BB greenhelix-x402-merchant-cookbook
The x402 Merchant Integration Cookbook: Put Any API Behind a Crypto Paywall in Under an Hour. Practical recipes for integrating x402 payments into any web service. Covers Express.js middleware, FastAPI integration, Cloudflare Workers, payment verification, settlement, and production deployment patterns.
As a process B 65/100 · Nearly there — weak spots: inputs and preconditions, execution cost
What is at stake
Medium-severity findings: the skill is probably honest, but read what alarmed the scanner.
Below is the worst case for this category. The finding here is medium: the guard saw a sign, not a proof.
The purpose itself is risky: wallets, browser password stores, offensive security. Even an honest implementation gives the agent access to things that cost money.
Explain in the description why the access is needed and how it is limited; add tests that show refusals on dangerous requests.
How to improve
- Say in the description WHEN to use the skill ("use when…", example requests): that is the agent's main cue.
- The SKILL.md body is over 5,000 tokens: move reference detail into references/ and load it when needed.
- Your own cases (evals/evals.json, 4–6 real requests with expected answers): the full check would then run those instead of a model-drafted suite.
- A spec.yaml with trigger phrases and assertions — a behaviour contract for CI; `skilltest init` writes a template.
Guard findings · 6
✓ No critical or high findings
Medium and low: 6
-
medium Risky intent
intent-wallet-secretsSKILL.md:107Handles crypto-wallet secrets (seed / mnemonic / private key) — a classic stealer target| with wallet private key] | |
-
low Secrets in code
secret-high-entropy-tokenSKILL.md:152High-entropy token-like string (may be an id, hash or a credential) (quoted — discussed, not commanded)"asset": "0x83…913",
quoted -
low Secrets in code
secret-high-entropy-tokenSKILL.md:173High-entropy token-like string (may be an id, hash or a credential) (quoted — discussed, not commanded)- **asset**: The ERC-20 token contract address. On Base mainnet, USDC is `0x83…913`. On Base Sepolia, it is `0x03…F7e`.
quoted -
low Secrets in code
secret-high-entropy-tokenSKILL.md:252High-entropy token-like string (may be an id, hash or a credential) (quoted — discussed, not commanded)? '0x83…913'
quoted -
low Secrets in code
secret-high-entropy-tokenSKILL.md:253High-entropy token-like string (may be an id, hash or a credential) (quoted — discussed, not commanded): '0x03…F7e';
quoted -
low Secrets in code
secret-high-entropy-tokenSKILL.md:604High-entropy token-like string (may be an id, hash or a credential) (quoted — discussed, not commanded)"0x83…913"
quoted
Files scanned: 2. Evidence is masked. Grey chips explain why severity was lowered.
Against the Agent Skills spec
- warning
description-no-whendescription does not say WHEN to use the skill (no "use when") - warning
body-longSKILL.md body ≈ 26205 tokens (recommended < 5000); move details to references/ - note
frontmatter-keyunknown frontmatter key "type" - note
frontmatter-keyunknown frontmatter key "price_usd" - note
frontmatter-keyunknown frontmatter key "content_type" - note
frontmatter-keyunknown frontmatter key "executable" - note
frontmatter-keyunknown frontmatter key "install" - note
frontmatter-keyunknown frontmatter key "credentials"
Process rating: all ten parameters 65/100
- 0Inputs and preconditions. Does not say what the process needs to start
- 10Execution cost. Instruction body is 26205 tokens: crowds the task out of the window
- 50When it triggers. No condition that starts the skill
- 60Tools and files. Uses tools (web, python) that frontmatter does not declare
- 60Result and completion. Output format stated, no completion criterion
- 100Steps. 78 steps
- 100Failures and branches. 13 branches, has a failure section
- 100Consistency. Name and required fields are in place
- 100Running it twice. Mutating operations check current state
- 100Progress reporting. Reports progress
- medium Safety rules and hard prohibitions inside a skill: they belong in the system prompt, here they protect nothing
- low 14 top-level sections: this looks like several domains in one skill
Everything here is measured from the skill text rather than judged by a model, so the numbers are checkable. A parameter weighs more when it is a more common reason for the process to stall.
Quality signals
- +5Description has no quoted example phrases that should trigger the skill
- +4Description does not say when NOT to use the skill (false activations)
- -2localhost URLs: will not work for another user
- +2Single-language instructions
- +3Description length 304: enough signal without eating the budget
- +4Structure: 64 headings
- +3Step-by-step instructions: 78 items
- +3Output format is stated explicitly
- +4Has examples (44 code blocks)
- +1License stated
Quality base 70; lint remarks subtract, signals add up to 100. Result: 61.