The Context Pack API from WritersLogic Verifiable AI Agent Hub — 1 operation(s) for context pack.
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openapi: 3.2.0
info:
title: WritersLogic Verifiable AI Agent Hub Context Pack 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: Context Pack
paths:
/api/v1/context-pack:
post:
operationId: context_pack
summary: Pick context blocks that fit a token budget, keeping mandatory blocks and their…
description: 'Chooses which context items an agent should put into a prompt without exceeding a token budget: every mandatory item and everything it depends on is always included, then optional items by descending priority (each with the dependencies it pulls in) while they fit. Token counts come from the caller or from o200k_base / cl100k_base; any other tokenizer name returns unsupported (there is no Claude tokenizer, so nothing is estimated). Greedy by priority, not an optimal knapsack; per-item counts are summed and do not model merges across item boundaries (use perItemOverhead for separators). Does not summarize or rewrite items.
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/context-pack
security:
- x402: []
- apiKey: []
requestBody:
required: true
content:
application/json:
schema:
type: object
additionalProperties: false
required:
- items
- budget
properties:
items:
type: array
items:
type: object
additionalProperties: false
properties:
id:
type: string
maxLength: 100
minLength: 1
description: Unique id.
text:
type: string
maxLength: 100000
description: Content to count when tokens is not given.
tokens:
type: integer
minimum: 0
maximum: 100000000
description: Caller-supplied token count; always accepted and used in preference to counting text.
priority:
type: number
minimum: -1000000
maximum: 1000000
description: Higher is packed first among optional items. Default 0.
mandatory:
type: boolean
description: Always included, with its dependencies; if they cannot fit the result is fail.
dependsOn:
type: array
items:
type: string
maxLength: 100
maxItems: 50
description: Ids that must be included whenever this item is.
required:
- id
maxItems: 500
minItems: 1
description: Up to 500 items, 300000 characters of text in total.
budget:
type: integer
minimum: 1
maximum: 100000000
description: Maximum total tokens (including perItemOverhead per included item).
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.
perItemOverhead:
type: integer
minimum: 0
maximum: 100000
description: Tokens added per included item for separators or wrappers. Default 0.
example:
items:
- id: system
tokens: 300
mandatory: true
- id: schema
tokens: 500
dependsOn:
- system
priority: 5
- id: history
tokens: 4000
priority: 1
- id: notes
text: Customer prefers email.
priority: 3
budget: 1000
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.'
budget:
type: integer
usedTokens:
type: integer
description: Total of included items; never above budget when status is pass.
remainingTokens:
type: integer
included:
type: array
items:
type: object
additionalProperties: false
properties:
id:
type: string
tokens:
type: integer
reason:
type: string
enum:
- mandatory
- dependency
- priority
maxItems: 500
description: In input order.
excluded:
type: array
items:
type: object
additionalProperties: false
properties:
id:
type: string
tokens:
type: integer
reason:
type: string
enum:
- over-budget
needsTokens:
type: integer
description: Cost of this item plus the dependencies it would pull in.
maxItems: 500
mandatoryTokens:
type: integer
description: Cost of the mandatory items and their dependencies.
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:
- Context Pack
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