The Calldata Decode API from WritersLogic Verifiable AI Agent Hub — 1 operation(s) for calldata decode.
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openapi: 3.2.0
info:
title: WritersLogic Verifiable AI Agent Hub Calldata Decode 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: Calldata Decode
paths:
/api/v1/calldata-decode:
post:
operationId: calldata_decode
summary: Decode EVM calldata, return data, revert data or event logs against an ABI
description: 'Decodes hex calldata (selector plus arguments), function return data, revert data or an event log against a caller-supplied ABI using ethers, for agents inspecting a transaction before signing or after it fails. Handles tuples, nested and dynamic arrays, bytes and strings, and the built-in Error(string) and Panic(uint256) reverts; a strict re-encode check flags trailing bytes, dirty padding and non-canonical offsets. Does not look up unknown selectors, fetch ABIs, simulate the call or judge whether the transaction is safe; a selector missing from the ABI returns unknown.
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/calldata-decode
security:
- x402: []
- apiKey: []
requestBody:
required: true
content:
application/json:
schema:
type: object
additionalProperties: false
required:
- abi
- data
properties:
abi:
type: array
minItems: 1
maxItems: 200
items:
description: JSON ABI fragment object or human-readable signature string.
description: Fragments of the contract ABI (JSON objects or human-readable strings).
mode:
type: string
enum:
- call
- return
- error
- event
description: 'Default call: data is selector plus arguments.'
data:
type: string
maxLength: 40002
description: 0x-prefixed hex, whole bytes; up to 20000 bytes.
function:
type: string
maxLength: 200
description: 'mode return: function name or signature.'
topics:
type: array
maxItems: 4
items:
type: string
maxLength: 66
description: 'mode event: 0x topics, topic0 first.'
example:
abi:
- function transfer(address to, uint256 amount) returns (bool)
data: '0xa9059cbb000000000000000000000000000000000000000000000000000000000000dead0000000000000000000000000000000000000000000000000000000000000005'
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.'
mode:
type: string
selector:
type: string
signature:
type: string
name:
type: string
args:
type: array
items:
type: object
properties:
name:
type: string
type:
type: string
value:
description: 'Decoded value: integers as decimal strings, bytes and addresses as hex, tuples as lists of {name,type,value}.'
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:
- Calldata Decode
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