DeFi MCP

Claude Code

Prerequisites

• Claude Code installed and signed in.

Add via CLI (recommended)

Choose a scope explicitly. Without --scope, the server is added at user scope, which is easy to forget later.

# Project scope — writes .mcp.json in the repo root, shared with your team
claude mcp add --scope project --transport http blockdaemon-defi \
  https://svc.blockdaemon.com/defi/v1/mcp/http \
  --header "X-Api-Key: ${BLOCKDAEMON_API_KEY}"

# User scope — writes ~/.claude.json, available in all your projects
claude mcp add --scope user --transport http blockdaemon-defi \
  https://svc.blockdaemon.com/defi/v1/mcp/http \
  --header "X-Api-Key: ${BLOCKDAEMON_API_KEY}"

Or configure by hand

.mcp.json in the project root:

{
  "mcpServers": {
    "blockdaemon-defi": {
      "type": "http",
      "url": "https://svc.blockdaemon.com/defi/v1/mcp/http",
      "headers": {
        "X-Api-Key": "${BLOCKDAEMON_API_KEY}"
      }
    }
  }
}

Authentication

Export the key before launching Claude Code, and reference it as ${BLOCKDAEMON_API_KEY} so the raw value never enters a committed file:

export BLOCKDAEMON_API_KEY="your-api-key"

Verify

claude mcp list

Confirm blockdaemon-defi reports as connected, then ask Claude to list the tools for that server.

Troubleshooting

Visual Studio Code

Prerequisites

• A recent VS Code build with MCP support. Confirm by checking that the Command Palette offers MCP: List Servers.

Configuration

• Workspace (committable): .vscode/mcp.json
• User level: Command Palette → MCP: Open User Configuration

{
  "inputs": [
    {
      "type": "promptString",
      "id": "blockdaemon-api-key",
      "description": "Blockdaemon API Key",
      "password": true
    }
  ],
  "servers": {
    "blockdaemon-defi": {
      "type": "http",
      "url": "https://svc.blockdaemon.com/defi/v1/mcp/http",
      "headers": {
        "X-Api-Key": "${input:blockdaemon-api-key}"
      }
    }
  }
}

Authentication

${input:...} prompts for the key once and caches it securely, so the raw key never lands in a committed mcp.json. To use an already-exported variable instead, replace the value with ${env:BLOCKDAEMON_API_KEY}.

Verify

Command Palette → MCP: List Servers → select blockdaemon-defi and confirm it's running. Tools also appear under Configure Tools in the Chat view.

Troubleshooting

OpenAI Codex CLI

Prerequisites

• Codex CLI installed (npm install -g @openai/codex or equivalent) and signed in.

Configuration

• Global: ~/.codex/config.toml
• Project scoped: .codex/config.toml in the project directory

Add the server, then add the header by editing config.toml — codex mcp add does not currently accept a custom-header flag.

codex mcp add blockdaemon-defi \
  --url https://svc.blockdaemon.com/defi/v1/mcp/http

[mcp_servers.blockdaemon-defi]
url = "https://svc.blockdaemon.com/defi/v1/mcp/http"

# IMPORTANT: the value below is the NAME of an environment variable,
# not the API key itself. Do not paste your key here.
env_http_headers = { "X-Api-Key" = "BLOCKDAEMON_API_KEY" }

startup_timeout_sec = 20.0
tool_timeout_sec = 60.0

Authentication

env_http_headers maps a header name to the name of an environment variable that holds the value. Export the variable in the shell Codex is launched from:

export BLOCKDAEMON_API_KEY="your-api-key"

📘

Note

Codex CLI's custom-header field name has changed across releases. If the header isn't picked up, run codex mcp add --help and check codex --version against the Codex CLI docs, then adjust the field name.

Verify

codex mcp list
codex mcp get blockdaemon-defi

Troubleshooting

Cursor

Prerequisites

• Cursor installed and signed in.

Configuration

• Project scope (committable): .cursor/mcp.json in the repo root
• User scope (all projects): ~/.cursor/mcp.json

{
  "mcpServers": {
    "blockdaemon-defi": {
      "url": "https://svc.blockdaemon.com/defi/v1/mcp/http",
      "headers": {
        "X-Api-Key": "YOUR_BLOCKDAEMON_API_KEY"
      }
    }
  }
}

Authentication

Replace YOUR_BLOCKDAEMON_API_KEY with your key. If using the project-scope file, keep it out of version control by adding .cursor/mcp.json to .gitignore, or use the user-scope file (~/.cursor/mcp.json) so the key never enters the repo.

Verify

Open Cursor, go to Settings → Tools & MCPs → Installed MCP Servers, and confirm blockdaemon-defi shows as connected.

Troubleshooting

Claude Desktop

Prerequisites

• Claude Desktop installed and signed in.
• Node.js, which provides npx for the proxy below.

Configuration

🚧

Custom headers need a proxy

Claude Desktop can't attach custom auth headers to a direct HTTP server entry. Bridge the connection through the mcp-remote proxy, which forwards a custom header to the remote HTTP endpoint over a local stdio connection.

Option A — key from an environment variable (recommended for shared or managed machines)

{
  "mcpServers": {
    "blockdaemon-defi": {
      "command": "npx",
      "args": [
        "mcp-remote",
        "https://svc.blockdaemon.com/defi/v1/mcp/http",
        "--header",
        "X-Api-Key:${BLOCKDAEMON_API_KEY}"
      ],
      "env": {
        "BLOCKDAEMON_API_KEY": "your-api-key"
      }
    }
  }
}

This keeps the key in a single named field rather than embedded in an argument string, which makes it easier to swap and rotate. To keep the key out of the file entirely, choose one of the following:

• Omit the env block. If BLOCKDAEMON_API_KEY is already set in the system environment Claude Desktop inherits, the substitution resolves without the block. This is the most secure option.
• Treat "your-api-key" as a placeholder. On managed machines, leave a placeholder value and have your MDM or configuration tooling overwrite it at provisioning time, so the real key never sits in a hand-edited file.

Storing a literal key in the env block is no more secure than Option B below — the advantage is only that the value is isolated and easy to replace.

❗️

Watch the spacing

When substituting a variable inside a --header argument, write X-Api-Key:${VAR} with no space after the colon. Arguments are split on whitespace, so a space breaks the substitution.

Option B — key inline (acceptable on a personal machine)

{
  "mcpServers": {
    "blockdaemon-defi": {
      "command": "npx",
      "args": [
        "mcp-remote",
        "https://svc.blockdaemon.com/defi/v1/mcp/http",
        "--header",
        "X-Api-Key: YOUR_BLOCKDAEMON_API_KEY"
      ]
    }
  }
}

claude_desktop_config.json is a local, per-user file that isn't committed, so an inline key is workable for a single-user machine. Restrict file permissions, and rotate the key if the machine is shared or lost.

Verify

Restart Claude Desktop fully, then open Settings → Connectors and confirm blockdaemon-defi shows as connected. A tools icon in the chat input is a second confirmation.

Troubleshooting