obelisk/references/retrieval-semantics.md

Obelisk Retrieval Semantics

Read this before designing a non-trivial query. This is the query design frame; pitfalls.md is only the debug checklist.

Four Principles

Scope First

Classify the user's request before choosing tools.

User signal	Locator mode	Start with	Avoid first
project name/path, session, cwd, file, time range	scope	sessions(), exact SQL on project_path, sessionId, fileHistory()	broad FTS
workflow, subagent, tool call, summary, edit	artifact	workflows(), subagents(), summaries(), tool_calls, tool_results	all-session search
concept, conclusion, design history, vague memory	semantic	search(), summaries, bounded facet sweep	session dumps

One-shot retrieval is not all-shot retrieval. A query script may perform multiple steps, but the first locator should be the narrowest semantic fit. If a scope locator finds the relevant project/session/file, do not also run broad FTS unless scoped evidence is insufficient and query_plan says why.

Project-like fields are distinct:

• sessions.project: stored Claude Code project slug.
• sessions.project_path: reconstructed absolute project path.
• messages.cwd: working directory at message time.
• helper project: SQL LIKE over sessions.project, not exact membership.

For exact project membership, use sql() with s.project = ? or s.project_path = ?. Empty or tiny scoped results are valid results; do not broaden unless the user asks or your query_plan explicitly marks a fallback.

Plan Before Probe

For conclusion, broad history, failure investigation, or file evolution tasks, prefer a retrieval script over interactive probing.

Good shape:

1. locate candidates with scope/artifact/semantic locators;
2. expand only selected hits;
3. dedupe and group in the script;
4. return compact evidence rows plus counts and limits.

If a second detail pass is needed, derive filters or facets from the first pass: candidate sessions, discovered vocabulary, files, tools, timestamps, or decisions. Prefer a learned faceted detail pass over LIMIT 25 session windows. If vocabulary is still unclear, use a small filtered window and say so in query_plan.

Structure Before Text

Use the database shape before asking the model to read text.

• Count and aggregate in SQL or JS (GROUP BY, COUNT, MAX, ORDER BY, LIMIT).
• Join metadata from the owner table instead of inventing fields.
• Project compact rows; do not return whole sessions, complete workflow trees, full raw messages, or entire tool results.
• Keep synthesis runtime JSON around 10k-12k chars when possible.
• For recent failures, aggregate by session/task and return sparse examples.
• For file evolution, filter fileHistory() to Edit/Write, group by session or phase, and return short deltas.

Ordering and context are semantic:

• sessions(), summaries(), workflows(), and failures() are newest first.
• fileHistory() is oldest first.
• search().context is temporal neighbors in one session, not causal context.
• context(uuid) and trace(uuid) are for parent-chain/causal expansion.

Evidence Before Conclusion

Obelisk stores original structure, not precompiled claims. It has sessions, messages, summaries, tool calls/results, files, subagents, workflows, parent chains, and raw JSONL windows. It does not store "claim", "stance", "contradiction", or "conclusion" entities.

For semantic questions, build a task-local evidence view:

{
  query_plan: { mode, scope, facets, limits },
  evidence: [
    { type, id, session_id, timestamp, facet, snippet }
  ],
  omitted: 0
}

Then synthesize the conclusion in the final answer. Do not pretend the evidence view is a stored Obelisk entity.

Text Search Semantics

search(text) passes text to SQLite FTS5 MATCH.

• Hyphens tokenize: for workflow-script, use "workflow script" or SQL LIKE for literal punctuation.
• Special characters may produce FTS syntax errors; simplify or quote the FTS query under the same scope.
• Exact phrase, token search, and literal punctuation are different semantics.
• Results are ordered by ORDER BY rank; lower rank sorts earlier. Prefer returned order over "closer to zero" comparisons.