api-fuzzing-bug-bounty

api-fuzzing-bug-bounty is a skill for Claude Code, Codex from rootcastleco/rei-skills. It costs 54 tokens per session (2,860 once invoked), scanned A, original, no licence file.

An API security testing guide for checking REST and GraphQL interfaces for weaknesses by sending varied or unexpected inputs.

In plain words
What is it for?
Testing API access controls, input handling, and related security issues during penetration tests or bug-bounty work.
Why use it?
It helps find security flaws such as IDOR, where one user can access another user's data by changing an identifier, before attackers do.

Skill for Claude CodeCodex

Which agent this was written for is unclear — body not stored (licence); the path alone says nothing.

Good fit Testing API access controls, input handling, and related security issues during penetration tests or bug-bounty work.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/rootcastleco/rei-skills/api-fuzzing-bug-bounty
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 rootcastleco/rei-skills --skill api-fuzzing-bug-bounty
Clone the repo
git clone --depth 1 https://github.com/rootcastleco/rei-skills

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-fuzzing-bug-bounty

README.md
[![agentmods](https://agentmods.dev/badge/skills/rootcastleco/rei-skills/api-fuzzing-bug-bounty/github.svg)](https://agentmods.dev/skills/rootcastleco/rei-skills/api-fuzzing-bug-bounty)
Your own site
<a href="https://agentmods.dev/skills/rootcastleco/rei-skills/api-fuzzing-bug-bounty"><img src="https://agentmods.dev/badge/skills/rootcastleco/rei-skills/api-fuzzing-bug-bounty/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-fuzzing-bug-bounty

Your own site · 80×15
<a href="https://agentmods.dev/skills/rootcastleco/rei-skills/api-fuzzing-bug-bounty"><img src="https://agentmods.dev/badge/skills/rootcastleco/rei-skills/api-fuzzing-bug-bounty.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 54 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,860 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 unknown 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 $0.00054 $0.02860
Opus 5 $0.00027 $0.01430
Sonnet 5 $0.00011 $0.00572
Haiku 4.5 $0.00005 $0.00286

Measured 11d ago against content hash 4c4c12b6d92b, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-10, from the pricing page.

Security

Grade A, and why

api-fuzzing-bug-bounty 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 11d 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.

curl -X POST https://target.com/graphql \
skills/api-fuzzing-bug-bounty/SKILL.md · 447 lines

The source is not reproduced here

A licence we could not identify

The repository carries a LICENSE file, but it is custom or dual enough that GitHub cannot name it and neither can this catalogue. Unknown terms are not permission, so the body is not copied here. Read the licence at the source and decide for yourself.

Read it on GitHub

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. 11d ago First seen · 447 lines · 54 tokens per session scan A 4c4c12b6d92b

Subscribe to this mod's changes

api-fuzzing-bug-bounty is a skill published in the GitHub repository rootcastleco/rei-skills (6 stars, last pushed yesterday), with no licence file. It adds 54 tokens to every session and 2,860 once invoked, about $0.0003 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 2026-08-31.

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