️ Claude Code vs Codex CLI
12-dimension technical comparison
Claude Code
Anthropic
Closed source
TypeScript/Bun
Codex CLI
OpenAI
Apache 2.0 Open
Rust + TypeScript
12-Dimension Comparison
| Dimension | Claude Code | Codex CLI |
|---|---|---|
| Open Source | Closed (leaked) | Apache 2.0 |
| Core Language | TypeScript/Bun | Rust + TypeScript |
| Default Model | Claude Opus 4.6 | GPT-5.4 |
| Context Window | 1M (standard pricing) | 1M (2× after 272K) |
| Tools Count | 54 | ~12 |
| Multi-Agent | 3 routes (Coordinator/Swarm/InProcess) | Single Agent |
| Memory System | 4-layer architecture | Simple cache |
| Remote Control | Bridge (3-gen) | None |
| Autonomous Mode | KAIROS | Limited |
| Plugin Ecosystem | MCP (7 transports) | None |
| Code Size | ~394K lines | ~50K lines |
| Sandbox | App-layer Hook chain | OS kernel (Seatbelt/Landlock) |
Architecture Philosophy
Claude Code: Supervised Autonomy
- Plan Mode for pre-execution review
- 17 Hook lifecycle events
- 3-tier permission (Allow/Deny/Ask)
- AI classifier assistance
- Default: Ask first, then do
Codex CLI: Unsupervised Autonomy
- Full-Auto mode (--full-auto)
- Cloud "fire-and-forget" execution
- 3-tier sandbox (coarse grain)
- Session Resume
- Default: Do first, report later
Sandbox Security
| Aspect | Claude Code | Codex CLI |
|---|---|---|
| Isolation Layer | Application | OS Kernel |
| Bypass Difficulty | Medium | Very High |
| Programmability | Very High (17 Hooks) | Low (3 modes) |
| Network Control | Hook-level | Kernel default-off |
| Enterprise Custom | Rich (Policy API) | Limited (Config) |
Pricing Comparison
| Tier | Claude Code | Codex CLI |
|---|---|---|
| Entry | Pro $20/mo | Plus $20/mo |
| Heavy User | Max $100-200/mo | API pay-as-you-go |
| API Input | Sonnet: $3/M, Opus: $5/M | GPT-5.4: $1.25/M |
| API Output | Sonnet: $15/M, Opus: $25/M | GPT-5.4: $10/M |
| Cache Read | -90% ($0.50/M for Opus) | Native support |
When to Choose Each
Choose Claude Code for:
- Complex code refactoring and architecture design
- React/frontend component development
- Large codebase deep analysis
- Enterprise security customization
Choose Codex CLI for:
- DevOps/infrastructure scripting
- CI/CD automation pipelines
- Budget-sensitive batch tasks (3-4× token efficiency)
- Security-critical environments (kernel sandbox)
- Open source audit and customization needs