github-router

github-router

Use your GitHub Copilot subscription to power Claude Code, Codex CLI, or any OpenAI/Anthropic-compatible tool.

github-router is a local reverse proxy that translates standard API formats to GitHub Copilot's backend. One command to start, copy-paste configs for your tools.

[!WARNING] Unofficial. Not supported by GitHub. May break. Use responsibly. Review the GitHub Copilot Terms and Acceptable Use Policies.

Quick Start

# 1. Authenticate (one-time)
npx github-router@latest auth

# 2. Start the proxy
npx github-router@latest start

The server runs at http://localhost:8787. Now pick your tool below.

Use with Claude Code

Option A: One-shot subcommand (recommended)

npx github-router@latest claude

Boots the proxy on a random port and spawns Claude Code wired to it. Sets ANTHROPIC_MODEL=claude-opus-4-8 (Anthropic's dashed slug — Claude Code's /model UI displays this as menu entry "Opus 4.8 (1M context)"). The proxy translates to Copilot's claude-opus-4.8 at request time (single base slug; the catalog entry's max_context_window_tokens already advertises 1M context — no -1m sibling needed for 4.8). Major.minor fallback chain: claude-opus-4-7 → claude-opus-4-6 → claude-opus-4-5. Override with -m:

npx github-router@latest claude -m claude-opus-4-8

The launcher sanitizes parent-env auth keys and sets CLAUDE_CONFIG_DIR=$HOME/.claude so the spawned claude ignores any persisted Console OAuth credential without requiring claude /logout. Settings, MCP servers, hooks, and CLAUDE.md auto-discovery still load from ~/.claude as normal.

Option B: Interactive launch-command generator

npx github-router@latest start --claude-code

Select your models, a launch command gets copied to your clipboard. Paste it in a new terminal.

Option C: Copy-paste config

Create .claude/settings.json in your project:

{
  "env": {
    "ANTHROPIC_BASE_URL": "http://localhost:8787",
    "ANTHROPIC_API_KEY": "dummy",
    "ANTHROPIC_AUTH_TOKEN": "dummy",
    "ANTHROPIC_MODEL": "gpt-4.1",
    "ANTHROPIC_DEFAULT_SONNET_MODEL": "gpt-4.1",
    "ANTHROPIC_SMALL_FAST_MODEL": "gpt-4.1-mini",
    "ANTHROPIC_DEFAULT_HAIKU_MODEL": "gpt-4.1-mini",
    "DISABLE_NON_ESSENTIAL_MODEL_CALLS": "1",
    "CLAUDE_CODE_DISABLE_NONESSENTIAL_TRAFFIC": "1"
  },
  "permissions": {
    "deny": ["WebSearch"]
  }
}

Then run claude as normal.

Peer-MCP review subagents

github-router claude auto-wires four peer-model adversarial reviewers plus a coordinator into the spawned Claude Code session. No setup, no prior MCP config, no .claude/agents/ files needed — they appear as Task subagent_type options the session can delegate to. Opt out with --no-codex-mcp.

Each persona is exposed both as a Claude Code subagent (callable via the Task tool) AND as an MCP tool at mcp__peers__<name>. Personas are stateless: each invocation runs a fresh request against its model with a baked persona prompt — they have no access to your scrollback or project memory, so the lead must paste the artifact into the brief.

Subagent	Model	Endpoint	Effort tiers (default)
codex-critic	gpt-5.5	/v1/responses	low | medium | high | xhigh (xhigh)
codex-reviewer	gpt-5.3-codex	/v1/responses	low | medium | high | xhigh (xhigh)
gemini-reviewer	gemini-3.1-pro-preview	/v1/chat/completions	low | medium | high (high)
opus-critic	claude-opus-4-6	/v1/messages	low | medium | high (high)
gemini-critic	gemini-3.1-pro-preview	/v1/chat/completions	low | medium | high (high)
peer-review-coordinator	(meta)	—	—

peer-review-coordinator is a subagent (not an MCP tool) that fans out to the right combination of the critics in parallel based on artifact type — plan, diff, single file, or long-context — and aggregates findings.

