Open Mercato is an open-source TypeScript foundation framework for building CRM, ERP, commerce, and other business applications with established architecture, specifications, permissions, events, and domain modules. It is for teams and developers who want AI coding assistants to build consistent business software on top of ready-made foundations. The catalogue add-ons teach agents the framework’s conventions and workflows for implementing, testing, reviewing, and debugging features.
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/open-mercato/open-mercatoWrote 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/open-mercato/open-mercato/entity-guard)<a href="https://agentmods.dev/rules/open-mercato/open-mercato/entity-guard"><img src="https://agentmods.dev/badge/rules/open-mercato/open-mercato/entity-guard/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/open-mercato/open-mercato/entity-guard"><img src="https://agentmods.dev/badge/rules/open-mercato/open-mercato/entity-guard.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 | $0.00000 | $0.00120 |
| Opus 5.5 | $0.00000 | $0.00048 |
| Sonnet 5.5 | $0.00000 | $0.00024 |
| Haiku 4.5 | $0.00000 | $0.00012 |
Grade A, and why
entity-guard 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.
What it actually says
Entity Schema Change
Follow root AGENTS.md and om-data-model-design:
- Run
yarn db:generateas a schema-diff probe. - Review and keep only scoped migration SQL plus the touched module snapshot.
- Run
yarn generatewhen discovery changed. - Ask before applying with
yarn db:migrate.
Never edit a shipped migration or generated registry.
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 · 18 lines · 0 tokens per session scan A fecb89e316b0
entity-guard is a cursor rule published in the GitHub repository open-mercato/open-mercato (1,877 stars, last pushed today), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 120 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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