lcm-diagnose

lcm-diagnose is a command for Claude Code from lossless-claude/lcm. It costs 27 tokens per session (247 once invoked), scanned A, original, MIT.

A troubleshooting command for reviewing recent Claude Code session records for failed hooks, broken connections to MCP servers, or outdated lcm setup.

In plain words
What is it for?
Use it after an error or when checking whether sessions were recorded correctly. It can scan recent or older records and show detailed or JSON results.
Why use it?
It helps explain past problems such as missing sessions or gaps in saved conversation history.

Command for Claude Code

Written for Claude Code: user-invocable in frontmatter. Also seen: mentions Claude Code.

Runs only inside its plugin — its command needs a path that Claude Code sets for a plugin’s own hooks and for nothing else. Install the plugin, not this.

Part of the lcm plugin — 8 skills, 10 commands, 4 agents shipped together

Good fit Use it after an error or when checking whether sessions were recorded correctly. It can scan recent or older records and show detailed or JSON results.

Compare 6 commands from other repositories ↓
Install

Getting it into your agent

This one installs as part of its plugin. Adding the marketplace and installing the plugin brings it with everything else the plugin ships.

Claude Code
/plugin marketplace add lossless-claude/lcm
Claude Code
/plugin install lcm

Made for: Claude Code.

Or install lcm, the plugin that ships this one along with the rest of its 8 skills, 10 commands, 4 agents.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for lcm-diagnose

README.md
[![agentmods](https://agentmods.dev/badge/commands/lossless-claude/lcm/lcm-diagnose/github.svg)](https://agentmods.dev/commands/lossless-claude/lcm/lcm-diagnose)
Your own site
<a href="https://agentmods.dev/commands/lossless-claude/lcm/lcm-diagnose"><img src="https://agentmods.dev/badge/commands/lossless-claude/lcm/lcm-diagnose/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for lcm-diagnose

Your own site · 80×15
<a href="https://agentmods.dev/commands/lossless-claude/lcm/lcm-diagnose"><img src="https://agentmods.dev/badge/commands/lossless-claude/lcm/lcm-diagnose.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 27 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 247 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00027 $0.00247
Opus 5 $0.00014 $0.00123
Sonnet 5 $0.00005 $0.00049
Haiku 4.5 $0.00003 $0.00025

Measured 9d ago against content hash dbf890ddc894, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

lcm-diagnose scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 9d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

.claude-plugin/commands/lcm-diagnose.md · 30 lines

What it actually says

/lcm-diagnose

Inspect recent Claude Code transcripts for historical lcm issues.

Instructions

Run lcm diagnose via Bash and display the output verbatim. If lcm is not on PATH (marketplace install), use node "${CLAUDE_PLUGIN_ROOT}/lcm.mjs" diagnose instead.

If the user asks for a wider scan, use:

  • lcm diagnose --all
  • lcm diagnose --all --days 30
  • lcm diagnose --verbose
  • lcm diagnose --json

After showing the results, suggest the next troubleshooting step:

  • lcm doctor for current install health
  • lcm import if sessions were missed and need recovery

When to use

  • After seeing hook errors in a Claude Code session
  • When investigating missing sessions or gaps in ingestion
  • During troubleshooting: lcm doctor for current state, lcm diagnose for history, lcm import for recovery
Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 9d ago First seen · 30 lines · 27 tokens per session scan A dbf890ddc894

Subscribe to this mod's changes

lcm-diagnose is a command published in the GitHub repository lossless-claude/lcm (26 stars, last pushed today), licensed MIT. It adds 27 tokens to every session and 247 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.