- name
- cass
- description
- Coding Agent Session Search - unified CLI/TUI to index and search local coding agent history from Claude Code, Codex, Gemini, Cursor, Aider, ChatGPT, Pi-Agent, Factory, and more. Purpose-built for AI agent consumption with robot mode.
# CASS - Coding Agent Session Search
Unified, high-performance CLI/TUI to index and search your local coding agent history. Aggregates sessions from **23 agents**, including Codex, Claude Code, Gemini CLI, Cline, OpenCode, Amp, Cursor, ChatGPT, Aider, Pi-Agent, Factory (Droid), OpenHands, Antigravity, and Grok Build.
## CRITICAL: Robot Mode Required for AI Agents
**NEVER run bare `cass`** - it launches an interactive TUI that blocks your session!
```bash
# WRONG - blocks terminal
cass
# CORRECT - JSON output for agents
cass search "query" --robot
cass search "query" --json # alias
```
**Always use `--robot` or `--json` flags for machine-readable output.**
---
## Quick Reference for AI Agents
### Bounded History Retrieval
For a quick project-history question, start with one scoped query. The flag set
below is verified on cass 0.8.0; check `cass --version` and `cass search --help`
once per installed version. If `--no-maintenance` is unsupported, stop and report
the version mismatch; silently removing it permits maintenance.
```bash
# Specific terms, one workspace, recent history, small cited result set
cass search "performance regression" --workspace /path/to/project --days 7 \
--mode lexical --no-maintenance --robot --robot-meta --fields minimal \
--limit 5 --max-tokens 2000 --timeout 2000
# Expand only a useful hit, using its exact source_path and line_number
cass view /path/to/session.jsonl -n 42 -C 3 --json --timeout 2000
```
`--timeout` is in milliseconds; `--max-tokens` is an approximate output budget,
not a CPU or memory limit. Apply a caller-side wall-clock deadline as well (for
example, GNU `timeout 10s` before the command). Exit 124 from that wrapper is an
incomplete attempt; its interrupted stdout may not be valid JSON. In JSON search
output, inspect `budget.timed_out` even after exit 0: empty timed-out hits do not
prove that no history exists.
`view -C 3` limits surrounding lines, not bytes or tokens; a single JSONL record
can be large. Check its output size before adding excerpts to a prompt.
Hybrid remains the product default. Explicit lexical mode keeps this workflow
out of semantic inference; `--no-maintenance` prevents index repair, catch-up,
and daemon auto-spawn. If it returns `maintenance-required`, report that blocker
and stop this retrieval attempt. Do not turn a summary request into an index,
repair, model-install, wildcard-aggregate, or repeated health/status workflow.
Use readiness commands when diagnosing readiness; review their proposed actions
before starting a separate mutating task. Broaden dates or terms deliberately
after a completed query; choose semantic/hybrid only when conceptual retrieval
is needed and its cost is acceptable. Preserve source/line citations in summaries.
### Essential Commands
```bash
# Find the current session for this workspace
cass sessions --current --json
# List recent sessions for a specific project
cass sessions --workspace "$(pwd)" --json --limit 5
# Common agent flow: find current session, then export it
cass export-html "$(cass sessions --current --json | jq -r '.sessions[0].path')" --json
# Search with JSON output
cass search "authentication error" --robot --limit 5
# Search with metadata (elapsed_ms, cache stats, freshness)
cass search "error" --robot --robot-meta
# Minimal payload (path, line, agent only)
cass search "bug" --robot --fields minimal
# View source at specific line
cass view /path/to/session.jsonl -n 42 --json
# Expand context around a line
cass expand /path/to/session.jsonl -n 42 -C 5 --json
# Capabilities discovery
cass capabilities --json
# Full API schema
cass introspect --json
# LLM-optimized documentation
cass robot-docs guide
cass robot-docs commands
cass robot-docs schemas
cass robot-docs examples
cass robot-docs exit-codes
```
---
## Why Use CASS
### Cross-Agent Knowledge Transfer
Your coding agents create scattered knowledge:
- Claude Code sessions in `~/.claude/projects`
- Codex sessions in `~/.codex/sessions`
- Cursor state in SQLite databases
- Aider history in markdown files
CASS **unifies all of this** into a single searchable index. When you're stuck on a problem, search across ALL your past agent sessions to find relevant solutions.
