Connect your agent

The Sidecars MCP server is a remote, streamable-HTTP MCP server. There is one URL, no API key, and no secret to paste into a config file. Sign-in happens through the standard MCP OAuth flow in your browser. The fastest way in is to let the agent you already have do the setup. The prompt works in any agent that manages its own MCP configuration. An agent that cannot configure the connection itself will walk you through the settings below instead.

Manual setup

https://mcp.sidecars.ai/mcp

The Developers page inside the app (sidebar → Developers, or sidecars.ai/developers) shows the exact URL for your deployment. The commands below are the same ones that page generates, with the production URL filled in. The URL is for MCP clients; opening it in a browser shows an error.

Per-host setup

claude mcp add --transport http sidecars https://mcp.sidecars.ai/mcp

Then run /mcp inside Claude Code, choose sidecars and pick Login.Or add it by hand to .mcp.json in your project (or ~/.claude.json):

{
  "mcpServers": {
    "sidecars": { "type": "http", "url": "https://mcp.sidecars.ai/mcp" }
  }
}

Use the Install in Cursor button on the Developers page, or add to ~/.cursor/mcp.json:

{
  "mcpServers": {
    "sidecars": { "url": "https://mcp.sidecars.ai/mcp" }
  }
}

code --add-mcp '{"name":"sidecars","type":"http","url":"https://mcp.sidecars.ai/mcp"}'

Or in .vscode/mcp.json:

{
  "servers": {
    "sidecars": { "type": "http", "url": "https://mcp.sidecars.ai/mcp" }
  }
}

codex mcp add sidecars --url https://mcp.sidecars.ai/mcp
codex mcp login sidecars

In ~/.codeium/windsurf/mcp_config.json:

{
  "mcpServers": {
    "sidecars": { "serverUrl": "https://mcp.sidecars.ai/mcp" }
  }
}

Zed connects through mcp-remote. In Zed’s settings.json:

{
  "context_servers": {
    "sidecars": {
      "source": "custom",
      "command": "npx",
      "args": ["-y", "mcp-remote", "https://mcp.sidecars.ai/mcp"]
    }
  }
}

Any other host

Cross-agent installer: npx add-mcp https://mcp.sidecars.ai/mcp
Hosts that cannot speak streamable HTTP: npx -y mcp-remote https://mcp.sidecars.ai/mcp

What happens on first use

Discovery is public

initialize, ping, tools/list and resources/list answer without a token, so a host can show the tool catalogue before you sign in.

The first tool call is challenged

The first tools/call returns 401 with a WWW-Authenticate challenge. The host reads the server’s protected-resource metadata, discovers the authorization server, and opens a browser tab.

You sign in (or sign up) and land on the consent screen, where you choose the workspace this connection acts in. A brand-new account can create its workspace right there.

The call is retried with a token

The host stores the access token and retries. Tokens expire after 24 hours; the host refreshes or re-prompts as needed.

Scopes are granted incrementally. A first connect asks only for identity and knowledge:read. The first time an agent calls a document, page, comment or export tool, the server answers 403 insufficient_scope naming the missing scope and the host re-runs consent for it. See Authentication and access.

Advanced setup

Transport details

Property	Value
Transport	Streamable HTTP, no sessions. Clients on the current protocol get `application/json` responses. Clients on the 2025-era shim get one SSE-framed event (`Content-Type: text/event-stream`) carrying the JSON-RPC message, with no stream kept open
`Accept` header	Send `application/json, text/event-stream`. The legacy shim answers `406` to anything less; the current protocol accepts either
Methods	`POST` for JSON-RPC; `OPTIONS` for CORS preflight
Protocol versions	Current spec plus the 2025-03-26 and 2025-06-18 era shim, so older clients are served
Batching	Not supported (removed from the protocol in 2025-06-18)
Discovery	`/.well-known/oauth-protected-resource/mcp` (RFC 9728) and `/.well-known/oauth-authorization-server` (RFC 8414, proxied for legacy clients)
Server name	`sidecars`

Get started

Use it

Reference

Connect your agent

Manual setup

Per-host setup

Any other host

What happens on first use

Advanced setup

​Manual setup

​Per-host setup

​Any other host

​What happens on first use

​Advanced setup

Manual setup

Per-host setup

Any other host

What happens on first use

Advanced setup