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