CC Gateway — AI API Identity Gateway

Skill by ara.so — Daily 2026 Skills collection.

CC Gateway is a TypeScript reverse proxy that sits between Claude Code clients and the Anthropic API. It normalizes 40+ device fingerprint dimensions (device ID, email, environment, RAM, headers, and system prompt content) to a single canonical identity, manages OAuth token refresh centrally, and prevents telemetry leakage from multi-machine setups.

Architecture Overview

Client (Claude Code + env vars + Clash)
  └─► CC Gateway (rewrite + auth inject + SSE passthrough)
        └─► api.anthropic.com (single canonical identity)

Gateway also contacts:
  platform.claude.com (OAuth token refresh only)

Three-layer defense:

Layer	Mechanism
Env vars	Route CC traffic to gateway, disable side channels
Clash rules	Block any direct Anthropic connections at network level
Gateway	Rewrite all 40+ fingerprint dimensions in-flight

Installation

Prerequisites

• Node.js 18+ or Docker
• A machine that has previously logged into Claude Code (for OAuth token extraction)

Clone and Install

git clone https://github.com/motiful/cc-gateway.git
cd cc-gateway
npm install

Generate Identity and Tokens

# Create a stable canonical identity (device_id, email, env profile)
npm run generate-identity

# Create a bearer token for a specific client machine
npm run generate-token my-laptop
npm run generate-token work-desktop

Extract OAuth Token (from a logged-in machine)

# macOS — copies refresh_token from Keychain
bash scripts/extract-token.sh

Configure

cp config.example.yaml config.yaml

Edit config.yaml:

# config.yaml
identity:
  device_id: "GENERATED_DEVICE_ID"          # from generate-identity
  email: "canonical@example.com"
  platform: "darwin"
  arch: "arm64"
  node_version: "20.11.0"
  shell: "/bin/zsh"
  home: "/Users/canonical"
  working_directory: "/Users/canonical/projects"
  memory_gb: 16                              # canonical RAM value

oauth:
  refresh_token: "EXTRACTED_REFRESH_TOKEN"  # from extract-token.sh

clients:
  - name: my-laptop
    token: "GENERATED_CLIENT_TOKEN"
  - name: work-desktop
    token: "ANOTHER_CLIENT_TOKEN"

server:
  port: 8443
  tls: false                                 # true for production with certs

Starting the Gateway

# Development (no TLS, hot reload)
npm run dev

# Production build
npm run build && npm start

# Docker Compose (recommended for production)
docker-compose up -d

Docker Compose Example

# docker-compose.yml
version: "3.8"
services:
  cc-gateway:
    build: .
    ports:
      - "8443:8443"
    volumes:
      - ./config.yaml:/app/config.yaml:ro
    restart: unless-stopped
    environment:
      - NODE_ENV=production

Verification

# Health check
curl http://localhost:8443/_health

# Show before/after rewrite diff (requires client token)
curl -H "Authorization: Bearer YOUR_CLIENT_TOKEN" \
     http://localhost:8443/_verify

Client Machine Setup

On each machine running Claude Code, set these environment variables:

# ~/.bashrc or ~/.zshrc

# Route all Claude Code API traffic through the gateway
export ANTHROPIC_BASE_URL="https://gateway.your-domain.com:8443"

# Disable side-channel telemetry (Datadog, GrowthBook, version checks)
export CLAUDE_CODE_DISABLE_NONESSENTIAL_TRAFFIC=1

# Skip browser OAuth — gateway handles authentication
export CLAUDE_CODE_OAUTH_TOKEN="gateway-managed"

# Authenticate to the gateway with the per-machine token
export ANTHROPIC_CUSTOM_HEADERS="Proxy-Authorization: Bearer YOUR_CLIENT_TOKEN"

Or use the interactive setup script:

bash scripts/client-setup.sh

Then just run claude — no login prompt required.

Clash Rules (Network-Level Blocking)

Add to your Clash configuration to block any direct Anthropic connections:

# clash-rules.yaml excerpt
rules:
  - DOMAIN,gateway.your-domain.com,DIRECT      # Allow your gateway
  - DOMAIN-SUFFIX,anthropic.com,REJECT          # Block direct API calls
  - DOMAIN-SUFFIX,claude.com,REJECT             # Block direct OAuth
  - DOMAIN-SUFFIX,claude.ai,REJECT              # Block Claude web
  - DOMAIN-SUFFIX,datadoghq.com,REJECT          # Block Datadog telemetry
  - DOMAIN-SUFFIX,statsig.com,REJECT            # Block feature flags

See clash-rules.yaml in the repo for the full template.

