lingcode CLI

Install

Two paths. Pick whichever you already have.

Standalone — no app required

curl -fsSL https://lingcode.dev/install-cli.sh | sh

Downloads a signed, notarized tarball to ~/.lingcode/cli/ and symlinks it to ~/.local/bin/lingcode. The bundled Node bridge ships inside, so the Claude provider works without LingCode.app installed (you still need Node.js and an API key).

From an installed LingCode.app

/Applications/LingCode.app/Contents/Resources/bin/lingcode install

The install subcommand tries /usr/local/bin first, falls back to ~/.local/bin, prints a PATH hint if needed.

Quickstart

# One command to store a key in the Keychain (opens browser)
lingcode auth login

# Interactive session (Claude by default)
lingcode

# Interactive session with another provider
lingcode --provider ollama --model llama3.2
lingcode --provider groq --model llama-3.1-70b-versatile

# One-shot
lingcode ask "explain this error" < build.log
echo "what's 2+2?" | lingcode ask -

# Check your setup
lingcode auth status
lingcode --help

Interactive REPL

lingcode with no arguments drops you into an interactive multi-turn session. It's the same as lingcode repl, just shorter to type.

The REPL has two flavors depending on provider:

• Claude mode — full agentic loop: tool use, file edits, MCP servers, hooks, session resumption, permission prompts, colored diffs. Runs via the bundled Node bridge + @anthropic-ai/claude-agent-sdk.
• OpenAI-compatible mode — text-only streaming chat with any OpenAI-compatible endpoint. No tool use, but works against OpenAI, Groq, Together, OpenRouter, Mistral, xAI, Fireworks, Ollama, DeepSeek, and custom proxies.

Input editor

When stdin is a TTY, you get a proper line editor:

Prompt

The REPL prompt shows turn count and cumulative cost once they're non-zero:

lingcode> explain this repo
…
lingcode [1t $0.003]> now suggest a refactor
…
lingcode [2t $0.011]>

Providers

Pick with --provider; override model, base URL, or API key env var as needed.

Any OpenAI-compatible endpoint

lingcode --provider openai \
  --base-url https://my-proxy.example.com/v1 \
  --api-key-env MY_KEY_VAR \
  --model gpt-4o

Tool use, MCP, hooks, and session resumption are Claude-only — those features depend on the Agent SDK. Everything else in the REPL (slash commands, markdown rendering, token display, history, tab completion) works across all providers.

One-shot ask

# Simple
lingcode ask "summarise this repo's architecture"

# Pipe content in
cat error.log | lingcode ask "explain this"

# Read the entire prompt from stdin
echo "what is 2+2?" | lingcode ask -

# Switch provider
lingcode ask --provider groq "quick: what does this regex do? /\d{3}-\d{4}/"

# Claude with full tool use, auto-approved
lingcode ask --provider claude --yolo "add a .gitignore entry for .DS_Store"

# Attach a file
lingcode ask --provider claude --file screenshot.png "what's wrong in this UI?"

# Structured output (good for scripts)
lingcode ask --output-format stream-json "fix the failing test in main.swift"

Useful flags

Slash commands

Type these at the REPL prompt.

All providers

Claude-only

OpenAI-compatible only

Custom

Put a Markdown file at .claude/commands/<name>.md and invoke it as /project:<name>. Files at ~/.claude/commands/ are invoked as /user:<name>. Bare /<name> checks project first, then user. Any text after the command name is appended to the body.

$ echo "Explain the changes staged in git in plain English." > .claude/commands/explain-staged.md
$ lingcode
lingcode> /project:explain-staged

Auth & API keys

Three sources, checked in this order: environment variable, macOS Keychain, config file. Any one is enough.

# Browser-assisted: opens the provider console, prompts for the key, stores in Keychain
lingcode auth login
lingcode auth login --provider deepseek

# Direct
lingcode auth set anthropic sk-ant-...
lingcode auth set deepseek sk-...

# See what's configured (values masked)
lingcode auth status

# Remove a key
lingcode auth delete anthropic

About OAuth: Anthropic does not issue OAuth client IDs to third-party CLIs, so a true /login OAuth flow is not possible. lingcode auth login is the practical replacement — it opens the console in your browser, waits for you to paste the key, and stores it.

Other providers (openai, groq, together, openrouter, mistral, xai, fireworks, ollama) don't use the Keychain path — just set their environment variable in your shell:

export OPENAI_API_KEY=sk-...
export GROQ_API_KEY=gsk-...

MCP servers, hooks, custom commands

Compatible with Claude Code's project conventions.

MCP servers

Put a .mcp.json at the project root (or ~/.claude.json globally):

{
  "mcpServers": {
    "filesystem": {
      "type": "stdio",
      "command": "npx",
      "args": ["-y", "@modelcontextprotocol/server-filesystem", "."]
    }
  }
}

Override with --mcp-config <path>. Disable with --no-mcp. MCP is Claude-only.

Hooks

Put hooks in .claude/settings.json. They run as shell commands with CLAUDE_TOOL_NAME, CLAUDE_TOOL_INPUT, and (for PostToolUse) CLAUDE_TOOL_RESULT in the environment:

{
  "hooks": {
    "PreToolUse": [
      { "matcher": "Write|Edit", "hooks": [{ "type": "command", "command": "echo about to edit: $CLAUDE_TOOL_INPUT" }] }
    ],
    "Stop": [
      { "hooks": [{ "type": "command", "command": "say done" }] }
    ]
  }
}

Custom slash commands

Markdown files under .claude/commands/ (project) or ~/.claude/commands/ (user). Same format as Claude Code — the file body is the prompt.

Talking to the running app

When LingCode.app is open, these commands drive it over a Unix socket at ~/Library/Application Support/LingCode/ipc.sock:

Pass --headless to ask to force local execution even with the app open.

Subcommand reference

Troubleshooting

lingcode: ANTHROPIC_API_KEY is not set

Fix with lingcode auth login, or export in your shell, or run lingcode config set anthropic-api-key sk-ant-....

lingcode: <PROVIDER_API_KEY> is not set

OpenAI-compatible providers use plain env vars. For custom names: lingcode --provider openai --api-key-env MY_KEY.

lingcode: couldn't find Claude agent bridge

The Claude provider needs bridge.mjs, which ships inside LingCode.app or the standalone CLI tarball. Either install LingCode.app at /Applications, or point at a dev copy with export LINGCODE_AGENT_BRIDGE_DIR=/path/to/agent-bridge.

lingcode: cannot find `node` on PATH

Install Node.js (nodejs.org), reopen your shell, then retry. Or set NODE to an explicit path. Only needed for the Claude provider; OpenAI-compatible providers use pure Swift.

Rate-limited / 429 / overloaded

Both ask and repl retry automatically with exponential backoff (up to 5 attempts, up to 60s apart). You'll see rate limited (attempt N/5) — retrying in Xs… on stderr.

The app responds, but I wanted headless

lingcode ask routes through the app by default when it's open. Pass --headless to force local execution.

I pasted an API key into my terminal

Rotate it at the provider's dashboard. Anything in your shell history or tmux scrollback should be treated as leaked. Prefer lingcode auth login (browser paste) or lingcode auth set <provider> <key> — neither writes the key to stdout.