In the latest Claude Code 2.1.72 update (released March 10, 2026), Anthropic introduced the /btw (By The Way) command. This feature addresses one of the most common frustrations in agentic coding: the “context bloat” caused by asking quick clarifying questions in the middle of a complex task.
The Problem: Context Contamination
When Claude Code is working on a major feature (like a refactor spanning five files), asking a side question (e.g., “What was that API endpoint again?”) usually injects that question and its answer into the main conversation history. This consumes tokens, clutters the “mental model” Claude has of your project, and can lead to performance degradation or “distraction” in the main task.
The Solution: /btw <question>
The /btw command acts as an isolated sidebar. When you use it, Claude spawns a temporary “ephemeral” agent to answer your query.
- Zero History Impact: The question and its answer are not saved to your current session’s conversation history.
- Context Isolation: It allows you to check documentation, verify a command, or ask for a quick explanation without “derailing” the main agentic loop.
- Instant Result: Once you have your answer, you can immediately continue your main coding task exactly where you left off, with a perfectly clean context window.
Common Use Cases
| You want to… | Use the /btw command like this: |
| Check a Syntax | /btw what is the regex for a valid UUID again? |
| Verify a Path | /btw where is the dev-config stored in this repo? |
| Review a Method | /btw remind me of the parameters for the 'sendNotification' utility. |
| Run a Quick Calc | /btw what is 2^24 in decimal? |
Other Key Commands in 2.1.72
Alongside /btw, the March update added several other high-utility commands for power users:
/loop <interval> <prompt>: Runs a specific prompt or command on a recurring timer (e.g.,/loop 5m check the deploy status)./plan <description>: A shortcut that enters Plan Mode and immediately starts analyzing the specific problem you described./resume: Now features a vastly improved UI that shows session names and branch details, making it easier to jump back into work from yesterday.
