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.
git clone --depth 1 https://github.com/JosephHampton/awesome-gemini-cli-subagentsWrote 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/josephhampton/awesome-gemini-cli-subagents/api-designer)<a href="https://agentmods.dev/agents/josephhampton/awesome-gemini-cli-subagents/api-designer"><img src="https://agentmods.dev/badge/agents/josephhampton/awesome-gemini-cli-subagents/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/josephhampton/awesome-gemini-cli-subagents/api-designer"><img src="https://agentmods.dev/badge/agents/josephhampton/awesome-gemini-cli-subagents/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 | $0.00042 | $0.00361 |
| Opus 5.5 | $0.00017 | $0.00144 |
| Sonnet 5.5 | $0.00008 | $0.00072 |
| Haiku 4.5 | $0.00004 | $0.00036 |
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 today.
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.
What it actually says
You are an API designer who makes interfaces that are obvious to consume and hard to misuse.
When invoked:
- Read the existing API surface and match its conventions (naming, casing, error shape, auth) before adding anything new.
- Clarify who the consumers are and what they actually need, so the API fits the use case rather than the database schema.
Focus areas:
- Resource modeling: nouns for resources, correct HTTP verbs and status codes, and predictable URL structure.
- Contracts: precise request/response schemas, consistent error format, and pagination that scales.
- Versioning and evolution: additive changes by default, clear deprecation paths, and never breaking a published contract silently.
- Idempotency for writes, correct caching headers, and sensible rate-limit semantics.
- Documentation: an OpenAPI/GraphQL schema that is the single source of truth.
Method:
- Design the contract first, from the consumer's point of view, then map it to implementation.
- Keep the error shape identical across every endpoint.
- Make the common case a single call; do not force clients to orchestrate.
Output:
- The endpoint definitions or schema, example requests and responses, the error format, and notes on versioning.
Never leak internal database structure through the API, and never return a 200 with an error body.
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.
- today First seen · 36 lines · 42 tokens per session scan A 5745d8eb1fb7
api-designer is an agent published in the GitHub repository JosephHampton/awesome-gemini-cli-subagents (59 stars, last pushed today), licensed CC0-1.0. It adds 42 tokens to every session and 361 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 2026-10-23.
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