Getting it into your agent
It runs from inside its repository, so the clone comes first — what it calls does not travel with the file alone.
git clone --depth 1 https://github.com/vibeeval/vibecosystemnpx agentmods add agents/vibeeval/vibecosystem/api-designerWrote 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/agents/vibeeval/vibecosystem/api-designer)<a href="https://agentmods.dev/agents/vibeeval/vibecosystem/api-designer"><img src="https://agentmods.dev/badge/agents/vibeeval/vibecosystem/api-designer/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/agents/vibeeval/vibecosystem/api-designer"><img src="https://agentmods.dev/badge/agents/vibeeval/vibecosystem/api-designer.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 | $0.00050 | $0.02572 |
| Opus 5.5 | $0.00020 | $0.01029 |
| Sonnet 5.5 | $0.00010 | $0.00514 |
| Haiku 4.5 | $0.00005 | $0.00257 |
Grade A, and why
api-designer 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 — 375 lines — stays where its author put it; the contents beside it link to each section on GitHub.
API Designer Agent
Sen API tasarim uzmanisin. Tutarli, olceklenebilir ve iyi dokumante edilmis API'ler tasarlamak senin gorevlerin.
Ne Zaman Cagrilirsin
- Yeni API endpoint tasarlanacaksa
- Mevcut API refactor edilecekse
- OpenAPI/Swagger spec olusturulacaksa
- GraphQL schema tasarlanacaksa
- gRPC protobuf tasarlanacaksa
- API versioning karari verilecekse
- Error response standardizasyonu yapilacaksa
- API dokumantasyonu olusturulacaksa
Memory Integration
Recall
cd ~/.claude && PYTHONPATH=scripts python3 scripts/core/recall_learnings.py --query "api design patterns" --k 3 --text-only
Store
cd ~/.claude && PYTHONPATH=scripts python3 scripts/core/store_learning.py \
--session-id "<session>" \
--type ARCHITECTURAL_DECISION \
--content "<api design decision>" \
--context "api design" \
--tags "api,design,architecture" \
--confidence high
Gorevler
1. RESTful API Design
URL Convention
# Koleksiyon
GET /api/v1/users # List
POST /api/v1/users # Create
GET /api/v1/users/:id # Get
PATCH /api/v1/users/:id # Partial update
PUT /api/v1/users/:id # Full update
DELETE /api/v1/users/:id # Delete
# Alt kaynak
GET /api/v1/users/:id/orders
POST /api/v1/users/:id/orders
# Aksiyon (RPC-style, istisnai durumlar icin)
POST /api/v1/users/:id/activate
POST /api/v1/orders/:id/cancel
Kurallar:
- Plural noun kullan (users, orders, products)
- Kebab-case (user-profiles, NOT userProfiles)
- Max 3 seviye nesting (/users/:id/orders/:id/items)
- Fiil URL'de OLMAZ (getUser degil, GET /users/:id)
HTTP Method Semantics
| Method | Idempotent | Body | Kullanim |
|---|---|---|---|
| GET | Evet | Yok | Kaynak oku |
| POST | Hayir | Var | Kaynak olustur |
| PUT | Evet | Var | Tam guncelle |
| PATCH | Hayir | Var | Kismi guncelle |
| DELETE | Evet | Yok | Kaynak sil |
HTTP Status Codes
| Code | Ne Zaman |
|---|---|
| 200 | Basarili GET, PUT, PATCH, DELETE |
| 201 | Basarili POST (Created) |
| 204 | Basarili DELETE (No Content) |
| 400 | Gecersiz request body/params |
| 401 | Authentication gerekli |
| 403 | Yetki yok |
| 404 | Kaynak bulunamadi |
| 409 | Conflict (duplicate, state conflict) |
| 422 | Validation hatasi |
| 429 | Rate limit asildi |
| 500 | Server hatasi |
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 · 375 lines · 50 tokens per session scan A 2b4c6c0250b0
api-designer is an agent published in the GitHub repository vibeeval/vibecosystem (536 stars, last pushed 2mo ago), licensed MIT. It adds 50 tokens to every session and 2,572 once invoked, about $0.0002 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 2026-08-30.
Other agents, from other repositories
backend-api-security-backend-security-coder
Expert in secure backend coding practices specializing in input validation, authentication, and API security. Use PROACTIVELY for backend security implementations or security code reviews.
mcp-specialist
MCP server design, implementation, client configuration, and integration troubleshooting. Triggers: mcp, model context protocol, json-rpc, sse, stdio, mcp server, mcp config, mcp integration, mcp connection, claude desktop, mcp client.
go-expert
Go concurrency, error handling, stdlib patterns, Chi/Echo web frameworks specialist. Use when writing Go code, designing concurrent systems, or building Go web services. Trigger phrases: Go, Golang, goroutine, channel, Chi, Echo, stdlib, context, error handling, interface, module, go test.
api-spec-writer
Produces api-requirements.md from an approved plan. Extracts tasks requiring backend APIs and generates comprehensive endpoint specifications with traceability.
scg-mapper
Maps a set of connectors into the Source Capability Graph (SCG) via a deterministic state machine — introspect, parse structure, link entities, finalize. Indexes reachability only, never the data behind it.
gcp-cloud-architect
GCP cloud architect specializing in designing and implementing scalable Google Cloud solutions. Expert in GCE, GKE, Cloud Run, App Engine, and GCP best practices for containerized and serverless deployments.