### Use Cases
```bash
# "I solved this before..."
cass search "TypeError: Cannot read property" --robot --days 30
# Cross-agent learning (what has ANY agent said about X?)
cass search "authentication" --robot --workspace /path/to/project
# Agent-to-agent handoff
cass search "database migration" --robot --fields summary
# Daily review
cass timeline --today --json
```
---
## Command Reference
### Indexing
```bash
# Full rebuild of DB and search index
cass index --full
# Incremental update (since last scan)
cass index
# Watch mode: auto-reindex on file changes
cass index --watch
# Force rebuild even if schema unchanged
cass index --full --force-rebuild
# Safe retries with idempotency key (24h TTL)
cass index --full --idempotency-key "build-$(date +%Y%m%d)"
# JSON output with stats
cass index --full --json
```
### Search
```bash
# Basic search (JSON output required for agents!)
cass search "query" --robot
# With filters
cass search "error" --robot --agent claude --days 7
cass search "bug" --robot --workspace /path/to/project
cass search "panic" --robot --today
# Time filters
cass search "auth" --robot --since 2024-01-01 --until 2024-01-31
cass search "test" --robot --yesterday
cass search "fix" --robot --week
# Wildcards
cass search "auth*" --robot # prefix: authentication, authorize
cass search "*tion" --robot # suffix: authentication, exception
cass search "*config*" --robot # substring: misconfigured
# Token budget management (critical for LLMs!)
cass search "error" --robot --fields minimal # path, line, agent only
cass search "error" --robot --fields summary # adds title, score
cass search "error" --robot --max-content-length 500 # truncate fields
cass search "error" --robot --max-tokens 2000 # soft budget (~4 chars/token)
cass search "error" --robot --limit 5 # cap results
# Pagination (cursor-based)
cass search "TODO" --robot --robot-meta --limit 20
# Use _meta.next_cursor from response:
cass search "TODO" --robot --robot-meta --limit 20 --cursor "eyJ..."
# Match highlighting
cass search "authentication error" --robot --highlight
# Query analysis/debugging
cass search "auth*" --robot --explain # parsed query, cost estimates
cass search "auth error" --robot --dry-run # validate without executing
# Aggregations (server-side counts)
cass search "error" --robot --aggregate agent,workspace,date
# Request correlation
cass search "bug" --robot --request-id "req-12345"
# Source filtering (for multi-machine setups)
cass search "auth" --robot --source laptop
cass search "error" --robot --source remote
# Traceability (for debugging agent pipelines)
cass search "error" --robot --trace-file /tmp/cass-trace.json
```
### Session Analysis
```bash
# Export conversation to markdown/HTML/JSON
cass export /path/to/session.jsonl --format markdown -o conversation.md
cass export /path/to/session.jsonl --format html -o conversation.html
cass export /path/to/session.jsonl --format json --include-tools
# Expand context around a line (from search result)
cass expand /path/to/session.jsonl -n 42 -C 5 --json
# Shows 5 messages before and after line 42
# View source at line
cass view /path/to/session.jsonl -n 42 --json
# Activity timeline
cass timeline --today --json --group-by hour
cass timeline --days 7 --json --agent claude
cass timeline --since 7d --json
# Find related sessions for a file
cass context /path/to/source.ts --json
```
### Status & Diagnostics
```bash
# Readiness diagnosis, when needed; not a prerequisite for every query
cass health --json
# Full status snapshot
cass status --json
cass state --json # alias
# Statistics
cass stats --json
cass stats --by-source # for multi-machine
# Full diagnostics
cass diag --verbose
```
---
## Aggregation & Analytics
Aggregate search results server-side to get counts and distributions without transferring full result data:
Aggregations reduce output volume, not necessarily scan work. They are not the
first step for a quick history question; use the scoped retrieval recipe above.
```bash
# Count results by agent
cass search "error" --robot --aggregate agent
# → { "aggregations": { "agent": { "buckets": [{"key": "claude_code", "count": 45}, ...] } } }
# Multi-field aggregation
cass search "bug" --robot --aggregate agent,workspace,date
# Combine with filters
cass search "TODO" --agent claude --robot --aggregate workspace
```
| Aggregation Field | Description |
|-------------------|-------------|
| `agent` | Group by agent type (claude_code, codex, cursor, etc.) |
| `workspace` | Group by workspace/project path |
| `date` | Group by date (YYYY-MM-DD) |
| `match_type` | Group by match quality (exact, prefix, fuzzy) |
Top 10 buckets returned per field, with `other_count` for remaining items.
