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X402 Amount Budget Check
x402
X402 Amount Budget Check is a paid API for AI agents from api.delx.ai, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-15).
Validates a raw payment amount against a caller-supplied maximum budget, returning an explicit accept/reject decision with mismatch reasoning for x402 payment challenges.
Price / call$0.001
Success—
StatusUnknown
How this service works
X402 Amount Budget Check: X402 Amount Budget Check checks challenge raw amount against an exact buyer call budget from bounded caller-supplied values without an external provider. Call X402 Amount Budget Check before paying for or accepting an x402 or agent delivery assembled from caller-supplied challenge and result metadata. Returns contract-specific checks, normalized evidence, mismatch reasons, and an explicit acceptance or rejection status for X402 Amount Budget Check as versioned determin…
Output
Returns a structured response containing: an explicit acceptance or rejection status, contract-specific validation checks, normalized evidence of the comparison, and mismatch reasons explaining why the amount was rejected (if applicable). The decision is deterministic and versioned, derived solely from the two caller-supplied raw values.
Example use cases
Pre-payment x402 budget gate
“We're about to pay an x402 challenge with a raw amount of '2000000'. Our budget cap is '1500000'. Check whether it fits and tell me if it's rejected and why.”
Agent delivery cost approval
“An agent just returned a delivery challenge quoting raw amount '750000'. My maximum allowed spend per call is '1000000'. Validate that amount against my budget and give me the acceptance status.”
Automated micropayment overspend guard
“Before my workflow approves any x402 micropayment, verify that the raw amount '9999999' doesn't exceed the maximum '5000000' — return the normalized evidence and any mismatch reasons so I can log them.”
Technical details
Endpoint
POSThttps://api.delx.ai/api/v1/x402/x402-amount-budget-checkWhen to prefer
Use this endpoint when you need a deterministic, no-external-dependency check of an x402 raw payment amount against a caller-defined budget cap before authorizing a payment or accepting an agent delivery. Prefer it over ad-hoc client-side comparisons when you need structured rejection reasons, normalized evidence, and a versioned audit-ready decision rather than a simple boolean.
Side effects
- Missing amount_raw or maximum_raw — endpoint requires both fields to compute a result
- Non-numeric or malformed raw strings may cause a validation error or unexpected rejection
- Values exceeding maxLength of 8192 characters will be rejected
- Network or service unavailability returning a non-200 response
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| amount_raw | string | Amount Raw supplied to X402 Amount Budget Check; used only for this bounded calculation and processed in memory without retention. |
| maximum_raw | string | Maximum Raw supplied to X402 Amount Budget Check; used only for this bounded calculation and processed in memory without retention. |
Output
Schema · Response
{
"type": "json",
"example": {
"result": {
"amount_raw": "1000",
"maximum_raw": "2000",
"within_budget": true
},
"schema": "delx/util-x402-amount-budget-check/v1",
"status": "pass",
"evidence": {
"retained": false,
"input_sha256": "95ec59ab3108f4c8d18b157c563dcdebd3f620f744be1691dbc78948f24b6667",
"external_calls": 0
},
"operation": "delivery_contract:x402_amount_budget_check"
}
}Tags
x402
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