Crypto Analysis & Developer Tools · x402 V2

EVM Storage Slot Compute

Use this service when you need this capability: compute mapping or dynamic-array storage slots from supplied Solidity layout inputs.

Price and endpoint

LivePOSTBase USDC

0.01 USDC per call

x402 V2 exact payment on Base mainnet (eip155:8453) using USDC. The HTTP 402 challenge confirms the exact requirements before an authorized payment.

POST https://signalharness.ai/api/agent/services/evm_storage_slot_compute/invoke

Purpose

Compute mapping or dynamic-array storage slots from supplied Solidity layout inputs.

Caller-supplied data is processed deterministically. These tools do not supply live market feeds, query blockchain RPC, host AI models, or verify that supplied history is complete. Payment remains Base USDC for every chain category.

Inputs

Request fields and validation limits
FieldTypeRequiredLimits
storage_slot_requeststringRequiredMinimum length 2; Maximum length 65536

Example request body

{
  "storage_slot_request": "{\"kind\":\"mapping\",\"slot\":\"0\",\"key_type\":\"address\",\"key\":\"0x0000000000000000000000000000000000000001\"}"
}
View complete input schema
{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "type": "object",
  "additionalProperties": false,
  "minProperties": 1,
  "maxProperties": 1,
  "required": [
    "storage_slot_request"
  ],
  "properties": {
    "storage_slot_request": {
      "type": "string",
      "minLength": 2,
      "maxLength": 65536
    }
  }
}

Realistic output shape

Illustrative output from the canonical adapter fixture and schema. It is not a completed paid execution or a current live observation.

{
  "service_id": "evm_storage_slot_compute",
  "evidence_scope": "caller_supplied_data",
  "computed_storage_slot": "{\"key_type\":\"address\",\"kind\":\"mapping\",\"slot\":\"0xada5013122d395ba3c54772283fb069b10426056ef8ca54750cb9bb552a59e7d\"}",
  "warnings": [
    "The caller must supply the correct layout and key encoding."
  ]
}
View complete output schema
{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "type": "object",
  "additionalProperties": false,
  "minProperties": 4,
  "maxProperties": 4,
  "required": [
    "service_id",
    "evidence_scope",
    "computed_storage_slot",
    "warnings"
  ],
  "properties": {
    "service_id": {
      "type": "string",
      "const": "evm_storage_slot_compute",
      "minLength": 24,
      "maxLength": 24
    },
    "evidence_scope": {
      "type": "string",
      "const": "caller_supplied_data",
      "minLength": 20,
      "maxLength": 20
    },
    "computed_storage_slot": {
      "type": "string",
      "minLength": 1,
      "maxLength": 65536
    },
    "warnings": {
      "type": "array",
      "minItems": 1,
      "maxItems": 8,
      "items": {
        "type": "string",
        "minLength": 1,
        "maxLength": 512
      }
    }
  }
}

Execution limits

  • MaxInputBytes: 131072
  • MaxOutputBytes: 131072
  • MaxConcurrentExecutions: 2
  • MaxArtifacts: 0
  • MaxArtifactBytes: 0
  • RateLimitPerMinute: 30
  • MaxNodes: 10000

Timeout: 5000 ms. Full schemas are in OpenAPI.

Copyable unpaid request

This schema-valid request returns the canonical HTTP 402 challenge without executing the service. A payment-capable client validates the challenge, signs only with prior authority and budget, and retries the identical body.

curl -i -X POST https://signalharness.ai/api/agent/services/evm_storage_slot_compute/invoke \
  -H "Content-Type: application/json" \
  --data '{"storage_slot_request":"{\"kind\":\"mapping\",\"slot\":\"0\",\"key_type\":\"address\",\"key\":\"0x0000000000000000000000000000000000000001\"}"}'

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