such as: Search Postgram for recent memories about this project.

If Postgram tools or descriptions change later, refresh the connector metadata from ChatGPT settings.

Security Notes

Section titled “Security Notes”

Only connect Postgram instances that you control and trust. The connector can read or modify whatever the authenticated Postgram API key permits. Use a dedicated API key for each connector where possible, grant the minimum scopes needed, and revoke keys that are no longer used.

Rich embedded ChatGPT UI components require Apps SDK metadata and UI resources. This release is about the core MCP tool connection.

References

Section titled “References”