Call before installing packages suggested by a language model
Call before installing packages suggested by a language model. Returns, for each npm or PyPI package name, whether it actually exists in the registry, whether it is deprecated or yanked, and — when the name is not found — the closest real package names. Catches hallucinated dependencies (slopsquatting) before an agent installs them. Never inspects package contents and never returns a safety verdict.
Answeringour last check, 2026-09-24
1 of 1checks answered this week
1070 msmedian answer time
$0.05listed price per call
$0.05price it asked us
Paid test badge: not yet. The checks above are free: we call the tool without paying and read the payment request it sends back. The Verified badge needs paid calls whose answers match the promised output, and nobody can buy a badge.
Endpoint
POST https://preflight402.com/v1/deps/check
| Category | Company and compliance |
|---|---|
| Provider host | preflight402.com |
| Networks | eip155:8453 |
| Payment schemes | exact |
| Self-reported calls, 30 days | 2 from 2 payers (the provider's figure, not ours) |
Our checks, last 30 days
| Day | Result | HTTP | Asked | Time |
|---|---|---|---|---|
| 2026-09-24 | valid payment request | 402 | $0.05 | 1070 ms |
Example input (from the provider)
{
"body": {
"ecosystem": "npm",
"packages": [
"left-pad"
]
},
"bodyType": "json",
"method": "POST",
"type": "http"
}
Promised output schema (from the provider)
{
"$schema": "https://json-schema.org/draft/2020-12/schema",
"properties": {
"input": {
"additionalProperties": false,
"properties": {
"body": {
"additionalProperties": false,
"properties": {
"ecosystem": {
"enum": [
"npm",
"pypi",
"crates"
],
"type": "string"
},
"packages": {
"items": {
"maxLength": 214,
"minLength": 1,
"type": "string"
},
"maxItems": 20,
"minItems": 1,
"type": "array"
}
},
"required": [
"ecosystem",
"packages"
],
"type": "object"
},
"bodyType": {
"enum": [
"json",
"form-data",
"text"
],
"type": "string"
},
"method": {
"enum": [
"POST"
],
"type": "string"
},
"type": {
"const": "http",
"type": "string"
}
},
"required": [
"type",
"method",
"bodyType",
"body"
],
"type": "object"
},
"output": {
"properties": {
"example": {
"type": "object"
},
"type": {
"type": "string"
}
},
"required": [
"type"
],
"type": "object"
}
},
"required": [
"input"
],
"type": "object"
}