Use Sumbloom MCP with OpenAI Codex CLI

Number puzzle API + MCP: solver-checked puzzles as JSON/SVG, daily puzzle. $5/mo; 50 free/day.

Remote MCP server (Streamable HTTP), nothing to install. Free: 50 free/day · Paid: $5/mo

Set it up

1. Open ~/.codex/config.toml (create it if needed).
2. Add the [mcp_servers] table shown and save.
3. Start Codex; the server's tools are available to the agent.
4. Ask a question the tools can answer.

Add to ~/.codex/config.toml:

[mcp_servers.sumbloom]
url = "https://sumbloom.cybermaxtools.com/mcp?via=use-with-codex"

With a paid key:

[mcp_servers.sumbloom]
url = "https://sumbloom.cybermaxtools.com/mcp?via=use-with-codex"
env_http_headers = { "x-api-key" = "CYBERMAX_API_KEY" }

env_http_headers maps the header to an environment variable name, so the key stays in your environment.

Where it goes:

• ~/.codex/config.toml (or .codex/config.toml in a trusted project)

Config format checked 2026-10-09 against OpenAI Codex CLI's MCP documentation.

Tools you get

Endpoint checked 2026-10-09: https://sumbloom.cybermaxtools.com/mcp answered an MCP initialize (protocol 2025-06-18) and tools/list with 1 tool, all marked read-only. No key was used and no tool was called.

Test the endpoint from a terminal

This lists the tools without a key and without calling any of them:

curl -s https://sumbloom.cybermaxtools.com/mcp \
  -H 'content-type: application/json' \
  -H 'accept: application/json, text/event-stream' \
  -d '{"jsonrpc":"2.0","id":1,"method":"tools/list"}'

If it does not work

• Each server is its own [mcp_servers.<name>] table; keep the name to letters, digits, dashes and underscores.
• For a fixed header value instead of an environment variable, Codex also documents http_headers.
• The free tier has a daily limit (see the pricing line above); a paid key raises it.

Sumbloom in other clients

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