What is memory-system?

A structured memory system for coding-agent sessions. It stores current state, typed memory records, session logs, and a linked history whose changes can be checked.

Use it to read or update focus and pending decisions, save facts or reasoning, record session summaries, and verify the integrity of the memory history.

It keeps project context and decisions organized and traceable instead of relying on one flat notes file or only on past chat messages.

memory-system — Skill for Claude Code and Codex by kostyk348

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.

Any agent

npx skills add kostyk348/sint-ua-v2.1 --skill memory-system

Clone the repo

git clone --depth 1 https://github.com/kostyk348/sint-ua-v2.1

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.

README.md

[![agentmods](https://agentmods.dev/badge/skills/kostyk348/sint-ua-v2.1/memory-system/github.svg)](https://agentmods.dev/skills/kostyk348/sint-ua-v2.1/memory-system)

Your own site

<a href="https://agentmods.dev/skills/kostyk348/sint-ua-v2.1/memory-system"><img src="https://agentmods.dev/badge/skills/kostyk348/sint-ua-v2.1/memory-system/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.

Your own site · 80×15

<a href="https://agentmods.dev/skills/kostyk348/sint-ua-v2.1/memory-system"><img src="https://agentmods.dev/badge/skills/kostyk348/sint-ua-v2.1/memory-system.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 47 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 1,669 The whole file, excluding the scripts and references it only reads on demand.

Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.

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.

Model	Per session	Once invoked
Fable 5.1	$0.00047	$0.01669
Opus 5.5	$0.00019	$0.00668
Sonnet 5.5	$0.00009	$0.00334
Haiku 4.5	$0.00005	$0.00167

Measured 1mo ago against content hash 4cdf52901297, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, 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 1mo 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.

skills/memory-system/SKILL.md · 214 lines

How it starts

The opening of the file, as written. The whole thing — 214 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Structured memory system with semantic typing and hash-chain provenance. Replaces STATE.MD with JSON blocks that agents read/write programmatically.

ARCHITECTURE

.opencode/memory/
├── state.json              # Current focus, pending decisions (small, fast)
├── chain.jsonl             # Global hash-chain: every block append-only
├── blocks/
│   ├── 0001.fact.json      # Semantic-typed memory blocks
│   ├── 0002.logic.json
│   └── ...
└── sessions/
    ├── 2026-07-13.jsonl    # Session logs (append-only)
    └── ...

MEMORY BLOCKS

Each block is a JSON file. Filename: {id}.{register}.json

{
  "id": "0042",
  "register": "FACT",
  "prev_hash": "a3f2c...",
  "hash": "7b1d9...",
  "timestamp": "2026-07-14T12:00:00Z",
  "project": "DSA",
  "content": "DSA 3D attenuation verified: near=0.25 far=0.0025",
  "source": "bench run 2026-07-13",
  "confidence": 0.95,
  "tags": ["3d", "attenuation", "verified"],
  "links": ["0038", "0040"]
}

Registers (semantic types)

Register	Use for	Example
`SENSE`	Raw observations, user input, logs	"recvfrom captured 264/324 pages"
`FACT`	Verified claims with sources	"Cipher = stream cipher [source: taint trap]"
`LOGIC`	Inferences from FACT/SENSE	"xRead key needed for full decrypt"
`OPINION`	Subjective assessments	"Option (a) preferred for RE approach"
`ACTION`	Execution plans, next steps	"RE logiovfs xRead next session"

Hash-chain

Every block references the previous block's hash:

block_N.prev_hash = block_{N-1}.hash
block_N.hash = sha256(id + register + content + prev_hash)

This creates a tamper-evident chain. If any block is modified, all subsequent hashes break.

HOW TO READ

Current state

Read state.json — it has focus, pending decisions, session count.

Find blocks by project

Search blocks/ for files containing "project": "DSA".

Find blocks by register

Search blocks/ for files named *.fact.json etc.

Read the full file on GitHub · 214 lines

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.

1mo ago First seen · 214 lines · 47 tokens per session scan A 4cdf52901297

Subscribe to this mod's changes

memory-system is a skill published in the GitHub repository kostyk348/sint-ua-v2.1 (0 stars, last pushed 13d ago), licensed Apache-2.0. It adds 47 tokens to every session and 1,669 once invoked, about $0.0002 per session on Opus 5.5. 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 2026-08-31.

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