# `pubchem__pubchem_search_assays`
**Search Assays**
Find PubChem bioassays associated with a biological target. Search by gene symbol (e.g. "EGFR"), protein name, NCBI Gene ID, or UniProt accession. Returns a page of assay IDs (AIDs) — page past maxResults with offset — which can be explored further with pubchem_get_summary.
- Server: [PubChem](https://gateway.mcpharbor.dev/docs/servers/pubchem) (`dev.mcpharbor.gateway/pubchem`)
- Price per call: $0.0001 (100 micro-USD); only tools/call is charged
- Endpoint: `https://gateway.mcpharbor.dev/mcp` or `https://gateway.mcpharbor.dev/mcp/pubchem`
- Upstream tool: exposed by the provider; called through this gateway as `pubchem__pubchem_search_assays`
- Provider terms: (verified 2026-09-19)
- Upstream API documentation:
- Rate limit: 350 requests per minute
- Attribution required: Attribution to source recommended, not mandatory
## Parameters
- `maxResults` (integer, optional): Max AIDs to return per page (1-200). Popular targets may have thousands of assays; use offset to reach the ones past this page. Default: 50. Default: `50`.
- `offset` (integer, optional): Zero-based index of the first AID to return. Pass the nextOffset from a previous call to read the following page. Default: 0. Default: `0`.
- `targetQuery` (string, required): Target identifier. Examples: "EGFR" (genesymbol), "Epidermal growth factor receptor" (proteinname), "1956" (geneid), "P00533" (proteinaccession).
- `targetType` (string, required): Target identifier type. "genesymbol" and "proteinname" accept text names. "geneid" accepts NCBI Gene IDs. "proteinaccession" accepts UniProt accessions. One of: `genesymbol`, `proteinname`, `geneid`, `proteinaccession`.
## Example call
Request headers and body:
```http
POST /mcp HTTP/1.1
Host: gateway.mcpharbor.dev
Authorization: Bearer
Content-Type: application/json
Accept: application/json, text/event-stream
MCP-Protocol-Version: 2026-07-28
Mcp-Method: tools/call
Mcp-Name: pubchem__pubchem_search_assays
```
```json
{
"id": 1,
"jsonrpc": "2.0",
"method": "tools/call",
"params": {
"_meta": {
"io.modelcontextprotocol/clientCapabilities": {},
"io.modelcontextprotocol/clientInfo": {
"name": "example-agent",
"version": "1.0.0"
},
"io.modelcontextprotocol/protocolVersion": "2026-07-28"
},
"arguments": {
"targetQuery": "example",
"targetType": "genesymbol"
},
"name": "pubchem__pubchem_search_assays"
}
}
```
A successful response:
```json
{
"id": 1,
"jsonrpc": "2.0",
"result": {
"_meta": {
"dev.mcpharbor.gateway/call": {
"chargedMicroUsd": 100,
"id": ""
}
},
"content": [
{
"text": "",
"type": "text"
}
],
"resultType": "complete"
}
}
```
This call costs $0.0001 (100 micro-USD). Reading this page and listing the tool cost nothing.
The `dev.mcpharbor.gateway/call` record in the result is the receipt for that charge. Each
POST is metered separately, so sending the same call again buys another one: see
[agent.txt](https://gateway.mcpharbor.dev/agent.txt), section 7, before retrying.
## Attribution
This provider requires the attribution below wherever you use results from its tools.
