# FDA Warning Letters Search

> FDA Warning Letters Search is a paid API for AI agents from api.govparse.io, paid per call via x402, $1.25/call, status unknown (last checked 2026-09-14).

Search the FDA Warning Letters index by company, product area, issuing office, subject, or status to identify firms with open compliance violations.

## Facts

- Endpoint: GET https://api.govparse.io/v1/fda/warning-letters/search
- Price: $1.25/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/fda-warning-letters-search-1f46dd73
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_4AFyPqbvMt9Z0PbsQ2y7S

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 fda-warning-letters-search-1f46dd73
```

Example prompt: Can you check if Acme Labs has any open FDA warning letters — specifically any related to CGMP violations in drugs? Show me the most recent ones first.

## When to prefer this

Choose this endpoint when you need structured, filterable access to FDA Warning Letters with entity resolution, especially for compliance screening of suppliers or counterparties, regulatory monitoring workflows, or due diligence pipelines. Prefer over manual FDA website searches when you need machine-readable results, date-range filtering, or the ability to pivot to a resolved business entity ID across other govparse.io datasets.

## Known failure modes

- Company name not found — returns empty results if name spelling differs significantly from FDA index
- No results for very recent letters not yet indexed or posted by FDA
- Invalid product_area enum value returns an error or empty set
- Date format errors if not supplied as YYYY-MM-DD
- Rate limits or payment failures via x402 protocol returning 402 status
- entity_id pivot may return no results if entity resolution has not been performed for a firm

## How this service works

Which FDA-regulated firms have an open FDA warning letter? Search the FDA Warning Letters index by company, product area (drugs, devices, biologics, food, dietary-supplement, cosmetics, tobacco, veterinary), issuing office, subject (CGMP, adulterated, misbranded), open/closed status, or issue/posted date. Returns the recipient firm (entity-resolved where possible), issuing office, subject, and response/close-out dates — a documented compliance gap and remediation trigger.

## Output

Returns a paginated list of FDA warning letter records matching the query, each including the recipient firm name (entity-resolved where possible), the issuing FDA office or district, the letter subject and alleged violation type, issue date, posted date, and any response or close-out dates indicating open or resolved compliance status.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "properties": {
  "input": {
   "type": "object",
   "required": [],
   "properties": {
    "sort": {
     "type": "string",
     "examples": [
      "letter_issue_date:desc"
     ],
     "description": "letter_issue_date | posted_date :asc|:desc. Default letter_issue_date:desc."
    },
    "limit": {
     "type": "integer",
     "examples": [
      25
     ],
     "description": "Max rows (default 25, cap 100)."
    },
    "since": {
     "type": "string",
     "examples": [
      "2026-01-01"
     ],
     "description": "Letter issue date on/after this date (YYYY-MM-DD)."
    },
    "closed": {
     "type": "string",
     "examples": [
      "false"
     ],
     "description": "false = open letters (no close-out) only; true = closed-out only."
    },
    "offset": {
     "type": "integer",
     "examples": [
      0
     ],
     "description": "Rows to skip."
    },
    "company": {
     "type": "string",
     "examples": [
      "Acme Labs"
     ],
     "description": "Recipient company name — suffix/punctuation-insensitive."
    },
    "subject": {
     "type": "string",
     "examples": [
      "CGMP"
     ],
     "description": "Subject / alleged-violation fragment."
    },
    "entity_id": {
     "type": "string",
     "examples": [
      "b7f3e2d1-4a5c-4e6f-8a9b-0c1d2e3f4a5b"
     ],
     "description": "Resolved employer entity UUID (pivots to business360)."
    },
    "responded": {
     "type": "string",
     "examples": [
      "false"
     ],
     "description": "true = a firm response letter is on record; false = none."
    },
    "posted_since": {
     "type": "string",
     "examples": [
      "2026-01-01"
     ],
     "description": "Posted date on/after this date (YYYY-MM-DD) — newly-published letters."
    },
    "product_area": {
     "type": "string",
     "examples": [
      "drugs"
     ],
     "description": "drugs | devices | biologics | food | dietary-supplement | cosmetics | tobacco | veterinary | other (CSV)."
    },
    "issuing_office": {
     "type": "string",
     "examples": [
      "Center for Drug Evaluation and Research"
     ],
     "description": "FDA center / district office fragment."
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/fda-warning-letters-search-1f46dd73/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.govparse.io](https://www.zero.xyz/host/api.govparse.io/llms.txt)