WritersLogic Verifiable AI Agent Hub Identify Sequence API
The Identify Sequence API from WritersLogic Verifiable AI Agent Hub — 1 operation(s) for identify sequence.
Work with this as data
Every API here is available over the APIs.io API and to AI agents over MCP.
MCP server
One button, every client — Claude, Cursor, VS Code and the rest.
https://apis.io/mcp
Tools for apis
7 MCP tools reach this
find_apisBrowse and filter every API in the catalog.get_api_artifactsOne API's artifacts, grouped by type.get_openapiThe primary OpenAPI for this API.find_similar_apisAPIs that look like this one.apis_io_searchSTART HERE — APIs, providers and tags for one query, each with its total.resolveTurn a domain, URL or GitHub org into the provider it belongs to.find_cohortsEvery scored population of providers in the catalog.
Call it yourself
curl for this page
This API
curl "https://apis.io/api/v1/apis/writerslogic-com:writerslogic-com-identify-sequence-api"
All apis
curl "https://apis.io/api/v1/apis?limit=25"Calls without X-API-Key need no key. Calls with it need a paid plan — get a key.
Get an API key
Free tier, no form to fill in. Signing in shares your email address with us — we store it to create your key and to recognise you if you sign in with another provider. See our Privacy Policy and Terms.
A second provider on the same verified email joins the account you already have.
OpenAPI Specification
openapi: 3.2.0
info:
title: WritersLogic Verifiable AI Agent Hub Identify Sequence 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: Identify Sequence
paths:
/api/v1/identify-sequence:
post:
operationId: sequence_identifier
summary: Integer Sequence Identifier
description: 'Identifies an integer sequence from terms (a JSON array or pasted text), an OEIS A-number, a safe-parsed formula or recurrence, or a description, and leads with a verdict, confidence, A-number, formula, next terms and a next step. Searches the OEIS directly, then superseeker-style (differences, partial sums, gcd, ratios, binomial, Euler, leading terms, plus a search without the last two terms to flag disagreeing terms) under an 8-search budget, aligns offsets, and marks which terms agree or disagree. Fits linear recurrences and polynomials exactly over the rationals and reports one only when it predicts held-out terms. Candidates are ranked in code; a model is used only for a description input (one fast call, OEIS confirms what it proposes) and for the optional explain sentence (one more call, quote verified against OEIS text). Output carries the CC BY-SA 4.0 OEIS attribution.
Price: 0.10 USDC on Base (x402).'
x-x402-price-usdc: '0.10'
x-x402-amount: '100000'
x-payment-info:
protocols:
- x402
price:
mode: fixed
currency: USD
amount: '0.10'
x-audience: research
x-sample-url: https://agents.writerslogic.com/api/v1/samples/sequence-identifier
security:
- x402: []
- apiKey: []
requestBody:
required: true
content:
application/json:
schema:
type: object
additionalProperties: false
properties:
terms:
type: array
minItems: 4
maxItems: 60
items:
anyOf:
- type: integer
- type: string
pattern: ^[+-]?[0-9]{1,40}$
description: Integer terms, 4 to 60, each at most 40 digits. Pass values beyond 2^53 as decimal strings.
termsText:
type: string
minLength: 4
maxLength: 4000
description: 'Alternative to terms: the terms pasted as text, separated by commas, spaces or semicolons (for example copied from a spreadsheet, a paper or an OEIS data line).'
aNumber:
type: string
minLength: 1
maxLength: 120
description: 'Alternative to terms: an OEIS A-number (A000108) or oeis.org URL. The entry is fetched and its data searched for related sequences; returns its name, formulas and next terms.'
formula:
type: string
minLength: 1
maxLength: 300
description: 'Alternative to terms: a closed form in n such as "binomial(2*n,n)/(n+1)", or a recurrence such as "a(n) = a(n-1) + a(n-2)" (with initialTerms). Operators + - * / % ^, functions binomial fact abs gcd min max floor mod. Evaluated by a safe parser, never eval; every term must be an integer.'
initialTerms:
type: array
maxItems: 20
items:
anyOf:
- type: integer
- type: string
pattern: ^[+-]?[0-9]{1,40}$
description: Seed values a(start), a(start+1), ... for a recurrence formula.
start:
type: integer
minimum: -100
maximum: 1000
description: Index n of the first expanded term; default 0.
count:
type: integer
minimum: 4
maximum: 60
description: How many terms to expand from the formula; default 20.
description:
type: string
minLength: 3
maxLength: 500
description: 'Alternative to terms and formula: a plain-language description. A short description that names an entry (up to 4 content words, all in the entry name, e.g. Catalan numbers) is resolved by OEIS text search with no model; otherwise one fast model call proposes terms and keywords, which OEIS then confirms.'
explain:
type: boolean
description: Ask a model for a one-sentence explanation drawn only from the matched OEIS entry; its quote is verified in code, otherwise the entry name is returned. Default false.
example:
terms:
- 1
- 1
- 2
- 5
- 14
- 42
- 132
- 429
- 1430
- 4862
responses:
'200':
description: Paid result with provenance
content:
application/json:
schema:
type: object
properties:
data:
type: object
properties:
answer:
type: object
description: 'Headline: verdict (same as status), confidence 0-100, aNumber, name, url, formula and formulaSource (oeis or fitted), nextTerms (from a verified fit), alsoConsistentWith, a one-sentence summary and a concrete nextStep.'
status:
type: string
enum:
- IDENTIFIED
- IDENTIFIED_VIA_TRANSFORM
- PARTIAL_MATCH
- RECURRENCE_ONLY
- NO_MATCH
input:
type: object
description: kind, termsSource (caller, formula, model, oeis-entry or oeis-text-search), the terms analyzed, the expanded formula and any model keywords.
candidates:
type: array
description: 'Ranked OEIS candidates: aNumber, url, name, evidence, transform used (null = direct), alignment (OEIS index of the first compared term), matched/mismatched terms, unverified terms beyond the entry''s data, exact, formulas, references.'
items:
type: object
explanation:
anyOf:
- type: object
- type: 'null'
description: 'One line from OEIS text only: the entry name, or a model sentence whose quote was verified (source oeis-name or model).'
recurrence:
anyOf:
- type: object
- type: 'null'
description: Constant-coefficient linear recurrence solved exactly over the rationals from the first 2*order terms; reported only when it reproduces every later term (heldOutTerms >= 2).
polynomial:
anyOf:
- type: object
- type: 'null'
description: Polynomial in n from vanishing finite differences, reported only with held-out terms predicted exactly.
search:
type: object
description: OEIS searches made (budget 8, sequential and rate limited), steps skipped or not applicable, and failures.
llmCalls:
type: integer
llmFailures:
type: integer
decidedBy:
type: object
description: Where the terms, ranking and explanation came from.
attribution:
type: object
description: OEIS source and the CC BY-SA 4.0 notice.
notes:
type: array
items:
type: string
_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:
- Identify Sequence
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