toolhive-studio: Skill for Claude Code

.claude/skills/testing-api-overrides/SKILL.md

testing-api-overrides is a skill for Claude Code from stacklok/toolhive-studio. It costs 42 tokens per session (1,455 once invoked), scanned A, original, Apache-2.0.

A testing guide for checking that software sends the right query parameters with read requests. Query parameters are extra values in a request used for filtering, sorting, or paging results.

In plain words
What is it for?
Use it to test filters, search, sorting, pagination, and other read operations where request arguments affect the displayed results.
Why use it?
It tests the behavior users see by making the fake API return different data for different parameters, rather than checking private implementation details.

Skill for Claude Code

Written for Claude Code: installed under .claude/.

This is stacklok/toolhive-studio's own configuration. It tells Claude Code how to work on toolhive-studio itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything toolhive-studio configures →

Reuse

Borrowing it

Nothing to install: this file belongs to stacklok/toolhive-studio. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/stacklok/toolhive-studio/main/.claude/skills/testing-api-overrides/SKILL.md
Clone the repo
git clone --depth 1 https://github.com/stacklok/toolhive-studio

Made for: Claude Code.

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 testing-api-overrides

README.md
[![agentmods](https://agentmods.dev/badge/skills/stacklok/toolhive-studio/testing-api-overrides/github.svg)](https://agentmods.dev/skills/stacklok/toolhive-studio/testing-api-overrides)
Your own site
<a href="https://agentmods.dev/skills/stacklok/toolhive-studio/testing-api-overrides"><img src="https://agentmods.dev/badge/skills/stacklok/toolhive-studio/testing-api-overrides/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 testing-api-overrides

Your own site · 80×15
<a href="https://agentmods.dev/skills/stacklok/toolhive-studio/testing-api-overrides"><img src="https://agentmods.dev/badge/skills/stacklok/toolhive-studio/testing-api-overrides.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 42 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,455 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
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 $0.00042 $0.01455
Opus 5.5 $0.00017 $0.00582
Sonnet 5.5 $0.00008 $0.00291
Haiku 4.5 $0.00004 $0.00145

Measured 2mo ago against content hash db8ec95881ac, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

testing-api-overrides 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 2mo 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.

.claude/skills/testing-api-overrides/SKILL.md · 220 lines

How it starts

The opening of the file, as written. The whole thing — 220 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Testing API Overrides

Test that your code sends correct API parameters by using conditional overrides that respond differently based on the request. This approach tests actual user-facing behavior rather than inspecting internal request details.

Philosophy

Good tests verify what users see, not implementation details.

Instead of:

  1. ❌ Recording the request and checking query params
  2. ❌ Asserting on internal function calls

Do this:

  1. ✅ Set up conditional mocks that respond based on params
  2. ✅ Verify the component renders the expected data

If the code sends wrong parameters, the mock returns wrong data, the UI shows wrong content, and the test fails. This catches real bugs.

When to Use Conditional Overrides

  • Testing list filtering (e.g., filter by group, status, search term)
  • Testing pagination parameters
  • Testing sort order
  • Any read operation where request parameters affect what data is returned

Note: For mutations (create/update/delete), use recordRequests() instead. See the testing-api-assertions skill.

conditionalOverride()

Returns different data based on request properties:

import { mockedGetApiV1BetaWorkloads } from '@mocks/fixtures/workloads/get'

mockedGetApiV1BetaWorkloads.conditionalOverride(
  // Predicate: when should this override apply?
  ({ query }) => query.group === 'archive',
  // Transform: what data to return?
  (data) => ({
    ...data,
    workloads: [], // Archive group is empty
  })
)

Predicate Function

The predicate receives parsed request info with easy access to query params, path params, body, and headers:

;({ query, path, body, headers }) => {
  // Query parameters (pre-parsed)
  query.group // '?group=archive' -> 'archive'
  query.status // '?status=running' -> 'running'

  // Path parameters (from route like /workloads/:name)
  path.name // for /workloads/:name

  // Request body (for POST/PUT/DELETE)
  body?.name // parsed JSON body

  // Headers
  headers.get('Authorization')

  return true // or false
}

Read the full file on GitHub · 220 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. 2mo ago First seen · 220 lines · 42 tokens per session scan A db8ec95881ac

Subscribe to this mod's changes

testing-api-overrides is a skill published in the GitHub repository stacklok/toolhive-studio (173 stars, last pushed today), licensed Apache-2.0. It adds 42 tokens to every session and 1,455 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.

Related

Other skills, from other repositories

run-tests

Run Embody's test suite and write new tests (Embody development).

dylanroscover/Embody · 18 tokens

testing

MUST READ before declaring any TouchDesigner build, fix or show done, and before any soak or performance test: the verification ladder (structure, errors, frame, motion, data, performance, soak, end to end), runsoaktest and the observer-effect rules that keep measuring from perturbing the show, the iterate-by-capture…

dylanroscover/Embody · 77 tokens

agent-tests

MUST READ before calling RunAgentTests or touching agent-tier test infrastructure -- these tests spawn real AI clients (Claude Code, Codex) and SPEND SUBSCRIPTION USAGE; never run casually. Tier model, async runner rationale, auth/isolation rules.

dylanroscover/Embody · 56 tokens

ganju-cli

Write, test, deploy and debug Ganju custom tools (Functions) with the ganju CLI and the @ganju/sdk handler API. Use this whenever the user works in a folder with a ganju.json, imports @ganju/sdk or defineTool, mentions @ganju/cli or any ganju command (init, link, build, test, deploy, logs, versions, rollback, secret…

MontoyaAndres/ganju · 148 tokens

elicitation-scenarios

Drive the elicitation tester's scenario catalogue over the modern protocol, where input requests arrive in the tool result and are answered from the chat.

mappedsky/seizu · 34 tokens

elicitation-scenarios-legacy

Drive the elicitation tester's scenario catalogue over the legacy protocol, where the server sends elicitation requests during the call instead of returning them in the result.

mappedsky/seizu · 39 tokens