reverse-api-engineer

Limitations

• This tool executes code locally using Claude Code—please monitor output
• Some websites employ advanced bot-detection that may limit capture or require manual interaction

🚀 Installation

Using uv (recommended)

# Basic installation
uv tool install reverse-api-engineer

# With agent mode support (includes browser-use with HAR recording)
uv tool install 'reverse-api-engineer[agent]' --with 'browser-use @ git+https://github.com/browser-use/browser-use.git@49a345fb19e9f12befc5cc1658e0033873892455'

Using pip

# Basic installation
pip install reverse-api-engineer

# With agent mode support
pip install 'reverse-api-engineer[agent]'
pip install git+https://github.com/browser-use/browser-use.git@49a345fb19e9f12befc5cc1658e0033873892455

Post-installation

Install Playwright browsers:

playwright install chromium

Enhanced Pricing Support (Optional)

By default, Reverse API Engineer includes pricing data for the most common models (Claude 4.6, Gemini 3). For extended model coverage (100+ additional models including OpenAI GPT, Mistral, DeepSeek, and more), install with pricing extras:

# With uv
uv tool install 'reverse-api-engineer[pricing]'

# With pip
pip install 'reverse-api-engineer[pricing]'

This enables automatic pricing lookup via LiteLLM for models not in the built-in database. The pricing system uses a 3-tier fallback:

1. Local pricing (highest priority) - Built-in pricing for common models
2. LiteLLM pricing (if installed) - Extended coverage for 100+ models
3. Default pricing (ultimate fallback) - Uses Claude Sonnet 4.6 pricing

Cost tracking will always work, with or without the pricing extras installed.

🚀 Quick Start

Launch the interactive CLI:

reverse-api-engineer

The CLI has four modes (cycle with Shift+Tab):

• manual: Browser capture + AI generation
• engineer: Re-process existing captures
• agent: Autonomous AI browser agent (default: auto mode with MCP-based browser + real-time reverse engineering)
• collector: AI-powered web data collection (very minimalist version for now)

Example workflow:

$ reverse-api-engineer
> fetch all apple jobs from their careers page

# Browser opens, navigate and interact
# Close browser when done
# AI generates production-ready API client

# Scripts saved to: ./scripts/apple_jobs_api/

📖 Usage Modes

Manual Mode

Full pipeline with manual browser interaction:

1. Start the CLI: reverse-api-engineer
2. Enter task description (e.g., "Fetch Apple job listings")
3. Optionally provide starting URL
4. Browse and interact with the website
5. Close browser when done
6. AI automatically generates the API client

Output locations:

• ~/.reverse-api/runs/scripts/{run_id}/ (permanent storage)
• ./scripts/{descriptive_name}/ (local copy with readable name)

Engineer Mode

Re-run AI generation on a previous capture:

# Switch to engineer mode (Shift+Tab) and enter run_id
# Or use command line:
reverse-api-engineer engineer <run_id>

Agent Mode

Fully automated browser interaction using AI agents:

1. Start CLI and switch to agent mode (Shift+Tab)
2. Enter task description (e.g., "Click on the first job listing")
3. Optionally provide starting URL
4. Agent automatically navigates and interacts
5. HAR captured automatically
6. API client generated automatically

Agent Provider Options:

• auto (default): Uses MCP-based browser automation with Claude Agent SDK & Opencode. Combines browser control and real-time reverse engineering in a single workflow. No additional installation required beyond the base package.
• browser-use: Uses browser-use library for browser automation. Requires installation with [agent] extra and browser-use from specific git commit (includes HAR recording support).
• stagehand: Uses Stagehand for browser automation with Computer Use models.

Change agent provider in /settings → "agent provider".

Collector Mode

Web data collection using Claude Agent SDK:

1. Start CLI and switch to collector mode (Shift+Tab)
2. Enter a natural language prompt describing the data to collect (e.g., "Find 3 JS frameworks")
3. The agent uses WebFetch, WebSearch, and file tools to autonomously collect structured data
4. Data is automatically exported to JSON and CSV formats

Output locations:

• ~/.reverse-api/runs/collected/{folder_name}/ (permanent storage)
• ./collected/{folder_name}/ (local copy with readable name)

Output files:

• items.json - Collected data in JSON format
• items.csv - Collected data in CSV format
• README.md - Collection metadata and schema documentation

Model Configuration: Collector mode uses the collector_model setting (default: claude-sonnet-4-6). This can be configured in ~/.reverse-api/config.json.

Example workflow:

$ reverse-api-engineer
> Find 3 JS frameworks

# Agent autonomously searches and collects data
# Data saved to: ./collected/js_frameworks/

🏷️ Tags

Tags provide additional control and functionality within each mode:

Manual/Agent Mode Tags

• @record-only - Record HAR file only, skip reverse engineering step

  • Example: @record-only navigate checkout flow
  • Useful when you want to capture traffic for later analysis

• @codegen - Record browser actions and generate Playwright automation script

  • Example: @codegen navigate to google
  • Captures clicks, fills, and navigations to create a reusable Playwright script

Engineer Mode Tags

• @id <run_id> - Switch context to a specific run ID

  • Example: @id abc123
  • Loads a previous capture session for re-engineering

• @id <run_id> <prompt> - Run engineer on a specific run with instructions

  • Example: @id abc123 extract user profile
  • Re-processes a capture with new instructions

• @id <run_id> --fresh <prompt> - Start fresh (ignore previous scripts)

  • Example: @id abc123 --fresh restart analysis
  • Generates new code from scratch, ignoring previous implementations

• @docs - Generate API documentation (OpenAPI spec) for the latest run

  • Example: @docs
  • Creates OpenAPI specification from captured traffic

• @id <run_id> @docs - Generate API documentation for a specific run

  • Example: @id abc123 @docs
  • Creates OpenAPI specification for a specific capture session

🔧 Configuration

Settings stored in ~/.reverse-api/config.json:

{
  "agent_provider": "auto",
  "browser_use_model": "bu-llm",
  "claude_code_model": "claude-sonnet-4-6",
  "collector_model": "claude-sonnet-4-6",
  "opencode_model": "claude-sonnet-4-6",
  "opencode_provider": "anthropic",
  "output_dir": null,
  "output_language": "python",
  "real_time_sync": true,
  "sdk": "claude",
  "stagehand_model": "openai/computer-use-preview-2025-03-11"
}

Model Selection

Choose from Claude 4.6 models for API generation:

• Sonnet 4.6 (default): Balanced performance and cost
• Opus 4.6: Maximum capability for complex