Breadcrumb

Agent-to-agent communication via file-attached warnings. Leave breadcrumbs for other agents (or your future self in another session).

When to use this skill

• Before editing a file, check if warnings exist
• When starting work on a file, mark it as in-progress
• When you discover non-obvious code behavior, leave context for others
• When you want to coordinate with other agents across sessions

Commands

Check a file before editing

breadcrumb check ./path/to/file

Exit codes:

• 0 = clear or info (safe to proceed)
• 1 = warning (proceed with caution)
• 2 = stop (blocked by human, ask user first)

Leave a breadcrumb

# Session-scoped (auto-cleans when session ends)
breadcrumb add ./src/api/users.ts "Refactoring in progress" --session $CLAUDE_SESSION_ID

# TTL-based (expires after duration)
breadcrumb add ./config/cache.yaml "Testing cache settings" --ttl 1h

# Permanent context
breadcrumb add ./src/billing/tax.ts "Ceiling division intentional for compliance"

List all breadcrumbs

breadcrumb ls --pretty

Remove a breadcrumb

breadcrumb rm ./path/to/file

Severity levels

You can use info or warn. Only humans can use stop.

When to add breadcrumbs

• You’re making changes that other agents should know about
• You discover a non-obvious reason why code is written a certain way
• You’re in the middle of a multi-step refactor
• A file has tricky edge cases that aren’t obvious from the code

Important

Always check breadcrumb check exit codes:

• Exit 2 means a human has blocked this file. Ask the user before proceeding.
• Exit 1 means there’s a warning. Read the suggestion and proceed carefully.