The Package Exists API from WritersLogic Verifiable AI Agent Hub — 1 operation(s) for package exists.
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openapi: 3.2.0
info:
title: WritersLogic Verifiable AI Agent Hub Package Exists API
version: 2.0.0
description: Pay-per-call agents settled in USDC on Base via x402. Every response carries a signed provenance envelope.
contact:
name: WritersLogic
url: https://writerslogic.com/agents
email: agents@writerslogic.com
servers:
- url: https://agents.writerslogic.com
tags:
- name: Package Exists
paths:
/api/v1/package-exists:
post:
operationId: package_exists
summary: Package exists on npm, PyPI or crates.io (hallucinated dependency check)
description: 'Checks whether up to 10 package names (optionally with a version) exist in the live npm, PyPI or crates.io registry, for coding agents about to add a dependency they may have invented. Per package: exists, latest version, deprecated or yanked flag, and for a missing name the closest names the registry''s own search returns (npm, crates.io; PyPI has no search API). Reads registry metadata only: never downloads or runs package code, and says nothing about whether a package is safe or the right one.
Price: 0.005 USDC on Base (x402).'
x-x402-price-usdc: '0.005'
x-x402-amount: '5000'
x-payment-info:
protocols:
- x402
price:
mode: fixed
currency: USD
amount: '0.005'
x-audience: developer
x-sample-url: https://agents.writerslogic.com/api/v1/samples/package-exists
security:
- x402: []
- apiKey: []
requestBody:
required: true
content:
application/json:
schema:
type: object
additionalProperties: false
required:
- ecosystem
- items
properties:
ecosystem:
type: string
enum:
- npm
- pypi
- crates
items:
type: array
minItems: 1
maxItems: 10
items:
type: object
additionalProperties: false
required:
- name
properties:
name:
type: string
maxLength: 214
version:
type: string
maxLength: 64
description: Exact version (npm also accepts a dist-tag).
description: At most 5 items for crates.io (its API policy allows one request per second).
example:
ecosystem: npm
items:
- name: left-pad
- name: lef-pad
responses:
'200':
description: Paid result with provenance
content:
application/json:
schema:
type: object
properties:
data:
type: object
properties:
status:
type: string
enum:
- pass
- fail
- unknown
- unsupported
description: 'pass: every rule held. fail: a rule was violated (see witnesses). unknown: the input lacks the evidence to decide. unsupported: outside what this engine covers. Missing evidence is never a pass.'
ecosystem:
type: string
requests:
type: integer
description: Registry requests made.
results:
type: array
items:
type: object
properties:
name:
type: string
version:
type: string
exists:
type: boolean
versionExists:
type: boolean
latest:
type: string
deprecated:
type: boolean
yanked:
type: boolean
closest:
type: array
items:
type: string
note:
type: string
witnesses:
type: array
items:
type: object
properties:
ruleId:
type: string
detail:
type: string
path:
type: string
description: JSON pointer or dotted path into the input.
offset:
type: integer
index:
type: integer
expected:
description: What the rule required.
actual:
description: What the input had.
versions:
type: object
description: Every semantic dependency of this answer (engine, tables and their as-of dates, tokenizer, calendar, rounding profile).
limits:
type: array
items:
type: string
deterministic:
type: boolean
description: 'Always true: pure code, no model.'
_provenance:
type: object
description: C2PA-aligned manifest and W3C VC 2.0 (eddsa-jcs-2022) issued by the hub DID; verify at POST /api/v1/verify-provenance
required:
- data
- _provenance
'400':
description: Invalid request (no payment consumed)
content:
application/json:
schema:
type: object
properties:
error:
type: string
code:
type: string
'401':
description: Invalid X-API-KEY
content:
application/json:
schema:
type: object
properties:
error:
type: string
code:
type: string
'402':
description: Payment required or invalid
content:
application/json:
schema:
type: object
description: x402 v2 PaymentRequired (also base64 in the PAYMENT-REQUIRED header)
properties:
x402Version:
type: integer
error:
type: string
code:
type: string
resource:
type: object
accepts:
type: array
items:
type: object
extensions:
type: object
'502':
description: Upstream failure; the payment is released or not settled
content:
application/json:
schema:
type: object
properties:
error:
type: string
code:
type: string
tags:
- Package Exists
components:
securitySchemes:
x402:
type: apiKey
in: header
name: PAYMENT-SIGNATURE
description: x402 v2 payment payload (base64) sent after a 402 challenge
apiKey:
type: apiKey
in: header
name: X-API-KEY