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Council of AI — A2A Agent Population Slice
x402
Council of AI — A2A Agent Population Slice is a paid API for AI agents from councilof.ai, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-02).
Returns a signed, attestation-backed population slice of distinct AI agents indexed in the A2A (Agent-to-Agent) registry frame, with cryptographic evidence for verification.
Price / call$0.01
Success—
StatusUnknown
How this service works
We measure how AI systems behave against frozen, published tests and publish checkable evidence. Issued measurement cards are signed; unsigned supporting runs are labelled. Read the live board and corrections ledger.
Output
A JSON object containing: the count of distinct agents (n), slice ID (a2a), kind label (slice), raw population rows/artifact bytes, an as_of timestamp, indexing state, unit description clarifying this is one frame (not a global count), schema version, settlement metadata (payer, network, transaction), source file paths, and a full attestation block with ed25519 signature, SHA-256 of rows, surface label, and card schema URL. The signature field may be null for unsigned supporting runs.
Example use cases
Audit A2A agent population count
“Can you fetch the Council of AI's signed population measurement for the A2A registry and tell me how many distinct agents are currently indexed, along with when the snapshot was taken?”
Verify cryptographic attestation of agent data
“Get me the Council of AI population slice for the A2A frame and confirm whether the ed25519 signature is present so I can verify the data hasn't been tampered with.”
Cross-check agent registry for compliance report
“I need the current A2A agent population data from Council of AI — including the source files and SHA-256 hashes — so I can cross-reference it for our AI governance compliance report.”
Technical details
Endpoint
GEThttps://councilof.ai/api/pop/a2a?utm_source=zero.xyzWhen to prefer
Choose this endpoint when you need a cryptographically signed, independently verifiable snapshot of the A2A agent population with checkable evidence — particularly for governance audits, compliance reporting, or cross-verification of agent registry claims. Prefer this over raw registry scrapes when attestation and tamper-evidence matter. Not suitable for real-time streaming or querying individual agent details.
Side effects
- Payment not included or invalid: returns HTTP 402 requiring x402 USDC payment
- Invalid method (POST, PUT, etc.): schema only accepts GET, HEAD, DELETE
- Data not yet indexed: state field may reflect non-INDEXED status
- Attestation signature null: unsigned supporting runs are labelled as such, not a hard error
- Network or provider downtime: standard HTTP 5xx response
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| inputrequired | object | |
| output | object |
Output
Schema · Response
{
"type": "json",
"example": {
"n": 391,
"id": "a2a",
"kind": "slice",
"rows": "<the population rows / artifact bytes, verbatim>",
"as_of": "2026-09-17T05:48:05Z",
"state": "INDEXED",
"n_unit": "distinct agents in the a2aregistry-org frame (one frame; not a global count)",
"schema": "csoai.population-door/0.1",
"settle": {
"payer": "<0x… or null>",
"network": "<caip2 or null>",
"transaction": "<0x… or null>"
},
"source": [
"/interop/agent-population-2026-09-17.json",
"/interop/a2a-directories.json"
],
"attestation": {
"schema": "https://councilof.ai/schema/card-v0.json",
"sha256": "<hex>",
"payload": {
"kind": "csoai.population.slice/0.1",
"rows_sha256": "<hex>"
},
"surface": "population.slice",
"sig_ed25519": "<hex or null>"
}
}
}Tags
x402
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