lcm-context

name	lcm-context
description	Use when deciding which lcm MCP tool to call — lcm_search, lcm_grep, lcm_expand, lcm_describe, lcm_store, lcm_doctor, or lcm_stats — or when an lcm tool returns an error.

lcm Memory Tool Guide

Lossless-claude provides 7 MCP tools. This skill helps you pick the right one and recover from errors.

Hooks already inject memory at session start. Do NOT re-query what was already injected. This skill is for active retrieval, storage, and error recovery — not session initialization.

Tool Decision Tree

Retrieval Tools (search → grep → expand)

These three tools chain from broad to deep:

1. lcm_search — Broad concept recall across sessions

   • Use: "how was auth implemented?", "what decisions were made about compaction?"
   • Returns: ranked results from FTS5 + semantic layers
   • Options: tags to filter, layers to scope (episodic/semantic)

2. lcm_grep — Exact keyword/regex in raw transcripts

   • Use: "JWT", "socket.unref", specific error messages
   • Returns: matching messages/summaries with context
   • Options: scope (messages/summaries/all), since date filter

3. lcm_expand — Drill into a compressed summary node

   • Use: when a search/grep result references a summary nodeId and you need the full content
   • Returns: decompressed source content from the DAG
   • Options: depth to control traversal levels

Chaining pattern: Start with lcm_search for broad recall → use lcm_grep to find exact references → use lcm_expand to decompress interesting nodes.

Inspection Tool

4. lcm_describe — Check a node's metadata without loading content
   • Use: when a nodeId came from grep and you don't know if it's worth expanding. Saves tokens if the node is stale, shallow, or unrelated.
   • Returns: depth, token count, parent/child links, promotion status

Storage Tool

5. lcm_store — Persist a decision or finding for future sessions
   • Use: architectural decisions, bug root causes, user preferences, integration patterns
   • Options: tags for categorization, metadata for project/session context

Operational Tools

6. lcm_doctor — Check system health (daemon, hooks, MCP, summarizer)
7. lcm_stats — View compression ratios and token savings

When to Use / When NOT to Use

Retrieval

Use when:

• You need context that wasn't in the hook-injected summary
• You're looking for a specific past decision or conversation
• A summary node looks relevant but needs more detail

Do NOT use when:

• The information is already in your current context (hook injected it)
• You're looking for general knowledge, not project memory
• You can answer from code/git alone

Storage

Use when:

• An architectural decision was made with rationale worth preserving
• A bug root cause was identified (the "why", not just the fix)
• User expressed a preference or feedback that affects future work
• A non-obvious integration pattern was discovered

Do NOT use when:

• The information is already in git (code, commit messages)
• It's a transient debugging step or ephemeral task detail
• It's already documented in CLAUDE.md or memory files
• It's general knowledge, not project-specific

Binary Resolution

If lcm is not on PATH, first try to install it by running:

LCM_DIR=$(ls -d ~/.claude/plugins/cache/*/lossless-claude/*/ 2>/dev/null | sort -V | tail -1)
node "${LCM_DIR}lcm.mjs" install

If install succeeds, lcm should now be available on PATH. If it is still not available, use the bundled binary directly: node "$(ls -d ~/.claude/plugins/cache/*/lossless-claude/*/ 2>/dev/null | sort -V | tail -1)lcm.mjs"

Error Self-Healing

Agent-Fixable (handle automatically)

Error	Recovery
Daemon not running	Run lcm start via Bash, then retry
"unauthorized" or version mismatch	Run lcm daemon restart via Bash, then retry — the daemon is likely running an older version than the MCP server expects
"No results" from search	Try lcm_grep with different keywords, or broaden the query
Node not found on expand	Use lcm_search to find the correct nodeId
Store succeeds but daemon restarted before SessionEnd	Call lcm_doctor to verify persistence; re-store if the node is missing

User Action Required (surface to user)

Error	What to tell the user
MCP server disconnected	Restart the session, then run /lcm-diagnose to audit for gaps
Hooks not firing	Call lcm_doctor to confirm; if hooks are missing, tell user to run lcm install
Summarizer failing	Tell user to run /lcm-doctor for full diagnostics

Quick Reference

lcm_search  → broad concept recall (FTS5 + semantic)
lcm_grep    → exact keyword/regex match
lcm_expand  → decompress a summary node
lcm_describe → inspect node metadata (check before expanding)
lcm_store   → persist decisions/findings
lcm_doctor  → health check
lcm_stats   → compression metrics