api-recon-and-docs

api-recon-and-docs is a skill for Claude Code, Codex from yaklang/hack-skills. It costs 38 tokens per session (451 once invoked), scanned A, original, MIT.

A playbook for mapping an API, the set of program endpoints that software can call, and reviewing its documentation. It looks for routes, schemas, versions, hidden parameters, and differences between user roles.

In plain words
What is it for?
Finding REST or GraphQL endpoints, checking OpenAPI or Swagger files, extracting request fields and roles, identifying legacy versions, and routing findings to authorization testing.
Why use it?
It helps developers understand the available API surface before testing it, including older or undocumented entry points that may otherwise be missed.

Skill for Claude CodeCodex

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

About the project

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.

yaklang/hack-skills · 2,064 stars · on GitHub

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.

agentmods
npx agentmods add skills/yaklang/hack-skills/api-recon-and-docs
Any agent
npx skills add yaklang/hack-skills --skill api-recon-and-docs
Clone the repo
git clone --depth 1 https://github.com/yaklang/hack-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-recon-and-docs

README.md
[![agentmods](https://agentmods.dev/badge/skills/yaklang/hack-skills/api-recon-and-docs.svg)](https://agentmods.dev/skills/yaklang/hack-skills/api-recon-and-docs)
Your own site
<a href="https://agentmods.dev/skills/yaklang/hack-skills/api-recon-and-docs"><img src="https://agentmods.dev/badge/skills/yaklang/hack-skills/api-recon-and-docs.svg" alt="Measured on agentmods" height="20"></a>
Per session 38 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 451 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 1 finding. Scan, not verified.
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 $0.00038 $0.00451
Opus 5 $0.00019 $0.00226
Sonnet 5 $0.00008 $0.00090
Haiku 4.5 $0.00004 $0.00045

Measured 6d ago against content hash eeb0dce2b9ed, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-05, from the pricing page.

Security

Grade A, and why

api-recon-and-docs 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 6d 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 https://target/app.js | grep -oE '(/api|/rest|/graphql)[^"'\'' ]+' | sort -u
Origin

Copies of this mod

4 near-identical copies found in the catalogue:

skills/api-recon-and-docs/SKILL.md · 61 lines

What it actually says

SKILL: API Recon and Docs — Endpoints, Schemas, and Version Surface

AI LOAD INSTRUCTION: Use this skill first when the target is a REST, mobile, or GraphQL API and you need to enumerate endpoints, documentation, versions, and hidden surface area before exploitation.

1. PRIMARY GOALS

  1. Discover all reachable API entrypoints.
  2. Extract schemas, optional fields, and role differences.
  3. Identify old versions, mobile paths, GraphQL endpoints, and undocumented parameters.

2. RECON CHECKLIST

JavaScript and client mining

curl https://target/app.js | grep -oE '(/api|/rest|/graphql)[^"'\'' ]+' | sort -u

Common documentation and schema paths

/swagger.json
/openapi.json
/api-docs
/docs
/.well-known/
/graphql
/gql

Version and product drift

/api/v1/
/api/v2/
/api/mobile/v1/
/legacy/

3. WHAT TO EXTRACT FROM DOCS

  • optional and undocumented fields
  • admin-only request examples
  • deprecated endpoints that may still be active
  • schema hints like additionalProperties: true
  • parameter names tied to filtering, sorting, IDs, roles, or tenancy

4. NEXT ROUTING

Finding Next Skill
object IDs everywhere api authorization and bola
JWT, OAuth, role claims api auth and jwt abuse
GraphQL or hidden fields graphql and hidden parameters
strong auth boundary but suspicious business flow business logic vulnerabilities
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. 6d ago First seen · 61 lines · 38 tokens per session scan A eeb0dce2b9ed

Subscribe to this mod's changes

api-recon-and-docs is a skill published in the GitHub repository yaklang/hack-skills (2,064 stars, last pushed 2mo ago), licensed MIT. It adds 38 tokens to every session and 451 once invoked, about $0.0002 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 2026-08-30.

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