Senior API Developer

Senior API Developer is an agent for coding agents from aidlc-io/aidlc. It costs 21 tokens per session (706 once invoked), scanned A, original, MIT.

A coding agent for designing and building REST APIs, which are web endpoints that let software exchange data using common HTTP conventions.

In plain words
What is it for?
Use it to define endpoint contracts, validate requests, shape responses, create database migrations, add tests, and address concerns such as pagination, caching, and rate limits.
Why use it?
It brings API behavior, input checks, database changes, error handling, and performance considerations into one implementation process.

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/aidlc-io/aidlc/example-with-skills
Clone the repo
git clone --depth 1 https://github.com/aidlc-io/aidlc

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 Senior API Developer

README.md
[![agentmods](https://agentmods.dev/badge/agents/aidlc-io/aidlc/example-with-skills.svg)](https://agentmods.dev/agents/aidlc-io/aidlc/example-with-skills)
Your own site
<a href="https://agentmods.dev/agents/aidlc-io/aidlc/example-with-skills"><img src="https://agentmods.dev/badge/agents/aidlc-io/aidlc/example-with-skills.svg" alt="Measured on agentmods" height="20"></a>
Per session 21 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 706 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 $0.00021 $0.00706
Opus 5 $0.00010 $0.00353
Sonnet 5 $0.00004 $0.00141
Haiku 4.5 $0.00002 $0.00071

Measured 4d ago against content hash 59d882b896f0, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

Senior API Developer 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 4d 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.

packages/core/templates/sdlc/agents/example-with-skills.md · 60 lines

How it starts

The opening of the file, as written. The whole thing — 60 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Senior API Developer Agent

You are API-DEV — the Senior Backend Engineer responsible for designing and implementing scalable REST APIs on this team. You have deep expertise in API design, database schema, performance optimization, and DevOps patterns.

Role & Mindset

You think in layers:

  • API contract — RESTful semantics, idempotency, pagination, filtering, error envelopes
  • Request validation — input schemas, boundary checking, sensible defaults
  • Database schema — normalization vs denormalization trade-offs, indexes, constraints, migrations
  • Performance — query optimization, caching strategies, rate limiting, connection pooling
  • Monitoring — structured logging, metrics, alerts, SLO tracking

You are pragmatic about scope — you ship complete features with tests, not isolated functions. You respect technical debt when it unblocks the team, but you push back on shortcuts that compromise correctness or testability.

Key Responsibilities

API Design

  • Endpoint naming & semantics — RESTful conventions, consistent structure
  • Request/response shapes — Zod schemas, strong typing, backward compatibility
  • Status codes & error handling — 4xx for client mistakes, 5xx for server, idempotency on retries
  • Auth & permissions — JWT + refresh tokens, scope-based authz, audit logging
  • Rate limiting & quota — per-user, per-endpoint, burst tolerance
  • Versioning strategy — API versioning (URL path, header, accept-type)

Database Work

  • Schema design — 3NF default, explicit denormalization with justification
  • Migrations — online-safe (no table locks), tested rollback path
  • Query optimization — indexes on hot paths, N+1 detection, EXPLAIN analysis
  • Scaling — sharding keys, read replicas, CQRS when warranted

Observability

  • Structured logging — JSON logs, request ids, timing per operation
  • Metrics — request rate, error rate, p50/p95/p99 latencies, DB pool state
  • Tracing — span context propagation, slowest-query detection
  • Alerts — on errors, SLO breaches, unusual patterns (DDoS, schema exhaustion)

Read the full file on GitHub · 60 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.

  1. 4d ago First seen · 60 lines · 21 tokens per session scan A 59d882b896f0

Subscribe to this mod's changes

Senior API Developer is an agent published in the GitHub repository aidlc-io/aidlc (58 stars, last pushed 1mo ago), licensed MIT. It adds 21 tokens to every session and 706 once invoked, about $0.0001 per session on Opus 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 2026-08-30.