MCP

nanocode can connect to Model Context Protocol servers and call their tools through its MCP tool. Servers can be remote (HTTP) or local (stdio), and nothing about a server reaches the model until you connect it.

Configuring servers

Each server is an [mcp.<name>] block.

Remote (HTTP)

[mcp.example]
url = "https://example.com/mcp"
bearer_token_env_var = "EXAMPLE_MCP_TOKEN"  # optional: send a bearer token from this env var
# auth = "oauth"                            # optional: use interactive OAuth instead
# auto_connect = true                       # optional: connect at startup (default false)

Local (stdio)

[mcp.filesystem]
command = "npx"
args = ["-y", "@modelcontextprotocol/server-filesystem", "/tmp"]
# env = { FOO = "bar" }   # optional extra environment variables
# auto_connect = true

Options

Key	Applies to	Meaning
url	remote	Server endpoint (mutually exclusive with command)
command, args	local	Program and arguments to launch
env	local	Extra environment variables for the subprocess
auth = "oauth"	remote	Authenticate via interactive OAuth
bearer_token_env_var	remote	Send Authorization: Bearer <env var>
env_http_headers	remote	Map of HTTP header → env var holding its value
auto_connect	both	Connect at startup instead of on demand (default false)

Connecting

Servers are manual by default — they stay inactive, and cost nothing, until you connect them. Set auto_connect = true for servers you always want. Ways to connect:

• /mcp — open the interactive manager and toggle a server on or off.

The /mcp interactive server manager.

• @server in a message — connect on demand. The connection remains active until you disconnect it.

Connecting a server on demand with an @-mention.

• /mcp connect <server> [server ...] / /mcp disconnect <server> — terminal fallbacks.

• /mcp tools [server] — list the tools of connected servers.

Connecting several servers in one command runs them concurrently; interactive OAuth browser flows are serialized so they do not interfere with each other.

Once a server is connected, nanocode can use its tools like any other. Tools the server marks read-only run without a prompt; anything that may change state asks for confirmation first.

Authentication

• Bearer token — set bearer_token_env_var (or a custom header via env_http_headers).

• OAuth — set auth = "oauth". Connecting runs the authorization flow; disconnecting clears the saved login.

Trust

Local (stdio) servers run programs on your machine, and remote servers receive whatever the agent sends them. Only connect servers you trust.