Reproduce it verbatim:
> Attribution to source recommended, not mandatory
## Tool definition
Exactly as `tools/list` returns it (free):
```json
{
"_meta": {
"dev.mcpharbor.gateway/pricing": {
"currency": "USD",
"pricePerCallMicroUsd": 100
}
},
"annotations": {
"idempotentHint": true,
"openWorldHint": true,
"readOnlyHint": true
},
"description": "Find PubChem bioassays associated with a biological target. Search by gene symbol (e.g. \"EGFR\"), protein name, NCBI Gene ID, or UniProt accession. Returns a page of assay IDs (AIDs) — page past maxResults with offset — which can be explored further with pubchem_get_summary.",
"inputSchema": {
"$schema": "https://json-schema.org/draft/2020-12/schema",
"additionalProperties": false,
"properties": {
"maxResults": {
"default": 50,
"description": "Max AIDs to return per page (1-200). Popular targets may have thousands of assays; use offset to reach the ones past this page. Default: 50.",
"maximum": 200,
"minimum": 1,
"type": "integer"
},
"offset": {
"default": 0,
"description": "Zero-based index of the first AID to return. Pass the nextOffset from a previous call to read the following page. Default: 0.",
"maximum": 9007199254740991,
"minimum": 0,
"type": "integer"
},
"targetQuery": {
"description": "Target identifier. Examples: \"EGFR\" (genesymbol), \"Epidermal growth factor receptor\" (proteinname), \"1956\" (geneid), \"P00533\" (proteinaccession).",
"type": "string"
},
"targetType": {
"description": "Target identifier type. \"genesymbol\" and \"proteinname\" accept text names. \"geneid\" accepts NCBI Gene IDs. \"proteinaccession\" accepts UniProt accessions.",
"enum": [
"genesymbol",
"proteinname",
"geneid",
"proteinaccession"
],
"type": "string"
}
},
"required": [
"targetType",
"targetQuery"
],
"type": "object"
},
"name": "pubchem__pubchem_search_assays",
"outputSchema": {
"$schema": "https://json-schema.org/draft/2020-12/schema",
"additionalProperties": false,
"anyOf": [
{
"not": {
"required": [
"error"
]
},
"required": [
"aids",
"targetType",
"targetQuery",
"totalFound",
"offset"
]
},
{
"required": [
"error"
]
}
],
"properties": {
"aids": {
"description": "PubChem Assay IDs.",
"items": {
"type": "number"
},
"type": "array"
},
"cap": {
"description": "The maxResults cap that was applied.",
"type": "number"
},
"error": {
"additionalProperties": {},
"description": "Present when the call failed. Absent on success.",
"properties": {
"code": {
"description": "JSON-RPC error code for this failure.",
"maximum": 9007199254740991,
"minimum": -9007199254740991,
"type": "integer"
},
"data": {
"additionalProperties": {},
"properties": {
"reason": {
"description": "Machine-readable failure mode. Declared by this tool: `blank_target_query`: targetQuery is empty or whitespace-only. `invalid_geneid_query`: targetType is \"geneid\" but targetQuery is not a positive integer. Other values are possible when a failure originates below the handler.",
"examples": [
"blank_target_query",
"invalid_geneid_query"
],
"type": "string"
},
"recovery": {
"additionalProperties": {},
"description": "Actionable next step for the caller.",
"properties": {
"hint": {
"type": "string"
}
},
"required": [
"hint"
],
"type": "object"
},
"retryable": {
"description": "Whether retrying may succeed.",
"type": "boolean"
}
},
"type": "object"
},
"message": {
"description": "Human-readable description of what went wrong.",
"type": "string"
}
},
"required": [
"code",
"message"
],
"type": "object"
},
"nextOffset": {
"description": "Offset to pass on the next call to continue past this page. Omitted when no further AIDs match.",
"type": "number"
},
"notice": {
"description": "Recovery guidance when no assays matched, when the offset runs past the result set, or when further pages remain. Absent when this page is complete and non-empty.",
"type": "string"
},
"offset": {
"description": "Zero-based index of the first AID returned.",
"type": "number"
},
"shown": {
"description": "AIDs returned on this page.",
"type": "number"
},
"targetQuery": {
"description": "Target identifier searched.",
"type": "string"
},
"targetType": {
"description": "Target identifier type used: genesymbol, proteinname, geneid, or proteinaccession.",
"type": "string"
},
"totalFound": {
"description": "Total AIDs found for this target, across all pages.",
"type": "number"
},
"truncated": {
"description": "True when matching AIDs remain past this page.",
"type": "boolean"
}
},
"type": "object"
},
"title": "Search Assays"
}
```