The Chunk Boundaries API from WritersLogic Verifiable AI Agent Hub — 1 operation(s) for chunk boundaries.
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openapi: 3.2.0
info:
title: WritersLogic Verifiable AI Agent Hub Chunk Boundaries 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: Chunk Boundaries
paths:
/api/v1/chunk-boundaries:
post:
operationId: chunk_boundaries
summary: Split text into chunks under a hard token cap without cutting a table, sentence…
description: 'Plans chunk boundaries for text an agent must feed to a model in pieces: every chunk is at most maxTokens in the named tokenizer (o200k_base or cl100k_base, verified by counting each finished chunk), boundaries fall only between sentences, blocks, whole Markdown or HTML tables and whole code fences, headings stay with the text that follows, and the chunks tile the input exactly (concatenating the spans gives the original). Spans carry offsets in UTF-16, code points, UTF-8 bytes and graphemes. If one sentence, table or fence alone exceeds the cap it is returned alone with exceedsCap and the status is fail; it is never cut. Sentence breaks follow ICU rules and can be wrong after abbreviations. Other tokenizer names (including Claude) return unsupported.
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: agent-infra
x-sample-url: https://agents.writerslogic.com/api/v1/samples/chunk-boundaries
security:
- x402: []
- apiKey: []
requestBody:
required: true
content:
application/json:
schema:
type: object
additionalProperties: false
required:
- text
- maxTokens
- tokenizer
properties:
text:
type: string
maxLength: 100000
minLength: 1
description: Text to chunk (Markdown, plain text or HTML tables).
maxTokens:
type: integer
minimum: 32
maximum: 1000000
description: Hard cap per chunk.
tokenizer:
type: string
maxLength: 64
description: o200k_base or cl100k_base. Any other name (including Claude models) returns status unsupported for items that need counting; caller token counts are always accepted.
minLength: 1
includeText:
type: boolean
description: Also return each chunk's text. Default false (slice by span).
example:
text: '# Title
First paragraph. It has two sentences.
| a | b |
|---|---|
| 1 | 2 |
```js
console.log(1)
```
'
maxTokens: 40
tokenizer: o200k_base
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.'
chunks:
type: array
items:
type: object
additionalProperties: false
properties:
index:
type: integer
tokens:
type: integer
description: Actual token count of the chunk text.
units:
type: integer
span:
type: object
description: 'Half-open [start,end) range in four coordinate systems: UTF-16 code units, code points, UTF-8 bytes, extended grapheme clusters (Intl.Segmenter).'
properties:
utf16:
type: object
properties:
start:
type: integer
end:
type: integer
codePoint:
type: object
properties:
start:
type: integer
end:
type: integer
utf8:
type: object
properties:
start:
type: integer
end:
type: integer
grapheme:
type: object
properties:
start:
type: integer
end:
type: integer
graphemeAligned:
type: boolean
exceedsCap:
type: boolean
text:
type: string
maxItems: 5000
totalTokens:
type: integer
description: Token count of the whole text.
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:
- Chunk Boundaries
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