CASS - Coding Agent Session Search
Unified, high-performance CLI/TUI to index and search your local coding agent history. Aggregates sessions from 11 agents: Codex, Claude Code, Gemini CLI, Cline, OpenCode, Amp, Cursor, ChatGPT, Aider, Pi-Agent, and Factory (Droid).
CRITICAL: Robot Mode Required for AI Agents
NEVER run bare cass - it launches an interactive TUI that blocks your session!
# 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
Pre-Flight Check
# Health check (exit 0=healthy, 1=unhealthy, <50ms)
cass health
# If unhealthy, rebuild index
cass index --full
Essential Commands
# 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
# "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
# 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
# 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
# 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
# Quick health (<50ms)
cass health
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:
# 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)
cass sources setup
The wizard:
- Discovers SSH hosts from
~/.ssh/config - Probes each for agent data and cass installation
- Optionally installs cass on remotes
- Indexes sessions on remotes
- Configures
sources.toml - Syncs data locally
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
# 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:
# 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→searchls,list,info,summary→statsst,state→statusreindex,idx,rebuild→indexshow,get,read→viewdocs,help-robot,robotdocs→robot-docs
Output Formats
# 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:
{
"error": {
"code": 3,
"kind": "index_missing",
"message": "Search index not found",
"hint": "Run 'cass index --full' to build the index",
"retryable": false
}
}
Exit Codes
| Code | Meaning | Action |
|------|---------|--------|
| 0 | Success | Parse stdout |
| 1 | Health check failed | Run cass index --full |
| 2 | Usage error | Fix syntax (hint provided) |
| 3 | Index/DB missing | Run cass index --full |
| 4 | Network error | Check connectivity |
| 5 | Data corruption | Run cass index --full --force-rebuild |
| 6 | Incompatible version | Update cass |
| 7 | Lock/busy | Retry later |
| 8 | Partial result | Increase --timeout |
| 9 | Unknown error | Check retryable flag |
Search Modes
Three search modes, selectable with --mode flag:
| Mode | Algorithm | Best For | |------|-----------|----------| | lexical (default) | BM25 full-text | Exact term matching, code searches | | semantic | Vector similarity | Conceptual queries, "find similar" | | hybrid | Reciprocal Rank Fusion | Balanced precision and recall |
cass search "authentication" --mode lexical --robot
cass search "how to handle user login" --mode semantic --robot
cass search "auth error handling" --mode hybrid --robot
Hybrid combines lexical and semantic using RRF:
RRF_score = Σ 1 / (60 + rank_i)
Pipeline Mode (Chained Search)
Chain searches by piping session paths:
# Find sessions mentioning "auth", then search within those for "token"
cass search "authentication" --robot-format sessions | \
cass search "refresh token" --sessions-from - --robot
# Build a filtered corpus from today's work
cass search --today --robot-format sessions > today_sessions.txt
cass search "bug fix" --sessions-from today_sessions.txt --robot
Use cases:
- Drill-down: Broad search → narrow within results
- Cross-reference: Find sessions with term A, then find term B within them
- Corpus building: Save session lists for repeated searches
Query Language
Basic Queries
| Query | Matches |
|-------|---------|
