Fine-Grained Tool Streaming Patch

Enables incremental streaming of tool call arguments (input_json_delta) in Claude Code cli.js.

Problem

Pristine Claude Code cli.js does NOT enable the fine-grained-tool-streaming-2025-05-14 beta by default. Tool arguments arrive as a single burst at the end instead of streaming character-by-character.

Solution

Add Q.push("fine-grained-tool-streaming-2025-05-14") to the betas builder function.

Patch Procedure

1. Find the patch point

grep -n "process.env.ANTHROPIC_BETAS" cli.js