Claude Historian

Search conversation history before starting fresh. You may already have the answer.

When to Use

Before WebSearch → search(query: "...", scope: "similar") or search(query: "...", scope: "conversations"). Past solutions beat web results.

Stuck on an error → search(query: "<error message>", scope: "errors"). Finds past fixes with code.

Entering a familiar project → search(scope: "sessions") for recent work. search(query: "...", scope: "plans") for past decisions.

Working on a familiar file → search(scope: "files", filepath: "src/index.ts"). Shows past changes with context.

Situation	Tool Call
Error with no obvious cause	`search(query: "<error>", scope: "errors")`
"Have I done this before?"	`search(query: "...", scope: "similar")`
Working on familiar file	`search(scope: "files", filepath: "...")`
Need past design reasoning	`search(query: "...", scope: "plans")`
What did I do last session?	`search(scope: "sessions")`
Successful tool workflows	`search(scope: "tools")`
General search	`search(query: "...", scope: "conversations")`
Deep-dive into session	`inspect(session_id: "...")`
Rules, skills, CLAUDE.md	`search(query: "...", scope: "config")`
Task management history	`search(query: "...", scope: "tasks")`
Memories across sessions	`search(query: "...", scope: "memories")`

scope: Target your search — conversations, errors, files, plans, config, tasks, similar, sessions, tools, memories, or all (default)
limit: Number of results (default 10)
project: Filter by project name substring (works with conversations, sessions)
timeframe: today, yesterday, week, month

Mistake	Fix
Going straight to WebSearch	Check historian first — past solutions are more relevant
Vague queries	Use specific terms: error messages, file paths, tool names
Using `scope: "all"` for errors	Use `scope: "errors"` — it has dedicated fix extraction
Long keyword-dump queries	Keep to 3-5 specific terms, not 10+ generic ones