| error | Messages containing "error" (case-insensitive) |
| python error | Both "python" AND "error" |
| "authentication failed" | Exact phrase |
Boolean Operators
| Operator | Example | Meaning |
|----------|---------|---------|
| AND | python AND error | Both terms required (default) |
| OR | error OR warning | Either term matches |
| NOT | error NOT test | First term, excluding second |
| - | error -test | Shorthand for NOT |
# Complex boolean query
cass search "authentication AND (error OR failure) NOT test" --robot
# Exclude test files
cass search "bug fix -test -spec" --robot
# Either error type
cass search "TypeError OR ValueError" --robot
Wildcard Patterns
| Pattern | Type | Performance |
|---------|------|-------------|
| auth* | Prefix | Fast (edge n-grams) |
| *tion | Suffix | Slower (regex) |
| *config* | Substring | Slowest (regex) |
Match Types
Results include match_type:
| Type | Meaning | Score Boost |
|------|---------|-------------|
| exact | Verbatim match | Highest |
| prefix | Via prefix expansion | High |
| suffix | Via suffix pattern | Medium |
| substring | Via substring pattern | Lower |
| fuzzy | Auto-fallback (sparse results) | Lowest |
Auto-Fuzzy Fallback
When exact query returns <3 results, CASS automatically retries with wildcards:
auth→*auth*- Results flagged with
wildcard_fallback: true
Flexible Time Input
CASS accepts a wide variety of time/date formats:
| Format | Examples |
|--------|----------|
| Relative | -7d, -24h, -30m, -1w |
| Keywords | now, today, yesterday |
| ISO 8601 | 2024-11-25, 2024-11-25T14:30:00Z |
| US Dates | 11/25/2024, 11-25-2024 |
| Unix Timestamp | 1732579200 (seconds or milliseconds) |
Ranking Modes
Cycle with F12 in TUI or use --ranking flag:
| Mode | Formula | Best For |
|------|---------|----------|
| Recent Heavy | relevance*0.3 + recency*0.7 | "What was I working on?" |
| Balanced | relevance*0.5 + recency*0.5 | General search |
| Relevance | relevance*0.8 + recency*0.2 | "Best explanation of X" |
| Match Quality | Penalizes fuzzy matches | Precise technical searches |
| Date Newest | Pure chronological | Recent activity |
| Date Oldest | Reverse chronological | "When did I first..." |
Score Components
- Text Relevance (BM25): Term frequency, inverse document frequency, length normalization
- Recency: Exponential decay (today ~1.0, last week ~0.7, last month ~0.3)
- Match Exactness: Exact phrase=1.0, Prefix=0.9, Suffix=0.8, Substring=0.6, Fuzzy=0.4
Blended Scoring Formula
Final_Score = BM25_Score × Match_Quality + α × Recency_Factor
| Mode | α Value | Effect | |------|---------|--------| | Recent Heavy | 1.0 | Recency dominates | | Balanced | 0.4 | Moderate recency boost | | Relevance Heavy | 0.1 | BM25 dominates | | Match Quality | 0.0 | Pure text matching |
Supported Agents (11 Connectors)
| Agent | Location | Format |
|-------|----------|--------|
| Claude Code | ~/.claude/projects | JSONL |
| Codex | ~/.codex/sessions | JSONL (Rollout) |
| Gemini CLI | ~/.gemini/tmp | JSON |
| Cline | VS Code global storage | Task directories |
| OpenCode | .opencode directories | SQLite |
| Amp | ~/.local/share/amp + VS Code | Mixed |
| Cursor | ~/Library/Application Support/Cursor | SQLite (state.vscdb) |
| ChatGPT | ~/Library/Application Support/com.openai.chat | JSON (v1 unencrypted) |
| Aider | ~/.aider.chat.history.md + per-project | Markdown |
| Pi-Agent | ~/.pi/agent/sessions | JSONL with thinking |
| Factory (Droid) | ~/.factory/sessions | JSONL by workspace |
Note: ChatGPT v2/v3 are AES-256-GCM encrypted (keychain access required). Legacy v1 unencrypted conversations are indexed automatically.
