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.
npx skills add bobmatnyc/claude-mpm-skills --skill session-compressiongit clone --depth 1 https://github.com/bobmatnyc/claude-mpm-skillsWrote 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.
[](https://agentmods.dev/skills/bobmatnyc/claude-mpm-skills/session-compression)<a href="https://agentmods.dev/skills/bobmatnyc/claude-mpm-skills/session-compression"><img src="https://agentmods.dev/badge/skills/bobmatnyc/claude-mpm-skills/session-compression/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.
<a href="https://agentmods.dev/skills/bobmatnyc/claude-mpm-skills/session-compression"><img src="https://agentmods.dev/badge/skills/bobmatnyc/claude-mpm-skills/session-compression.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- Socket pass
- Snyk fail
- NVIDIA SkillSpector warn
SkillSpector: 2 findings, up to medium
These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →
- medium Rogue Agent · line 1182 Skill establishes unauthorized persistence across sessions via cron jobs, startup scripts, or state files. Session persistence allows an attacker to maintain access beyond the current interaction.Fix: Remove any persistence mechanisms (cron jobs, startup scripts, state files). Skills should not maintain state across sessions without explicit user consent.
- medium Memory Poisoning · line 1448 Skill attempts to fill the context window with filler content, displacing legitimate instructions and safety constraints. This can degrade agent performance or bypass safety boundaries.Fix: Implement context-window management that detects and rejects padding or stuffing attempts. Prioritize system instructions over user-injected content.
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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00027 | $0.13293 |
| Opus 5 | $0.00014 | $0.06646 |
| Sonnet 5 | $0.00005 | $0.02659 |
| Haiku 4.5 | $0.00003 | $0.01329 |
Grade A, and why
session-compression 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 10d 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.
How it starts
The opening of the file, as written. The whole thing — 2,033 lines — stays where its author put it; the contents beside it link to each section on GitHub.
AI Session Compression Techniques
Summary
Compress long AI conversations to fit context windows while preserving critical information.
Session compression enables production AI applications to manage multi-turn conversations efficiently by reducing token usage by 70-95% through summarization, embedding-based retrieval, and intelligent context management. Achieve 3-20x compression ratios with minimal performance degradation.
Key Benefits:
- Cost Reduction: 80-90% token cost savings through hierarchical memory
- Performance: 2x faster responses with compressed context
- Scalability: Handle conversations exceeding 1M tokens
- Quality: Preserve critical information with <2% accuracy loss
When to Use
Use session compression when:
- Multi-turn conversations approach context window limits (>50% capacity)
- Long-running chat sessions (customer support, tutoring, code assistants)
- Token costs become significant (high-volume applications)
- Response latency increases due to large context
- Managing conversation history across multiple sessions
Don't use when:
- Short conversations (<10 turns) fitting easily in context
- Every detail must be preserved verbatim (legal, compliance)
- Single-turn or stateless interactions
- Context window usage is <30%
Ideal scenarios:
- Chatbots with 50+ turn conversations
- AI code assistants tracking long development sessions
- Customer support with multi-session ticket history
- Educational tutors with student progress tracking
- Multi-day collaborative AI workflows
Quick Start
Basic Setup with LangChain
from langchain.memory import ConversationSummaryBufferMemory
from langchain_anthropic import ChatAnthropic
from anthropic import Anthropic
# Initialize Claude client
llm = ChatAnthropic(
model="claude-3-5-sonnet-20241022",
api_key="your-api-key"
)
# Setup memory with automatic summarization
memory = ConversationSummaryBufferMemory(
llm=llm,
max_token_limit=2000, # Summarize when exceeding this
return_messages=True
)
# Add conversation turns
memory.save_context(
{"input": "What's session compression?"},
{"output": "Session compression reduces conversation token usage..."}
)
# Retrieve compressed context
context = memory.load_memory_variables({})
What ships with it
1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
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.
- 10d ago First seen · 2,033 lines · 27 tokens per session scan A c176f1d1be7d
session-compression is a skill published in the GitHub repository bobmatnyc/claude-mpm-skills (74 stars, last pushed 1mo ago), licensed MIT. It adds 27 tokens to every session and 13,293 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.
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