MODMUX

Model Routing Layer

One interface.
Every model.

Local gateway that routes requests between coding agents and GitHub Copilot. OpenAI-compatible endpoints, reversible configuration, zero external dependencies.

Install Modmux See the flow
  • Localhost only (127.0.0.1:11435)
  • Reversible agent configuration
  • Built-in status, health, and usage

$ modmux status

Service:  Not installed

State:    Running at http://localhost:11435

Agents:   claude-code, cline

Copilot:  Authenticated ✓

$ modmux configure claude-code

claude-code configured.

/v1/messages /v1/responses /v1/chat/completions /v1/usage /v1/models /health

Why Modmux

The model routing layer for coding agents.

Modmux normalizes differences between APIs so your agents can focus on logic—not plumbing. A stable, local gateway that keeps configuration reversible and visible.

One login, really

Authenticate once with GitHub Copilot. Supported agents reuse the same subscription path without extra API keys, provider sprawl, or a second bill.

Stays on your machine

Modmux stays on localhost. It acts as a local compatibility layer rather than a hosted relay, sync service, or remote control plane.

Easy to undo

Agent configuration is reversible by design. Run modmux unconfigure and restore supported agents to their previous state.

What It Does

Make the integration predictable so the tooling fades into the background.

One local API surface

Modmux exposes Anthropic-compatible and OpenAI-compatible local endpoints so supported tools can point at one place instead of drifting into one-off configuration branches.

Operational controls you can inspect

Start, stop, restart, inspect status, check health, and optionally install Modmux as an OS login service. The runtime stays visible instead of disappearing behind guesswork.

Predictable agent configuration

Configure and unconfigure supported agents from the CLI while keeping configuration state explicit, reversible, and easy to audit when something changes.

Supported agents today

  • Claude Code
  • Cline
  • Codex

Modmux is intentionally narrow: it stays focused on being a stable, reliable, predictable local gateway rather than becoming another chat client or an agent runtime of its own.

Install

Install it fast. Keep the setup explicit.

Most users should install from source. Direct binary downloads are available when you don't want to install Deno.

Recommended

From source

Clone and install with Deno. The most up-to-date installation method.

git clone https://github.com/modmux/modmux.git cd modmux deno task install
  1. Clone the repository and install globally.
  2. Run modmux start and complete GitHub authentication.
  3. Run modmux configure claude-code or configure another supported agent.

Direct binary

Download a platform build from GitHub Releases when you do not want a runtime dependency.

Open releases

How It Works

A narrow request path you can explain in one sentence.

Coding agent

Claude Code, Cline, or Codex sends a request to a local endpoint instead of managing a provider-specific path itself.

→

Modmux

Modmux runs on 127.0.0.1, exposes compatible endpoints, and translates request and response shapes through one stable local gateway between your tools and Copilot.

  • POST /v1/messages
  • POST /v1/responses
  • POST /v1/chat/completions
  • GET /v1/usage
  • GET /v1/models
  • GET /health
→

GitHub Copilot

Modmux authenticates with GitHub and forwards the translated request to Copilot-backed models while the trust boundary stays local and visible.

Trust boundary: Modmux is a local gateway, not a hosted relay. It binds to localhost and keeps configuration changes reversible.

Supported Agents

Support is explicit, current, and built into the product.

Claude Code

Canonical agent name: claude-code

Cline

Canonical agent name: cline

Codex

Canonical agent name: codex

Terminal Interface

Full visibility into your model routing.

$ modmux

┌─────────────────────────────────────┐
│  MODMUX v0.3.0                      │
├─────────────────────────────────────┤
│  Status:    Running                 │
│  Endpoint:  127.0.0.1:11435         │
│  Auth:      Authenticated ✓         │
├─────────────────────────────────────┤
│  Agents:                            │
│  [ ] claude-code                    │
│  [x] cline                          │
│  [ ] codex                          │
└─────────────────────────────────────┘

The TUI keeps your entire operational state visible: daemon status, authentication, and agent configuration in one terminal view. No hidden state, no guesswork—just run `modmux` and see everything.

Positioning

The problem is not setup. It is setup drift.

Approach What you manage What Modmux changes
Per-agent manual setup Separate provider wiring, local endpoints, and config details per tool Reliability depends on every local setup staying aligned over time
Modmux One local gateway, one install flow, reversible agent configuration The integration becomes shared, visible, and easier to keep stable

FAQ

Common questions before you put it in the loop.

Do I need a GitHub Copilot subscription?

Yes. Modmux routes requests through GitHub Copilot, so you need an active Copilot-backed account.

Does Modmux expose an API on my network?

No. The server binds to 127.0.0.1, which keeps the service local to your machine.

What if port 11435 is already in use?

Modmux starts at 11435 and scans upward if that port is occupied. Use modmux status to confirm the active local endpoint.

Can I undo a configuration change?

Yes. Modmux supports unconfiguring supported agents and is designed around reversible configuration management.

Which agents are supported right now?

The current built-in registry includes Claude Code, Cline, and Codex.

Do I need Deno to use Modmux?

Deno is required for the recommended from-source installation. If you don't want to install Deno, you can download a direct binary from GitHub Releases instead.

Status

Shipping now with a narrow scope and a practical operating model.

Current release posture

Modmux is at v0.3.0 and focused on a tight local gateway loop: authenticate, start the service, configure a supported agent, and route requests through one visible control point.

Operational model

The product stays local-first: localhost binding, explicit status, health checks, and reversible configuration instead of hidden background magic.

Read the README Read releases

Product boundaries

Modmux is not a hosted relay, a chat app, or an agent runtime. It is a stable local compatibility layer for supported agents on GitHub Copilot, and it is better for staying narrow.