claude-code-pi

claude-code-pi registers a claude-code-cli provider in Pi and delegates every model call to the local Claude Code CLI with claude -p / --print.

This extension is intentionally a CLI bridge. It does not use the Anthropic SDK, direct HTTP APIs, or Pi's built-in Claude provider as a fallback. If claude -p is unavailable or fails, the Pi model turn fails with setup guidance instead of silently using another transport.

Requirements

• Pi Coding Agent
• Claude Code CLI installed and available on the same machine:

claude --version

• Claude Code authenticated/configured according to your local Claude Code setup.

Install

From this repository:

npm run install-extensions

Then restart Pi or run:

/reload

For one-off development testing without copying:

pi -e ./extensions/claude-code-pi/src/index.ts

Usage

Pick provider claude-code-cli from /model, or start Pi directly:

pi --provider claude-code-cli --model sonnet

Bundled model aliases mirror common Claude Code CLI --model aliases:

Pi provider	Pi model id	Passed to Claude Code
claude-code-cli	sonnet	claude -p --model sonnet
claude-code-cli	opus	claude -p --model opus
claude-code-cli	fable	claude -p --model fable

Print-mode smoke test:

pi -p --provider claude-code-cli --model sonnet "Reply with exactly OK"

Direct Claude Code transport check:

claude -p --model sonnet --no-session-persistence --tools "" "Reply with exactly OK"

Commands:

/claude-code-pi status
/claude-code-pi models
/claude-code-pi test
/claude-code-pi help

Configuration

Environment variable	Description
CLAUDE_CODE_PI_BIN	Override the Claude Code executable path. Defaults to claude.
CLAUDE_CODE_PI_MODELS	Comma- or space-separated model aliases to register. Defaults to sonnet,opus,fable.
CLAUDE_CODE_PI_TIMEOUT_MS	Per-turn claude -p timeout in milliseconds. Defaults to 300000.
CLAUDE_CODE_PI_CONTEXT_WINDOW	Override the advertised context window in tokens. Defaults to 1000000 (current Claude aliases serve 1M-token context windows).

Example:

CLAUDE_CODE_PI_MODELS="sonnet,opus,claude-fable-5" pi

Thinking levels

Pi thinking levels map to Claude Code's --effort flag:

Pi thinking level	Passed to Claude Code
off / unset	no --effort flag
minimal, low	--effort low
medium	--effort medium
high	--effort high
xhigh	--effort xhigh

Images

Models advertise image input. When a turn contains images, the extension switches to the stream-json transport (--input-format stream-json --output-format stream-json --verbose) and sends images as base64 content blocks over stdin. Text-only turns keep the plain-text transport.

How it works

For each Pi model turn, the extension:

1. Serializes Pi's system prompt, conversation transcript, and available tool schemas into one text prompt.
2. Spawns the local Claude Code CLI with claude -p --model <selected> --no-session-persistence --tools "" --output-format text, plus --effort <level> when a thinking level is set.
3. Writes the serialized prompt (or a stream-json user message with base64 image blocks) to Claude Code over stdin.
4. Converts Claude Code stdout into a Pi assistant text message, or converts <pi_tool_call>{...}</pi_tool_call> markers into native Pi tool calls.
5. Emits a clear assistant error if the CLI is missing, exits non-zero, is aborted, or times out.

The extension disables Claude Code's own tools with --tools "". Pi tool schemas are included in the prompt, and explicit <pi_tool_call>{...}</pi_tool_call> markers are handed back to Pi so Pi executes tools through its normal pipeline.

Notes and limitations

• This is slower than native HTTP providers because a claude -p process starts for each model turn.
• Tool calling is prompt-bridged with <pi_tool_call>{...}</pi_tool_call> markers, so it is less reliable than native provider tool calling but still keeps execution in Pi.
• Image input requires the stream-json transport and is supported for base64 image blocks; availability checks use claude --version, so real model calls may still fail if local Claude Code auth or account access is not configured.