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SignalHarness Search Query Expander
x402
SignalHarness Search Query Expander is a paid API for AI agents from signalharness.ai, paid per call via x402, $0.01/call, status unknown (last checked 2026-09-13).
Expands a set of supplied search terms into a broader, enriched set of related queries for improved search coverage
Price / call$0.01
Success—
StatusUnknown
How this service works
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Output
Returns a JSON analysis containing expanded and related search queries derived from the supplied terms, along with a list of warnings (e.g. to verify caller-supplied data), a service_id, and a receipt confirming the successful x402 micropayment execution on Base USDC.
Example use cases
Broader research query coverage
“I'm researching 'climate change mitigation strategies' and 'carbon capture' — can you expand those into a fuller set of related search queries so I don't miss important subtopics?”
SEO keyword expansion for content team
“We're targeting 'project management software' and 'team collaboration tools' — expand those into a richer set of related search queries our content team can use to find gaps in our coverage.”
Agent search loop enrichment
“My agent is searching for information on 'quantum computing hardware' and 'qubit error correction' — expand those terms into more query variants so the search loop covers more ground.”
Technical details
Endpoint
POSThttps://signalharness.ai/api/agent/services/search_query_expand_from_supplied_terms/invokeWhen to prefer
Choose this endpoint when an AI agent needs to broaden its search coverage by generating related query variants from a seed set of terms, especially in agentic search loops where recall matters more than precision. It is well-suited for research, SEO, and multi-step retrieval workflows where the initial query set is narrow. At $0.01 USDC per call via x402 micropayment, it is cost-effective for repeated use in automated pipelines.
Side effects
- Invalid or empty request_json causes schema validation failure
- request_json exceeds 65536 character limit returns error
- Malformed JSON string in request_json field causes parse error
- Insufficient USDC balance results in payment failure and no result
- Service returns warnings when caller-supplied data cannot be fully validated
- Network issues on Base (eip155:8453) may delay payment settlement
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| request_json | string |
Output
Schema · Response
{
"type": "json",
"example": {
"replay": false,
"result": {
"warnings": [
"Verify the caller-supplied data before relying on this result."
],
"service_id": "search_query_expand_from_supplied_terms",
"analysis_json": "{\"example\":\"schema-valid caller-supplied data\"}",
"evidence_scope": "caller_supplied_data"
},
"status": "succeeded",
"receipt": {
"asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
"usage": [],
"status": "succeeded",
"network": "eip155:8453",
"artifacts": [],
"endedAtMs": 0,
"latencyMs": 0,
"paymentId": "example-payment",
"receiptId": "example-receipt",
"requestId": "example-request",
"serviceId": "search_query_expand_from_supplied_terms",
"executionId": "example-execution",
"startedAtMs": 0,
"amountAtomic": "10000",
"resultSha256": "eda53192d0bd5caf451b5cba46c646c305ad2e190269356948daf3d7e2380bf8",
"serviceVersion": "1.0.0",
"settlementReference": "0x0000000000000000000000000000000000000000000000000000000000000000"
},
"artifacts": [],
"requestId": "example-request",
"executionId": "example-execution"
}
}Tags
x402
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