What Gets Rewritten

Layer	Field	Transformation
Identity	device_id	→ canonical ID from config
Identity	email	→ canonical email
Environment	env object (40+ fields)	→ entire object replaced
Process	constrainedMemory (physical RAM)	→ canonical value
Process	rss, heapTotal, heapUsed	→ randomized in realistic range
Headers	User-Agent	→ canonical CC version string
Headers	Authorization	→ real OAuth token (injected)
Headers	x-anthropic-billing-header	→ canonical fingerprint
Prompt text	Platform, Shell, OS Version	→ canonical values
Prompt text	/Users/xxx/, /home/xxx/	→ canonical home prefix
Leak fields	baseUrl	→ stripped
Leak fields	gateway provider field	→ stripped

TypeScript Usage Examples

Custom Rewriter Extension

// src/rewriters/custom-field-rewriter.ts
import { RequestRewriter } from '../types';

export const customFieldRewriter: RequestRewriter = {
  name: 'custom-field-rewriter',

  rewriteBody(body: Record<string, unknown>, config: CanonicalConfig): Record<string, unknown> {
    // Strip any custom analytics fields your org adds
    const { __analytics, __session_debug, ...cleaned } = body as any;

    // Normalize any additional identity fields
    if (cleaned.metadata?.user_id) {
      cleaned.metadata.user_id = config.identity.device_id;
    }

    return cleaned;
  },

  rewriteHeaders(headers: Record<string, string>, config: CanonicalConfig): Record<string, string> {
    return {
      ...headers,
      'x-custom-client': 'canonical',
    };
  }
};

Programmatic Gateway Start

// scripts/start-with-monitoring.ts
import { createGateway } from '../src/gateway';
import { loadConfig } from '../src/config';

async function main() {
  const config = await loadConfig('./config.yaml');

  const gateway = await createGateway(config);

  gateway.on('request', ({ clientId, path }) => {
    console.log(`[${new Date().toISOString()}] ${clientId} → ${path}`);
  });

  gateway.on('rewrite', ({ field, before, after }) => {
    console.log(`Rewrote ${field}: ${before} → ${after}`);
  });

  gateway.on('tokenRefresh', ({ expiresAt }) => {
    console.log(`OAuth token refreshed, expires: ${expiresAt}`);
  });

  await gateway.listen(config.server.port);
  console.log(`Gateway running on port ${config.server.port}`);
}

main().catch(console.error);

Token Generation (Programmatic)

// scripts/provision-client.ts
import { generateClientToken, addClientToConfig } from '../src/auth';

async function provisionNewMachine(machineName: string) {
  const token = await generateClientToken(machineName);

  await addClientToConfig('./config.yaml', {
    name: machineName,
    token,
    created_at: new Date().toISOString(),
  });

  console.log(`Client token for ${machineName}:`);
  console.log(token);
  console.log('\nAdd to client machine:');
  console.log(`export ANTHROPIC_CUSTOM_HEADERS="Proxy-Authorization: Bearer ${token}"`);
}

provisionNewMachine(process.argv[2] ?? 'new-machine');

Key npm Scripts

Command	Purpose
npm run dev	Start with hot reload (development)
npm run build	Compile TypeScript to dist/
npm start	Run compiled production build
npm test	Run rewriter test suite (13 tests)
npm run generate-identity	Create canonical device profile
npm run generate-token <name>	Create per-client bearer token

Common Patterns

Multiple Machines, One Identity

# On gateway server — generate once
npm run generate-identity
# → device_id: abc-123, email: canonical@proxy.local

# Provision each machine
npm run generate-token laptop-home    # → token-aaa
npm run generate-token laptop-work    # → token-bbb
npm run generate-token desktop        # → token-ccc

# All three machines present as the same device to Anthropic

Rotating the Canonical Identity

# Generate a new identity (e.g., after a suspected flag)
npm run generate-identity --force

# Update config.yaml with new device_id
# Restart gateway — all clients immediately use new identity
docker-compose restart cc-gateway

Checking for New Telemetry Fields After CC Updates

# After a Claude Code update, use _verify to diff
curl -H "Authorization: Bearer $TOKEN" \
     http://localhost:8443/_verify | jq '.unrewritten_fields'

# Monitor Clash logs for new endpoints
# Any REJECT hits on new domains = new hardcoded endpoints

Troubleshooting

claude still prompts for browser login

• Ensure CLAUDE_CODE_OAUTH_TOKEN=gateway-managed is exported
• Verify ANTHROPIC_BASE_URL points to your running gateway
• Check gateway logs: docker-compose logs -f cc-gateway

401 Unauthorized from gateway

• Confirm ANTHROPIC_CUSTOM_HEADERS contains Proxy-Authorization: Bearer <token>
• Verify the token in config.yaml matches the one set in env var
• Run curl -H "Authorization: Bearer $TOKEN" http://localhost:8443/_health

OAuth token expired

# Re-extract from a logged-in machine
bash scripts/extract-token.sh
# Paste new refresh_token into config.yaml
docker-compose restart cc-gateway

MCP servers bypassing gateway

MCP uses mcp-proxy.anthropic.com which ignores ANTHROPIC_BASE_URL. Add to Clash:

- DOMAIN,mcp-proxy.anthropic.com,REJECT

Requests reaching Anthropic directly (Clash not blocking)

• Check Clash is running: clash -v
• Verify rules are loaded: look for REJECT entries in Clash dashboard
• Test: curl https://api.anthropic.com — should fail if Clash is active

Gateway rewrite not applying to a new field

After a Claude Code update, new telemetry fields may not be covered. Check /_verify for unrewritten_fields, then open an issue or add a custom rewriter (see Custom Rewriter Extension above).

Caveats

• MCP servers — hardcoded endpoint, use Clash to block if not needed
• CC updates — monitor Clash REJECT logs after every Claude Code update for new endpoints
• Refresh token lifetime — if the OAuth refresh token expires, re-run extract-token.sh
• ToS — do not use for account sharing; intended for managing your own devices under one subscription
• Alpha — test with a non-primary account before production use