Codex MCP guide

Test webhooks with Codex.

Register the remote Streamable HTTP endpoint in Codex, then use its tools to exercise and diagnose webhook flows from the repository you are changing.

AnonymousStreamable HTTP8 tools
Codex CLI
codex mcp add webhooktest --url https://webhooktest.net/mcp

# Equivalent config.toml entry
[mcp_servers.webhooktest]
url = "https://webhooktest.net/mcp"

Setup and test workflow

01

Register the remote server

Run the official Codex CLI form below, or add the equivalent mcp_servers table to your Codex config.toml. URL selects Streamable HTTP; no bearer token is needed.

02

Verify the connection

Run codex mcp list, start a new Codex session, and confirm webhooktest tools are available. If a managed policy controls MCP servers, an administrator may need to allow the exact URL.

03

Ask for an end-to-end check

Have Codex create a bucket, update the local integration to use its endpoint, run the trigger, then wait for and inspect the capture. Keep unrelated production data out of the request.

04

Use confirmation for cleanup

When the test passes, ask Codex to clear captures or delete the bucket. The destructive tools require confirm:true and advertise destructive annotations to clients.

What the server exposes

Create and understand

`create_webhook_bucket` creates a temporary endpoint; `get_webhook_bucket` reads its name and response settings.

Observe deliveries

`wait_for_webhook` waits up to 25 seconds; `list_webhooks` paginates summaries; `get_webhook` returns one scoped capture.

Control and clean up

`configure_webhook_response` changes the reply. `clear_webhooks` and `delete_webhook_bucket` require explicit confirmation.

Privacy and limits

Authorization, cookie, API-key, token, secret, password, and signature-like header or query values are redacted by default. Agents must explicitly request sensitive values. Bodies are limited to 64 KiB in tool output by default and can be raised only to 256 KiB. Use synthetic data: the endpoint is a debugging service, not a production processor.

Troubleshooting

  • Use the exact HTTPS URL and select remote or Streamable HTTP transport.
  • Restart or reload the client after changing MCP configuration.
  • Check that corporate policy allows the endpoint and outbound HTTPS.
  • A timeout with received:false is successful; verify the sender used the returned bucket URL.
  • HTTP 429 means the per-IP call, creation, bucket, or concurrent-wait limit was reached.

Client guides

MCP workflowClaudeCursorCodex