MCP server

Claude Code

1. Put the key in your shell as CROSSFEED_API_KEY: in bash or zsh, run this, paste the key, and press Return. Nothing shows as you paste, and the key stays out of your shell’s history. On Windows, run these steps in WSL or Git Bash: in PowerShell, $CROSSFEED_API_KEY is empty, and claude mcp add would save the header without the key.

   read -rs CROSSFEED_API_KEY && export CROSSFEED_API_KEY

2. Add Crossfeed’s MCP server to Claude Code, in the folder you’ll use it from. Claude Code keeps the key from then on, in plain text in its own config file, ~/.claude.json.

   claude mcp add --transport http crossfeed \
     https://crossfeed.m1kuorg.workers.dev/mcp \
     --header "Authorization: Bearer $CROSSFEED_API_KEY"

3. Check it: claude mcp list should show it connected.

   claude mcp list

   crossfeed: https://crossfeed.m1kuorg.workers.dev/mcp (HTTP) - ✔ Connected

The Crossfeed plugin installs two skills that teach Claude Code to plan launch promos and triage guest pitches, with the MCP server: see Skills and plugin.

Claude

1. Add Crossfeed as a custom connector, which Claude Desktop gets too: each link opens Claude’s Add custom connector dialog with Crossfeed’s name and address filled in, for you to check.

   Add to Claude

   Opens claude.ai in a new tab, asking you to sign in first if you haven’t. On a Team or Enterprise plan, only an Owner, or a custom role allowed to, adds a connector, so ask an Owner.

   Add for your organization

   Opens your organization’s connectors in a new tab, for a Team or Enterprise Owner, who adds Crossfeed for everyone in the organization, who then share its key.

2. For Authentication, choose No sign-in. Then under Request headers, choose authorization, enter Bearer, a space and your key, mark it Required, and choose Add. Claude keeps the key and doesn’t show it again, and can’t change these settings later: for a mistyped key, remove the connector and add it again. Request headers are a beta that only some organizations have: if the dialog has none, connect Claude Desktop as below, or use Claude Code.

3. In a chat, turn Crossfeed on under the + button’s Connectors.

{
  "mcpServers": {
    "crossfeed": {
      "command": "npx",
      "args": [
        "-y",
        "mcp-remote",
        "https://crossfeed.m1kuorg.workers.dev/mcp",
        "--header",
        "Authorization:${AUTH_HEADER}"
      ],
      "env": {
        "AUTH_HEADER": "Bearer cf_live_…"
      }
    }
  }
}

Cursor

1. Put the key in your shell as CROSSFEED_API_KEY: in bash or zsh, run this, paste the key, and press Return. Nothing shows as you paste, and the key stays out of your shell’s history. On Windows, in PowerShell, the first two lines ask for the key without showing it and set it for that window, and the third keeps it for apps you start afterwards, in plain text in your user environment.

   read -rs CROSSFEED_API_KEY && export CROSSFEED_API_KEY

   $k = Read-Host 'Crossfeed API key' -AsSecureString
   $env:CROSSFEED_API_KEY =
     [System.Net.NetworkCredential]::new('', $k).Password
   [Environment]::SetEnvironmentVariable(
     'CROSSFEED_API_KEY', $env:CROSSFEED_API_KEY, 'User')

2. Quit Cursor, then start it again from that terminal with cursor: Cursor reads the variable as it starts, and started from the Dock, it doesn’t see one set in a terminal. On a Mac, run Shell Command: Install ‘cursor’ command in PATH from Cursor’s Command Palette once first, so the terminal has cursor.

3. Add Crossfeed’s MCP server: follow the link, and Cursor asks before it adds it, or paste this into ~/.cursor/mcp.json, for every project. Either way, Cursor sends the key from the variable.

   Add to Cursor

   Opens Cursor if it’s installed. Start Cursor from the terminal where you set the variable first, or it has no key to send.

   {
     "mcpServers": {
       "crossfeed": {
         "url": "https://crossfeed.m1kuorg.workers.dev/mcp",
         "headers": {
           "Authorization": "Bearer ${env:CROSSFEED_API_KEY}"
         }
       }
     }
   }

VS Code

1. Put the key in your shell as CROSSFEED_API_KEY: in bash or zsh, run this, paste the key, and press Return. Nothing shows as you paste, and the key stays out of your shell’s history. On Windows, in PowerShell, the first two lines ask for the key without showing it and set it for that window, and the third keeps it for apps you start afterwards, in plain text in your user environment.

   read -rs CROSSFEED_API_KEY && export CROSSFEED_API_KEY

   $k = Read-Host 'Crossfeed API key' -AsSecureString
   $env:CROSSFEED_API_KEY =
     [System.Net.NetworkCredential]::new('', $k).Password
   [Environment]::SetEnvironmentVariable(
     'CROSSFEED_API_KEY', $env:CROSSFEED_API_KEY, 'User')

2. Quit VS Code, then start it again from that terminal with code: VS Code reads the variable as it starts, and started from the Dock, it doesn’t see one set in a terminal. On a Mac, run Shell Command: Install ‘code’ command in PATH from VS Code’s Command Palette once first, so the terminal has code.

3. Add Crossfeed’s MCP server: follow the link, and VS Code asks before it adds it, or run MCP: Open User Configuration from the Command Palette and paste this in. Either way, VS Code sends the key from the variable.

   Add to VS Code

   Opens VS Code if it’s installed. Start VS Code from the terminal where you set the variable first, or it has no key to send.

   {
     "servers": {
       "crossfeed": {
         "type": "http",
         "url": "https://crossfeed.m1kuorg.workers.dev/mcp",
         "headers": {
           "Authorization": "Bearer ${env:CROSSFEED_API_KEY}"
         }
       }
     }
   }

{
  "inputs": [
    {
      "type": "promptString",
      "id": "crossfeed-api-key",
      "description": "Crossfeed API key",
      "password": true
    }
  ],
  "servers": {
    "crossfeed": {
      "type": "http",
      "url": "https://crossfeed.m1kuorg.workers.dev/mcp",
      "headers": {
        "Authorization": "Bearer ${input:crossfeed-api-key}"
      }
    }
  }
}

Codex

1. Put the key in your shell as CROSSFEED_API_KEY: in bash or zsh, run this, paste the key, and press Return. Nothing shows as you paste, and the key stays out of your shell’s history. On Windows, run these steps, and codex, in WSL or Git Bash.

   read -rs CROSSFEED_API_KEY && export CROSSFEED_API_KEY

2. Add Crossfeed’s MCP server to Codex. Codex reads the key from the variable each time it starts, so it never writes the key down.

   codex mcp add crossfeed \
     --url https://crossfeed.m1kuorg.workers.dev/mcp \
     --bearer-token-env-var CROSSFEED_API_KEY

3. Start codex from a shell where the variable is set: its /mcp command lists Crossfeed among its servers.

Another MCP client

1. Give it the MCP server’s address, which serves Streamable HTTP.

   https://crossfeed.m1kuorg.workers.dev/mcp

2. Have it send the key in the Authorization header, as Bearer, a space and the key, with every request.

   Authorization: Bearer cf_live_…