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 CSOAI-ORG/councilof-ai --skill x402-discoverygit clone --depth 1 https://github.com/CSOAI-ORG/councilof-aiWrote 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/csoai-org/councilof-ai/x402-discovery)<a href="https://agentmods.dev/skills/csoai-org/councilof-ai/x402-discovery"><img src="https://agentmods.dev/badge/skills/csoai-org/councilof-ai/x402-discovery/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/csoai-org/councilof-ai/x402-discovery"><img src="https://agentmods.dev/badge/skills/csoai-org/councilof-ai/x402-discovery.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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 | $0.00367 | $0.01139 |
| Opus 5.5 | $0.00147 | $0.00456 |
| Sonnet 5.5 | $0.00073 | $0.00228 |
| Haiku 4.5 | $0.00037 | $0.00114 |
Grade A, and why
x402-discovery 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 13d 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 — 32 lines — stays where its author put it; the contents beside it link to each section on GitHub.
x402 discovery + free door
Agents discover paid artefact rails via GET https://councilof.ai/.well-known/x402.json (mode is reported from runtime env, Base eip155:8453, USDC; amounts from challenge only — no invent price). Catalog GET /api/x402. Free door GET /api/free-door amount 0 settles and charges nothing — proves the rail. Living board GET /api/gspc. Verification stays free at /gspc-verify. payTo is merchant receive, never the signer. Self-settle proves the rail; stranger revenue is separate (do not invent buyers). Coming—Paddle not live. No card-processor invent. Measurement, never certification. Signed offers and receipts are conditional: a 402 carries extensions['offer-receipt'].info.offers[] only when BOARD_SIGN_KEY_PKCS8_B64 is provisioned and an accepts[] entry can be committed; otherwise csoai.offer_receipt names the gap. A signed receipt appears in the X-PAYMENT-RESPONSE SettlementResponse only after facilitator-confirmed settlement when the facilitator names a payer and the board key is available; otherwise receiptGap states why no signed receipt was attached. Emitted signatures use format jws, alg EdDSA, kid did:web:csoai.org#board-attestation-1. Verify one without trusting us: POST it to /api/receipts/verify, or run scripts/verify_receipt.py against https://csoai.org/.well-known/did.json. Your own receipts: GET /api/receipts?payer=0x... (status UNRECORDED means no store is bound on that deployment, never that you did not pay). No eip712 is emitted — the edge has no secp256k1 signer.
How to call it
This is an A2A skill of the Council of AI measurement agent (agent card: https://councilof.ai/.well-known/agent-card.json).
Send SendMessage to POST https://councilof.ai/api/a2a with header A2A-Version: 1.0; params.message carries a messageId and parts,
and one structured part selects the skill: {"data": {"skill": "x402-discovery", "input": {...}}, "mediaType": "application/json"}.
Calling it needs no account, key or registration (see https://councilof.ai/auth.md).
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.
- 13d ago First seen · 32 lines · 367 tokens per session scan A 6a36efd83a77
x402-discovery is a skill published in the GitHub repository CSOAI-ORG/councilof-ai (3 stars, last pushed today), licensed MIT. It adds 367 tokens to every session and 1,139 once invoked, about $0.0015 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 2026-10-03.
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