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 nirholas/XActions --skill x402-paymentsgit clone --depth 1 https://github.com/nirholas/XActionsWrote 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/xactions/x402-payments)<a href="https://agentmods.dev/skills/nirholas/xactions/x402-payments"><img src="https://agentmods.dev/badge/skills/nirholas/xactions/x402-payments/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/xactions/x402-payments"><img src="https://agentmods.dev/badge/skills/nirholas/xactions/x402-payments.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector warn
SkillSpector: 1 finding, up to medium
These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →
- medium Data Exfiltration · line 48 Data is being sent to an external URL. This could be legitimate telemetry or data exfiltration. Manual review is recommended.Fix: Verify the destination URL is trusted and necessary. Remove or replace with documented APIs. Ensure no secrets, tokens, or PII are transmitted.
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 | $0.00055 | $0.00757 |
| Opus 5 | $0.00028 | $0.00378 |
| Sonnet 5 | $0.00011 | $0.00151 |
| Haiku 4.5 | $0.00006 | $0.00076 |
Grade A, and why
x402-payments 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 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.
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 — 99 lines — stays where its author put it; the contents beside it link to each section on GitHub.
x402 Payments
XActions supports the x402 payment protocol — an HTTP-native micropayment standard for pay-per-use API access with cryptocurrency.
Entry Points
| Goal | Route | Method |
|---|---|---|
| Discover payment capabilities | GET /.well-known/x402 |
Public |
| Get OpenAPI spec with payment info | GET /api/x402/openapi |
Public |
| Make a paid API call | Any protected route | REST API (with x402 headers) |
Configuration
Config lives in api/config/x402-config.js. Key settings:
{
networks: ['base', 'ethereum', 'polygon', 'arbitrum'], // Supported chains
tokens: {
base: ['USDC', 'ETH'],
ethereum: ['USDC', 'USDT', 'ETH'],
polygon: ['USDC', 'MATIC'],
arbitrum: ['USDC', 'ETH'],
},
pricing: {
'POST /api/operations/unfollow': { amount: '0.01', token: 'USDC' },
'POST /api/operations/follow': { amount: '0.005', token: 'USDC' },
// ... per-route pricing
}
}
Discovery (/.well-known/x402)
Returns a JSON manifest describing all payable routes, supported networks, and token addresses:
GET https://api.xactions.io/.well-known/x402
Response includes:
- List of payable API endpoints with prices
- Supported blockchain networks
- Token contract addresses per network
- Payment verification endpoint
Making a Paid Request
x402-compatible clients handle payment automatically. For manual integration:
# 1. Get payment requirements (HTTP 402 response)
POST /api/operations/unfollow → 402 Payment Required
X-Payment-Required: { amount, token, network, recipient }
# 2. Submit on-chain payment + proof
POST /api/operations/unfollow
X-Payment: <signed-payment-proof>
Middleware
api/middleware/x402.js handles:
- Detecting x402-protected routes
- Returning
402 Payment Requiredwith payment details - Verifying payment proofs before processing requests
- Multi-chain verification across Base, Ethereum, Polygon, Arbitrum
Supported Clients
Any x402-compatible client works automatically:
x402-axios— Axios adapter with auto-paymentx402-fetch— Fetch adapter with auto-payment- Claude agents with x402 MCP tools
- Custom implementations following the x402 spec
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.
- 6d ago First seen · 99 lines · 55 tokens per session scan A 4735c584d8ca
x402-payments is a skill published in the GitHub repository nirholas/XActions (516 stars, last pushed 2d ago), licensed Apache-2.0. It adds 55 tokens to every session and 757 once invoked, about $0.0003 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 2026-09-03.
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