TUI Features (for Humans)
Launch with cass (no flags):
Keyboard Shortcuts
Navigation:
Up/Down: Move selectionLeft/Right: Switch panesTab/Shift+Tab: Cycle focusEnter: Open in$EDITORSpace: Full-screen detail viewHome/End: Jump to first/last resultPageUp/PageDown: Scroll by page
Filtering:
F3: Agent filterF4: Workspace filterF5/F6: Time filters (from/to)Shift+F3: Scope to current result's agentShift+F4: Clear workspace filterShift+F5: Cycle presets (24h/7d/30d/all)Ctrl+Del: Clear all filters
Modes:
F2: Toggle theme (6 presets)F7: Context window size (S/M/L/XL)F9: Match mode (prefix/standard)F12: Ranking modeCtrl+B: Toggle border style
Selection & Actions:
m: Toggle selectionCtrl+A: Select allA: Bulk actions menuCtrl+Enter: Add to queueCtrl+O: Open all queuedy: Copy path/contentCtrl+Y: Copy all selected/: Find in detail panen/N: Next/prev match
Views & Palette:
Ctrl+P: Command palette1-9: Load saved viewShift+1-9: Save view to slot
Source Filtering (multi-machine):
F11: Cycle source filter (all/local/remote)Shift+F11: Source selection menu
Global:
Ctrl+C: QuitF1or?: Toggle helpCtrl+Shift+R: Force re-indexCtrl+Shift+Del: Reset all TUI state
Detail Pane Tabs
| Tab | Content | Switch With |
|-----|---------|-------------|
| Messages | Full conversation with markdown | [ / ] |
| Snippets | Keyword-extracted summaries | [ / ] |
| Raw | Unformatted JSON/text | [ / ] |
Context Window Sizing
| Size | Characters | Use Case | |------|------------|----------| | Small | ~200 | Quick scanning | | Medium | ~400 | Default balanced view | | Large | ~800 | Longer passages | | XLarge | ~1600 | Full context, code review |
Peek Mode (Ctrl+Space): Temporarily expand to XL without changing default.
Theme Presets
Cycle through 6 built-in themes with F2:
| Theme | Description | Best For | |-------|-------------|----------| | Dark | Tokyo Night-inspired deep blues | Low-light environments | | Light | High-contrast light background | Bright environments | | Catppuccin | Warm pastels, reduced eye strain | All-day coding | | Dracula | Purple-accented dark theme | Popular developer theme | | Nord | Arctic-inspired cool tones | Calm, focused work | | High Contrast | Maximum readability | Accessibility needs |
All themes validated against WCAG contrast requirements (4.5:1 minimum for text).
Role-Aware Message Styling
| Role | Visual Treatment | |------|------------------| | User | Blue-tinted background, bold | | Assistant | Green-tinted background | | System | Gray/muted background | | Tool | Orange-tinted background |
Saved Views
Save filter configurations to 9 slots for instant recall.
What Gets Saved:
- Active filters (agent, workspace, time range)
- Current ranking mode
- The search query
Keyboard:
Shift+1throughShift+9: Save current view1through9: Load view from slot
Via Command Palette: Ctrl+P → "Save/Load view"
Views persist in tui_state.json across sessions.
Density Modes
Control lines per search result. Cycle with Shift+D:
| Mode | Lines | Best For | |------|-------|----------| | Compact | 3 | Maximum results visible | | Cozy | 5 | Balanced view (default) | | Spacious | 8 | Detailed preview |
Bookmark System
Save important results with notes and tags:
In TUI: Press b to bookmark, add notes and tags.
Bookmark Structure:
title: Short descriptionsource_path,line_number,agent,workspacenote: Your annotationstags: Comma-separated labelssnippet: Extracted content
Storage: ~/.local/share/coding-agent-search/bookmarks.db (SQLite)
Optional Semantic Search
Local-only semantic search using MiniLM (no cloud):
Required files (place in data directory):
model.onnxtokenizer.jsonconfig.jsonspecial_tokens_map.jsontokenizer_config.json
Vector index stored as vector_index/index-minilm-384.cvvi.
CASS does NOT auto-download models; you must manually install them.
Hash Embedder Fallback: When MiniLM not installed, CASS uses a hash-based embedder for approximate semantic similarity.
Watch Mode
Real-time index updates:
cass index --watch
- Debounce: 2 seconds (wait for burst to settle)
- Max wait: 5 seconds (force flush during continuous activity)
- Incremental: Only re-scans modified files
TUI automatically starts watch mode in background.
