/claude-historian

name: claude-historian
description: Automatic history search — checks past sessions before web research, planning, and debugging, siblings deepen coverage
triggers: [PreToolUse, PostToolUse]

Historian Plugin

Session memory. Checks past sessions before redundant research, planning, or debugging.

Hooks

| Hook | When | Action | |------|------|--------| | **PreToolUse(WebSearch/WebFetch)** | Before web research | Checks `find_similar_queries()` first | | **PreToolUse(EnterPlanMode)** | Before planning | Searches `search_plans()` for past approaches | | **PreToolUse(Task)** | Before agents | Checks `find_tool_patterns()` for workflows | | **PostToolUse(Bash)** | After errors | Suggests `get_error_solutions()` |

Commands

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

Workflows

Search (standalone)

1. `search_conversations("query")` — full-text across all sessions 2. If error-related: `get_error_solutions("error pattern")` 3. If file-related: `find_file_context("filename")` 4. Summarize relevant findings

Search (with siblings)

1. `search_conversations("query")` — historian's own search 2. If **praetorian** active: `praetorian_restore("query")` for compacted context (denser than raw history) 3. If **oracle** active: `search("query")` when error patterns suggest a missing tool 4. Combine: historian provides breadth (all sessions), praetorian provides depth (curated insights)

Error Resolution (standalone)

1. `get_error_solutions("error pattern")` — how was this fixed before? 2. If found: apply the previous solution 3. If not: proceed with normal debugging

Error Resolution (with siblings)

1. `get_error_solutions("error pattern")` — historian checks past fixes 2. If **oracle** active: `search("error tool")` for tools that address this error class 3. If **gladiator** active: check if this error was already observed as a pattern 4. Present combined findings: past fix + available tools + pattern context

Sibling Synergy

| Sibling | Value | How | |---------|-------|-----| | **Praetorian** | Research will be compacted after | Praetorian prompts saving after web searches historian triggers | | **Oracle** | Tools found for error patterns | Oracle searches for tools when historian finds recurring errors | | **Gladiator** | Observations correlate with history | Past solutions enrich gladiator reflection | | **Vigil** | Checkpoints complement history | File state preserved alongside session history |

MCP Tools Reference

| Tool | Purpose | |------|---------| | `search_conversations` | General history search | | `find_similar_queries` | Find related past questions | | `get_error_solutions` | Find how errors were fixed | | `find_file_context` | Track file changes | | `find_tool_patterns` | Discover successful workflows | | `list_recent_sessions` | Browse recent work | | `search_plans` | Find past implementation plans |

Requires

claude mcp add historian -- npx claude-historian-mcp