Use this service when you need this capability: fetches one public HTTPS HTML resource and performs explicit deterministic selector, attribute, metadata, or JSON-LD path extraction.
0.02 USDC per call
x402 V2 exact payment on Base mainnet (eip155:8453) using USDC. The HTTP 402 challenge confirms the exact requirements before an authorized payment.
POST https://signalharness.ai/api/agent/services/structured_extract/invokeFetches one public HTTPS HTML resource and performs explicit deterministic selector, attribute, metadata, or JSON-LD path extraction.
Documented public-source retrieval is bounded by the URL, byte, redirect, and timeout limits below. Source availability can affect execution; review the input schema and returned source metadata.
| Field | Type | Required | Limits |
|---|---|---|---|
| url | string | Required | Pattern: ^https://; Minimum length 9; Maximum length 2048 |
| fields | array | Required | Minimum 1 item(s); Maximum 32 item(s) |
{
"url": "https://example.com/",
"fields": [
{
"name": "heading",
"kind": "text",
"selector": "h1",
"all": false
}
]
}{
"$schema": "https://json-schema.org/draft/2020-12/schema",
"type": "object",
"additionalProperties": false,
"minProperties": 2,
"maxProperties": 2,
"required": [
"url",
"fields"
],
"properties": {
"url": {
"type": "string",
"pattern": "^https://",
"minLength": 9,
"maxLength": 2048
},
"fields": {
"type": "array",
"minItems": 1,
"maxItems": 32,
"items": {
"type": "object",
"additionalProperties": false,
"minProperties": 2,
"maxProperties": 7,
"required": [
"name",
"kind"
],
"properties": {
"name": {
"type": "string",
"pattern": "^[A-Za-z][A-Za-z0-9_]{0,63}$",
"minLength": 1,
"maxLength": 64
},
"kind": {
"type": "string",
"enum": [
"text",
"attribute",
"metadata",
"json_ld"
],
"minLength": 4,
"maxLength": 9
},
"selector": {
"type": "string",
"minLength": 1,
"maxLength": 256
},
"attribute": {
"type": "string",
"minLength": 1,
"maxLength": 128
},
"metadataKey": {
"type": "string",
"minLength": 1,
"maxLength": 256
},
"path": {
"type": "string",
"minLength": 1,
"maxLength": 256
},
"all": {
"type": "boolean"
}
}
}
}
}
}Illustrative output from the canonical adapter fixture and schema. It is not a completed paid execution or a current live observation.
{
"sourceUrl": "example00",
"results": [
{
"name": "example",
"kind": "text",
"matched": 0,
"values": [
"example"
]
}
],
"warnings": [
"Verify the caller-supplied data before relying on this result."
]
}{
"$schema": "https://json-schema.org/draft/2020-12/schema",
"type": "object",
"additionalProperties": false,
"minProperties": 3,
"maxProperties": 3,
"required": [
"sourceUrl",
"results",
"warnings"
],
"properties": {
"sourceUrl": {
"type": "string",
"minLength": 9,
"maxLength": 2048
},
"results": {
"type": "array",
"minItems": 0,
"maxItems": 32,
"items": {
"type": "object",
"additionalProperties": false,
"minProperties": 4,
"maxProperties": 4,
"required": [
"name",
"kind",
"matched",
"values"
],
"properties": {
"name": {
"type": "string",
"minLength": 1,
"maxLength": 64
},
"kind": {
"type": "string",
"enum": [
"text",
"attribute",
"metadata",
"json_ld"
],
"minLength": 4,
"maxLength": 9
},
"matched": {
"type": "integer",
"minimum": 0,
"maximum": 256
},
"values": {
"type": "array",
"minItems": 0,
"maxItems": 256,
"items": {
"type": "string",
"minLength": 0,
"maxLength": 32768
}
}
}
}
},
"warnings": {
"type": "array",
"minItems": 0,
"maxItems": 32,
"items": {
"type": "string",
"minLength": 1,
"maxLength": 1024
}
}
}
}Timeout: 15000 ms. Full schemas are in OpenAPI.
This schema-valid request returns the canonical HTTP 402 challenge without executing the service. A payment-capable client validates the challenge, signs only with prior authority and budget, and retries the identical body.
curl -i -X POST https://signalharness.ai/api/agent/services/structured_extract/invoke \
-H "Content-Type: application/json" \
--data '{"url":"https://example.com/","fields":[{"name":"heading","kind":"text","selector":"h1","all":false}]}'