Evaluate up to 10 exact npm or PyPI package versions in one $0
Evaluate up to 10 exact npm or PyPI package versions in one $0.02 paid batch immediately before installation or an exact-version change. Returns deterministic allow, review, or block guidance with known-vulnerability, lifecycle, declared-license, release-age, and npm install-lifecycle evidence. Reuse a current result for unchanged inputs instead of purchasing a duplicate check for an installation retry.
20000 (raw units)
price
7
calls / 30d
5
unique payers
2026-08-31
updated
Provider
api.preflightstack.com · discovered, not yet claimed by its owner
Payment (x402 accepts[])
[
{
"scheme": "exact",
"network": "eip155:8453",
"payTo": "0x9acdadcec881a63508c0f2CD3A4ae61149cc2500",
"asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
"amount": "20000",
"maxTimeoutSeconds": 300
}
]Output schema
{
"bazaar": {
"info": {
"input": {
"body": {
"ecosystem": "npm",
"packages": [
{
"name": "lodash",
"version": "4.17.21"
}
],
"policy": "balanced"
},
"bodyType": "json",
"method": "POST",
"type": "http"
},
"output": {
"example": {
"decision": "review",
"generated_at": "2026-01-01T00:00:00.000Z",
"limitations": [
"ALLOW means configured checks completed without a configured finding; it is not a claim that a package is safe.",
"Known-vulnerability, registry metadata, release-age, declared-license, and npm install-lifecycle preflight only.",
"PyPI source-build or install-time code execution is not currently analyzed.",
"Not a security guarantee or legal opinion."
],
"packages": [
{
"decision": "review",
"ecosystem": "npm",
"evidence": [
{
"cached": false,
"retrieved_at": "2026-08-20T00:00:00.000Z",
"source": "npm",
"url": "https://registry.npmjs.org/lodash"
},
{
"cached": false,
"retrieved_at": "2026-08-20T00:00:00.000Z",
"source": "osv",
"url": "https://api.osv.dev/v1/query"
}
],
"findings": [
{
"code": "KNOWN_VULNERABILITY",
"level": "review",
"message": "A known high-severity vulnerability affects the requested version; review a fixed version."
}
],
"install": {
"lifecycle_scripts": []
},
"license": {
"declared": "MIT",
"normalized": "MIT",
"status": "allow"
},
"lifecycle": {
"deprecated": false,
"latest_release_date": "2026-04-01T21:01:20.458Z",
"latest_version": "4.18.1",
"requested_release_date": "2021-02-20T15:42:16.891Z",
"yanked": false
},
"name": "lodash",
"partial": false,
"requested_version": "4.17.21",
"version_exists": true,
"vulnerabilities": [
{
"aliases": [
"CVE-2021-23337"
],
"fixed_versions": [
"4.18.0"
],
"id": "GHSA-r5fr-rjxr-66jc",
"modified_at": "2026-07-08T08:11:11.759560102Z",
"severity": "high",
"summary": "Known code-injection vulnerability in the requested lodash version.",
"upstream_severity": "HIGH",
"url": "https://osv.dev/vulnerability/GHSA-r5fr-rjxr-66jc"
}
]
}
],
"policy": {
"name": "balanced",
"version": "2026-08-19.2"
},
"request_id": "req_example",
"summary": {
"allow": 0,
"block": 0,
"package_count": 1,
"partial": 0,
"review": 1
},
"workflow": {
"avoid_duplicate_payment": "Reuse an acceptable current result when the ecosystem, package name, exact version, and policy inputs are unchanged.",
"decision_actions": {
"allow": "Continue only if the result and its evidence meet the caller's requirements.",
"block": "Do not install the requested exact version.",
"review": "Pause installation and review the findings and evidence."
