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-cli-command} 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-cli-command} ci search "retry with exponential backoff" --type code

# Browse memories by type
{oak-cli-command} ci memories --type decision

# Get impact context for a specific file
{oak-cli-command} 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

Command	Purpose
{oak-cli-command} ci search "query" --type code	Semantic vector search for code
{oak-cli-command} ci search "query" --type memory	Semantic search for memories
{oak-cli-command} ci search "query" -n 20	Broader search with more results
{oak-cli-command} ci context "task" -f <file>	Get context for current work
{oak-cli-command} ci remember "observation"	Store a memory (NOT via SQL)
{oak-cli-command} ci memories --type gotcha	Browse memories by type
{oak-cli-command} ci memories --status active	Browse memories by lifecycle status
{oak-cli-command} ci resolve <id>	Mark observation as resolved
{oak-cli-command} ci resolve --session <id>	Bulk-resolve all observations from a session
{oak-cli-command} ci sessions	List session summaries
{oak-cli-command} team status	Check daemon status

MCP tools

MCP Tool	CLI Equivalent	Purpose
oak_search	{oak-cli-command} ci search "query"	Semantic vector search
oak_remember	{oak-cli-command} ci remember "observation"	Store a memory
oak_context	{oak-cli-command} ci context "task"	Get task-relevant context
oak_resolve_memory	{oak-cli-command} ci resolve <uuid>	Mark observation resolved/superseded (UUID from oak_search)

Direct SQL

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

When to Use What

Need	Tool	Example
Find similar implementations	{oak-cli-command} ci search --type code	"retry with exponential backoff"
Understand component relationships	{oak-cli-command} ci context	"how auth middleware relates to session handling"
Assess refactoring risk	{oak-cli-command} ci search --type code -n 20	"PaymentProcessor error handling"
Find past decisions/gotchas	{oak-cli-command} ci search --type memory	"gotchas with auth changes"
Recall previous discussions	sqlite3 -readonly	SELECT title, summary FROM sessions WHERE ...
Find what was done before	{oak-cli-command} ci memories / sqlite3	"what did we decide about caching?"
Query session history	sqlite3 -readonly	SELECT * FROM sessions ORDER BY ...
Aggregate usage stats	sqlite3 -readonly	SELECT agent_name, sum(cost_usd) FROM agent_runs ...
Resolve stale observations	{oak-cli-command} ci resolve	After completing work that addresses a gotcha
Find unresolved planning items	sqlite3 -readonly	SELECT ... WHERE status='active' AND session_origin_type='planning'
Run automated analysis	{oak-cli-command} ci agent run	{oak-cli-command} ci agent run usage-report

Why Semantic Search Over Grep

Grep	Semantic Search
Finds "UserService" literally	Finds code about user management regardless of naming
Misses synonyms (auth vs authentication)	Understands concepts are related
Can't find "conceptually similar" code	Groups code by purpose, not text
No relevance ranking	Returns most relevant first

Core Tables Overview

Table	Purpose	Key Columns
memory_observations	Extracted memories/learnings	observation, memory_type, status, context, tags, importance, session_origin_type
sessions	Coding sessions (launch to exit)	id, agent, status, summary, title, title_manually_edited, started_at, created_at_epoch
prompt_batches	User prompts within sessions	session_id, user_prompt, classification, response_summary
activities	Raw tool executions	session_id, tool_name, file_path, success, error_message
agent_runs	CI agent executions	agent_name, task, status, result, cost_usd, turns_used
session_link_events	Session linking analytics	session_id, event_type, old_parent_id, new_parent_id
session_relationships	Semantic session relationships	session_a_id, session_b_id, relationship_type, similarity_score
agent_schedules	Cron scheduling state	task_name, cron_expression, enabled, additional_prompt, last_run_at, next_run_at
resolution_events	Cross-machine resolution propagation	observation_id, action, source_machine_id, applied, content_hash
governance_audit_events	Audit trail for governance actions	session_id, agent, tool_name, action, rule_id, enforcement_mode, created_at
team_outbox	Outbound sync queue for team relay	event_type, payload, source_machine_id, content_hash, status, created_at
team_pull_cursor	Inbound sync cursor per relay	server_url, cursor_value, updated_at
team_sync_state	Team relay sync metadata	key, value, updated_at
team_reconcile_state	Per-machine reconciliation tracking	machine_id, last_reconcile_at, last_hash_count, last_missing_count

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-cli-command} 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-cli-command} ci agent run usage-report              # Cost and token usage trends
{oak-cli-command} ci agent run productivity-report       # Session quality and error rates
{oak-cli-command} ci agent run codebase-activity-report  # File hotspots and tool patterns
{oak-cli-command} 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