Codex CLI connects to Octogen through a dedicated compatibility endpoint rather than the standard MCP base URL. This endpoint handles OAuth discovery and token minting in a way that is compatible with how Codex implements the OAuth 2.1 flow. Everything else — the tools, the response shapes, and the catalog grants — is identical to other clients.Documentation Index
Fetch the complete documentation index at: https://www.octogen.ai/docs/llms.txt
Use this file to discover all available pages before exploring further.
Always use
https://codex-mcp.octogen.ai/mcp with Codex CLI. Do not substitute the standard https://mcp.octogen.ai/mcp URL — authentication will not complete correctly.Register the Octogen MCP server
Run the following command in your terminal:This registers a server named
octogen in your Codex configuration.Alternatively, add the entry manually to your Codex config file at ~/.codex/config.toml:Sign in to Octogen
Trigger the OAuth sign-in flow by running:Codex opens a browser tab with the Octogen sign-in page. Complete the sign-in flow:
- Enter the email that belongs to your Catalog Partner organization.
- Authenticate using your organization’s configured method (password, SSO, or magic link).
- If your account belongs to multiple organizations, select the Catalog Partner organization you want to act as.
- Consent to the requested scopes.
Access tokens are valid for approximately five minutes. Codex refreshes them transparently — you will not be prompted again unless your Octogen sign-in session expires.
Why a separate URL?
The Codex CLI uses a different OAuth discovery path than other MCP clients. The compatibility endpoint athttps://codex-mcp.octogen.ai advertises OAuth resource indicator support and handles the authorize and token requests in the format Codex expects. Internally, it attaches the canonical MCP resource identifier (https://mcp.octogen.ai) before forwarding the request to Octogen AuthKit, so the access token it issues is audience-bound to the same resource as every other client. The separate hostname is purely a compatibility shim — your catalog grants, tool calls, and response shapes are identical regardless of which endpoint you authenticated through.
What your agent can do
Once connected, your agent has access to three tools:list_catalogs()— discover which catalogs your organization has access to.lookup_product(canonical_url, catalogs?)— resolve a product page URL to a full product record.search_products(catalog, query?, limit?, cursor?)— search products by keyword within a single catalog.