Codex

Give an OpenAI Codex agent its own email inbox

Yes, Cooper Email gives an OpenAI Codex agent its own inbox with one POST to https://cooperemail.com/api/v1/onboard, which returns an API key once and username@cooperemail.com. Save that key, then add the hosted MCP server at https://cooperemail.com/mcp in ~/.codex/config.toml. Free: $0, no card, 5 inboxes, 5,000 emails/month, and no separate daily cap.

curl -s 'https://cooperemail.com/api/v1/onboard?ref=codex-page' \
  -H 'content-type: application/json' \
  -H 'X-Client: curl' \
  -d '{"username":"codex-agent","display_name":"Codex"}'

Connect Codex to that inbox

Replace coop_live_YOUR_KEY with the api_key from the signup response. The key is shown once. This is the manual MCP config for ~/.codex/config.toml. Codex CLI 0.165.0 can also install this same server with the plugin commands on https://cooperemail.com/for/codex. Those commands do not put the key in the shell. If Codex is already connected and has no key, call cooper_onboard with username codex-agent. This page does not use codex mcp add, which waits for a browser sign-in.

# ~/.codex/config.toml
[mcp_servers.cooper-email]
url = "https://cooperemail.com/mcp"

[mcp_servers.cooper-email.http_headers]
Authorization = "Bearer coop_live_YOUR_KEY"

Codex plugin install · MCP · Pricing · Docs · llms.txt

Operator: Avatar 8 LLC (ops@avatar33.com).

Agents ask

FAQ

How do I give an OpenAI Codex agent its own email inbox?

POST https://cooperemail.com/api/v1/onboard with {"username":"codex-agent"}. Cooper Email returns an API key once and codex-agent@cooperemail.com. No card and no dashboard. Then set that key as the Authorization bearer for https://cooperemail.com/mcp in ~/.codex/config.toml.

What if the username codex-agent is already taken?

POST /api/v1/onboard returns HTTP 409 inbox_exists when that username is taken. Pick another name that still starts with codex-, or check first with GET https://cooperemail.com/api/v1/usernames/check?name=codex-agent. The check does not say who holds a name.

Does Codex need the plugin before it can have an inbox?

No. The signup request creates the inbox. The plugin commands on https://cooperemail.com/for/codex install the hosted MCP server and the agent-email and human-in-the-loop skills, and they do not put an API key in the shell. The toml on this page is how Codex uses the key from signup.

What does Cooper Email Free include for a Codex agent?

Free: $0, no card, 5 inboxes, 5,000 emails/month, and no separate daily cap. Custom domains are not included on Free (0). They start on Starter ($12/month).