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.
git clone --depth 1 https://github.com/Aiyo28/memento-osWrote 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/rules/aiyo28/memento-os/memento-conventions)<a href="https://agentmods.dev/rules/aiyo28/memento-os/memento-conventions"><img src="https://agentmods.dev/badge/rules/aiyo28/memento-os/memento-conventions/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/rules/aiyo28/memento-os/memento-conventions"><img src="https://agentmods.dev/badge/rules/aiyo28/memento-os/memento-conventions.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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 | $0.01035 | $0.01035 |
| Opus 5.5 | $0.00414 | $0.00414 |
| Sonnet 5.5 | $0.00207 | $0.00207 |
| Haiku 4.5 | $0.00103 | $0.00103 |
Grade A, and why
memento-conventions 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.
How it starts
The opening of the file, as written. The whole thing — 117 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Memento OS — Conventions
This project uses Memento OS for persistent AI memory. Store conclusions, not notes. The vault is a retrieval source — search before generating from training data.
Artifact Format
Every piece of memory is a reasoning artifact — a pre-computed conclusion with an expiration condition.
[D] conclusion — invalidates if trigger [priority] [YYYY-MM-DD]
[I] insight — invalidates if condition [priority] [YYYY-MM-DD]
[E] what went wrong — root cause: why [settled] [YYYY-MM-DD]
[S] idea — activates when condition [priority] [YYYY-MM-DD]
| Prefix | Type | Purpose |
|---|---|---|
[D] |
Decision | A choice between alternatives — has an invalidation trigger |
[I] |
Insight | A reusable conclusion — survives the session that produced it |
[E] |
Error | A mistake with root cause + fix — defaults to settled |
[S] |
Seed | A deferred idea — activates when its condition is met, not when time passes |
Optional expiry (for time-bound conclusions only):
[D] conclusion — invalidates if trigger — expires: YYYY-MM-DD [priority] [YYYY-MM-DD]
Do NOT add expiry to foundational architecture decisions.
Priority Matrix
Priority is derived from confidence × impact:
| High Impact | Low Impact | |
|---|---|---|
| High Confidence | critical | settled |
| Medium Confidence | volatile | settled |
| Low Confidence | volatile | noise |
- AI proposes confidence (high / medium / low)
- Ask user: "High or low impact?"
[E]errors default to settled; once resolved → noise- noise priority: ask "store anyway or discard?" — default: discard
Kobe Cap: 24 Artifacts
Maximum 24 artifacts per project in the Active Reasoning Artifacts table.
Eviction order when over cap: noise → settled → volatile → critical (never auto-evict).
Archive evicted artifacts to Decisions/ folder with status: superseded, archived, or active.
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 · 117 lines · 1,035 tokens per session scan A 7f9330211664
memento-conventions is a cursor rule published in the GitHub repository Aiyo28/memento-os (4 stars, last pushed 3d ago), licensed MIT. It adds 1,035 tokens to every session, about $0.0041 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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