What does the new /fork do in Claude Code 2.1.212?

In Claude Code 2.1.212, /fork copies the current conversation into a brand-new background session that shows up in claude agents while the original session keeps running. The old in-session subagent that /fork used to launch is now called /subtask, so branching and in-session delegation are separate commands.

Why did Claude Code add caps on WebSearch and subagents?

Claude Code 2.1.212 caps WebSearch tool calls and subagent spawns at 200 per session by default so a runaway loop cannot burn through tokens or the search quota. Both caps are tunable through CLAUDE_CODE_MAX_WEB_SEARCHES_PER_SESSION and CLAUDE_CODE_MAX_SUBAGENTS_PER_SESSION, and /clear resets the subagent budget.

What is MCP auto-background in Claude Code 2.1.212?

Claude Code 2.1.212 automatically moves MCP tool calls to the background once they run longer than two minutes so the interactive session stays responsive instead of blocking on a slow tool. The threshold is configurable through the CLAUDE_CODE_MCP_AUTO_BACKGROUND_MS environment variable.

How do I install or update to Claude Code 2.1.212?

Claude Code 2.1.212 ships via npm and Anthropic's own auto-updater. Running npm i -g @anthropic-ai/claude-code pulls the release, and existing installs will pick it up on next launch. The tagged release is on GitHub at github.com/anthropics/claude-code/releases/tag/v2.1.212.

Anthropic · 2026-07-17 · major

Claude Code 2.1.212 — /fork forks to a background session, agents get budgets

Claude Code 2.1.212 turns /fork into a background-session brancher, adds default 200-call caps on WebSearch and subagent spawns, and moves any MCP tool call over two minutes to the background so the session stays usable.

GitHub release page for anthropics/claude-code v2.1.212

Claude Code's latest release makes /fork a background-session brancher and gives long-running tool calls and subagents hard budgets.

Quick facts

Product	Claude Code
Version	v2.1.212
Released	2026-07-17
WebSearch cap	200 per session
Subagent spawn cap	200 per session
MCP auto-background	2 minutes
Install	npm i -g @anthropic-ai/claude-code

What is it?

Version 2.1.212 of Claude Code is a workflow release built around branching and budgets. /fork now copies the current chat into a new background session so you can explore a variation while the main run keeps going, and the in-session helper it used to launch is renamed /subtask.

How does it work?

Session-level counters cap WebSearch tool calls and subagent spawns at 200 by default, and /clear resets the subagent budget. MCP tool calls that pass a two-minute wall clock get pushed into the background automatically, controlled by CLAUDE_CODE_MCP_AUTO_BACKGROUND_MS.

Why does it matter?

The 2.1.212 changes address the two most common ways an agent hangs or burns tokens — a runaway search loop and a slow MCP tool that freezes the session. Combined with the branching /fork, Claude Code makes long, multi-thread agent runs easier to keep on the rails.

Who is it for?

Developers who run Claude Code as a long-lived agent with subagents, MCP servers, or heavy WebSearch use.

Frequently asked questions

What does the new /fork do in Claude Code 2.1.212?: In Claude Code 2.1.212, /fork copies the current conversation into a brand-new background session that shows up in claude agents while the original session keeps running. The old in-session subagent that /fork used to launch is now called /subtask, so branching and in-session delegation are separate commands.
Why did Claude Code add caps on WebSearch and subagents?: Claude Code 2.1.212 caps WebSearch tool calls and subagent spawns at 200 per session by default so a runaway loop cannot burn through tokens or the search quota. Both caps are tunable through CLAUDE_CODE_MAX_WEB_SEARCHES_PER_SESSION and CLAUDE_CODE_MAX_SUBAGENTS_PER_SESSION, and /clear resets the subagent budget.
What is MCP auto-background in Claude Code 2.1.212?: Claude Code 2.1.212 automatically moves MCP tool calls to the background once they run longer than two minutes so the interactive session stays responsive instead of blocking on a slow tool. The threshold is configurable through the CLAUDE_CODE_MCP_AUTO_BACKGROUND_MS environment variable.
How do I install or update to Claude Code 2.1.212?: Claude Code 2.1.212 ships via npm and Anthropic's own auto-updater. Running npm i -g @anthropic-ai/claude-code pulls the release, and existing installs will pick it up on next launch. The tagged release is on GitHub at github.com/anthropics/claude-code/releases/tag/v2.1.212.

Try it

npm i -g @anthropic-ai/claude-code