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 ancoleman/ai-design-components --skill designing-sdksgit clone --depth 1 https://github.com/ancoleman/ai-design-componentsWrote 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/ancoleman/ai-design-components/designing-sdks)<a href="https://agentmods.dev/skills/ancoleman/ai-design-components/designing-sdks"><img src="https://agentmods.dev/badge/skills/ancoleman/ai-design-components/designing-sdks.svg" alt="Measured on agentmods" 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 | $0.00039 | $0.03070 |
| Opus 5 | $0.00019 | $0.01535 |
| Sonnet 5 | $0.00008 | $0.00614 |
| Haiku 4.5 | $0.00004 | $0.00307 |
Grade A, and why
designing-sdks scanned grade A 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 8d 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.
Makes network callslowCapability
Not a fault in itself. Listed so you know the mod talks to something, and to what.
const response = await fetch(url, { How it starts
The opening of the file, as written. The whole thing — 486 lines — stays where its author put it; the contents beside it link to each section on GitHub.
SDK Design
Design client libraries (SDKs) with excellent developer experience through intuitive APIs, robust error handling, automatic retries, and consistent patterns across programming languages.
When to Use This Skill
Use when building a client library for a REST API, creating internal service SDKs, implementing retry logic with exponential backoff, handling authentication patterns, creating typed error hierarchies, implementing pagination with async iterators, or designing streaming APIs for real-time data.
Core Architecture Patterns
Client → Resources → Methods
Organize SDK code hierarchically:
Client (config: API key, base URL, retries, timeout)
├─ Resources (users, payments, posts)
│ ├─ create(), retrieve(), update(), delete()
│ └─ list() (with pagination)
└─ Top-Level Methods (convenience)
Resource-Based (Stripe style):
const client = new APIClient({ apiKey: 'sk_test_...' })
const user = await client.users.create({ email: '[email protected]' })
Use for APIs <100 methods. Prioritizes developer experience.
Command-Based (AWS SDK v3):
import { S3Client, PutObjectCommand } from '@aws-sdk/client-s3'
await client.send(new PutObjectCommand({ Bucket: '...' }))
Use for APIs >100 methods. Prioritizes bundle size and tree-shaking.
For detailed architectural guidance, see references/architecture-patterns.md.
Language-Specific Patterns
TypeScript: Async-Only
const user = await client.users.create({ email: '[email protected]' })
All methods return Promises. Avoid callbacks.
Python: Dual Sync/Async
# Sync
client = APIClient(api_key='sk_test_...')
user = client.users.create(email='[email protected]')
# Async
async_client = AsyncAPIClient(api_key='sk_test_...')
user = await async_client.users.create(email='[email protected]')
Provide both clients. Users choose based on architecture.
Go: Sync with Context
client := apiclient.New("api_key")
user, err := client.Users().Create(ctx, req)
What ships with it
17 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.
- examples/go/basic-client.go 5.5 KB
- examples/go/channel-pagination.go 1.4 KB
- examples/go/context-client.go 1.2 KB
- examples/python/async-client.py 4.2 KB runs code
- examples/python/dual-client.py 1.8 KB runs code
- examples/python/sync-client.py 3.6 KB runs code
- examples/typescript/advanced-client.ts 7.7 KB runs code
- examples/typescript/basic-client.ts 3.3 KB runs code
- examples/typescript/resource-based.ts 1.6 KB runs code
- outputs.yaml 7.0 KB
- references/architecture-patterns.md 12 KB
- references/authentication.md 17 KB
- references/error-handling.md 9.2 KB
- references/pagination.md 4.1 KB
- references/retry-backoff.md 11 KB
- references/testing-sdks.md 3.0 KB
- references/versioning.md 1.9 KB
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.
- 8d ago First seen · 486 lines · 39 tokens per session scan A 01bfebc7cbec
designing-sdks is a skill published in the GitHub repository ancoleman/ai-design-components (519 stars, last pushed 9mo ago), licensed MIT. It adds 39 tokens to every session and 3,070 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
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