Claude Code × OpenCode × Codex: a three-way deep comparison

3.1 Product sovereignty: closed-source peak vs community kitchen vs official open hangar

Who it is for

• team already in the Anthropic ecosystem → Claude Code
• want to embed in your own product / multi-model → OpenCode
• want to audit the sandbox and the Rust implementation / lean OpenAI → Codex

flowchart LR
  A["要改引擎源码"] --> B{"要多模型中立?"}
  B -->|是| OC["OpenCode"]
  B -->|否·偏 OpenAI| CX["Codex"]
  A2["不要源码·要体验"] --> CC["Claude Code"]

3.2 Permission routes: five gates vs Ruleset vs approval × OS sandbox

Pros and cons

• CC: semantically rich, teaching-friendly; but you cannot see the full proprietary implementation
• OpenCode: configurable down to the grain; misconfiguration risk sits on the user
• Codex: even if the user clicked allow, the OS sandbox may still block—two walls on different layers

Who it is for: strong compliance / untrusted code execution → look at Codex’s sandbox first; want fine-grained product semantics of “may this command run” → CC/OpenCode rule systems.

3.3 Tool ABI: full family vs large toolbox vs shell+patch

Pros and cons

• Full family: the model dreams less; permissions can be tagged per tool
• shell+patch: aligned with some models’ training distribution, narrower implementation surface, but shell is too wide and needs the sandbox as a backstop

MiMo footnote: on OpenCode, hide read/edit from GPT and expose bash/apply_patch/exec—that is leaning toward the Codex ABI.

3.4 Context philosophy: CLAUDE.md vs Memory/Config vs AGENTS.md+constitution

Who it is for: want an “external long-term memory workspace” → look at OpenCode/MiMo; want “historical hygiene + typed injection” → look at Codex; want official CC habits → CLAUDE.md.

3.5 Architecture shape: single product vs server-as-body vs Rust hangar

flowchart TB
  subgraph CC["Claude Code"]
    C1["产品循环"]
  end
  subgraph OC["OpenCode"]
    O1["Server"] --> O2["TUI/Desktop/Web"]
  end
  subgraph CX["Codex"]
    X1["codex-core"] --> X2["TUI"]
    X1 --> X3["Exec"]
    X1 --> X4["App-server"]
    X1 --> X5["MCP server"]
  end

5.1 If you have only one weekend

1. Claude Code: how it works (deep dive) Chapters 4–7 (input, context, loop, permissions)—build the concept dictionary
2. opencode analysis Chapters 2, 6, 7—see the open-source server shape
3. Codex: tasks/regular.rs + the first 350 lines of turn.rs + AskForApproval + SandboxType

5.2 If you are writing your own agent

5.3 If you have to do a “comparison defense”

Prepare three unbeatable sentences:

1. “CC wins on integrated experience, loses on an engine you cannot fork.”
2. “OpenCode wins on neutrality and clients, loses on you having to be the integrator.”
3. “Codex wins on official open source + OS sandbox, loses on docs living elsewhere and OpenAI gravity.”

8.1 A weekend personal project

You are one person changing a side project, already on Claude Pro:

• Prefer Claude Code: shortest path; the tool atlas is teaching-friendly
• If you want to look at an open implementation to practice: clone Codex, run doctor, read the first 350 lines of run_turn

8.2 The company wants multi-model and self-hosting

Legal wants MIT; the model has to be swappable to domestic / third-party:

• Prefer OpenCode
• Use Codex as a “sandbox reference implementation” and copy the Seatbelt/Landlock idea, rather than locking OpenAI

8.3 Must run an agent non-interactively in CI

• Codex: codex exec + AskForApproval::Never + a tight sandbox
• OpenCode: headless/serve + permission rules
• Claude Code: look at official non-interactive / CI guidance (product-facing)

8.4 Building a design host (driving several CLIs)

• Look at Open Design first: it treats claude / codex / opencode as engines
• This comparison helps you understand the temperament of the three engines on “the other end of the socket”

8.5 Already using MiMo

You see a GPT ABI on an OpenCode fork—go back to Codex and read apply_patch / shell / view_image, then back to MiMo and read usesGPTToolset, and a closed loop forms.

sequenceDiagram
  participant Dev as 你
  participant CC as Claude_Code
  participant OC as OpenCode
  participant CX as Codex
  Dev->>CC: 建立词典（输入/循环/权限）
  Dev->>OC: 看开源服务器形态
  Dev->>CX: 看 OS 沙箱与 turn 工业态
  Dev->>Dev: 决定抄哪一层

11.1 “Delete the build directory”

11.2 “A long session changing a week of requirements”

11.3 “Embed it in your own IDE”

11.4 “Must be multi-model”

Only OpenCode (and forks) treat multi-provider as first-class; CC/Codex each anchor their own model ecosystem (Codex has crates such as ollama, but the main narrative is still OpenAI).

flowchart TB
  S["用户故事"] --> T1["删目录"]
  S --> T2["长会话"]
  S --> T3["嵌 IDE"]
  S --> T4["多模型"]
  T1 --> X1["看权限×沙箱"]
  T2 --> X2["看压缩×记忆"]
  T3 --> X3["看协议面"]
  T4 --> X4["几乎只能 OpenCode"]