Effort tiers are exposed via the MCP tool's effort argument; subagents pass it through. xhigh routinely runs 60–90s; the proxy responds to tools/call requests with SSE-streamed responses (per MCP 2025-06-18 Streamable HTTP transport spec) so the connection stays open past the standard ~60s MCP per-tool-call ceiling and long calls complete transparently with no user setup.

gemini-critic and gemini-reviewer both register only when gemini-3.1-pro-preview (or another gemini-3.x-pro model) is present in your Copilot model catalog — gemini-critic is the architecture-level critic, gemini-reviewer the line-level second-lab code reviewer on the same model at its highest reasoning tier. If absent, both personas are silently dropped from the MCP tools/list and the subagent set, and peer-review-coordinator skips them in routing decisions.

For codex-side write capability (a codex-implementer persona that can mutate files via Codex's tool-use sandbox), pass --codex-cli. Requires codex CLI 0.129+ on PATH; falls back to HTTP-only with a warning if codex is missing or older. Pass --codex-mcp-only to also pass --strict-mcp-config to Claude Code so only the proxy's MCP servers are loaded (hides any MCP servers in your existing ~/.claude/mcp.json).

Code search (mcp__search__code)

Alongside the peer reviewers, the same MCP surface exposes a code tool (under the search server — mcp__search__code) — fast structured code search over the workspace, ranked by BM25F (Robertson, Zaragoza, Taylor 2004) over four code-aware fields: matched line, surrounding context, file path tokens, and a symbol-definition heuristic. On top of that, the top hits get a tree-sitter pass that promotes true identifier-definition sites over incidental string matches; depth is controlled by the optional structural argument ("full" parses the top 50 hits, "topN" parses the top 10 for tighter latency on big repos). A single notice field surfaces in the response on the rare occasions an actionable degradation fires — the structural pass overran its 200ms wall-clock budget, or the response hit the 256KB size cap and was truncated; the message text tells the model what to retry. Defaults to a semantic mode (mode: "semantic"): it ranks by MEANING via ColBERT over a per-workspace index, and transparently falls back to lexical BM25F when that index isn't ready (building / stale / not yet provisioned), labelling the response source (semantic, lexical, or lexical-fallback) so a degrade is never silent. The lexical mode is the BM25F + tree-sitter path with shoulder pruning (best for exact symbols); exact and regex force fixed-string / PCRE2 search, and ast matches ast-grep structural patterns. Single-identifier queries in the lexical modes auto-expand across camelCase / snake_case / kebab-case skeletons so getUserName also matches get_user_name. (This one tool absorbs what was previously a separate semantic_search tool; ColBERT semantic search is just its default mode.)

workspace is any absolute path the proxy process can read — typically the project root or a sub-tree you're working in. The model picks it. There's no allow-set or secret-shape file denylist: the threat model is symmetric since Claude Code already has Read / Bash / Edit tools that reach the same paths, so gating one tool would have been inconsistency rather than defense. Paths in results are returned relative to the workspace, never absolute.

Ripgrep is provided via the @vscode/ripgrep npm dependency (per-platform binary via optionalDependencies — no postinstall script needed). The proxy prefers system rg on PATH when available and falls back to the bundled binary otherwise. To opt into raw query/path logging for debugging, set GH_ROUTER_DEBUG_CODE_SEARCH=1 — by default the proxy logs only counts and timings.

Use with Codex CLI

The fastest path is the codex subcommand — it boots the proxy on a random port and spawns Codex CLI wired to it:

npx github-router@latest codex

Defaults to gpt-5.5; falls back to gpt-5.4 → gpt-5.3-codex → gpt-5.2-codex if your Copilot tier doesn't expose 5.5 yet. Override with -m:

npx github-router@latest codex -m gpt-5.3-codex

Or run the proxy and Codex CLI separately:

npx github-router@latest start --codex   # interactive launch-command generator
# — or set env vars yourself —
export OPENAI_BASE_URL="http://localhost:8787/v1"
export OPENAI_API_KEY="dummy"
codex --full-auto -m gpt-5.5

Use with any OpenAI-compatible tool

Point any tool at http://localhost:8787/v1:

curl http://localhost:8787/v1/chat/completions \
  -H "Content-Type: application/json" \
  -d '{"model": "gpt-4.1", "messages": [{"role": "user", "content": "Hello"}]}'

API Endpoints

Endpoint	Method	Format
/v1/chat/completions	POST	OpenAI Chat Completions
/v1/responses	POST	OpenAI Responses (Codex models)
/v1/messages	POST	Anthropic Messages
/v1/messages/count_tokens	POST	Anthropic token counting
/v1/models	GET	OpenAI model list
/v1/embeddings	POST	OpenAI embeddings
/v1/search	POST	Web search
/usage	GET	Copilot usage & quotas

OpenAI-compatible endpoints are also available without the /v1 prefix (for example, /chat/completions). Anthropic endpoints are only available under /v1/messages.

