HackSkills is an organized knowledge base of installable skills that gives AI agents practical security knowledge across areas such as web security, privilege escalation, reverse engineering, and digital forensics. It is intended for bug bounty work, penetration testing, CTF competitions, and authorized security research. The catalogue entries are the project's own master, category, and topic skills.
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.
npx skills add yaklang/hack-skills --skill api-authorization-and-bolagit clone --depth 1 https://github.com/yaklang/hack-skillsWrote 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/skills/yaklang/hack-skills/api-authorization-and-bola)<a href="https://agentmods.dev/skills/yaklang/hack-skills/api-authorization-and-bola"><img src="https://agentmods.dev/badge/skills/yaklang/hack-skills/api-authorization-and-bola.svg" alt="Measured on agentmods" height="20"></a>- Socket warn
- Snyk pass
- NVIDIA SkillSpector pass
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 | $0.00036 | $0.00447 |
| Opus 5 | $0.00018 | $0.00224 |
| Sonnet 5 | $0.00007 | $0.00089 |
| Haiku 4.5 | $0.00004 | $0.00045 |
Grade A, and why
api-authorization-and-bola 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 8d 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.
Copies of this mod
4 near-identical copies found in the catalogue:
- api-authorization-and-bola — 100% identical, 0 lines differ
- api-authorization-and-bola — 100% identical, 0 lines differ
- api-authorization-and-bola — 100% identical, 0 lines differ
- api-authorization-and-bola — 88% identical, 4 lines differ
What it actually says
SKILL: API Authorization and BOLA — Object Access, Function Access, and Mass Assignment
AI LOAD INSTRUCTION: Use this skill when an API exposes object IDs, nested resources, or role-sensitive functions and you need a focused authorization test path: BOLA, BFLA, method abuse, and hidden field control.
1. CORE TEST LOOP
- Create Account A and Account B.
- As Account A, capture create, read, update, and delete flows.
- Replay with Account B's token.
- Test sibling endpoints, nested endpoints, and alternate HTTP verbs.
2. TEST SURFACES
| Surface | Example |
|---|---|
| object read | /api/v1/orders/123 |
| nested object | /api/v1/users/1/invoices/9 |
| admin or internal function | /api/v1/admin/users |
| update path | PUT, PATCH, DELETE variants |
| hidden JSON fields | role, org, verified, tier |
3. QUICK PAYLOADS
{"role":"admin"}
{"isAdmin":true}
{"org":"target-company"}
{"verified":true}
4. WHAT TESTERS MISS
- object IDs in headers, cookies, GraphQL args, and nested objects
- alternate methods sharing the same route but weaker authz
- parent check present, child resource check missing
- admin docs revealing extra writable fields
5. NEXT ROUTING
- For JWT or token-layer abuse: api auth and jwt abuse
- For GraphQL and hidden parameter discovery: graphql and hidden parameters
- For broader IDOR patterns outside APIs: idor broken object authorization
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.
- 8d ago First seen · 48 lines · 36 tokens per session scan A 449db8e0e1fd
api-authorization-and-bola is a skill published in the GitHub repository yaklang/hack-skills (2,133 stars, last pushed 2mo ago), licensed MIT. It adds 36 tokens to every session and 447 once invoked, about $0.0002 per session on Opus 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.
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