use-any-api

use-any-api is a skill for Claude Code from GeckoVision/gecko-surf. It costs 0 tokens per session (863 once invoked), scanned A, original, Apache-2.0.

A skill for making an unfamiliar API's first call correctly. It turns messy documentation or an incomplete specification into MCP tools, a format that lets agents call external services.

In plain words
What is it for?
Use it when integrating a new API, especially when its documentation is unclear, its authentication is unusual, or initial requests fail with errors such as 403, 404, or 422.
Why use it?
It removes trial and error over endpoints, parameters, authentication, units, and required fields. Secrets are supplied at call time instead of being exposed to the agent.

Skill for Claude Code

Written for Claude Code: user-invocable in frontmatter. Also seen: mentions Claude Code.

Part of the gecko-surf plugin — 6 skills, 2 commands, 2 agents shipped together

Good fit Use it when integrating a new API, especially when its documentation is unclear, its authentication is unusual, or initial requests fail with errors such as 403, 404, or 422.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/geckovision/gecko-surf/use-any-api
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.

Any agent
npx skills add GeckoVision/gecko-surf --skill use-any-api
Clone the repo
git clone --depth 1 https://github.com/GeckoVision/gecko-surf

Made for: Claude Code.

Or install gecko-surf, the plugin that ships this one along with the rest of its 6 skills, 2 commands, 2 agents.

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 use-any-api

README.md
[![agentmods](https://agentmods.dev/badge/skills/geckovision/gecko-surf/use-any-api/github.svg)](https://agentmods.dev/skills/geckovision/gecko-surf/use-any-api)
Your own site
<a href="https://agentmods.dev/skills/geckovision/gecko-surf/use-any-api"><img src="https://agentmods.dev/badge/skills/geckovision/gecko-surf/use-any-api/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.

agentmods 80×15 button for use-any-api

Your own site · 80×15
<a href="https://agentmods.dev/skills/geckovision/gecko-surf/use-any-api"><img src="https://agentmods.dev/badge/skills/geckovision/gecko-surf/use-any-api.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 0 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 863 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 1 finding. A grade says what 26 rules found in the file — not that it is safe.
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 5.1 $0.00000 $0.00863
Opus 5 $0.00000 $0.00432
Sonnet 5 $0.00000 $0.00173
Haiku 4.5 $0.00000 $0.00086

Measured 10d ago against content hash 2e47b7639e77, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

use-any-api 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 10d 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.

description: Use when an agent needs to CALL a new or unfamiliar API and get the first call right — when a first call fails (404 / 422 / wrong params / bad auth), when the docs are messy, human-shaped, or have no OpenAPI
skills/use-any-api/SKILL.md · 53 lines

How it starts

The opening of the file, as written. The whole thing — 53 lines — stays where its author put it; the contents beside it link to each section on GitHub.

use-any-api — make your agent first-call-correct on any API

Reach for this the moment you're about to integrate an API the agent doesn't already one-shot. Coding agents write a clean client for a well-documented API in an afternoon — so you don't need Gecko there. You need it on the painful ones: broken or missing specs, undocumented required params, an auth handshake the docs assume, a WAF that 403s your script, a field that renamed last week. That's where a raw spec makes the agent's first call a guess.

What it does

Point Gecko at the API and it turns the surface into question-shaped, first-call-correct MCP tools: the right endpoint for the intent, params placed correctly (path vs query vs body, units, enums), required fields validated before the call fires, and auth injected at call time, hidden from the agent and pinned to the API's host so a secret can't leak. Your agent calls the real API directly; Gecko is control-plane only — it never stores your responses or your keys.

Run it (one command)

# have an OpenAPI URL:
uvx --from "gecko-surf[serve]" gecko <openapi-url>
#   → serves first-call-correct MCP tools at http://127.0.0.1:8000/mcp

# no spec, just docs? comprehend from the docs page instead:
uvx --from "gecko-surf[serve]" gecko from-docs <docs-url>

Then add it to your agent (Claude Code / Cursor / any MCP client):

claude mcp add --transport http myapi http://127.0.0.1:8000/mcp    # Claude Code
# Cursor / others: add { "myapi": { "url": "http://127.0.0.1:8000/mcp" } } to your mcp config

Ask your agent the thing you actually wanted — it calls the API right, first try.

When the docs are JavaScript-rendered

If curl <docs-url> returns an empty shell, a spinner, or a 403, the page is a SPA — use the [[read-js-docs]] skill first to render and extract the surface, then comprehend it.

Why it works (the honest claim)

A raw OpenAPI dump costs ~18,000 tokens for a small API and lowers tool-selection accuracy as it grows (43%→14%); Gecko projects the same surface to ~1,900 tokens (−89%) at equal-or-better first-call-correctness. Measured FCC lift: 10% → 65% on a painful API, ~0 on clean ones. Point it where agents actually fail.

Read the full file on GitHub · 53 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. 10d ago First seen · 53 lines · 0 tokens per session scan A 2e47b7639e77

Subscribe to this mod's changes

use-any-api is a skill published in the GitHub repository GeckoVision/gecko-surf (6 stars, last pushed today), licensed Apache-2.0. It costs nothing until one of its globs matches a file; then it loads 863 tokens. 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 2026-08-31.

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