Api Endpoint

EVM Nonce Gap Check

EVM Nonce Gap Check: calculates the gap between pending and proposed transaction nonces using only bounded caller-supplied values. Call when you need a bounded evm nonce gap check result before signing, submitting, replacing, or accepting an EVM/Base transaction assembled from caller-owned data. Returns normalized transaction evidence, calculated budget or shape findings, and a fail-closed preflight status for EVM Nonce Gap Check as versioned deterministic JSON. Price: $0.001 USDC via x402 on B…

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Offering

Provider: api.delx.ai
Method: POST
Offering type: Api Endpoint
Transport type: http
Category: Blockchain And Crypto
Delivery: Not provided
Pricing model: Not provided
x402 version: 2

Endpoint context

URL: https://api.delx.ai/api/v1/x402/evm-nonce-gap-check
MIME type: application/json
First seen: 2026-10-16T01:51:10.599Z
Last seen: 2026-11-04T04:21:16.712Z
Tags: Base, EVM, preflight

Website

Payment pricing

x402 payment terms are the authoritative price for calling this endpoint.

Payment option 1: 0.001 USDC
Atomic price: 1000 · Network: eip155:8453 · Asset: USDC · Scheme: exact
Payment option 2: 0.001 USDC
Atomic price: 1000 · Network: eip155:8453 · Asset: USDC · Scheme: exact
Payment option 3: 0.001 USDC
Atomic price: 1000 · Network: solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp · Asset: USDC · Scheme: exact

Raw x402 terms

[
  {
    "scheme": "exact",
    "network": "eip155:8453",
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "amount": "1000",
    "payTo": "0x9f8bd9875b3E0b632a24A3A7C73f7787175e73A2"
  },
  {
    "scheme": "exact",
    "network": "eip155:8453",
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "amount": "1000",
    "payTo": "0x9f8bd9875b3E0b632a24A3A7C73f7787175e73A2"
  },
  {
    "scheme": "exact",
    "network": "solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp",
    "asset": "EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v",
    "amount": "1000",
    "payTo": "28heAMpFkeUJsL7o7apiK4oJwZWq2fUHinRwbgYYsemG"
  }
]

Observed health

Status: Healthy
Latest latency: 373 ms
Average latency: 1437 ms
HTTP status: 204
Last checked: 2026-11-02T15:44:38.693Z
Reachability: 100% over 11 checks

Latency is measured to the first response headers. A reachable result does not verify response accuracy or merchant identity.

Input schema

{
  "properties": {
    "body": {
      "$schema": "https://json-schema.org/draft/2020-12/schema",
      "additionalProperties": false,
      "properties": {
        "maximum_gap": {
          "description": "Maximum Gap supplied to EVM Nonce Gap Check; used only for this bounded calculation and processed in memory without retention.",
          "type": "integer"
        },
        "pending_nonce": {
          "description": "Pending Nonce supplied to EVM Nonce Gap Check; used only for this bounded calculation and processed in memory without retention.",
          "type": "integer"
        },
        "proposed_nonce": {
          "description": "Proposed Nonce supplied to EVM Nonce Gap Check; used only for this bounded calculation and processed in memory without retention.",
          "type": "integer"
        }
      },
      "required": [
        "pending_nonce",
        "proposed_nonce",
        "maximum_gap"
      ],
      "type": "object"
    },
    "bodyType": {
      "const": "json",
      "type": "string"
    },
    "method": {
      "const": "POST",
      "type": "string"
    },
    "type": {
      "const": "http",
      "type": "string"
    }
  },
  "required": [
    "type",
    "method",
    "bodyType",
    "body"
  ],
  "type": "object"
}

Output schema

{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "properties": {
    "input": {
      "properties": {
        "body": {
          "$schema": "https://json-schema.org/draft/2020-12/schema",
          "additionalProperties": false,
          "properties": {
            "maximum_gap": {
              "description": "Maximum Gap supplied to EVM Nonce Gap Check; used only for this bounded calculation and processed in memory without retention.",
              "type": "integer"
            },
            "pending_nonce": {
              "description": "Pending Nonce supplied to EVM Nonce Gap Check; used only for this bounded calculation and processed in memory without retention.",
              "type": "integer"
            },
            "proposed_nonce": {
              "description": "Proposed Nonce supplied to EVM Nonce Gap Check; used only for this bounded calculation and processed in memory without retention.",
              "type": "integer"
            }
          },
          "required": [
            "pending_nonce",
            "proposed_nonce",
            "maximum_gap"
          ],
          "type": "object"
        },
        "bodyType": {
          "const": "json",
          "type": "string"
        },
        "method": {
          "const": "POST",
          "type": "string"
        },
        "type": {
          "const": "http",
          "type": "string"
        }
      },
      "required": [
        "type",
        "method",
        "bodyType",
        "body"
      ],
      "type": "object"
    },
    "output": {
      "additionalProperties": true,
      "description": "Versioned bounded first-party JSON result with input evidence; caller data is processed in memory and not retained.",
      "properties": {
        "evidence": {
          "additionalProperties": true,
          "properties": {
            "external_calls": {
              "type": "integer"
            },
            "input_sha256": {
              "type": "string"
            },
            "retained": {
              "type": "boolean"
            }
          },
          "type": "object"
        },
        "operation": {
          "type": "string"
        },
        "result": {
          "additionalProperties": true,
          "properties": {
            "gap": {
              "type": "integer"
            },
            "possible_replacement": {
              "type": "boolean"
            },
            "within_budget": {
              "type": "boolean"
            }
          },
          "type": "object"
        },
        "schema": {
          "type": "string"
        },
        "status": {
          "type": "string"
        }
      },
      "type": "object"
    }
  },
  "required": [
    "input",
    "output"
  ],
  "type": "object"
}