# Capital Markets Knowledge Graph API

> Capital Markets Knowledge Graph API is a paid API for AI agents from capitalmarketsknowledgegraph.ai, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-13).

Retrieves a signed, public-record node or record from a capital markets knowledge graph, returning an EdDSA-signed receipt permanently resolvable by nonce.

## Facts

- Endpoint: GET https://capitalmarketsknowledgegraph.ai/api?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/capital-markets-knowledge-graph-api-6e6e2489
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_VVplZ6nMj9ehXmSzokHO8

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 capital-markets-knowledge-graph-api-6e6e2489
```

Example prompt: Can you pull the public record for a capital markets node from the knowledge graph and give me the signed receipt I can use to verify it later?

## When to prefer this

Choose this endpoint when you need a cryptographically verifiable, permanently resolvable public record from a structured capital markets knowledge graph, especially when auditability and proof of data retrieval matter. Prefer this over generic financial data APIs when you need an EdDSA-signed receipt tied to a specific nonce for downstream verification or compliance purposes.

## Known failure modes

- Invalid or missing 'type' or 'method' input fields return a validation error
- Unsupported HTTP method (e.g. POST or PUT) returns an error since only GET, HEAD, DELETE are allowed
- Payment not fulfilled results in HTTP 402 response blocking data access
- Node or record not found returns an empty or null result
- Nonce collision or receipt resolution failure may prevent permanent link from resolving

## How this service works

One paid call on capitalmarketsknowledgegraph.ai for $0.01 USDC: the surface's own statement of record (a market node: its list_nodes line; a product: its record of record; allooloo.io: the estate scale block), public-record only, with an EdDSA-signed receipt that resolves forever at https://capitalmarketsknowledgegraph.ai/x402/receipt/{nonce}. Doctrine: https://agentic-x402.ai/.

## Output

Returns the public record for the requested capital markets node or product, along with an EdDSA-signed receipt that is permanently resolvable at https://capitalmarketsknowledgegraph.ai/x402/receipt/{nonce}, providing cryptographic proof of the data retrieval.

## 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"
    }
   }
  },
  "output": {
   "type": "object"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/capital-markets-knowledge-graph-api-6e6e2489/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from capitalmarketsknowledgegraph.ai](https://www.zero.xyz/host/capitalmarketsknowledgegraph.ai/llms.txt)