# Council of AI — Stablecoins Population Slice

> Council of AI — Stablecoins 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, frozen, verifiable catalog slice of stablecoin assets tracked by the Council of AI measurement universe.

## Facts

- Endpoint: GET https://councilof.ai/api/pop/stablecoins?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-02
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/council-of-ai-stablecoins-population-slice-5c77e0fa
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_ZXAlIq4Ck9pa7FWE5fE2v

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability council-of-ai-stablecoins-population-slice-5c77e0fa
```

Example prompt: Pull the Council of AI stablecoin population slice — the signed, frozen catalog of all stablecoin assets in their measurement universe — and tell me how many assets are indexed and what the attestation hash is.

## When to prefer this

Choose this endpoint when you need a cryptographically attested, independently re-verifiable, frozen snapshot of the stablecoin asset universe as measured by the Council of AI. It is ideal for research, auditing, or compliance workflows that require provenance and tamper-evidence rather than live market data. Prefer this over generic crypto APIs when attestation, immutability, and signed verification are requirements.

## Known failure modes

- Payment not included or invalid — returns 402 Payment Required
- Population slice not yet indexed — state may not be INDEXED
- Upstream corpus file unavailable — source reference may be stale
- Signature null if attestation not yet finalized (sig_ed25519 may be null)
- Network errors or service downtime returning 5xx responses

## 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

Returns a JSON object containing: the number of stablecoin assets catalogued (n), a population slice identifier (id='stablecoins'), the raw population rows/artifact bytes, an as-of ISO timestamp, index state, unit description, schema version, settlement info (payer address, network, transaction), source corpus file reference, and a full attestation block with schema URL, SHA-256 hash, payload hash, surface label, and an ed25519 signature for independent verification.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET",
      "HEAD",
      "DELETE"
     ],
     "type": "string"
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "n": 425,
  "id": "stablecoins",
  "kind": "slice",
  "rows": "<the population rows / artifact bytes, verbatim>",
  "as_of": "2026-09-16T12:06:54Z",
  "state": "INDEXED",
  "n_unit": "assets catalogued in the frozen universe (not supply, not a sum)",
  "schema": "csoai.population-door/0.1",
  "settle": {
   "payer": "<0x… or null>",
   "network": "<caip2 or null>",
   "transaction": "<0x… or null>"
  },
  "source": [
   "/interop/stablecoin-corpus-index-2026-09-16.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>"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/council-of-ai-stablecoins-population-slice-5c77e0fa/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from councilof.ai](https://www.zero.xyz/host/councilof.ai/llms.txt)