/api/v1/regulatory/drugs/:key/similar-by-targetSimilar By Target
Returns the targets affected by a given drug plus other drugs that affect any of those same targets, along with counts. Use it to find drugs sharing a mechanism of action with a reference drug. Returns an empty target and similar-drug list when the drug has no known targets. Responds 400 for invalid query parameters or when the requested data is not loaded, and 500 on internal failure.
When to use it
- Find drugs that share targets with a reference drug
- List the targets of a drug and the other drugs hitting them
- Explore mechanism-of-action overlap between drugs
Getting started
Base URL
https://app.caelrith.com/api/v1/toolsAuthentication
Include your API key in the x-api-key header.
Rate limit
Every call counts against your workspace’s daily quota for regulatoryApiCallsPerDay. Exceeding it returns HTTP 429.
Plans and daily limits
| Plan | Available | Calls / day |
|---|---|---|
| free | yes | 30 |
| pro | yes | 200 |
| custom (default) | yes | 10,000 |
Plan defaults. A custom workspace may carry per-tenant overrides.
Parameters
Path parameters
| Parameter | Type | Required | Description |
|---|---|---|---|
| key(path) | string | Yes |
Query parameters
| Parameter | Type | Required | Description |
|---|---|---|---|
| limit | integer | No | Range 1-100; default 20 (range 1-100; default 20) Range: 1 to 100 |
Example request
curl -H "x-api-key: YOUR_API_KEY" \
"https://app.caelrith.com/api/v1/regulatory/drugs/{key}/similar-by-target"Response envelope
This endpoint returns an implicit 2xx response - there is no success flag in the body.
{
"data": { /* payload */ },
"meta": { /* pagination, totals */ }
}
// No "success" flag on this endpoint - any 2xx JSON is a success.Catalog version mcp-2026-10-28 · generated from the live MCP catalog