---
## Remote Sources (Multi-Machine Search)
Search across sessions from multiple machines via SSH/rsync.
### Setup Wizard (Recommended)
```bash
cass sources setup
```
The wizard:
1. Discovers SSH hosts from `~/.ssh/config`
2. Probes each for agent data and cass installation
3. Optionally installs cass on remotes
4. Indexes sessions on remotes
5. Configures `sources.toml`
6. Syncs data locally
```bash
cass sources setup --hosts css,csd,yto # Specific hosts only
cass sources setup --dry-run # Preview without changes
cass sources setup --resume # Resume interrupted setup
```
### Manual Setup
```bash
# Add a remote machine
cass sources add user@laptop.local --preset macos-defaults
cass sources add dev@workstation --path ~/.claude/projects --path ~/.codex/sessions
# List sources
cass sources list --json
# Sync sessions
cass sources sync
cass sources sync --source laptop --verbose
# Check connectivity
cass sources doctor
cass sources doctor --source laptop --json
# Path mappings (rewrite remote paths to local)
cass sources mappings list laptop
cass sources mappings add laptop --from /home/user/projects --to /Users/me/projects
cass sources mappings test laptop /home/user/projects/myapp/src/main.rs
# Remove source
cass sources remove laptop --purge -y
```
Configuration stored in `~/.config/cass/sources.toml` (Linux) or `~/Library/Application Support/cass/sources.toml` (macOS).
---
## Robot Mode Deep Dive
### Self-Documenting API
CASS teaches agents how to use itself:
```bash
# Quick capability check
cass capabilities --json
# Returns: features, connectors, limits
# Full API schema
cass introspect --json
# Returns: all commands, arguments, response shapes
# Topic-based docs (LLM-optimized)
cass robot-docs commands # all commands and flags
cass robot-docs schemas # response JSON schemas
cass robot-docs examples # copy-paste invocations
cass robot-docs exit-codes # error handling
cass robot-docs guide # quick-start walkthrough
cass robot-docs contracts # API versioning
cass robot-docs sources # remote sources guide
```
### Forgiving Syntax (Agent-Friendly)
CASS auto-corrects common mistakes:
| What you type | What CASS understands |
|---------------|----------------------|
| `cass serach "error"` | `cass search "error"` (typo corrected) |
| `cass -robot -limit=5` | `cass --robot --limit=5` (single-dash fixed) |
| `cass --Robot --LIMIT 5` | `cass --robot --limit 5` (case normalized) |
| `cass find "auth"` | `cass search "auth"` (alias resolved) |
| `cass --limt 5` | `cass --limit 5` (Levenshtein <=2) |
**Command Aliases:**
- `find`, `query`, `q`, `lookup`, `grep` → `search`
- `ls`, `list`, `info`, `summary` → `stats`
- `st`, `state` → `status`
- `reindex`, `idx`, `rebuild` → `index`
- `show`, `get`, `read` → `view`
- `docs`, `help-robot`, `robotdocs` → `robot-docs`
### Output Formats
```bash
# Pretty-printed JSON (default)
cass search "error" --robot
# Streaming JSONL (header + one hit per line)
cass search "error" --robot-format jsonl
# Compact single-line JSON
cass search "error" --robot-format compact
# With performance metadata
cass search "error" --robot --robot-meta
```
**Design principle:** stdout = JSON only; diagnostics go to stderr.
### Token Budget Management
LLMs have context limits. Control output size:
| Flag | Effect |
|------|--------|
| `--fields minimal` | Only `source_path`, `line_number`, `agent` |
| `--fields summary` | Adds `title`, `score` |
| `--fields score,title,snippet` | Custom field selection |
| `--max-content-length 500` | Truncate long fields (UTF-8 safe) |
| `--max-tokens 2000` | Soft budget (~4 chars/token) |
| `--limit 5` | Cap number of results |
Truncated fields include `*_truncated: true` indicator.
---
## Structured Error Handling
Errors are JSON with actionable hints:
```json
{
"error": {
"code": 3,
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