# Invoket SVHC Candidate List Lookup

> Invoket SVHC Candidate List Lookup is a paid API for AI agents from api.invoket.com, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-10).

Checks whether a chemical substance is listed on ECHA's SVHC Candidate List, returning a dated official verdict with provenance, given a CAS number, EC number, or Candidate List name.

## Facts

- Endpoint: GET https://api.invoket.com/label/chem/svhc?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-10
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/invoket-svhc-candidate-list-lookup-03b9cb73
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_3XApf_rXJdDiCdnQe1HMc

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 invoket-svhc-candidate-list-lookup-03b9cb73
```

Example prompt: Is the chemical with CAS number 107-06-2 currently on the EU SVHC Candidate List? I need a dated official verdict with provenance before we include it in our product.

## When to prefer this

Use this endpoint when you need a machine-readable, provenance-backed, official verdict on whether a specific chemical is on the ECHA SVHC Candidate List — particularly in automated compliance workflows, product due-diligence pipelines, or supplier onboarding checks. Prefer this over manual ECHA web searches when you need a dated, auditable answer with structured output that an agent can act on directly. It is especially valuable when checking single substances at high frequency or as a pre-action gate before product release, procurement, or export.

## Known failure modes

- 400 if CAS checksum validation fails — verify the CAS number format and check digit
- 400 if more than one key (cas, ec, name) or zero keys are provided — submit exactly one identifier
- 400 if EC number checksum is invalid
- 200 not_listed if the substance is valid but not on the Candidate List — still billed; absence does not confirm safety
- Ambiguous results possible for UVCB substances that have no CAS/EC — use the exact Candidate List name instead

## How this service works

The checks your agent runs before it acts: verify a bank account, a phone number, a law in force, the weather or a vehicle — computed from official sources, with provenance in every response. You only pay for answers.

## Output

A JSON object indicating whether the queried substance is listed on the ECHA SVHC Candidate List, stamped with the version date of the list used for the check and provenance information. If not listed, the response confirms absence as of the served list date (a 'not_listed' verdict is still billed). If the CAS/EC checksum is invalid or multiple/zero keys are provided, returns HTTP 400. Valid but unlisted substances return HTTP 200 with a 'not_listed' verdict.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "cas"
 ],
 "properties": {
  "cas": {
   "type": "string",
   "description": "CAS number, checksum-validated. Provide exactly ONE key among: cas, ec (EC number, checksum-validated), name (exact Candidate List name - the only key for UVCB entries published without CAS/EC). Zero or several keys = 400; bad checksum = 400; valid but not listed = 200 not_listed (billed - the verdict is dated to the served list and absence does not mean no concern)"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "object"
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/invoket-svhc-candidate-list-lookup-03b9cb73/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.invoket.com](https://www.zero.xyz/host/api.invoket.com/llms.txt)