The Union Branch API from WritersLogic Verifiable AI Agent Hub — 1 operation(s) for union branch.
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openapi: 3.2.0
info:
title: WritersLogic Verifiable AI Agent Hub Union Branch 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: Union Branch
paths:
/api/v1/union-branch:
post:
operationId: union_branch
summary: Which oneOf / anyOf branch a JSON value matches, or why several or none do
description: 'Evaluates a JSON value against every branch of a oneOf or anyOf in a caller-supplied JSON Schema 2020-12 (or OpenAPI schema converted to it) and reports which branches match, the exact errors of each branch that fails with the JSON pointer of each offending value, the closest branch, and which branch an OpenAPI `discriminator` points to. For agents debugging why a tool or API payload is rejected with ''matches more than one'' or ''matches none''. Local $ref only; patterns that risk catastrophic backtracking and unknown keywords are reported as unsupported, never as a match. It does not repair the value.
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/union-branch
security:
- x402: []
- apiKey: []
requestBody:
required: true
content:
application/json:
schema:
type: object
additionalProperties: false
required:
- schema
- value
properties:
schema:
description: The root schema; $ref targets are resolved inside it. Full JSON Schema 2020-12 (local $ref only).
value:
description: The JSON value to classify.
at:
type: string
maxLength: 500
description: JSON pointer to the subschema holding the union ("" for the root, "/properties/pet" for a nested one).
keyword:
type: string
enum:
- oneOf
- anyOf
description: Required only when the subschema has both.
example:
schema:
oneOf:
- type: object
required:
- card
properties:
card:
type: string
- type: object
required:
- iban
properties:
iban:
type: string
value:
card: '4111'
iban: DE89
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.'
keyword:
type: string
at:
type: string
branches:
type: array
items:
type: object
properties:
index:
type: integer
ref:
anyOf:
- type: string
- type: 'null'
verdict:
type: string
enum:
- match
- no-match
- unknown
errorCount:
type: integer
errors:
type: array
items:
type: object
properties:
instancePath:
type: string
keyword:
type: string
message:
type: string
schemaPath:
type: string
unsupported:
type: array
items:
type: string
matchedIndexes:
type: array
items:
type: integer
closestBranch:
anyOf:
- type: integer
- type: 'null'
discriminator:
anyOf:
- type: object
properties:
propertyName:
type: string
value:
description: Discriminator value found in the instance.
branchIndex:
anyOf:
- type: integer
- type: 'null'
agreesWithMatch:
anyOf:
- type: boolean
- type: 'null'
- type: 'null'
siblings:
type: string
enum:
- match
- no-match
- unknown
- none
description: Result of the keywords next to the union (everything except the union keyword).
explanation:
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:
- Union Branch
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