AGENTS.backend-api

AGENTS.backend-api is an agent for coding agents from jeremylongworth-source/AgentSkills. It costs 0 tokens per session (292 once invoked), scanned A, original, MIT.

A routing guide for backend and API development work. It directs requests to local guidance for designing APIs, databases, authentication, services, errors, and tests.

In plain words
What is it for?
Use it when designing endpoints, schemas, login and permissions, service boundaries, error responses, rate limits, API documentation, or backend testing.
Why use it?
It helps choose the right review or planning guidance instead of handling backend concerns inconsistently or overlooking important details.

Agent

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 agents/jeremylongworth-source/agentskills/agents.backend-api
Clone the repo
git clone --depth 1 https://github.com/jeremylongworth-source/AgentSkills

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.

agentmods badge for AGENTS.backend-api

README.md
[![agentmods](https://agentmods.dev/badge/agents/jeremylongworth-source/agentskills/agents.backend-api.svg)](https://agentmods.dev/agents/jeremylongworth-source/agentskills/agents.backend-api)
Your own site
<a href="https://agentmods.dev/agents/jeremylongworth-source/agentskills/agents.backend-api"><img src="https://agentmods.dev/badge/agents/jeremylongworth-source/agentskills/agents.backend-api.svg" alt="Measured on agentmods" height="20"></a>
Per session 0 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 292 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 $0.00292
Opus 5 $0.00000 $0.00146
Sonnet 5 $0.00000 $0.00058
Haiku 4.5 $0.00000 $0.00029

Measured 3d ago against content hash d9d9aaa89bb1, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

AGENTS.backend-api 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 3d 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.

agents/AGENTS.backend-api.md · 31 lines

What it actually says

Use local skills as the primary routing layer for backend and API work.

Use api-contract-design when defining endpoints, resource models, request and response schemas, status codes, idempotency, pagination, filtering, and versioning.

Use database-schema-review when reviewing schema design, migrations, indexes, constraints, relationships, tenant boundaries, and data integrity.

Use auth-flow-design when planning authentication, authorization, sessions, tokens, roles, permissions, service accounts, tenant access, and auth errors.

Use service-boundary-design when defining backend module or service responsibilities, owned data, interfaces, dependencies, transaction boundaries, and migration paths.

Use error-handling-contracts for API and backend error envelopes, status-code mapping, validation errors, retry behavior, logging, and client-safe messages.

Use rate-limit-design when defining quotas, throttling, abuse controls, headers, retry guidance, monitoring, and support override paths.

Use api-doc-writing for published API docs, backend-test-plan for backend verification coverage, skill-threat-model for high-risk backend review, qa-test-strategy for broader QA strategy, and concise-technical-writing for clear design memos.

Default to design and review outputs. Do not apply migrations, deploy services, change auth policy, rotate credentials, alter production data, or change live rate limits without explicit approval.

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. 3d ago First seen · 31 lines · 0 tokens per session scan A d9d9aaa89bb1

Subscribe to this mod's changes

AGENTS.backend-api is an agent published in the GitHub repository jeremylongworth-source/AgentSkills (1 stars, last pushed yesterday), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 292 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 2026-08-31.