claude-historian

name	claude-historian
description	Session history search — INVOKE before planning, before web research, after errors, or when looking for past conversation content. Use INSTEAD of manually grepping .jsonl session files.
triggers	["PreToolUse","PostToolUseFailure"]

Historian Plugin

Session memory. Use INSTEAD of grepping .jsonl files manually. Checks past sessions before redundant research, planning, or debugging.

Hooks

Hook	When	Action
PreToolUse(WebSearch/WebFetch)	Before web research	Checks search(scope="similar") first
PostToolUseFailure(Bash/Edit)	After tool errors	Suggests search(scope="errors")

Commands

Command	Description
/search-historian <query>	Search past sessions for solutions, decisions, context

MCP Tool: search(query, scope)

One tool, many scopes:

Scope	What It Finds	When to Use
conversations	Full-text across all sessions	General search
similar	Related past questions	Before web research
errors	How errors were previously fixed	After tool failures
plans	Past implementation plans	Before planning
files	File changes across sessions (needs filepath)	Before editing familiar files
tools	Successful tool workflows	Before launching agents
sessions	Recent work sessions	Browse history
config	.claude rules, skills, agents	Config troubleshooting
tasks	Task management data	Check past tasks
memories	Saved memories	Cross-session memory

MCP Tool: inspect(session_id)

Deep summary of a specific session with key insights.

Workflows

Before Planning

search(query="feature name", scope="plans")

Before Web Research

search(query="topic", scope="similar")

If found: use past results, skip web search.

After Errors

search(query="error message", scope="errors")

If found: apply previous solution.

General Search

search(query="topic", scope="conversations")
search(scope="files", filepath="path/to/file")
search(scope="sessions")

Sibling Synergy

• With praetorian: historian gives raw session context, praetorian gives distilled insights. Check both.
• With gladiator: historian finds past error solutions, gladiator records new ones.