# 2026-05-12 — Claude Tool Adapter

## Summary

The local Gateway Companion now has a bounded Anthropic tool-use adapter for Claude Code traffic.

## What Changed

- Anthropic request `tools` are rendered into a strict instruction for the text backend.
- OpenAI-style tool calls and compact JSON tool decisions are converted into Anthropic `tool_use` blocks.
- Forced `tool_choice: {type:"tool"}` returns a valid `tool_use` block even when the text backend returns an empty response.
- Streaming tool use emits Anthropic-compatible SSE:
  - `message_start`
  - `content_block_start`
  - `content_block_delta` with `input_json_delta`
  - `content_block_stop`
  - `message_delta`
  - `message_stop`

## Verification

- Non-stream synthetic request:
  - Tool: `read_file`
  - Result: `content[0].type=tool_use`
  - Input: `{"path":"/tmp/hello.txt"}`
- Streaming synthetic request:
  - Tool: `read_file`
  - Result: `input_json_delta`
  - Input: `{"path":"/tmp/stream.txt"}`
- Claude Code CLI smoke after the change still reached the Gateway and produced dashboard rows for `claude-code-companion`.

## Boundary

The Erik `claude-bridge` remains text-only and calls `claude --print --output-format text`. Native hosted Anthropic tool-use parity is not complete. The adapter now transports and synthesizes tool blocks for forced tool calls, but autonomous tool selection still depends on the text backend following the JSON tool instruction.