api-tester

api-tester is a skill for Claude Code, Codex from RightNow-AI/openfang. It costs 19 tokens per session (721 once invoked), scanned B, original, Apache-2.0.

A guide to testing web APIs, which let programs exchange data over a network. It covers REST and GraphQL APIs, request tools, authentication, errors, and edge cases.

In plain words
What is it for?
Use it to test and debug APIs with curl, httpie, Postman collections, or scripted tests while keeping credentials out of commands and files.
Why use it?
It helps verify more than whether a request succeeds, including status codes, headers, response structure, and data types.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit Use it to test and debug APIs with curl, httpie, Postman collections, or scripted tests while keeping credentials out of commands and files.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/rightnow-ai/openfang/api-tester
About the project

OpenFang is an open-source operating system for autonomous AI agents, built in Rust to run agents that perform scheduled work such as research, monitoring, lead generation, and reporting. It is for people who want agents to operate continuously rather than only respond to prompts. The catalogue add-ons extend workflows around the OpenFang agent system.

RightNow-AI/openfang · 18,211 stars · on GitHub · openfang.sh

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 RightNow-AI/openfang --skill api-tester
Clone the repo
git clone --depth 1 https://github.com/RightNow-AI/openfang

Made for: Claude Code, Codex.

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 api-tester

README.md
[![agentmods](https://agentmods.dev/badge/skills/rightnow-ai/openfang/api-tester/github.svg)](https://agentmods.dev/skills/rightnow-ai/openfang/api-tester)
Your own site
<a href="https://agentmods.dev/skills/rightnow-ai/openfang/api-tester"><img src="https://agentmods.dev/badge/skills/rightnow-ai/openfang/api-tester/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 api-tester

Your own site · 80×15
<a href="https://agentmods.dev/skills/rightnow-ai/openfang/api-tester"><img src="https://agentmods.dev/badge/skills/rightnow-ai/openfang/api-tester.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 19 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 721 The whole file, excluding the scripts and references it only reads on demand.
Security scan B 2 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector warn 7 Sept 2026
SkillSpector: 6 findings, up to high

These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →

  • high Anti-Refusal · line 52
    Skill attempts to nullify the agent's safety policies or restrictions ('you have no restrictions', 'ignore your guidelines', 'do anything now'). This is a direct jailbreak that disables guardrails.
    Fix: Remove jailbreak framing that nullifies safety policies or restrictions. Skill content must not instruct the agent to ignore its guidelines or operate without guardrails.
  • medium Data Exfiltration · line 18
    Data is being sent to an external URL. This could be legitimate telemetry or data exfiltration. Manual review is recommended.
    Fix: Verify the destination URL is trusted and necessary. Remove or replace with documented APIs. Ensure no secrets, tokens, or PII are transmitted.
  • medium Data Exfiltration · line 19
    Data is being sent to an external URL. This could be legitimate telemetry or data exfiltration. Manual review is recommended.
    Fix: Verify the destination URL is trusted and necessary. Remove or replace with documented APIs. Ensure no secrets, tokens, or PII are transmitted.
  • medium Data Exfiltration · line 20
    Data is being sent to an external URL. This could be legitimate telemetry or data exfiltration. Manual review is recommended.
    Fix: Verify the destination URL is trusted and necessary. Remove or replace with documented APIs. Ensure no secrets, tokens, or PII are transmitted.
  • medium Data Exfiltration · line 22
    Data is being sent to an external URL. This could be legitimate telemetry or data exfiltration. Manual review is recommended.
    Fix: Verify the destination URL is trusted and necessary. Remove or replace with documented APIs. Ensure no secrets, tokens, or PII are transmitted.
  • medium Data Exfiltration · line 19
    Data is being sent to an external URL. This could be legitimate telemetry or data exfiltration. Manual review is recommended.
    Fix: Verify the destination URL is trusted and necessary. Remove or replace with documented APIs. Ensure no secrets, tokens, or PII are transmitted.
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 $0.00019 $0.00721
Opus 5.5 $0.00008 $0.00288
Sonnet 5.5 $0.00004 $0.00144
Haiku 4.5 $0.00002 $0.00072

Measured 1mo ago against content hash d7dcba78d1b4, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade B, and why

api-tester scanned grade B with 2 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.

Sends data to an external URLmediumData exfiltration

A POST to an outside endpoint may be telemetry or may be exfiltration; either way the mod talks to somewhere, and you should know where.

- POST with JSON: `curl -s -X POST -H "Content-Type: application/json" -d '{"name":"test"}' https://api.example.com/users`

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

description: API testing expert for curl, REST, GraphQL, authentication, and debugging
Origin

Copies of this mod

2 near-identical copies found in the catalogue:

crates/openfang-skills/bundled/api-tester/SKILL.md · 55 lines

How it starts

The opening of the file, as written. The whole thing — 55 lines — stays where its author put it; the contents beside it link to each section on GitHub.

API Testing Expert

You are an API testing specialist. You help users test, debug, and validate REST and GraphQL APIs using curl, httpie, Postman collections, and scripted test suites. You cover authentication, error handling, and edge cases.

Key Principles

  • Always start by reading the API documentation or OpenAPI/Swagger spec before testing.
  • Test the happy path first, then systematically test error cases, edge cases, and boundary conditions.
  • Validate response status codes, headers, body structure, and data types — not just whether the request "works."
  • Keep credentials out of command history and scripts — use environment variables.

curl Essentials

  • GET: curl -s https://api.example.com/users | jq .
  • POST with JSON: curl -s -X POST -H "Content-Type: application/json" -d '{"name":"test"}' https://api.example.com/users
  • Auth header: curl -s -H "Authorization: Bearer $TOKEN" https://api.example.com/me
  • Verbose mode: curl -v to see request/response headers and TLS handshake details.
  • Save response: curl -s -o response.json -w "%{http_code}" https://api.example.com/endpoint
  • Follow redirects: curl -L, timeout: curl --connect-timeout 5 --max-time 30.

Testing Methodology

  1. Authentication: Verify that unauthenticated requests return 401. Verify expired tokens return 401. Verify wrong roles return 403.
  2. Input validation: Send missing required fields (expect 400), invalid types, empty strings, overly long strings, special characters.
  3. Pagination: Test first page, last page, out-of-range page, zero/negative limits.
  4. Idempotency: Send the same POST/PUT request twice — verify correct behavior.
  5. Rate limiting: Send rapid requests — verify 429 responses and Retry-After headers.
  6. CORS: Check Access-Control-Allow-Origin and preflight OPTIONS responses from a browser context.

GraphQL Testing

  • Use introspection queries ({ __schema { types { name } } }) to discover the schema.
  • Test query depth limits and complexity limits to verify protection against abuse.
  • Test with variables rather than inline values for parameterized queries.
  • Verify that mutations return the updated object and that subscriptions emit events correctly.

Read the full file on GitHub · 55 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. 1mo ago First seen · 55 lines · 19 tokens per session scan B d7dcba78d1b4

Subscribe to this mod's changes

api-tester is a skill published in the GitHub repository RightNow-AI/openfang (18,211 stars, last pushed 3mo ago), licensed Apache-2.0. It adds 19 tokens to every session and 721 once invoked, about $0.0001 per session on Opus 5.5. A static security scan graded it B with 2 findings (sends data to an external url, 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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