custodian

custodian is a skill for Claude Code from modeled-information-format/mnemonic. It costs 58 tokens per session (1,049 once invoked), scanned A, original, MIT.

A maintenance skill for a file-based memory system. It checks memory files, links, relationships, freshness scores, and organization.

In plain words
What is it for?
Use it to check memory health, validate files, repair links, update decay scores, relocate memories, audit namespaces, and produce maintenance reports.
Why use it?
It helps find invalid links, duplicate or abandoned memories, outdated strength scores, and files that need moving after a project rename.

Skill for Claude Code

Written for Claude Code: allowed-tools in frontmatter.

Part of the mnemonic plugin — 10 skills, 14 commands, 4 agents, 1 hook, 1 plugin 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 skills/modeled-information-format/mnemonic/custodian
Any agent
npx skills add modeled-information-format/mnemonic --skill custodian
Clone the repo
git clone --depth 1 https://github.com/modeled-information-format/mnemonic

Made for: Claude Code.

Or install mnemonic, the plugin that ships this one along with the rest of its 10 skills, 14 commands, 4 agents, 1 hook, 1 plugin.

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 custodian

README.md
[![agentmods](https://agentmods.dev/badge/skills/modeled-information-format/mnemonic/custodian.svg)](https://agentmods.dev/skills/modeled-information-format/mnemonic/custodian)
Your own site
<a href="https://agentmods.dev/skills/modeled-information-format/mnemonic/custodian"><img src="https://agentmods.dev/badge/skills/modeled-information-format/mnemonic/custodian.svg" alt="Measured on agentmods" height="20"></a>
Per session 58 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,049 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 $0.00058 $0.01049
Opus 5 $0.00029 $0.00524
Sonnet 5 $0.00012 $0.00210
Haiku 4.5 $0.00006 $0.00105

Measured 6d ago against content hash ba3b643871a3, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade A, and why

custodian 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 6d ago.

The scan reads SKILL.md. This mod also ships 8 executable files (lib/__init__.py, lib/custodian.py, lib/decay.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.

skills/custodian/SKILL.md · 138 lines

How it starts

The opening of the file, as written. The whole thing — 138 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Memory

Search first: /mnemonic:search {relevant_keywords} Capture after: /mnemonic:capture {namespace} "{title}"

Run /mnemonic:list --namespaces to see available namespaces from loaded ontologies.

Custodian Skill

Provides custodial services for the mnemonic memory system: auditing, validation, link repair, decay management, relocation, and summarization.

When to Use

  • Proactively when session_start reports low health scores or potential duplicates
  • On request when user asks about memory health, broken links, or maintenance
  • After project renames to relocate memories and update references
  • Periodically to keep decay scores current and identify orphaned memories

Architecture

The custodian operates through focused Python modules:

Module Responsibility
memory_file.py Parse/validate/update MIF frontmatter
link_checker.py Build UUID/slug index, validate links, find orphans
decay.py Calculate exponential/linear/step decay, update strength
relocator.py Move files + update all cross-references
validators.py MIF schema validation, ontology relationship checks
report.py Structured findings with markdown/JSON output
custodian.py CLI orchestrator dispatching to modules

Subcommands

audit (default)

Runs all checks in a single pass. This is the recommended entry point.

/mnemonic:custodian audit [--fix] [--dry-run]

Checks performed:

  1. Frontmatter: Required fields, UUID format, type enum, date format
  2. Links: Wiki-links resolve to existing memories
  3. Relationships: Types match MIF built-in or ontology-defined types
  4. Decay: Recalculates strength values using configured model
  5. Orphans: Detects memories with no incoming references

relocate

Moves memories when project or org names change:

/mnemonic:custodian relocate <old-path> <new-path> [--dry-run]

Read the full file on GitHub · 138 lines

Files

What ships with it

8 files 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. 6d ago First seen · 138 lines · 58 tokens per session scan A ba3b643871a3

Subscribe to this mod's changes

custodian is a skill published in the GitHub repository modeled-information-format/mnemonic (23 stars, last pushed 1mo ago), licensed MIT. It adds 58 tokens to every session and 1,049 once invoked, about $0.0003 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.