Model / endpoint compatibility

Model	/chat/completions	/responses	/v1/messages
gpt-4.1, gpt-4o	Yes	Yes	No
gpt-5.5, gpt-5.4	No	Yes	No
gpt-5.3-codex, gpt-5.2-codex	No	Yes	No
claude-opus-4.8 (1M context as the single base slug)	Yes	No	Yes
claude-opus-4.7-1m-internal (enterprise), claude-opus-4.7	Yes	No	Yes
claude-opus-4.6-1m, claude-opus-4.6, claude-sonnet-4.6	Yes	No	Yes
o3, o4-mini	Yes	Yes	No

Docker

Pre-built images on GitHub Container Registry:

docker pull ghcr.io/animeshkundu/github-router:latest
docker run -p 8787:8787 -e GH_TOKEN=your_token ghcr.io/animeshkundu/github-router

Or build locally:

docker build -t github-router .
docker run -p 8787:8787 -e GH_TOKEN=your_token github-router

Docker Compose

services:
  github-router:
    build: .
    ports:
      - "8787:8787"
    environment:
      - GH_TOKEN=your_github_token_here
    restart: unless-stopped

Persistent token storage

mkdir -p ./github-router-data
docker run -p 8787:8787 -v $(pwd)/github-router-data:/root/.local/share/github-router github-router

CLI Reference

github-router start [options]    Start the proxy server
github-router claude [options]   Start proxy + spawn Claude Code wired to it
github-router codex [options]    Start proxy + spawn Codex CLI wired to it
github-router auth               Authenticate with GitHub
github-router check-usage        Show Copilot usage/quotas
github-router debug              Print diagnostic info

The claude and codex subcommands accept all the shared flags below plus -m/--model to override the default model. Default models live in src/lib/port.ts:

• claude → claude-opus-4-8 (Anthropic dashed slug for UI compatibility; the proxy translates to Copilot's claude-opus-4.8 — the single base slug already advertises 1M context via max_context_window_tokens, so no -1m sibling exists). Major.minor fallback chain: claude-opus-4-7 → claude-opus-4-6 → claude-opus-4-5.
• codex → gpt-5.5 → gpt-5.4 → gpt-5.3-codex → gpt-5.2-codex

Fallback chains fire only on the implicit-default path; explicit -m/--model is always respected as-is.

Flag	Description	Default
--port, -p	Port	8787
--verbose, -v	Debug logging	false
--account-type, -a	individual / business / enterprise	individual
--rate-limit, -r	Min seconds between requests	-
--wait, -w	Queue requests instead of rejecting on rate limit	false
--manual	Approve each request manually	false
--github-token, -g	Pass token directly (skip auth flow)	-
--claude-code, -c	Generate Claude Code launch command	false
--codex	Generate Codex CLI launch command	false
--show-token	Print tokens to console	false
--proxy-env	Use HTTP_PROXY/HTTPS_PROXY env vars	false

Additional flags accepted only by the claude subcommand:

Flag	Description	Default
--model, -m	Override the default Claude model	claude-opus-4-8
--codex-mcp / --no-codex-mcp	Wire peer-MCP review subagents (codex-critic / opus-critic / gemini-critic / codex-reviewer / peer-review-coordinator) into the spawned session	true
--codex-cli	Add a codex mcp-server stdio backend so codex-implementer can mutate files. Requires codex CLI 0.129+; falls back to HTTP-only if absent	false
--codex-mcp-only	Pass --strict-mcp-config to Claude Code so only the proxy's MCP servers load (hides any user MCP servers in ~/.claude/mcp.json)	false
--stealth	Opt back into VS Code-only beta-header filtering. Loses leverage features (task budgets, token-efficient tools, prompt caching, etc.) but minimizes the wire-fingerprint diff from VS Code Copilot Chat	false
--auto-update / --no-auto-update	Check for and install latest Claude Code on launch (throttled to once per hour). Falls back gracefully if npm/network unavailable	true
--update-check / --no-update-check	Check the npm registry for a newer Claude Code version on launch and warn if stale (~500ms cost). --no-update-check implies no auto-install	true

Development

bun install          # Install deps
bun run dev          # Dev server with hot reload
bun test             # Run tests
bun run lint:all     # Lint
bun run typecheck    # Type check
bun run build        # Build for distribution

License

MIT