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.
npx skills add first-fluke/fullstack-starter --skill oma-backendgit clone --depth 1 https://github.com/first-fluke/fullstack-starterWrote 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/skills/first-fluke/fullstack-starter/oma-backend)<a href="https://agentmods.dev/skills/first-fluke/fullstack-starter/oma-backend"><img src="https://agentmods.dev/badge/skills/first-fluke/fullstack-starter/oma-backend/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/skills/first-fluke/fullstack-starter/oma-backend"><img src="https://agentmods.dev/badge/skills/first-fluke/fullstack-starter/oma-backend.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 | $0.00024 | $0.02152 |
| Opus 5.5 | $0.00010 | $0.00861 |
| Sonnet 5.5 | $0.00005 | $0.00430 |
| Haiku 4.5 | $0.00002 | $0.00215 |
Grade C, and why
oma-backend scanned grade C with 1 finding 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 14d 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.
Hidden instructionshighPrompt injection
Directives inside HTML comments, invisible characters or bidirectional overrides are read by the model and not by the person reviewing the file.
<!-- oma-docs:ignore-start --> This is a copy
100% identical to oma-backend — 0 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.
How it starts
The opening of the file, as written. The whole thing — 202 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Backend Agent - API & Server Specialist
Scheduling
Goal
Implement or review backend APIs, authentication, database integration, server-side business logic, and migrations using the project's existing backend stack and clean architecture boundaries.
Intent signature
- User asks for API, endpoint, REST, GraphQL, auth, server, migration, repository, service, router, or background job work.
- User needs backend code that coordinates validation, business logic, persistence, transactions, and backing services.
When to use
- Building REST APIs or GraphQL endpoints
- Database design and migrations
- Authentication and authorization
- Server-side business logic
- Background jobs and queues
When NOT to use
- Frontend UI -> use Frontend Agent
- Mobile-specific code -> use Mobile Agent
Expected inputs
- Target feature, endpoint, migration, auth flow, or server behavior
- Existing backend stack files such as manifests, routes, services, models, and database config
- API contracts, schemas, validation rules, and persistence requirements
- Required verification commands or project conventions
Expected outputs
- Backend code changes in router, service, repository, model, migration, or test files
- Validated inputs, safe queries, transaction boundaries, and error handling
- Verification results from the execution checklist
Dependencies
- Project stack manifests and existing backend conventions
resources/execution-protocol.md,resources/checklist.md, andresources/orm-reference.md
- Optional
stack/stack.yaml,stack/tech-stack.md, snippets, and API templates
- Database, queue, cache, mail, auth, or external API resources configured through environment or secret managers
Control-flow features
- Branches by detected stack, ORM/query pattern, auth requirement, migration impact, and transaction scope
- Reads and writes codebase files
- May touch local database migrations or generated code
- Must not hardcode secrets or share unsafe ORM lifecycle objects across concurrent work
What ships with it
5 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.
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.
- 14d ago Changed · +2 lines 654a442b41e2
- 1mo ago Changed · -4 lines · -17 tokens per session 4a9cb12718e0
- 1mo ago First seen · 204 lines · 41 tokens per session scan C 23a51b126bc1
oma-backend is a skill published in the GitHub repository first-fluke/fullstack-starter (224 stars, last pushed yesterday), licensed MIT. It adds 24 tokens to every session and 2,152 once invoked, about $0.0001 per session on Opus 5.5. A static security scan graded it C with 1 finding (hidden instructions). It is 100% identical to oma-backend, differing in 0 lines, and is treated as a copy.
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