har-api-reverse-engineering

har-api-reverse-engineering is a skill for Claude Code, Codex from JPeetz/agent-skills. It costs 109 tokens per session (1,391 once invoked), scanned B, original, no licence file.

A workflow for finding and safely reusing a website's hidden or undocumented API. A HAR file is a browser recording of the requests a website makes.

In plain words
What is it for?
It is for recording requests, deriving the required API calls, building a replayable client, and verifying it.
Why use it?
It replaces guesswork with captured browser requests and checks that the resulting client works outside the browser.

Skill for Claude CodeCodex

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/jpeetz/agent-skills/har-api-reverse-engineering
Any agent
npx skills add JPeetz/agent-skills --skill har-api-reverse-engineering
Clone the repo
git clone --depth 1 https://github.com/JPeetz/agent-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 har-api-reverse-engineering

README.md
[![agentmods](https://agentmods.dev/badge/skills/jpeetz/agent-skills/har-api-reverse-engineering.svg)](https://agentmods.dev/skills/jpeetz/agent-skills/har-api-reverse-engineering)
Your own site
<a href="https://agentmods.dev/skills/jpeetz/agent-skills/har-api-reverse-engineering"><img src="https://agentmods.dev/badge/skills/jpeetz/agent-skills/har-api-reverse-engineering.svg" alt="Measured on agentmods" height="20"></a>
Per session 109 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,391 The whole file, excluding the scripts and references it only reads on demand.
Security scan B 2 findings. Scan, not verified.
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 $0.00109 $0.01391
Opus 5 $0.00055 $0.00696
Sonnet 5 $0.00022 $0.00278
Haiku 4.5 $0.00011 $0.00139

Measured 4d ago against content hash 96ea8d4c81b6, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade B, and why

har-api-reverse-engineering 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 4d 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.

Asks for rootmediumPrivilege escalation

A mod that escalates privileges can change anything on the machine, not only the project.

- chmod 600 every HAR you keep; never commit one to a repo; never paste it (or the

Makes network callslowCapability

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

- curl
skills/api-backend/har-api-reverse-engineering/SKILL.md · 117 lines

The source is not reproduced here

No licence file

A repository with no LICENSE is all rights reserved by default, so the body is not copied here. The metadata, the measurements and the link are.

Read it on GitHub

Files

What ships with it

4 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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. 4d ago First seen · 117 lines · 109 tokens per session scan B 96ea8d4c81b6

Subscribe to this mod's changes

har-api-reverse-engineering is a skill published in the GitHub repository JPeetz/agent-skills (5 stars, last pushed 4d ago), with no licence file. It adds 109 tokens to every session and 1,391 once invoked, about $0.0005 per session on Opus 5. A static security scan graded it B with 2 findings (asks for root, 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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