chatchain

ChatChain

A lightweight, cross-platform AI chat CLI built with Go. Supports multiple providers, streaming responses, file attachments, and an interactive terminal UI.

Features

• Multi-provider — OpenAI, OpenAI Responses API, Anthropic, Gemini, Vertex AI, and OpenClaw, with custom base URL support
• Interactive model selection — arrow-key navigation with filtering
• Streaming responses — real-time token output with loading spinner
• File attachments — send images, PDFs, and text files alongside messages with Tab-completion for file paths
• Non-interactive mode — single message in, response out, pipe-friendly
• Conversation history — full context maintained within a session
• System prompt — set via flag or interactive input
• Config file — persistent API keys, default models, and custom provider aliases via ~/.chatchain.yaml
• Styled terminal output — color-coded prompts

Install

Homebrew (macOS)

brew tap joyqi/tap
brew install chatchain

Go

go install github.com/joyqi/chatchain@latest

Build from source

git clone https://github.com/joyqi/chatchain.git
cd chatchain
go build -o chatchain .

Claude Code Plugin

ChatChain provides a Claude Code plugin, allowing you to call other LLMs directly within Claude Code.

Plugin Install

# Add the marketplace
/plugin marketplace add joyqi/chatchain

# Install the plugin
/plugin install chatchain@chatchain-marketplace

Plugin Usage

Slash command — manually ask another LLM:

/chatchain:ask openai gpt-4o "What is the meaning of life?"
/chatchain:ask anthropic claude-sonnet-4-20250514 "Explain monads"
/chatchain:ask gemini "Write a haiku"

Agent skill — Claude automatically uses ChatChain when you ask it to query another LLM:

> Use chatchain to ask GPT what is 1+1
> Ask Gemini to explain quicksort via chatchain

Local Testing

claude --plugin-dir ./chatchain-plugin

Usage

chatchain [openai|anthropic|gemini|vertexai|openresponses|openclaw] [flags]

Flags

Flag	Short	Description
--key	-k	API key (or set via env var)
--url	-u	Custom base URL
--model	-M	Model name (skip interactive selection)
--temperature	-t	Sampling temperature, 0.0-2.0 (omit to use provider default)
--message	-m	Send a single message and print the response (non-interactive, use - to read from stdin)
--system	-s	System prompt (omit value for interactive input)
--list	-l	List configured providers, or models for a given provider
--config	-c	Path to config file (default: ~/.chatchain.yaml)
--verbose	-v	Print HTTP request/response bodies for debugging

Environment Variables

Variable	Provider
OPENAI_API_KEY	OpenAI / OpenResponses
ANTHROPIC_API_KEY	Anthropic
GOOGLE_API_KEY	Gemini / Vertex AI
OPENCLAW_GATEWAY_TOKEN	OpenClaw

Config File

ChatChain supports YAML config files for persistent settings and custom provider aliases.

Config Lookup Order

1. ~/.chatchain.yaml or ~/.chatchain.yml (global)
2. ./.chatchain.yaml or ./.chatchain.yml (project-local, merges over global)
3. -c/--config <path> (explicit, highest priority, used alone)

Same-name providers in later files override earlier ones.

Priority

For individual values: CLI flag > env var > config file.

Example

# ~/.chatchain.yaml
providers:
  openai:
    key: sk-official
    model: gpt-4o

  deepseek:                  # custom alias
    type: openai             # underlying provider type
    key: sk-deepseek-xxx
    url: https://api.deepseek.com/v1
    model: deepseek-chat
    system: "You are a helpful coding assistant"

  claude:
    type: anthropic
    key: sk-ant-xxx
    model: claude-sonnet-4-20250514

With this config:

# Use the "deepseek" alias — resolves to OpenAI provider with DeepSeek's key/URL/model
chatchain deepseek -m "hello"

# Config key used, no need for -k
chatchain openai -m "hi" -M gpt-4o

# CLI flag overrides config
chatchain openai -k sk-override -m "hi" -M gpt-4o

Chat Commands

In interactive mode, the following commands are available:

Command	Description
/file <path>	Attach a file (image, PDF, or text). Supports Tab completion for file paths.
/files	List all currently attached files
/clear	Remove all attached files
/save [path]	Save conversation history to a Markdown file (default: history.md)
/import [path]	Import conversation history from a saved Markdown file (default: history.md)

Attached files are sent with your next message, then cleared automatically.

Supported File Types