topic-switch

topic-switch

A Claude Code plugin that notices when you've drifted to a new topic and gently reminds you to save context before moving on.

The Problem

Long Claude Code sessions accumulate context from multiple tasks. You start fixing a bug in auth, jump to adding a volume feature, then tweak the CI pipeline. By message 40, Claude is carrying context from three unrelated tasks -- slowing things down and wasting tokens.

How It Works

topic-switch watches what files you're touching. When you drift from one area of your codebase to another, Claude gets a gentle nudge:

You've moved from cmd/vm to cmd/volume. Want me to save context and compact before continuing?

• Say yes -- Claude saves a session summary to memory, compacts the conversation, and you continue with a clean slate
• Ignore it -- the reminder disappears on its own, no interruption

It also nudges after 30+ messages (configurable), regardless of topic -- because long sessions get heavy.

No LLM calls. No slowdown.

Detection runs entirely in bash. Three lightweight hooks:

1. PostToolUse -- tracks which files you're touching (~5ms, async)
2. UserPromptSubmit -- checks if a topic shift was detected (one file read)
3. SessionStart -- resets state, nudges setup on first run

Claude itself decides whether the shift is worth mentioning. False positives get naturally filtered by Claude's judgment.

Install

From Claude Code Plugin Marketplace

claude plugin install topic-switch

From Source

git clone https://github.com/nusmql/topic-switch.git
claude --plugin-dir /path/to/topic-switch

Quick Start

On first run in a project, you'll see:

[topic-switch] New project detected. Run /topic-switch:init to set up topic detection.

Run /topic-switch:init and the plugin will:

1. Scan your project structure
2. Propose topic boundaries it detected (e.g., cmd/*, src/features/*)
3. Ask you to confirm or adjust
4. Save the config -- you're done

Takes about 30 seconds.

Commands

Command	What it does
/topic-switch:init	Set up topic boundaries for your project
/topic-switch:save-and-compact	Save session summary to memory + compact context

Configuration

Stored per-project at .claude/topic-switch.json (not committed to git):

{
  "topic_roots": ["internal/verda-cli/cmd/*"],
  "ignore": ["internal/verda-cli/cmd/util"],
  "message_threshold": 30
}

Field	Description	Default
topic_roots	Glob patterns defining topic boundaries in your project	(detected by init)
ignore	Directories to skip (shared utilities, etc.)	[]
message_threshold	Message count before suggesting a compact	30

Supported project patterns

The init scan auto-detects common structures:

Stack	Detected patterns
Go	cmd/*, internal/*, pkg/*
React / Next.js	src/features/*, src/pages/*, src/components/*, app/*
Monorepo	packages/*, apps/*, services/*
Python	src/*, root modules with __init__.py
Other	Top-level directories with 3+ source files

You can always adjust the patterns manually or re-run /topic-switch:init.

How Detection Works

You edit cmd/vm/create.go, cmd/vm/wizard.go    (topic: vm)
You edit cmd/vm/list.go                        (topic: vm, no shift)
You edit cmd/volume/create.go                  (topic: volume -- SHIFT!)
                                                       |
                              next prompt gets a gentle reminder
                                                       |
                              Claude asks: "Want to save and compact?"

Runtime state is stored in ~/.cache/topic-switch/ (auto-cleaned, never committed).

Requirements

• Claude Code CLI
• bash and jq

License

MIT