Casting

Cast a Persona onto your CLI 🎭

Casting is a wrapper tool that gives existing CLI tools an AI-driven "personality". Transform mundane command-line tools into friendly characters that assist you.

• Easy Setup: Automatically generate system prompts from existing tool's --help output or OpenAPI specs
• Customizable Personas: Specify personality with keywords like akarui (cheerful), teineina (polite)
• Claude Code Integration: Launch Claude Code with generated prompts for interactive REPL dialogue
• API Support: Create personas for REST APIs using OpenAPI v3 specifications
• Backward Compatible: Automatic migration of old configurations to new format

cargo install casting-cli

git clone https://github.com/ynishi/casting.git
cd casting
cargo install --path crates/casting-cli

After installation, the casting command will be available in your PATH.

Shell Completion (Optional)

To enable shell completion for zsh, run:

casting completion zsh > ~/.zsh/completions/_casting

Then add the following to your ~/.zshrc if not already present:

fpath=(~/.zsh/completion $fpath)
autoload -Uz compinit && compinit

For other shells (bash, fish, powershell, elvish), replace zsh with the appropriate shell name.

git clone https://github.com/yourusername/casting.git
cd casting
cargo build --release

Use ./target/release/casting to run the tool.

For CLI Tools:

# Configure git with a "polite" persona
casting make git --persona teineina

# Configure ls with a "cheerful" persona
casting make ls --persona akarui

For APIs (OpenAPI v3):

# Configure Petstore API with a "cheerful" persona
casting make petstore \
  --spec https://petstore3.swagger.io/api/v3/openapi.json \
  --base-url https://petstore3.swagger.io/api/v3 \
  --persona akarui

casting list

Example output:

📁 Configured Tools:

  petstore
    🎭 Persona: akarui
    🌐 Type: API
    📍 Base URL: https://petstore3.swagger.io/api/v3
    📄 Spec: https://petstore3.swagger.io/api/v3/openapi.json
    📅 Created: 2025-11-28 03:02:26

  git
    🎭 Persona: teineina
    📍 Type: CLI
    📍 Binary: /opt/homebrew/bin/git
    📅 Created: 2025-11-23 13:17:03

  ls
    🎭 Persona: akarui
    📍 Type: CLI
    📍 Binary: /bin/ls
    📅 Created: 2025-11-23 13:16:10

💡 Use with: casting repl <TOOL>

For CLI Tools:

casting repl git

Claude Code launches and behaves as the git persona:

> Introduce yourself!

⏺ Hello! I'm Git 🌿

  I'm a version control system here to support
  your code development with utmost care.

  ...

For APIs:

casting repl petstore

Claude Code launches with the Petstore API persona and can make API calls on your behalf:

> Show me all available pets!

⏺ Let me fetch all the pets for you! ✨

  [Makes API call via Bash tool...]
  curl -X GET "https://petstore3.swagger.io/api/v3/pet/findByStatus?status=available"

  Found 3 available pets! 🐾
  ...

※ Can be created without persona - defaults to standard support tone

Casting supports OpenAPI v3 specifications, allowing you to create personas for REST APIs.

• OpenAPI v3 only: Swagger v2 is not supported
• Spec URL: Must be accessible via HTTP/HTTPS
• Base URL: The API's base endpoint

• Automatic Documentation: Parses OpenAPI spec and generates human-readable endpoint documentation
• Persona Integration: APIs can have personalities just like CLI tools
• Claude-Powered Interactions: Claude Code uses the Bash tool to make curl requests on your behalf

# Public OpenAPI v3 APIs
casting make petstore \
  --spec https://petstore3.swagger.io/api/v3/openapi.json \
  --base-url https://petstore3.swagger.io/api/v3 \
  --persona akarui

# Your own API
casting make myapi \
  --spec https://api.example.com/openapi.json \
  --base-url https://api.example.com/v1 \
  --persona teineina

casting/
├── crates/
│   ├── casting-cli/    # Main CLI tool
├── docs/
│   └── design/         # Design documents
│       └── overview.md
└── README.md

• MVP Implementation
  • casting make - Create tool configuration
  • casting list - List configured tools
  • casting repl - Launch Claude Code
• API Support
  • OpenAPI v3 spec parsing
  • API endpoint documentation generation
  • API personas with curl integration
  • Backward-compatible config migration (v1 → v2)

For detailed design philosophy and architecture, refer to:

• Design Overview - Architecture and implementation approach

Issues and Pull Requests are welcome!

Licensed under either of

• Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)

at your option.