apipick
[ search · endpoint ]Search API · Chemistry

Chemistry & Drug Discovery Search API

Query ChEMBL bioactivity (IC50/Ki/Kd/EC50), PubChem structures and properties, and Open Targets target-disease associations from one endpoint. Pre-shaped JSON for AI-driven drug discovery, cheminformatics, and biomedical research.

●30 credits / call●60 req / minPOST /api/search/chemistry
[ 01 · live ]

Try Chemistry Search Live

Enter your API key and run a real query against the live endpoint.

auth · x-api-key

Don't have an API key?

Sign in to your account to create and manage your API keys.

Sign InManage API Keys
5 sample queries — click to load
[ 02 · integrate ]

Integration guide

Copy a snippet, replace your API key, run. Works in any HTTP client — examples below in cURL, JavaScript, and Python.

spec
POST/api/search/chemistry
base
https://www.apipick.com

Semantic search across ChEMBL, PubChem, and Open Targets. Returns ranked records with source URLs ready for downstream LLMs.

parameters
querystringrequired

Natural-language search query

max_num_resultsintegeroptional

1–5, default 5

relevance_thresholdnumberoptional

0.0–1.0 quality filter

country_codestringoptional

ISO country code (e.g. US, GB)

start_datestringoptional

ISO date YYYY-MM-DD

end_datestringoptional

ISO date YYYY-MM-DD

curl -X POST "https://www.apipick.com/api/search/chemistry" \
  -H "Content-Type: application/json" \
  -H "x-api-key: YOUR_API_KEY" \
  -d '{
  "query": "Kinase inhibitor selectivity for EGFR",
  "max_num_results": 5,
  "country_code": "US",
  "start_date": "2026-01-01"
}'
● 200 · response
{
  "query": "Kinase inhibitor selectivity for EGFR",
  "results": [
    {
      "title": "Example result",
      "url": "https://example.com/article",
      "snippet": "Short excerpt of the page content…",
      "source_type": "web",
      "published_at": "2026-04-15",
      "score": 0.92
    }
  ],
  "result_count": 1,
  "credits_used": 30,
  "remaining_credits": 99
}
[ 03 · limits ]

Rate limits

Throttling is per API key, sliding 60-second window. Hit the limit and you get a clean 429 with a Retry-After header.

request rate

60req/min

Per API key, per endpoint. Sliding 60-second window.

concurrency

3concurrent

Max simultaneous in-flight requests per API key.

response headers
X-RateLimit-LimitMaximum requests allowed per minute
X-RateLimit-RemainingRequests remaining in the current window
X-RateLimit-ResetSeconds until the current window resets
Retry-AfterSeconds to wait before retrying (only on 429)
● 429 · too many requests
HTTP/1.1 429 Too Many Requests
Retry-After: 12
X-RateLimit-Limit: 60
X-RateLimit-Remaining: 0
X-RateLimit-Reset: 12

{
  "error": "rate_limit_exceeded",
  "message": "Rate limit exceeded: 60 requests/minute per API key. Retry after 12s.",
  "retry_after": 12
}
[ faq ]

Frequently Asked Questions

01

Why is this 30 credits per call?

ChEMBL, PubChem, and Open Targets are large, structured scientific datasets that require ongoing index maintenance, so the endpoint is priced at 30 credits (≈ $0.03 per call) — a fraction of dedicated cheminformatics platforms.

02

Which sources are covered?

ChEMBL (bioactivity: IC50/Ki/Kd/EC50), PubChem (100M+ chemical structures and properties), and Open Targets (target-disease associations and validation). All three are queried in parallel.

03

Can I search by compound or target?

Yes. Pass a compound name, a target/gene, or a natural-language query like 'EGFR kinase inhibitor selectivity' and the endpoint ranks the most relevant records.

04

Date filtering?

Yes. Pass start_date and end_date in YYYY-MM-DD to scope to a specific window.

05

Tool schema for OpenAI / Claude?

GET /api/search/chemistry/tool-schema returns ready-to-paste OpenAI function and Claude tool-use definitions.