About Harbor
Harbor is a native macOS app for organizing and managing local development servers. Developers can launch projects, inspect listeners, logs, and resource use, while coding agents can access approved project operations through its local MCP server.
Key features
- 01Detect project services and configurations
- 02Launch, stop, and restart projects
- 03Allocate and resolve service ports
- 04Monitor logs, health, CPU, and memory
- 05Inventory local TCP listeners
- 06Restart crashed services optionally
Use cases
- 01Starting a project and its dependencies together
- 02Checking local ports and possible duplicate servers
- 03Reviewing service logs and resource use
- 04Letting Claude or Codex operate approved projects
MCP support
Harbor runs a loopback-only MCP server that exposes project and server state, logs, and operations for registered projects. Agent-created configurations require local approval before use.
Configuration
Remote servers need no local install. Pick your client, then copy the config or install in one click.
http://127.0.0.1:7777/mcpclaude mcp add --transport http harbor http://127.0.0.1:7777/mcp{"mcpServers":{"harbor":{"type":"http","url":"http://127.0.0.1:7777/mcp"}}}Open in Cursor{"servers":{"harbor":{"type":"http","url":"http://127.0.0.1:7777/mcp"}}}Open in VS Code{"mcpServers":{"harbor":{"type":"http","url":"http://127.0.0.1:7777/mcp"}}}{"mcpServers":{"harbor":{"serverUrl":"http://127.0.0.1:7777/mcp"}}}Run commands in a terminal; paste JSON into the client’s MCP config and restart. Servers that need sign-in will prompt on first connect.
http://127.0.0.1:7777/mcpAuth requiredTools
Details
From the project READMEHarbor
Know what’s running. Stop the port chaos.
Harbor makes local servers on your Mac understandable—what is running, where it came from, and which copies look duplicated. Start a whole project in one click, or let Claude or Codex inspect and operate projects you have approved.
Website · Download Harbor · Quick start · Connect an AI agent
macOS 11+ · Apple Silicon + Intel · Signed and notarized · No account · MIT
Note: Harbor is unrelated to the CNCF Harbor container registry.
Why Harbor
See the servers already running on your Mac
Harbor inventories current-user TCP listeners and shows their port, process, command, working folder, HTTP response, and likely framework. Strong evidence maps servers to registered projects; probable duplicate project runs and network-visible binds are flagged while unknown listeners remain visible.
Start a project, not a pile of terminals
Add a folder and review the services Harbor detects. It starts dependencies in order, streams logs, monitors health and resources, and resolves project ports. Before starting another copy, Harbor checks whether the project already has a matching server it can safely reuse.
Give coding agents the same source of truth
Harbor exposes its live project and server state through a loopback-only MCP server. Claude and Codex can inspect local listeners, detect a project, read logs, and operate registered projects. A config created by an agent stays paused until you approve that exact config in Harbor.
Install
Download the app
Download the .dmg from the
latest release,
open it, and drag Harbor to Applications.
Install with Homebrew
brew install --cask luke-fairbanks/tap/harbor
Production releases are signed by Faba Development and notarized by Apple. Harbor supports macOS 11 Big Sur or later on Apple Silicon and Intel Macs.
Starting with v0.4.0, Harbor checks for signed updates shortly after launch and every six hours. It always asks before installing. You can also check manually from project settings → Harbor updates. Managed project processes remain online while Harbor updates and relaunches.
Quick start
- Open Harbor and choose Add project, or drag a project folder onto the window.
- Review the detected services and commands, then choose Add to Harbor.
- Open the project and choose Start project.
- Open Local servers to see its ports alongside other listeners already running under your macOS user.
Harbor recognizes common JavaScript frameworks and package managers, Django,
FastAPI, Flask, Go, Rails, and static sites. If detection misses, you can import
or edit a harbor.json configuration instead.
Conservative by design
- Observation is not ownership. Matching a server to a project does not give Harbor permission to stop it.
- Duplicate prevention favors certainty. Harbor reuses a strongly matched server; ambiguous matches block launch and ask you to inspect them.
- Cleanup is identity-protected. Stop is offered only for isolated, untracked servers. Harbor rechecks PID, process start time, and port before it signals the process, and refuses terminals, IDEs, coding agents, and Harbor itself. “Safe to stop” describes process isolation—not whether the process has unsaved work.
- Agent-written commands require local approval. Approval applies to the exact registered config. Changing it through MCP requires a new approval.
- MCP stays local. The server binds to
127.0.0.1and uses a new bearer token on every Harbor launch. Its descriptor and Harbor’s app-data directory are owner-only on macOS, and the native bridge verifies listener ownership before forwarding credentials. - Fix with AI is explicit. When you invoke it, Harbor passes the service command, working path, exit state, and recent logs to your installed Codex or Claude CLI. That data is then handled under the privacy terms of whichever provider Harbor invokes.
