Borrowing it
Nothing to install: this file belongs to nirholas/three.ws. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/nirholas/three.ws/main/.agents/skills/x402/SKILL.mdgit clone --depth 1 https://github.com/nirholas/three.wsWrote 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/nirholas/three.ws/x402)<a href="https://agentmods.dev/skills/nirholas/three.ws/x402"><img src="https://agentmods.dev/badge/skills/nirholas/three.ws/x402/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.
<a href="https://agentmods.dev/skills/nirholas/three.ws/x402"><img src="https://agentmods.dev/badge/skills/nirholas/three.ws/x402.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- 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 | $0.00140 | $0.01868 |
| Opus 5.5 | $0.00056 | $0.00747 |
| Sonnet 5.5 | $0.00028 | $0.00374 |
| Haiku 4.5 | $0.00014 | $0.00187 |
Grade A, and why
x402 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 14d 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.
How it starts
The opening of the file, as written. The whole thing — 161 lines — stays where its author put it; the contents beside it link to each section on GitHub.
x402 Payment Protocol
Use the npx [email protected] x402 commands to discover, inspect, and call paid API endpoints using the X402 payment protocol. Payments are made in USDC on Base.
Which payment stack (arbitration)
three.ws runs two x402/payment stacks. Pick one deterministically: never settle a payment through a signing path the user didn't ask for.
- This stack (awal / three.ws-native): the default. Use it to browse the bazaar and settle a plain x402 402 with a one-shot USDC-on-Base payment.
- OKX
onchainosstack (okx-agent-payments-protocol): use only when the user names OKX/OnchainOS, or the 402 is one OKX handles specifically: a payment channel / voucher / session,permit2,upto/metered billing, MPP charge, or an a2a-paypaymentId. Hand off there and do not pay from here.
Workflow
The typical x402 workflow is:
- Find a service - Search the bazaar or get details for a known endpoint
- Check requirements - Inspect price, method, and input schema
- Make the request - Call the endpoint with automatic USDC payment
Commands
Search the Bazaar
Find paid services by keyword using CDP's vector search:
npx [email protected] x402 bazaar search <query> [-k <n>] [--network <network>] [--scheme <scheme>] [--max-price <price>] [--json]
| Option | Description |
|---|---|
-k, --top <n> |
Number of results, 1 to 20 (default: 20) |
--network <name> |
Filter by chain (base, base-sepolia, polygon, solana, solana-devnet) |
--scheme <scheme> |
Filter by payment scheme: exact or upto |
--max-price <price> |
Maximum price in USD (e.g. 0.01) |
--asset <address> |
Filter by payment asset address |
--pay-to <address> |
Filter by recipient wallet address |
--extensions <type> |
Filter by extension type (e.g. outputSchema, bazaar) |
--json |
Output as JSON |
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.
- 14d ago Changed d5d6139d39eb
- 20d ago Changed a9806cd3186e
- 2mo ago First seen · 161 lines · 140 tokens per session scan A 564d8fa89aff
x402 is a skill published in the GitHub repository nirholas/three.ws (269 stars, last pushed yesterday), licensed Apache-2.0. It adds 140 tokens to every session and 1,868 once invoked, about $0.0006 per session on Opus 5.5. 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.
x402 compared with skills from other repositories
| Mod | Type | Stars | Last push | Licence | Scan | Tokens | Works with |
|---|---|---|---|---|---|---|---|
| x402nirholas/three.ws | Skill | 269 | yesterday | Apache-2.0 | A | 140 | Claude Code |
| fastapi-patternsaffaan-m/ECC | Skill | 298k | 4d ago | MIT | A | 35 | Claude Code, Kiro |
| webappkortix-ai/suna | Skill | 20k | 4d ago | none | A | 28 | Claude Code, Codex |
| file-upload-media-expertroedyrustam/vibes-plug | Skill | 121 | yesterday | MIT | A | 46 | Cursor |
| openapi-expertRightNow-AI/openfang | Skill | 18k | 4mo ago | Apache-2.0 | A | 20 | Claude Code, Codex |
| magicbasedtyq/magic | Skill | 5.1k | 13d ago | none | A | 63 | Claude Code, Codex |
| openai-django-webhooksbtfranklin/skills | Skill | 6 | 8d ago | MIT | A | 65 | Codex |