oak

name: oak description: >- Find out what happened, what was decided, and what depends on what in your codebase. Use this skill whenever you need to: recall past decisions or discussions ("what did we decide about X?"), check what might break before refactoring ("what depends on this module?"), find conceptually similar code that grep would miss ("all the retry/backoff logic"), look up past bugs, gotchas, or learnings, query session history or agent run costs, store observations about the codebase, or understand how components connect end-to-end. Powered by semantic search, memory lookup, and direct SQL against the Oak CI database (.oak/ci/activities.db). Also use when the user mentions oak_search, oak_context, oak_remember, oak_resolve_memory, or asks to run queries against activities.db or oak. allowed-tools: Bash, Read user-invocable: true

OAK

Prefer MCP tools (oak_search, oak_context, oak_remember, oak_resolve_memory) over CLI when available. Fall back to CLI or direct SQL for queries not covered by MCP tools. If .oak/ci/activities.db does not exist, inform the user to run oak-dev team start first.

Quick Start

MCP tools (preferred when available)

# Search knowledge — memories, plans, and sessions (default)
oak_search(query="authentication refactor decision")

# Narrow by category
oak_search(query="form validation logic", search_type="code")
oak_search(query="backup directory decision", search_type="memory")
oak_search(query="migration plan", search_type="plans")

# Impact analysis — get context for a specific file
oak_context(task="impact of changes to executor", files=["src/features/agent_runtime/executor.py"])

# Store an observation
oak_remember(observation="The backup dir uses a 3-tier priority", memory_type="decision")

# Mark a resolved gotcha
oak_resolve_memory(id="<uuid from oak_search>")

CLI fallback

# Semantic search
oak-dev ci search "retry with exponential backoff" --type code

# Browse memories by type
oak-dev ci memories --type decision

# Get impact context for a specific file
oak-dev ci context "impact of changes" -f src/services/auth.py

Direct SQL (for aggregations, history, custom queries)

# Recent sessions
sqlite3 -readonly -header -column .oak/ci/activities.db \
  "SELECT id, agent, title, status, datetime(created_at_epoch, 'unixepoch', 'localtime') as started FROM sessions ORDER BY created_at_epoch DESC LIMIT 5;"

# Query anything
sqlite3 -readonly -header -column .oak/ci/activities.db "SELECT count(*) FROM sessions;"

Commands Reference

CLI commands

MCP tools

Direct SQL

sqlite3 -readonly -header -column .oak/ci/activities.db "YOUR QUERY HERE"

When to Use What

Why Semantic Search Over Grep

Core Tables Overview

Memory Types

The memory_type column in memory_observations uses these values:

• gotcha — Non-obvious behavior or quirk
• bug_fix — Solution to a bug with root cause
• decision — Architectural/design decision with rationale
• discovery — General insight about the codebase
• trade_off — Trade-off that was made and why
• session_summary — LLM-generated session summary

Observation Status

The status column tracks lifecycle state:

• active — Current and relevant (default for all new observations)
• resolved — Issue was addressed in a later session
• superseded — Replaced by a newer, more accurate observation

Resolving Observations

When oak_search or oak_context surfaces a gotcha, bug_fix, or discovery that you then address during your session, resolve it so future sessions don't see stale guidance:

1. Note the observation UUID from the oak_search results (e.g., "id": "8430042a-1b01-4c86-8026-6ede46cd93d9").
2. After completing the fix or addressing the issue, call:
   • MCP: oak_resolve_memory(id="8430042a-1b01-4c86-8026-6ede46cd93d9")
   • CLI: oak-dev ci resolve 8430042a-1b01-4c86-8026-6ede46cd93d9
3. For superseded observations (replaced by a better one), use status="superseded".

When to resolve:

• You fixed a bug that was tracked as a bug_fix observation
• You addressed a gotcha (e.g., refactored the problematic code)
• A discovery about a problem is no longer accurate after your changes
• A decision was reversed or replaced by a new decision

When NOT to resolve:

• The observation is still accurate even after your changes
• You only partially addressed the issue
• The observation is a permanent architectural insight (e.g., "service X uses eventual consistency")

Session Origin Types

The session_origin_type column classifies how the session that created the observation operated:

• planning — Planning-phase session (high read:edit ratio, few modifications)
• investigation — Exploration/debugging session (many reads, minimal edits)
• implementation — Active coding session (significant file modifications)
• mixed — Combined activity patterns

Planning/investigation observations are automatically capped at importance 5.

