# EMBL-EBI ChEMBL Bioactive Molecule Search

> EMBL-EBI ChEMBL Bioactive Molecule Search is a paid API for AI agents from api.healthtravel-api.workers.dev, paid per call via x402, $0.002/call, status unknown (last checked 2026-10-29).

Search the ChEMBL database for bioactive molecules by name or term, returning ChEMBL ID, preferred name, clinical phase, molecule type, molecular weight, canonical SMILES, first approval year, and ATC codes.

## Facts

- Endpoint: GET https://api.healthtravel-api.workers.dev/api/health/chEMBL-bioactive-molecules?utm_source=zero.xyz
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-29
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/embl-ebi-chembl-bioactive-molecule-search-dc24b2f3
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_vGkfHuFSGbxqHzeKi8ivc

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 embl-ebi-chembl-bioactive-molecule-search-dc24b2f3
```

Example prompt: Search ChEMBL for 'metformin' and give me its ChEMBL ID, molecular weight, canonical SMILES, clinical phase, first approval year, and ATC codes — return up to 5 results.

## When to prefer this

Choose this endpoint when you need structured ChEMBL database records for named drug compounds, including regulatory and chemical metadata like SMILES, clinical phase, ATC codes, and approval year. Prefer over PubChem lookup (also on this provider) when you specifically need ChEMBL IDs, clinical phase data, or ATC classifications. Best for pharmaceutical research, drug discovery pipelines, and cheminformatics workflows requiring ChEMBL-sourced data.

## Known failure modes

- Query term too short (under 2 characters) or too long (over 100 characters) returns a validation error
- No matching molecules found returns an empty result list with total count of 0
- ChEMBL upstream API unavailable returns a 5xx error
- Invalid 'max' parameter value (outside 1–20) may return an error or be clamped to defaults
- Special characters other than letters, digits, spaces, and hyphens may be rejected

## How this service works

EMBL-EBI ChEMBL molecule search: ChEMBL ID, preferred name, maximum clinical phase, molecule type, molecular weight, canonical SMILES, first approval year and ATC codes. Up to 20 molecules per call, with total match count.

## Output

A list of up to 20 matching molecules (default 5), each with: ChEMBL ID, preferred name, maximum clinical phase (0–4), molecule type (e.g. Small molecule, Protein), molecular weight, canonical SMILES string, first approval year, and ATC codes. Also includes the total count of matching records in the ChEMBL database.

## 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"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "q"
     ],
     "properties": {
      "q": {
       "type": "string",
       "description": "Molecule name or term, letters, digits, spaces and hyphens, 2 to 100 characters"
      },
      "max": {
       "type": "string",
       "description": "How many molecules, 1 to 20 (default 5)"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/embl-ebi-chembl-bioactive-molecule-search-dc24b2f3/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.healthtravel-api.workers.dev](https://www.zero.xyz/host/api.healthtravel-api.workers.dev/llms.txt)