Deduplication Strategy
CASS uses multi-layer deduplication:
- Message Hash: SHA-256 of
(role + content + timestamp)- identical messages stored once - Conversation Fingerprint: Hash of first N message hashes - detects duplicate files
- Search-Time Dedup: Results deduplicated by content similarity
Noise Filtering:
- Empty messages and pure whitespace
- System prompts (unless searching for them)
- Repeated tool acknowledgments
Performance Characteristics
| Operation | Latency | |-----------|---------| | Prefix search (cached) | 2-8ms | | Prefix search (cold) | 40-60ms | | Substring search | 80-200ms | | Full reindex | 5-30s | | Incremental reindex | 50-500ms | | Health check | <50ms |
Memory: 70-140MB typical (50K messages) Disk: ~600 bytes/message (including n-gram overhead)
Response Shapes
Search Response:
{
"query": "error",
"limit": 10,
"count": 5,
"total_matches": 42,
"hits": [
{
"source_path": "/path/to/session.jsonl",
"line_number": 123,
"agent": "claude_code",
"workspace": "/projects/myapp",
"title": "Authentication debugging",
"snippet": "The error occurs when...",
"score": 0.85,
"match_type": "exact",
"created_at": "2024-01-15T10:30:00Z"
}
],
"_meta": {
"elapsed_ms": 12,
"cache_hit": true,
"wildcard_fallback": false,
"next_cursor": "eyJ...",
"index_freshness": { "stale": false, "age_seconds": 120 }
}
}
Aggregation Response:
{
"aggregations": {
"agent": {
"buckets": [
{"key": "claude_code", "count": 120},
{"key": "codex", "count": 85}
],
"other_count": 15
}
}
}
Environment Variables
| Variable | Purpose |
|----------|---------|
| CASS_DATA_DIR | Override data directory |
| CHATGPT_ENCRYPTION_KEY | Base64 key for encrypted ChatGPT |
| PI_CODING_AGENT_DIR | Override Pi-Agent sessions path |
| CASS_CACHE_SHARD_CAP | Per-shard cache entries (default 256) |
| CASS_CACHE_TOTAL_CAP | Total cached hits (default 2048) |
| CASS_DEBUG_CACHE_METRICS | Enable cache debug logging |
| CODING_AGENT_SEARCH_NO_UPDATE_PROMPT | Skip update checks |
Shell Completions
cass completions bash > ~/.local/share/bash-completion/completions/cass
cass completions zsh > "${fpath[1]}/_cass"
cass completions fish > ~/.config/fish/completions/cass.fish
cass completions powershell >> $PROFILE
API Contract & Versioning
cass api-version --json
# → { "version": "0.4.0", "contract_version": "1", "breaking_changes": [] }
cass introspect --json
# → Full schema: all commands, arguments, response types
Guaranteed Stable:
- Exit codes and their meanings
- JSON response structure for
--robotoutput - Flag names and behaviors
_metablock format
Integration with CASS Memory (cm)
CASS provides episodic memory (raw sessions). CM extracts procedural memory (rules and playbooks):
# 1. CASS indexes raw sessions
cass index --full
# 2. Search for relevant past experience
cass search "authentication timeout" --robot --limit 10
# 3. CM reflects on sessions to extract rules
cm reflect
Troubleshooting
| Issue | Solution |
|-------|----------|
| "missing index" | cass index --full |
| Stale warning | Rerun index or enable watch |
| Empty results | Check cass stats --json, verify connectors detected |
| JSON parsing errors | Use --robot-format compact |
| Watch not triggering | Check watch_state.json, verify file event support |
| Reset TUI state | cass tui --reset-state or Ctrl+Shift+Del |
Installation
# One-liner install
curl -fsSL https://raw.githubusercontent.com/Dicklesworthstone/coding_agent_session_search/main/install.sh \
| bash -s -- --easy-mode --verify
# Windows
irm https://raw.githubusercontent.com/Dicklesworthstone/coding_agent_session_search/main/install.ps1 | iex
Integration with Flywheel
| Tool | Integration | |------|-------------| | CM | CASS provides episodic memory, CM extracts procedural memory | | NTM | Robot mode flags for searching past sessions | | Agent Mail | Search threads across agent history | | BV | Cross-reference beads with past solutions |