Spark Invocation Assurance
Validate an intended paid API request against its declared contract before spending. Returns VALID, INVALID, or UNKNOWN with machine-readable reasons. Target URL is never called.
Offering
- Provider
- spark-api-preflight.replit.app
- Method
- POST
- Offering type
- Api Endpoint
- Transport type
- http
- Category
- Api
- Delivery
- Not provided
- Pricing model
- Not provided
- x402 version
- 2
Endpoint context
- URL
https://spark-api-preflight.replit.app/api/validate- MIME type
- application/json
- First seen
- 2026-10-16T02:01:31.612Z
- Last seen
- Tags
- preflight, Validation, X402, api, Agents
Payment pricing
x402 payment terms are the authoritative price for calling this endpoint.
- Payment option 1
- 0.001 USDC
Atomic price: 1000 · Network: eip155:8453 · Asset: USDC · Scheme: exact
Raw x402 terms
[
{
"scheme": "exact",
"network": "eip155:8453",
"asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
"amount": "1000",
"payTo": "0xc2a3246d70733169b5228caaea799afe138c2b91"
}
]Observed health
- Status
- Degraded
- Latest latency
- 33 ms
- Average latency
- 543 ms
- HTTP status
- 404
- Last checked
- Reachability
- 100% over 14 checks
Latency is measured to the first response headers. A reachable result does not verify response accuracy or merchant identity.
Input schema
{
"body": {
"query": {
"id": "123"
},
"targetUrl": "https://example.com/items",
"requiredQuery": [
{
"name": "id",
"schema": {
"type": "string"
},
"required": true
}
],
"declaredMethod": "GET",
"intendedMethod": "GET"
},
"type": "http",
"method": "POST",
"bodyType": "json"
}Output schema
{
"type": "object",
"$schema": "https://json-schema.org/draft/2020-12/schema",
"required": [
"input"
],
"properties": {
"input": {
"type": "object",
"required": [
"type",
"method",
"bodyType",
"body"
],
"properties": {
"body": {
"type": "object",
"required": [
"targetUrl",
"intendedMethod",
"declaredMethod",
"requiredQuery"
],
"properties": {
"body": {
"description": "Proposed request body checked against bodySchema."
},
"query": {
"type": "object",
"description": "Proposed query parameter values checked against requiredQuery."
},
"targetUrl": {
"type": "string",
"description": "Intended API target URL, kept as data only and never called."
},
"bodySchema": {
"type": "object",
"description": "Declared schema used to check the request body; unsupported features may produce UNKNOWN."
},
"requiredQuery": {
"type": "array",
"description": "Query parameter requirements from the contract; each rule has a name, required flag, and optional value schema."
},
"declaredMethod": {
"type": "string",
"description": "Uppercase HTTP method declared by the contract; compared with intendedMethod."
},
"intendedMethod": {
"type": "string",
"description": "Uppercase HTTP method the agent intends to use for the target request."
}
}
},
"type": {
"type": "string",
"const": "http"
},
"method": {
"enum": [
"POST"
],
"type": "string"
},
"bodyType": {
"enum": [
"json",
"form-data",
"text"
],
"type": "string"
}
},
"additionalProperties": false
},
"output": {
"type": "object",
"required": [
"type"
],
"properties": {
"type": {
"type": "string"
},
"example": {
"type": "object",
"required": [
"verdict",
"errors",
"validator"
],
"properties": {
"errors": {
"type": "array",
"items": {
"type": "object",
"required": [
"code",
"path",
"message",
"fix"
],
"properties": {
"fix": {
"type": "string"
},
"code": {
"type": "string"
},
"path": {
"type": "string"
},
"message": {
"type": "string"
}
}
}
},
"verdict": {
"enum": [
"VALID",
"INVALID",
"UNKNOWN"
],
"type": "string"
},
"validator": {
"type": "object",
"required": [
"name",
"version"
],
"properties": {
"name": {
"type": "string"
},
"version": {
"type": "string"
}
}
}
}
}
}
}
}
}