Codex Context Studio

Codex Context Studio

🧠 Context Control Panel for Codex

Make Codex's context visible, locatable, and precisely manageable — like memory.

Features · Architecture · Install · FAQ

English · 中文

---

⚡ In One Line

This project lets you see Codex's context consumption, what's retained after compression, and edit it yourself. It also lets you replace Codex's system prompt to break through Codex's limitations, and replace Codex's compression prompt for better compressed output.

---

🎯 Core Features

🔬 Context Visualization — See Inside Codex's Brain

View Codex's context by role, check token usage per turn, and see when prompts are injected.

✂️ Context Management — Take Over Codex's Memory

Chat with a dedicated secondary model to analyze, edit, compress, and manage the main Codex's context. You can plug in a cheap secondary model.

💡 Automatic Context Maintenance — Stay Focused Without Losing Memory

Automatically maintain Codex's context by compressing completed or unrelated history while preserving key decisions, constraints, current task state, and useful working memory. Codex stays focused without losing important context.

📈 Usage Panel — How Much Did This Session Cost?

View token consumption, cache hit rate, and estimated cost across your Codex session.

🔀 Prompt Replacement — Rewrite Codex's Default Prompts

Replace Codex's system prompt and native compression prompt for jailbreaking and better compression quality.

🔌 Local Proxy — Transparent, Non-Invasive

No Codex source code changes, no official tools replaced. Sits in the middle as a local proxy, compatible with all native features.

---

📸 Screenshots

Context Map & Secondary Model Chat

Context Compression Result

Automatic Context Maintenance

Prompt Replacement

Usage Panel

---

🏗️ Architecture

flowchart LR
    CD["Codex CLI / Desktop"]
    PX["Responses Proxy\n:8787"]
    WEB["Web Backend\n:8765"]
    FE["React Workbench"]
    OAI["OpenAI API / Upstream Model"]

    CD -- "POST /v1/responses" --> PX
    PX -- "Rebuilt request" --> OAI
    OAI -- "SSE stream" --> PX
    PX -- "SSE stream" --> CD

    FE -- "HTTP edit/settings" --> WEB
    WEB -- "HTTP proxy control" --> PX
    PX -. "WebSocket realtime events" .-> FE

How It Works:

Every Codex request follows the same path — there is no "pass-through if unedited" branch:

flowchart LR
    A["Codex sends request"] --> B["cursor diff"] --> C["Update transcript"] --> D["Rebuild input"] --> E["Forward upstream"]

• Transcript is the single source of truth: what users see in the workbench, edit, and what ultimately gets sent upstream
• Without edits, the rebuilt input is naturally equivalent to the original Codex input
• With edits, upstream receives the edited transcript + new content from the current turn
• During compression, Codex's native compression prompt is replaced with a custom version, and the result is written back to the transcript

---

🚀 Quick Start

1. Install

Download and run the latest Windows installer from Releases.

2. Enable CLI Proxy

codex ctx proxy on      # Enable proxy
codex                   # Use Codex normally
codex ctx proxy status  # Check status
codex ctx proxy off     # Disable proxy

3. Desktop Support