Essential Queries

Recent Sessions

SELECT id, agent, title, status,
       datetime(created_at_epoch, 'unixepoch', 'localtime') as started,
       prompt_count, tool_count
FROM sessions
ORDER BY created_at_epoch DESC
LIMIT 10;

What Files Were Touched in a Session

SELECT DISTINCT file_path, tool_name, count(*) as times
FROM activities
WHERE session_id = 'SESSION_ID' AND file_path IS NOT NULL
GROUP BY file_path, tool_name
ORDER BY times DESC;

Recent Memories

SELECT memory_type, substr(observation, 1, 150) as observation,
       context,
       datetime(created_at_epoch, 'unixepoch', 'localtime') as created
FROM memory_observations
ORDER BY created_at_epoch DESC
LIMIT 20;

Agent Run History

SELECT agent_name, task, status, turns_used,
       printf('$%.4f', cost_usd) as cost,
       datetime(created_at_epoch, 'unixepoch', 'localtime') as created
FROM agent_runs
ORDER BY created_at_epoch DESC
LIMIT 10;

Full-Text Search on Memories

SELECT m.memory_type, m.observation, m.context
FROM memory_observations m
JOIN memories_fts fts ON m.rowid = fts.rowid
WHERE memories_fts MATCH 'authentication'
ORDER BY rank
LIMIT 10;

Scheduled Tasks

SELECT task_name, enabled, cron_expression, description,
       datetime(last_run_at_epoch, 'unixepoch', 'localtime') as last_run,
       datetime(next_run_at_epoch, 'unixepoch', 'localtime') as next_run
FROM agent_schedules
ORDER BY next_run_at_epoch;

Observation Lifecycle Status

SELECT status, count(*) as count
FROM memory_observations
GROUP BY status;

Active Observations from Planning Sessions

SELECT substr(observation, 1, 120) as observation, memory_type,
       context, session_origin_type,
       datetime(created_at_epoch, 'unixepoch', 'localtime') as created
FROM memory_observations
WHERE status = 'active' AND session_origin_type = 'planning'
ORDER BY created_at_epoch DESC
LIMIT 20;

Resolution Provenance (what resolved what)

SELECT m.id, substr(m.observation, 1, 100) as observation,
       m.resolved_by_session_id, s.title as resolving_session,
       m.resolved_at
FROM memory_observations m
LEFT JOIN sessions s ON m.resolved_by_session_id = s.id
WHERE m.status = 'resolved'
ORDER BY m.resolved_at DESC
LIMIT 10;

Important Notes

• Always use -readonly flag with sqlite3 to prevent accidental writes
• The database uses WAL mode — safe to read while the daemon is writing
• Epoch timestamps are Unix seconds — use datetime(col, 'unixepoch', 'localtime') to format
• FTS5 tables (activities_fts, memories_fts) use MATCH syntax, not LIKE
• JSON columns (tool_input, files_affected, files_created) can be queried with json_extract()
• Database location: .oak/ci/activities.db

Automated Analysis

For automated analysis that runs queries and produces reports:

oak-dev ci agent run usage-report              # Cost and token usage trends
oak-dev ci agent run productivity-report       # Session quality and error rates
oak-dev ci agent run codebase-activity-report  # File hotspots and tool patterns
oak-dev ci agent run prompt-analysis           # Prompt quality and recommendations

Reports are written to oak/insights/ (git-tracked, team-shareable).

Deep Dives

Consult these reference documents when the task requires deeper detail:

• references/finding-related-code.md — Consult when searching for semantically related code across files or discovering component relationships
• references/impact-analysis.md — Consult before refactoring to assess blast radius and identify affected consumers
• references/querying-databases.md — Consult when writing custom SQL queries beyond the essential queries above
• references/schema.md — Consult for complete CREATE TABLE statements, indexes, and FTS5 table definitions (auto-generated)
• references/queries.md — Consult for advanced joins, aggregations, window functions, and debugging queries
• references/analysis-playbooks.md — Consult when running structured multi-query workflows for usage, productivity, or activity analysis