What Harbor manages
- Dependency-aware start, stop, restart, and one-click project launch
- Preferred-to-next-free port allocation on IPv4 and IPv6
${PORT}and${services.<name>.port}rewiring between services- Recognition of commands that pin their own port
- HTTP, TCP, log-pattern, and process-alive readiness checks
- Live logs, CPU, and memory for each managed process group
- Opt-in crash restart with bounded backoff
- Re-adoption of verified Harbor processes that survive an app restart
- A menu-bar popover for common project actions
- Framework-aware project detection and editable
harbor.jsonconfigs
Local server inventory
The Local servers view scans TCP listeners owned by your current macOS user. It combines process, working-directory, command, port, and bounded HTTP evidence to classify each listener as unknown, matched, Harbor-managed, or eligible for identity-safe cleanup.
Harbor can recognize a strongly matching server on a service’s preferred port before allocating another one. If that process shares a group with a terminal, IDE, Claude, or Codex, Harbor leaves it monitor-only and will not take down the host process.
Connect Claude or Codex
Open AI connections and choose Connect Claude Code, Connect Desktop, or Connect Codex. The guided setup installs Harbor's signed, owner-only native bridge. New client configurations contain only its stable command path: no bearer token, environment variables, Node.js installation, or first-run download is required. If Harbor is closed, the bridge opens it quietly in the background. After connecting for the first time, start a new client session (or fully quit and reopen an already-running client) so it loads the new entry.
The client-owned stdio process stays connected while Harbor quits and reopens. It re-reads Harbor's protected endpoint descriptor, follows token and port rotations, and replays the MCP backend lifecycle before forwarding the next request. Upgrading from Harbor v0.4.2's legacy launcher requires one final client restart; normal Harbor restarts after that do not. A later Harbor update that replaces the bridge binary itself also requires a client restart before the running client can use the new bridge code.
Harbor distinguishes a saved configuration from an observed Bridge running process; the latter means the client launched the bridge, while the client's own MCP tool list is the final confirmation that it accepted the catalog.
Advanced users can connect directly over Streamable HTTP. Read the current port
and token from
~/Library/Application Support/com.harbor.desktop/mcp.json; the port can differ
from 7777 and the token changes after every Harbor restart.
SETTINGS="$HOME/Library/Application Support/com.harbor.desktop/mcp.json"
PORT="$(plutil -extract port raw -o - "$SETTINGS")"
TOKEN="$(plutil -extract token raw -o - "$SETTINGS")"
claude mcp add harbor --scope user --transport http "http://127.0.0.1:${PORT}/mcp" \
--header "Authorization: Bearer ${TOKEN}"
Then try:
What local servers are running, and do any look duplicated?
MCP tools
| Tool | Purpose |
|---|---|
list_apps | List registered projects and their current run status |
app_status(app) | Inspect services, resolved ports, and the port plan |
detect_app(path) | Scan a folder and propose a config without saving it |
register_app(config) | Add or replace a config as approval required |
start_app(app, profile?) | Start an approved project or profile |
stop_app(app) | Stop Harbor-managed services for a project |
restart_app(app, profile?) | Restart an approved project or profile |
get_logs(app, service, lines?) | Read recent captured logs |
list_local_servers | Inventory listeners, matches, and probable duplicates |
stop_local_server(pid, port, startedAt) | Request identity-safe cleanup of an isolated server |
open_app(app) | Open a running project’s primary URL |
Build from source
Harbor uses Tauri 2 with a Rust core and a React 19 / Radix Themes interface.
npm install
npm run prepare:bridge
npm run tauri dev
Run the local production build without updater artifacts:
npm run tauri:build:local
Verify changes
npm run prepare:bridge
npm test
npm run build
npm run test:rust
cargo fmt --manifest-path src-tauri/Cargo.toml --all -- --check
cargo fmt --manifest-path src-tauri/mcp-bridge/Cargo.toml --all -- --check
cargo clippy --manifest-path src-tauri/Cargo.toml --locked --all-targets -- -D warnings
cargo clippy --manifest-path src-tauri/mcp-bridge/Cargo.toml --locked --all-targets -- -D warnings
cargo test --manifest-path src-tauri/mcp-bridge/Cargo.toml --locked
When changing MCP schemas, transport, authentication, or the native bridge, start the patched Harbor build after using one-click setup at least once, then exercise the exact installed Claude/Codex bridge for 90 seconds:
node scripts/mcp-bridge-soak.mjs --restart-harbor --duration-ms 90000 --interval-ms 30000
The harness performs Claude-compatible initialization, validates all advertised
tool schemas, and repeatedly calls the read-only list_apps tool. It must end
with PASS and no schema, authentication, transport, or reconnect errors.
See DESIGN.md for the shipped architecture, ROADMAP.md for planned work, and DISTRIBUTING.md for the signed release process.
Feedback and contributing
Found a listener Harbor misidentified, a project it could not detect, or an MCP
client that would not connect? Open a guided issue.
Please remove tokens, credentials, .env contents, and private paths before
posting logs or commands.
Issues and pull requests are welcome. Security vulnerabilities should be reported privately through GitHub’s security advisory form.
License
MIT © Luke Fairbanks
Comments
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