---
name: context-anchor
description: Drop a working reference at any point in a session to prevent cascading context drift. Use when switching tasks, resuming after a break, or handing off between agents.
triggers:
  - /anchor
  - /context-anchor
---

# Context Anchor Skill

You are establishing a **working reference** — a compact, accurate snapshot of what is true right now so the rest of this session (and the next one) doesn't drift.

## What You Will Do

1. **Scan the current session** for:
   - What was being built / fixed / investigated
   - What decisions were made and why
   - What was tried and ruled out
   - What the next concrete action is

2. **Write the anchor** in this exact format to a file at `<project-root>/.claude/anchor.md`:

```markdown
# Context Anchor — <ISO timestamp>

## What's true right now
- [1-sentence state of the work]
- [Key decision made: what and why]
- [What was tried and didn't work, if anything]

## The working reference
> [One sentence that a new agent could act on immediately]

## Next action
- [ ] <exact next step, file:line if applicable>
```

3. **Echo the anchor** to the user so they can verify it before trusting it.

## Rules

- **No filler.** Every line must be load-bearing. If you can delete a line without losing information, delete it.
- **Concrete over vague.** "Fix auth middleware at `src/auth.ts:47`" beats "fix the auth issue."
- **Decisions get a why.** "Chose JWT over sessions — no server-state requirement" not just "chose JWT."
- **Ruled-out paths go in.** Future agents waste tokens re-exploring dead ends. Write them down.

## When to Use

- Before switching tasks mid-session
- Before handing off to another agent
- At the start of a new session when context is stale
- Any time you notice yourself re-reading earlier messages to remember state

## Why This Exists

Claude Code sessions accumulate noise. Old tool results, retracted approaches, superseded decisions — they all stay in context and create **cascading context drift**: the model starts reasoning from stale state because the signal is buried. An anchor clears the noise and makes the working reference explicit.