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Lesson 14
8 min
CASS: Learning from History
Search across all past agent sessions
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Search across all past agent sessions
Mark complete to track your learning progress.
Search across all past agent sessions to reuse solved problems.
CASS (Coding Agent Session Search) indexes all your past agent conversations—Claude Code, Codex, Antigravity, Cursor, and more—so you can find solutions to problems you've already solved.
It's like having a searchable memory of everything your agents have ever done across all projects.
Claude, Codex, Antigravity/Gemini, Cursor, ChatGPT sessions
Search across code, prompts, and responses
Find solutions from any project or machine
Instant results with context snippets
You've likely solved many problems before with agents. Without CASS:
You hit an error you've seen before but can't remember the fix
Search CASS for the error message → find the exact solution
New project needs auth—you've implemented it before
Search 'authentication' → find your past implementation
Different agent solved a similar problem better
Search across all agents → find the best approach
Important: Never run bare cass—it launches a TUI that may block your session. Always use --robot or --json.
Find any mention of a term
cass search "database migration" --robot
Only search Claude Code sessions
cass search "error handling" --agent claude --robot
Search last 7 days
cass search "docker" --days 7 --robot
Just essential fields
cass search "auth" --robot --fields minimal --limit 10
Find solutions to specific errors
cass search "Cannot read property of undefined" --robot
Find past solutions for specific error messages across all agent sessions
CASS returns structured results with session info and snippets:
$ cass search "PostgreSQL connection" --robot --limit 2{"hits": [{"source_path": "/home/ubuntu/.claude/projects/.../session.jsonl","line_number": 87,"agent": "claude_code","workspace": "/projects/myapp","snippet": "...fixed the PostgreSQL connection by setting pool_size=20...","score": 0.92},{"source_path": "/home/ubuntu/.codex/sessions/2025-01-12.jsonl","line_number": 45,"agent": "codex","workspace": "/projects/backend","snippet": "...PostgreSQL connection string format: postgres://user:pass...","score": 0.85}],"_meta": { "query": "PostgreSQL connection", "took_ms": 42 }}
cass expand with the source path and line number to see the full conversation context!Use specific search terms
'PostgreSQL timeout error' is better than just 'error'
Filter by agent for focused results
If you remember which agent solved it, use --agent
Check multiple solutions
Different agents may have solved it differently
Use --days for recent context
Older solutions might use outdated patterns
1# Check your indexing status2$ cass health34# Search for a common pattern5$ cass search "import" --robot --limit 367# View full documentation8$ cass robot-docs guide