Chapter 3: Provider Configuration and Transformer Strategy

Welcome to Chapter 3: Provider Configuration and Transformer Strategy. In this part of Claude Code Router Tutorial: Multi-Provider Routing and Control Plane for Claude Code, you will build an intuitive mental model first, then move into concrete implementation details and practical production tradeoffs.

This chapter focuses on building reliable provider definitions and transformation pipelines.

Learning Goals

• configure providers with environment-variable-safe secrets
• select transformers by provider API compatibility needs
• understand global vs model-scoped transformer application
• avoid brittle provider configs that fail under load

Provider Configuration Essentials

Field	Why It Matters
name	routing and model reference key
api_base_url	provider endpoint compatibility
api_key	secure auth, ideally via env interpolation
models	allowed model surface for routing
transformer	request/response compatibility adjustments

Source References

• README: Configuration
• README: Transformers
• Server Config: Providers

Summary

You now have a stable foundation for provider onboarding and transformer management.

Next: Chapter 4: Routing Rules, Fallbacks, and Custom Router Logic

Source Code Walkthrough

docs/sidebars.ts

The sidebars module in docs/sidebars.ts handles a key part of this chapter's functionality:

import type { SidebarsConfig } from '@docusaurus/plugin-content-docs';

const sidebars: SidebarsConfig = {
  tutorialSidebar: [
    {
      type: 'category',
      label: 'CLI',
      link: {
        type: 'generated-index',
        title: 'Claude Code Router CLI',
        description: 'Command-line tool usage guide',
        slug: 'category/cli',
      },
      items: [
        'cli/intro',
        'cli/installation',
        'cli/quick-start',
        {
          type: 'category',
          label: 'Commands',
          link: {
            type: 'generated-index',
            title: 'CLI Commands',
            description: 'Complete command reference',
            slug: 'category/cli-commands',
          },
          items: [
            'cli/commands/start',
            'cli/commands/model',
            'cli/commands/status',
            'cli/commands/statusline',
            'cli/commands/preset',
            'cli/commands/other',
          ],
        },

This module is important because it defines how Claude Code Router Tutorial: Multi-Provider Routing and Control Plane for Claude Code implements the patterns covered in this chapter.

tsconfig.base.json

The tsconfig.base module in tsconfig.base.json handles a key part of this chapter's functionality:

{
  "compilerOptions": {
    "target": "ES2022",
    "module": "CommonJS",
    "strict": true,
    "esModuleInterop": true,
    "skipLibCheck": true,
    "forceConsistentCasingInFileNames": true,
    "resolveJsonModule": true,
    "moduleResolution": "node",
    "noImplicitAny": true,
    "allowSyntheticDefaultImports": true,
    "sourceMap": true,
    "declaration": true,
    "typeRoots": ["./node_modules/@types", "./packages/*/node_modules/@types"]
  }
}

This module is important because it defines how Claude Code Router Tutorial: Multi-Provider Routing and Control Plane for Claude Code implements the patterns covered in this chapter.

package.json

The package module in package.json handles a key part of this chapter's functionality:

{
  "name": "@musistudio/claude-code-router",
  "version": "2.0.0",
  "description": "Use Claude Code without an Anthropics account and route it to another LLM provider",
  "scripts": {
    "build": "pnpm build:shared && pnpm build:core && pnpm build:server && pnpm build:cli && pnpm build:ui",
    "build:core": "pnpm --filter @musistudio/llms build",
    "build:shared": "pnpm --filter @CCR/shared build",
    "build:cli": "pnpm --filter @CCR/cli build",
    "build:server": "pnpm --filter @CCR/server build",
    "build:ui": "pnpm --filter @CCR/ui build",
    "build:docs": "pnpm --filter claude-code-router-docs build",
    "release": "pnpm build && bash scripts/release.sh all",
    "release:npm": "bash scripts/release.sh npm",
    "release:docker": "bash scripts/release.sh docker",
    "dev:cli": "pnpm --filter @CCR/cli dev",
    "dev:server": "pnpm --filter @CCR/server dev",
    "dev:ui": "pnpm --filter @CCR/ui dev",
    "dev:core": "pnpm --filter @musistudio/llms dev",
    "dev:docs": "pnpm --filter claude-code-router-docs start",
    "serve:docs": "pnpm --filter claude-code-router-docs serve"
  },
  "bin": {
    "ccr": "dist/cli.js"
  },
  "keywords": [
    "claude",
    "code",
    "router",
    "llm",
    "anthropic"
  ],
  "author": "musistudio",
  "license": "MIT",
  "devDependencies": {

This module is important because it defines how Claude Code Router Tutorial: Multi-Provider Routing and Control Plane for Claude Code implements the patterns covered in this chapter.

How These Components Connect

flowchart TD
    A[sidebars]
    B[tsconfig.base]
    C[package]
    A --> B
    B --> C