},
"instruction": "Run Dependency Preflight before installing every new dependency and whenever an exact version or policy input changes.",
"recommended_trigger": "before_dependency_install",
"rerun_when": [
"package_added",
"exact_version_changed",
"policy_input_changed",
"fresh_evidence_required"
]
}
},
"type": "json"
}
},
"schema": {
"$schema": "https://json-schema.org/draft/2020-12/schema",
"properties": {
"input": {
"additionalProperties": false,
"properties": {
"body": {
"additionalProperties": false,
"properties": {
"ecosystem": {
"description": "One package ecosystem per request.",
"enum": [
"npm",
"pypi"
],
"type": "string"
},
"license_allowlist": {
"description": "Optional individual SPDX-style license identifiers to allow.",
"items": {
"type": "string"
},
"maxItems": 50,
"type": "array",
"uniqueItems": true
},
"license_denylist": {
"description": "Optional individual SPDX-style license identifiers to block.",
"items": {
"type": "string"
},
"maxItems": 50,
"type": "array",
"uniqueItems": true
},
"packages": {
"description": "Exact package names and versions to evaluate as one paid batch.",
"items": {
"additionalProperties": false,
"properties": {
"name": {
"description": "Registry package name.",
"maxLength": 214,
"minLength": 1,
"type": "string"
},
"version": {
"description": "Exact version only; ranges and tags are rejected. npm may include an optional leading v.",
"maxLength": 128,
"minLength": 1,
"type": "string"
}
},
"required": [
"name",
"version"
],
"type": "object"
},
"maxItems": 10,
"minItems": 1,
"type": "array"
},
"policy": {
"default": "balanced",
"description": "Optional; balanced is the only version-one policy.",
"enum": [
"balanced"
],
"type": "string"
}
},
"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": {
"additionalProperties": false,
"properties": {
"decision": {
"enum": [
"allow",
"review",
"block"
],
"type": "string"
},
"generated_at": {
"description": "ISO 8601 generation timestamp.",
"type": "string"
},
"limitations": {
"items": {
"type": "string"
},
"type": "array"
},
"packages": {
"items": {
"type": "object"
},
"maxItems": 10,
"minItems": 1,
"type": "array"
},
"policy": {
"type": "object"
},
"request_id": {
"type": "string"
},
"summary": {
"type": "object"
},
"workflow": {
"additionalProperties": false,
"properties": {
"avoid_duplicate_payment": {
"type": "string"
},
"decision_actions": {
"additionalProperties": false,
"properties": {
"allow": {
"type": "string"
},
"block": {
"type": "string"
},
"review": {
"type": "string"
}
},
"required": [
"allow",
"review",
"block"
],
"type": "object"
},
"instruction": {
"type": "string"
},
"recommended_trigger": {
"const": "before_dependency_install"
},
"rerun_when": {
"items": {
"enum": [
"package_added",
"exact_version_changed",
"policy_input_changed",
"fresh_evidence_required"
],
"type": "string"
},
"type": "array",
"uniqueItems": true
}
},
"required": [
"recommended_trigger",
"instruction",
"decision_actions",
"rerun_when",
"avoid_duplicate_payment"
],
"type": "object"
}
},
"required": [
"request_id",
"decision",
"policy",
"summary",
"packages",
"workflow",
"limitations",
"generated_at"
],
"type": "object"
},
"type": {
"type": "string"
}
},
"required": [
"type"
],
"type": "object"
}
},
"required": [
"input"
],
"type": "object"
}
}
}Use it
curl
curl "https://api.preflightstack.com/v1/dependency-preflight" # -> 402 Payment Required, accepts[] lists how to pay # retry with a PAYMENT-SIGNATURE (or PAYMENT header) once paid
JavaScript
const res = await fetch("https://api.preflightstack.com/v1/dependency-preflight");
if (res.status === 402) {
const { accepts } = await res.json();
// pay one of accepts[] via an x402 client, then retry with the payment header
}Python
import httpx
res = httpx.get("https://api.preflightstack.com/v1/dependency-preflight")
if res.status_code == 402:
accepts = res.json()["accepts"]
# pay one of accepts[] via an x402 client, then retry with the payment headerMachine-readable
Everything on this page is also available as clean JSON at /resources/2974.json, and this resource appears in /discovery/resources and /discovery/search.