# Claude Code Reverse Engineering > Reverse-engineered design documents for Anthropic Claude Code CLI - implementation-ready specifications - **Type:** MCP server - **Install:** `agentstack add mcp-jung-wan-kim-claude-code-reverse-engineering` - **Verified:** Yes — security-reviewed for prompt injection and unsafe behavior - **Seller:** [jung-wan-kim](https://agentstack.voostack.com/s/jung-wan-kim) - **Installs:** 0 - **Category:** [Cloud & Infrastructure](https://agentstack.voostack.com/c/cloud-infrastructure) - **Latest version:** 0.1.0 - **License:** MIT - **Upstream author:** [jung-wan-kim](https://github.com/jung-wan-kim) - **Source:** https://github.com/jung-wan-kim/claude-code-reverse-engineering ## Install ```sh agentstack add mcp-jung-wan-kim-claude-code-reverse-engineering ``` Requires the [AgentStack CLI](https://agentstack.voostack.com/docs/cli). Works with Claude Code, Cursor, and any MCP-compatible agent. ## About # Claude Code CLI — Reverse Engineering Design Documents > **Implementation-ready** reverse engineering specifications for Anthropic's [Claude Code](https://docs.anthropic.com/en/docs/claude-code) CLI tool. > Extracted via source map analysis of the npm package (March 2026). --- ## At a Glance ``` ┌─────────────────────────────────────────────────────────────────────┐ │ Claude Code CLI │ │ │ │ ~1,900 files · 512,000+ LOC · TypeScript Strict · Bun │ │ │ │ ┌──────────┐ ┌──────────┐ ┌──────────┐ ┌──────────┐ │ │ │ React │ │ Ink │ │ Yoga │ │Commander │ │ │ │ 19 │ │ (custom │ │ (WASM │ │ .js │ │ │ │ │ │ fork) │ │ layout) │ │ │ │ │ └────┬─────┘ └────┬─────┘ └────┬─────┘ └────┬─────┘ │ │ └──────────────┴──────────────┴──────────────┘ │ │ Terminal UI │ │ ┌─────────────────────────────────────────────────────────────┐ │ │ │ Core Engine │ │ │ │ ┌─────────┐ ┌──────────┐ ┌───────────┐ ┌──────────────┐ │ │ │ │ │ 45+ │ │ Query │ │ Streaming │ │ Cost │ │ │ │ │ │ Tools │ │ Engine │ │ Executor │ │ Tracker │ │ │ │ │ └─────────┘ └──────────┘ └───────────┘ └──────────────┘ │ │ │ └─────────────────────────────────────────────────────────────┘ │ │ ┌─────────────────────────────────────────────────────────────┐ │ │ │ Extension Layer │ │ │ │ ┌─────┐ ┌────────┐ ┌────────┐ ┌──────┐ ┌─────┐ ┌──────┐ │ │ │ │ │ MCP │ │Plugins │ │ Skills │ │Hooks │ │ LSP │ │Bridge│ │ │ │ │ └─────┘ └────────┘ └────────┘ └──────┘ └─────┘ └──────┘ │ │ │ └─────────────────────────────────────────────────────────────┘ │ │ ┌─────────────────────────────────────────────────────────────┐ │ │ │ Services │ │ │ │ ┌────────┐ ┌──────┐ ┌───────────┐ ┌────────┐ ┌─────────┐ │ │ │ │ │ API │ │ Auth │ │ Analytics │ │Settings│ │Migration│ │ │ │ │ │(4 back)│ │OAuth │ │ DD+OTel │ │5-layer │ │ chain │ │ │ │ │ └────────┘ └──────┘ └───────────┘ └────────┘ └─────────┘ │ │ │ └─────────────────────────────────────────────────────────────┘ │ │ ┌─────────────────────────────────────────────────────────────┐ │ │ │ Security & Permissions │ │ │ │ ┌──────────┐ ┌───────────┐ ┌──────────┐ ┌──────────────┐ │ │ │ │ │ 7 Perm │ │ 23 Bash │ │ Path │ │ Auto-Mode │ │ │ │ │ │ Modes │ │ Checks │ │Validator │ │ Classifier │ │ │ │ │ └──────────┘ └───────────┘ └──────────┘ └──────────────┘ │ │ │ └─────────────────────────────────────────────────────────────┘ │ └─────────────────────────────────────────────────────────────────────┘ ``` --- ## Design Documents ### Part 1 — Architecture Overview > [`docs/01-architecture-overview.md`](docs/01-architecture-overview.md) · 1,101 lines ``` Startup Sequence (5 phases) ═══════════════════════════════════════════ Phase 0 ─► Module-level side effects (MDM, Keychain prefetch) Phase 1 ─► main() entry, basic initialization Phase 2 ─► Commander preAction → init() → migrations Phase 3 ─► action() → setup() → auth/permissions Phase 4 ─► REPL render + deferred prefetches ``` | Topic | Key Details | |-------|-------------| | **Module System** | ESM-only, `.js` extensions required, lazy `require()` for cycles | | **Build** | Bun bundler, `feature()` flags for dead code elimination | | **Config** | 7 layers: Global → Project → Settings(5 sources) → CLI → MDM | | **Feature Flags** | 89 flags via GrowthBook, `bun:bundle` compile-time DCE | | **State** | 110 global fields in `bootstrap/state.ts`, `DO NOT ADD MORE` policy | --- ### Part 2 — Core Engine > [`docs/02-core-engine.md`](docs/02-core-engine.md) · 1,352 lines ``` Tool Execution Pipeline ═══════════════════════════════════════════ User Input ──► QueryEngine ──► LLM API (streaming) │ tool_use block │ ┌───────────────┼───────────────┐ ▼ ▼ ▼ ┌──────────┐ ┌──────────┐ ┌──────────┐ │ Bash │ │ FileEdit │ │ Agent │ │ Tool │ │ Tool │ │ Tool │ └────┬─────┘ └────┬─────┘ └────┬─────┘ │ │ │ ▼ ▼ ▼ ToolResult ToolResult ToolResult { data, newMessages?, contextModifier?, mcpMeta? } │ ◄─────┘ Next LLM turn with results ``` | Topic | Key Details | |-------|-------------| | **Tool Interface** | 60+ fields, `buildTool()` factory, 7 defaultable keys | | **Concurrency** | `isConcurrencySafe` flag — safe tools run parallel, unsafe exclusive | | **Recovery** | 8-stage chain: streaming fallback → model fallback → collapse drain → reactive compact | | **Cost Tracking** | Per-session USD accumulator, multi-provider normalization | --- ### Part 3 — Permission & Security > [`docs/03-permission-security.md`](docs/03-permission-security.md) · 1,178 lines ``` Permission Decision Pipeline (4 steps + auto-mode) ═══════════════════════════════════════════════════ Step 0 Config deny rules ──► deny (immediate) Step 1 Tool.checkPermissions() ──► allow/deny/ask/passthrough Step 2 Permanent allow rules ──► allow (skip prompt) Step 3 passthrough → ask conversion Step 4 Post-processing: ├── dontAsk mode ──► auto deny ├── auto mode ──► classifier pipeline: │ ├── acceptEdits fast-path │ ├── safe-tool allowlist │ └── YOLO classifier (2-stage) │ ├── allowed ──► allow │ ├── blocked ──► deny + denial tracking │ └── unavailable ──► iron_gate fail-closed └── headless ──► hook or deny ``` | Topic | Key Details | |-------|-------------| | **7 Modes** | `default`, `plan`, `acceptEdits`, `bypassPermissions`, `dontAsk`, `auto`, `bubble` | | **Bash Security** | 23 check IDs, 19 cross-platform + 7 Unix + 11 ANT-only patterns | | **Path Validation** | 6-step: normalize → symlink resolve → traversal → Windows patterns → scope | | **TOCTOU Warning** | Path validation and file access are not atomic — race condition window | --- ### Part 4 — Multi-Agent & Memory > [`docs/04-multi-agent-memory.md`](docs/04-multi-agent-memory.md) · 1,416 lines ``` Agent Hierarchy ═══════════════════════════════════════════ ┌───────────────┐ │ Coordinator │ (orchestrator — no direct tool use) └───────┬───────┘ ┌────────────┼────────────┐ ▼ ▼ ▼ ┌──────────┐ ┌──────────┐ ┌──────────┐ │ Worker │ │ Worker │ │ Worker │ │ (fork) │ │ (spawn) │ │(in-proc) │ └──────────┘ └──────────┘ └──────────┘ Memory Hierarchy (5 layers) ═══════════════════════════════════════════ [1] Session Memory ── in-context summaries [2] Project Memory ── .claude/memory/ files [3] User Memory ── ~/.claude/memory/ [4] Team Memory ── server-synced shared memory [5] External ── MCP servers, LSP, git ``` | Topic | Key Details | |-------|-------------| | **3 Swarm Backends** | `fork` (shared context), `spawn` (independent), `in-process teammate` | | **Task Types** | 7 types with ID prefixes: `b`ash, `w`orkflow, `a`gent, `t`eammate, `r`emote, `m`onitor, `d`ream | | **Mailbox** | File-based: `.claude/teams/{team}/inboxes/{agent}.json` | | **Team Sync** | ETag-based conflict detection (412), no local file locking | --- ### Part 5 — Extension Systems > [`docs/05-extension-systems.md`](docs/05-extension-systems.md) · 1,709 lines ``` 6 Extension Points ═══════════════════════════════════════════ ┌─────┐ ┌────────┐ ┌────────┐ ┌──────┐ ┌─────┐ ┌──────┐ │ MCP │ │Plugins │ │ Skills │ │Hooks │ │ LSP │ │Bridge│ │ │ │ │ │ │ │ │ │ │ │ │ │8 cfg│ │market- │ │17 bun- │ │27 │ │code │ │IDE │ │types│ │place + │ │dled + │ │events│ │intel│ │comms │ │ │ │builtin │ │custom │ │ │ │ │ │ │ └─────┘ └────────┘ └────────┘ └──────┘ └─────┘ └──────┘ ``` | Topic | Key Details | |-------|-------------| | **MCP Transports** | `TransportSchema`: 6 types; `McpServerConfig`: 8 (+ ws-ide, claudeai-proxy) | | **Hook Priority** | `deny` > `ask` > `allow` — any hook's deny overrides all allows | | **Plugin Loading** | Parallel (marketplace + session) → builtins → merge → dependency verify | | **Reconnection** | MAX_ERRORS_BEFORE_RECONNECT=3, SSE maxRetries=2, 15min poll timeout | --- ### Part 6 — UI Layer > [`docs/06-ui-layer.md`](docs/06-ui-layer.md) · 1,784 lines ``` Render Pipeline ═══════════════════════════════════════════ React Component Tree │ ▼ Custom Reconciler (React 19 HostConfig) │ ▼ Yoga Layout Engine (WASM) │ ┌──────────────────────┐ ├──│ Box (flexbox node) │ ├──│ Text (measure func) │ └──│ Button (interactive) │ └──────────────────────┘ │ ▼ Output Renderer (ANSI diff) │ ▼ Terminal stdout (throttled at FRAME_INTERVAL_MS) ``` | Topic | Key Details | |-------|-------------| | **Ink Fork** | 96 files in `src/ink/`, custom reconciler, Yoga WASM integration | | **Components** | 346 `.tsx` files in `src/components/` | | **Hooks** | 85+ custom hooks (`useTextInput`, `useTerminalSize`, `useStdin`, etc.) | | **Concurrency** | `maySuspendCommit()` always returns `false` — Suspense disabled | --- ### Part 7 — Services & Infrastructure > [`docs/07-services-infrastructure.md`](docs/07-services-infrastructure.md) · 1,845 lines ``` API Client Factory (4 backends) ═══════════════════════════════════════════ ┌──────────────────┐ │ buildFetch() │ │ + withRetry() │ └────────┬─────────┘ ┌────────────────┼────────────────┐──────────────┐ ▼ ▼ ▼ ▼ ┌──────────┐ ┌──────────┐ ┌──────────┐ ┌──────────┐ │ Anthropic│ │ Bedrock │ │ Foundry │ │ Vertex │ │ (Direct) │ │ (AWS) │ │ (Azure) │ │ (GCP) │ └──────────┘ └──────────┘ └──────────┘ └──────────┘ Retry Strategy: 429 → Retry-After (≤20s: sleep, >20s: 30min cooldown) 529 → MAX_529_RETRIES=3 (non-subscriber only) 401 → token refresh → retry (no max refresh limit!) ``` | Topic | Key Details | |-------|-------------| | **Analytics** | Datadog (44 allowed events, 16 tag fields) + OpenTelemetry + 1P logger | | **OAuth** | PKCE flow, macOS Keychain with plaintext fallback (30s TTL cache) | | **Settings Merge** | 5 sources: `user → project → local → flag → policy` (arrays concat, not override!) | | **Migrations** | 11 sync + 1 async, includes `migrateLegacyOpusToCurrent` (ant-only DCE) | --- ### Part 8 — Types, Schemas & API > [`docs/08-types-schemas-api.md`](docs/08-types-schemas-api.md) · 2,194 lines ``` Type System Layers ═══════════════════════════════════════════ ┌─────────────────────────────────────────┐ │ Branded IDs │ │ SessionId, AgentId, TaskId, ToolUseId │ ├─────────────────────────────────────────┤ │ Core Types │ │ Tool, ToolResult, │ │ ValidationResult, ToolUseContext (30+) │ ├─────────────────────────────────────────┤ │ Zod Schemas │ │ HookCommand (discriminated union), │ │ SettingsSchema (~100 fields), │ │ TransportSchema (6 literals) │ ├─────────────────────────────────────────┤ │ AppState │ │ DeepImmutable<> wrapper, │ │ ~85 fields + Store pattern │ ├─────────────────────────────────────────┤ │ Environment Variables (60+) │ │ Feature Flags (89) │ │ Analytics Events (44 Datadog) │ └─────────────────────────────────────────┘ ``` | Topic | Key Details | |-------|-------------| | **SettingsJson** | ~100 fields across 15 categories (auth, permissions, MCP, hooks, model, UI...) | | **Settings Merge** | `policySettings` internal priority: remote > HKLM/plist > file > HKCU | | **Env Vars** | 60+ variables across 7 groups (API, model, auth, debug, feature, proxy, internal) | | **Feature Flags** | 89 `bun:bundle` `feature()` calls, compile-time dead code elimination | --- ## Infrastructure & Deployment > [`infrastructure/`](infrastructure/) — Complete deployment blueprints with Terraform IaC ``` Deployment Options ═══════════════════════════════════════════ ┌──────────────┐ ┌──────────────┐ ┌──────────────┐ ┌──────────────┐ │ Local Dev │ │ AWS │ │ Azure │ │ Supabase │ │ │ │ │ │ │ │ │ │ Ollama/vLLM │ │ ECS Fargate │ │ Container │ │ Edge Funcs │ │ Docker Stack │ │ Bedrock │ │ Apps │ │ Realtime │ │ RTX 4090 │ │ Lambda │ │ Azure OpenAI │ │ PostgreSQL │ │ │ │ Cognito │ │ AD B2C │ │ Auth │ │ $0-50/mo │ │ $45-180/mo │ │ $50-190/mo │ │ $0-25/mo │ └──────────────┘ └──────────────┘ └──────────────┘ └──────────────┘ ``` | Document | Description | |----------|-------------| | [`01-local-development.md`](infrastructure/01-local-development.md) | Ollama, vLLM, LM Studio, Docker Compose full stack | | [`02-aws-architecture.md`](infrastructure/02-aws-architecture.md) | VPC, ECS, Bedrock, Lambda sandbox, CloudWatch | | [`03-azure-architecture.md`](infrastructure/03-azure-architecture.md) | Container Apps, Azure OpenAI, Functions, Monitor | | [`04-supabase-backend.md`](infrastructure/04-supabase-backend.md) | 10-table schema, RLS policies, Edge Functions | | [`05-cost-analysis.md`](infrastructure/05-cost-analysis.md) | Real pricing: $9/mo solo → $25/dev enterprise | | [`06-architecture-diagram.md`](infrastructure/06-architecture-diagram.md) | 7 ASCII diagrams: system, data flow, auth, agents | | [`terraform/`](infrastructure/terraform/) | 10 `.tf` files — production-ready AWS IaC | ### Cost Quick Reference | Scale | Supabase + API | AWS Full | Hybrid (Local GPU) | |-------|:--------------:|:--------:|:-------------------:| | **Solo** (1 dev) | $9–103/mo | $240–280/mo | $50/mo | | **Team** (10 devs) | $46–116/dev | $65–110/dev | $35–60/dev | | **Enterprise** (100 devs) | N/A | $45–111/dev | **$25/dev** | > LLM token costs represent 60–95% of total spend at every scale. --- ## Verification Status These documents went through **8 rigorous verification passes** against the actual source code: ``` Pass 1 ████████████████ 16 corrections (type/value accuracy) Pass 2 ████ 4 fixes (blocking implementation gaps) Pass 3 ███████ 7 corrections (line-by-line precision) Pass 4 ███ 3 fixes (missing schemas/flows) Pass 5 ███████ 7 additions (Bridge, MDM, Keychain, Plugin) Pass 6 ██████████████ 42 caveats (structural problem warnings) Pass 7 ██ 2 micro-fixes (convergence check) Pass 8 ─────────────── CONVERGED (24/24 spot-checks verified) ═══════════════ Total: 39 corrections + 42 implementation caveats ``` --- ## Quick Start ```bash # Clone the repo git clone https://github.com/jung-wan-kim/claude-code-reverse-engineering.git cd claude-code-reverse-engineering # Read the design do … ## Source & license This open-source MCP server is cataloged on AgentStack and links to its original source — we do not rehost the code. - **Author:** [jung-wan-kim](https://github.com/jung-wan-kim) - **Source:** [jung-wan-kim/claude-code-reverse-engineering](https://github.com/jung-wan-kim/claude-code-reverse-engineering) - **License:** MIT Install and usage instructions live in the source repository linked above. ## Pricing - **Free** — Free ## Security capabilities Automated source analysis of v0.1.0 — what this tool can access: - **Network access:** no - **Filesystem access:** no - **Shell / process execution:** no - **Environment & secrets:** no - **Dynamic code execution:** no *"Yes" means the capability is present in the source — more access means more to trust, not that it is unsafe.* ## Versions - **0.1.0** — security scan: passed — Imported from the upstream source. ## Links - Listing page: https://agentstack.voostack.com/l/mcp-jung-wan-kim-claude-code-reverse-engineering - Seller: https://agentstack.voostack.com/s/jung-wan-kim - Browse the marketplace: https://agentstack.voostack.com/browse --- Listed on AgentStack — the marketplace for AI agent skills and MCP servers. Every listing is security-reviewed. Creators keep 70%.