memory-system

A memory-management rule set for projects that keep shared notes in files such as memory.md, todo.md, and checkpoint.md. It says that the codebase and database are the final sources of truth.

In plain words
What is it for?
Maintaining project memory, checking remembered facts against files and data, and deciding which detailed notes to load when needed.
Why use it?
It helps an assistant retain useful project context while preventing outdated notes from overriding what the code actually does.

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/criterium/opencode-lab/memory-system
Any agent
npx skills add criterium/opencode-lab --skill memory-system
Clone the repo
git clone --depth 1 https://github.com/criterium/opencode-lab

Made for: Claude Code, Codex.

Per session 0 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 5,504 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 $0.00000 $0.05504
Opus 5 $0.00000 $0.02752
Sonnet 5 $0.00000 $0.01101
Haiku 4.5 $0.00000 $0.00550

Measured 2d ago against content hash e753ac8cbbe0, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

memory-system 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 2d 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.

research/memory-system/SKILL.md · 374 lines

How it starts

The opening of the file, as written. The whole thing — 374 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Memory System — editing rules

Loaded by custom.md upon receiving >> or <<. Single file per scope (memory.md) that accumulates relevant project information. In effect until the skill is loaded again. Apply the certainty rule without asking.

Terminology

  • memory-system or m-s: memory files of the scope managed by this skill: memory.md, memory/*.md, todo.md, checkpoint.md. sessions.md is an optional historical record, not included.

Source of truth

The definitive source of truth is codebase + database. Memory describes, code executes. Any claim in memory about files, symbols, data structures or schemas must be verifiable against the code on disk. If memory and code disagree, code prevails. The model decides how and what to verify based on context and available tools (grep, glob, DFM parsing).

Division principle

  • memory.md self-contained for initial orientation: critical rules, context, map. An agent without context must be able to start with << ./ and understand the project.
  • memory/*.md is on-demand deepening: implementation detail, specific references. Loaded only when the task requires them.
  • The index of memory.md must include a column indicating for which type of task to load each file from memory/.
  • todo.md: pending tasks. << shows it. >> <scope> check reports status. Written via >> <scope> todo <content> or manually.

Writing principle

Any content under this skill must prioritize precision and effectiveness over verbosity or human-oriented explanations. Prefer: imperative over descriptive, concrete examples over generalities, direct references over introductions. No politeness, narrative or justifications. Compactness is a consequence, not a goal — do not sacrifice clarity for brevity.

Verification criteria:

  • (a) Unambiguous. In what is stated, not in what is omitted. Uncertainty is declared, not hidden in vague wording.
  • (b) Action, not description. For instructions and prompts: what to do, not what each thing is. Conditions, preconditions and guard clauses are part of the instruction.
  • (c) Action precedes reason. For instructions and prompts: the what before the why.
  • (d) No fossils. Do not include implementation dates, versions ("since X"), or counts that expire ("17 forms"). Current state describes how things are, not when they changed. The temporal delta belongs to git / sessions.md.
  • (e) Compact by default. One idea = one paragraph. Tables for relatable data. If something is explained in one line, do not expand it to three.
  • (f) Relevant. Only what an agent would lose without help deserves memory. Do not store: obvious code structure, standard framework patterns, available official documentation, or conventions inferable from project context.
  • (g) Fresh and actionable. Information must be the latest available. If it describes code, verify the code still exists (files, functions, routes). If it describes a decision, it must be the current one. An entry unverified since creation is a review candidate. Prioritize: design decisions, undocumented workarounds, execution orders, non-obvious setup, context inferred from multiple sources.

Read the full file on GitHub · 374 lines

Files

What ships with it

3 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. 2d ago First seen · 374 lines · 0 tokens per session scan A e753ac8cbbe0

Subscribe to this mod's changes

memory-system is a skill published in the GitHub repository criterium/opencode-lab (44 stars, last pushed 23d ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 5,504 tokens. 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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