Bru

An MCP (Model Context Protocol) server that exposes the Bruno CLI (bru) as tools for AI agents. It allows agents like Claude, GitHub Copilot, and others to discover, inspect, and execute Bruno API collections directly through the MCP protocol.

Requirements

• Node.js 18 or later
• Bruno CLI installed and available on your PATH

Install the Bruno CLI globally if you haven't already:

npm install -g @usebruno/cli

Installation

Option A — Clone and build

git clone https://github.com/h-mergel/bru-mcp.git
cd bru-mcp
npm install
npm run build

Option B — Install globally from the cloned repo

After cloning and building, install the bru-mcp binary globally so it is available on your PATH:

npm install -g .

This makes bru-mcp available as a standalone command, which simplifies the MCP configuration (see below).

MCP Configuration

Add bru-mcp as an MCP server in your client's configuration. The server communicates over stdio.

Via npx — no local clone needed (recommended)

Since the compiled output is included in the repository, you can run bru-mcp directly from GitHub without cloning or building manually:

{
  "mcpServers": {
    "bru-mcp": {
      "command": "npx",
      "args": ["github:h-mergel/bru-mcp"]
    }
  }
}

Via global install

If you installed with npm install -g .:

{
  "mcpServers": {
    "bru-mcp": {
      "command": "bru-mcp"
    }
  }
}

Via local path

If you cloned the repository and prefer a direct path:

{
  "mcpServers": {
    "bru-mcp": {
      "command": "node",
      "args": ["/absolute/path/to/bru-mcp/dist/src/index.js"]
    }
  }
}

Claude Desktop

The configuration file is located at:

• macOS: ~/Library/Application Support/Claude/claude_desktop_config.json
• Windows: %APPDATA%\Claude\claude_desktop_config.json
• Linux: ~/.config/Claude/claude_desktop_config.json

OpenCode

Add the server to your OpenCode MCP configuration (.opencode/config.json or the global config). Any of the three snippets above works.

Tools

The server exposes four tools. For single-collection setups, auto-detection runs automatically — just call bru_list_requests, bru_run, or bru_run_collection directly and the collection is resolved from the current working directory. Use bru_find_collections only when multiple collections are present or auto-detection fails.

bru_find_collections

Recursively scans a directory for Bruno collections (identified by bruno.json files). Use this only when working with multiple collections or when auto-detection fails.

Parameter	Type	Required	Description
startPath	string	No	Directory to search from. Defaults to the current working directory.

Returns: A list of collection paths, their available environments, and the number of requests in each.

---

bru_list_requests

Lists all .bru request files in a collection, grouped by folder. Also shows available environments. The collection is auto-detected if collectionPath is omitted.

Parameter	Type	Required	Description
collectionPath	string	No	Path to the Bruno collection directory (the folder containing bruno.json). Reuse from a previous response to skip auto-detection. Takes precedence over startPath.
startPath	string	No	Directory to search for a Bruno collection. Checks well-known subdirectories (bruno, .bruno, api-tests, api, tests) first, then falls back to a recursive search. Defaults to the current working directory.

Returns: A grouped list of requests and available environments, plus a structured JSON representation.

---

bru_run

Runs a specific request file or folder within a collection using the bru CLI. The collection is auto-detected if collectionPath is omitted.

Parameter	Type	Required	Description
collectionPath	string	No	Path to the Bruno collection directory. Reuse from a previous response to skip auto-detection. Takes precedence over startPath.
startPath	string	No	Directory to search for a Bruno collection. Defaults to the current working directory.
target	string	Yes	Relative path to a .bru file or subfolder (e.g. cards/find-cards.bru or cards).
env	string	No	Environment name to use (e.g. dev, prod). Must exist in environments/.
envVars	object	No	Key-value pairs to override environment variables (e.g. {"baseUrl": "http://localhost:3000"}).
recursive	boolean	No	Run requests in subfolders recursively. Default: false.
insecure	boolean	No	Allow insecure (self-signed) TLS connections. Default: false.
testsOnly	boolean	No	Only run requests that have tests or assertions. Default: false.
bail	boolean	No	Stop after the first failing request. Default: false.
tags	string[]	No	Only run requests with these tags.
excludeTags	string[]	No	Exclude requests with these tags.
verbose	boolean	No	Enable verbose output. Default: false.

Returns: The full CLI output, the constructed command, and parsed JSON results if available.

---

bru_run_collection

Runs all requests in a collection recursively. Supports tag filtering and all the same options as bru_run (except target and recursive, which are implicit). The collection is auto-detected if collectionPath is omitted.

Parameter	Type	Required	Description
collectionPath	string	No	Path to the Bruno collection directory. Reuse from a previous response to skip auto-detection. Takes precedence over startPath.
startPath	string	No	Directory to search for a Bruno collection. Defaults to the current working directory.
env	string	No	Environment name to use.
envVars	object	No	Key-value pairs to override environment variables.
tags	string[]	No	Only run requests with these tags.
excludeTags	string[]	No	Exclude requests with these tags.
insecure	boolean	No	Allow insecure TLS connections. Default: false.
testsOnly	boolean	No	Only run requests that have tests. Default: false.
bail	boolean	No	Stop after first failure. Default: false.
verbose	boolean	No	Enable verbose output. Default: false.

Returns: A summary with total/passed/failed/skipped counts, the full CLI output, and parsed JSON results.

Development

# Compile TypeScript to dist/
npm run build

# Watch mode (recompiles on changes)
npm run dev

# Run tests (builds first)
npm test

Project structure

bru-mcp/
├── src/
│   ├── helpers.ts       # Pure helper functions (collection discovery, arg building, JSON extraction)
│   └── index.ts         # MCP server setup and tool definitions
├── test/
│   ├── helpers.test.ts  # Unit tests for all helper functions
│   └── fixtures/        # Static Bruno collections used by tests
├── dist/src/            # Compiled output (committed to repo for npx usage)
├── package.json
├── tsconfig.json
├── AGENTS.md
├── LICENSE
└── README.md

Running tests

Tests use the built-in node:test runner and run against the compiled output in dist/. No additional test framework is needed.

npm test

Contributing

After making changes to the source code:

# 1. Run tests — must all pass before committing
npm test

# 2. Stage the updated compiled output along with the source changes
git add src/ dist/src/

# 3. Commit and push
git commit -m "..."
git push

The compiled dist/src/ is committed to the repository so that users can run the server via npx github:h-mergel/bru-mcp without a local build step.

Security notes

• Path traversal: The target parameter in bru_run is validated to ensure it cannot escape the collection directory (e.g. ../../etc/passwd is rejected).
• Shell injection: The bru process is spawned without a shell on Linux/macOS (shell: true is only enabled on Windows where .cmd wrappers require it), so shell metacharacters in arguments are not interpreted.

License

MIT