evolve-lite:retention

evolve-lite:retention is a skill for Claude Code, Codex from AgentToolkit/altk-evolve. It costs 34 tokens per session (1,035 once invoked), scanned A, original, Apache-2.0.

A data-retention tool for a local evolve store, which contains saved entities and session transcripts. It finds old or unused items and can mark them or delete them according to rules in evolve.config.yaml.

In plain words
What is it for?
For flagging or deleting entities and expired sessions based on age or lack of use, including optionally deleting entities derived from removed sessions.
Why use it?
It helps control stale stored data while making accidental changes less likely: it previews actions by default and only changes files when --apply is used.

Skill for Claude CodeCodex

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 skills/agenttoolkit/altk-evolve/evolve-lite-retention
Any agent
npx skills add AgentToolkit/altk-evolve --skill evolve-lite-retention
Clone the repo
git clone --depth 1 https://github.com/AgentToolkit/altk-evolve

Made for: Claude Code, Codex.

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 evolve-lite:retention

README.md
[![agentmods](https://agentmods.dev/badge/skills/agenttoolkit/altk-evolve/evolve-lite-retention.svg)](https://agentmods.dev/skills/agenttoolkit/altk-evolve/evolve-lite-retention)
Your own site
<a href="https://agentmods.dev/skills/agenttoolkit/altk-evolve/evolve-lite-retention"><img src="https://agentmods.dev/badge/skills/agenttoolkit/altk-evolve/evolve-lite-retention.svg" alt="Measured on agentmods" height="20"></a>
Per session 34 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,035 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 $0.00034 $0.01035
Opus 5 $0.00017 $0.00517
Sonnet 5 $0.00007 $0.00207
Haiku 4.5 $0.00003 $0.00103

Measured 4d ago against content hash 4456d3b67054, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

evolve-lite:retention 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 4d ago.

The scan reads SKILL.md. This mod also ships 1 executable file (scripts/run_retention.py), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

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.

Origin

Copies of this mod

1 near-identical copy found in the catalogue:

  • retention — 100% identical, 6 lines differ
platform-integrations/bob/evolve-lite/skills/evolve-lite-retention/SKILL.md · 101 lines

How it starts

The opening of the file, as written. The whole thing — 101 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Retention

Overview

Runs the data-retention rules configured in evolve.config.yaml against the local .evolve/ store: private entities under .evolve/entities/ and session transcripts under .evolve/trajectories/. Rules match by entity type plus age (max_age_days, from file mtime) or disuse (max_unused_days, from recall rows in .evolve/audit.log), and either flag (a non-destructive frontmatter marker) or delete. A delete rule on trajectories with cascade_derived: true also deletes the entities derived from those sessions (linked by their trajectory: frontmatter).

The script is dry-run by default — it never mutates anything unless --apply is passed.

Workflow

Step 1: Require rules

Read evolve.config.yaml. If there is no retention: block with a rules: list, show the user this example and stop:

retention:
  rules:
    - name: stale-guidelines
      entity_type: guideline
      max_age_days: 90
      action: flag
    - name: old-sessions
      entity_type: trajectory
      max_age_days: 365
      action: delete
      cascade_derived: true

Each rule needs a name and at least one of max_age_days / max_unused_days; action is flag (default) or delete. Rules are checked top-to-bottom and the first match wins, so put narrow rules first — and put a longer-threshold delete before a shorter-threshold flag on the same type, or the flag shadows the delete and it never fires.

A delete rule may also set on_missing_access_signal to say what happens when an unused match has no recorded recall (disuse measured from file mtime): skip (default, fail-safe — spare it and report it as skipped), flag (downgrade the delete to a non-destructive flag), or delete (delete on the mtime fallback anyway). The safe default means an unused delete never destroys a memory the agent simply never recorded a recall for.

Step 2: Dry run

From the project root:

python3 .bob/skills/evolve-lite-retention/scripts/run_retention.py

Read the full file on GitHub · 101 lines

Files

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.

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. 4d ago First seen · 101 lines · 34 tokens per session scan A 4456d3b67054

Subscribe to this mod's changes

evolve-lite:retention is a skill published in the GitHub repository AgentToolkit/altk-evolve (105 stars, last pushed 8d ago), licensed Apache-2.0. It adds 34 tokens to every session and 1,035 once invoked, about $0.0002 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.