csm-compaction

csm-compaction is a command for coding agents from NovasPlace/CSM. It costs 9 tokens per session (172 once invoked), scanned A, original, MIT.

A project command for reviewing context usage and how the system handled compressed conversation history.

In plain words
What is it for?
Checking context pressure, available budget, compression details, and whether a handoff is advisable.
Why use it?
It shows how much context remains and whether saving a checkpoint or handoff would be sensible before continuing.

Command

Part of the cross-session-memory plugin — 2 skills, 12 commands, 3 agents shipped together

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add commands/novasplace/csm/csm-compaction
Clone the repo
git clone --depth 1 https://github.com/NovasPlace/CSM

Or install cross-session-memory, the plugin that ships this one along with the rest of its 2 skills, 12 commands, 3 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 csm-compaction

README.md
[![agentmods](https://agentmods.dev/badge/commands/novasplace/csm/csm-compaction.svg)](https://agentmods.dev/commands/novasplace/csm/csm-compaction)
Your own site
<a href="https://agentmods.dev/commands/novasplace/csm/csm-compaction"><img src="https://agentmods.dev/badge/commands/novasplace/csm/csm-compaction.svg" alt="Measured on agentmods" height="20"></a>
Per session 9 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 172 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
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 $0.00009 $0.00172
Opus 5 $0.00005 $0.00086
Sonnet 5 $0.00002 $0.00034
Haiku 4.5 $0.00001 $0.00017

Measured 5d ago against content hash 9d2a10825146, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-05, from the pricing page.

Security

Grade A, and why

csm-compaction 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 5d 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.

plugins/cross-session-memory/commands/csm-compaction.md · 13 lines

What it actually says

Show CSM context pressure and compaction health $ARGUMENTS.

  1. Resolve projectRoot to the current workspace root.
  2. Call csm_context_pressure and csm_context_budget for the current window state.
  3. Call csm_compaction_audit and get_compaction_report to review recent compaction attribution and token accounting.
  4. Summarize pressure, headroom, and whether a checkpoint/handoff is advisable before continuing.
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. 5d ago First seen · 13 lines · 9 tokens per session scan A 9d2a10825146

Subscribe to this mod's changes

csm-compaction is a command published in the GitHub repository NovasPlace/CSM (42 stars, last pushed yesterday), licensed MIT. It adds 9 tokens to every session and 172 once invoked, about $0.0000 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.