Give Codex a mailbox on your own domain
With the contract in the session, Codex can list the domains your account owns, list the addresses on one of them, create a single new address, read the inbound event log with a cursor, open a durable wait and poll it, search the mailbox, and send from the domain your key is bound to. The hosted MCP server at https://mcp.flowmails.net/mcp mounts the same ten tools with a per-tool scope check, so a session that speaks MCP natively never has to remember a method name.
Step 1
Install the skill
The skill carries the SDK contract into the session — the package name, the constructor options, the error classes, the retry policy — so Codex stops inventing method names.
npx skills add wms-why/flowmails-sdk-plugin@flowmails-sdkThe skill follows the Agent Skills spec, so a Codex checkout reads it from its own skills directory. A repository that does not read a skill directory can carry the same contract in an AGENTS.md block instead, and the hosted MCP server at https://mcp.flowmails.net/mcp needs no skill at all.
Step 2
Or point it at the MCP server
The hosted Model Context Protocol server answers on https://mcp.flowmails.net/mcp over streamable HTTP. It mounts ten tools, and each one checks the credential’s scope before it runs — a credential without the scope gets a typed scope_denied answer rather than a failed call.
| Tool | Scope |
|---|---|
| list_domains | addresses:read |
| create_address | addresses:write |
| list_events | events:read |
| wait_for_email | waits:write |
| send_email | messages:send |
The full table of ten tools and their scopes is on the MCP server page.
The boundary
What the agent does, and what you do
What Codex does
- List the domains your account owns and the addresses on one of them.
- Create one new address on a domain you already have.
- Read the inbound event log, open a durable wait, poll it, and fetch the body of a message it points at.
- Send from the domain your credential is bound to, and read the delivery status afterwards.
What you do, once
- Create the account and connect your Cloudflare account.
- Add and verify a domain — the DNS records are yours.
- Deploy the per-account receive worker.
- Mint the key, then narrow it: a scoped credential names exactly the tools the agent may call.
Those four steps happen in the dashboard, once. After them, Codex can read the mailbox and send from the bound domain on its own initiative — there is no approval step in between — and you revoke the credential from the dashboard when you want it to stop.
FAQ
Common questions about Codex and Flowmails
Other coding agents