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PostAgent Address Verification API
x402
PostAgent Address Verification API is a paid API for AI agents from postagent-api.interpretai.tech, paid per call via x402, $0.02/call, status unknown (last checked 2026-09-15).
Verifies a postal address for deliverability using CASS standardization (US) or international validation, paid per-call in USDC via x402
Price / call$0.02
Success—
StatusUnknown
How this service works
Verify a postal address for deliverability, paid in USDC. POST a JSON body { "address": { "line1", "city", "state", "zip", "country?" } } with an X-PAYMENT header to get CASS-standardized deliverability (US) or international verification (2-letter non-US country code). Flat price per call; the same request without a payment header returns the 402 challenge.
Output
Returns a CASS-standardized deliverability result for US addresses (line1, city, state, ZIP corrected and confirmed deliverable or not), or an international verification result for non-US addresses identified by a 2-letter ISO country code. On success, the agent receives structured address validation data. Without a valid payment header, the endpoint returns a 402 payment challenge with pricing details.
Example use cases
Validate customer address before mailing
“I'm about to send promotional postcards to our customer list. Can you check each address to make sure they're actually deliverable before we commit to printing them?”
Standardize international shipping addresses
“We've got a bunch of orders from Canada and UK customers. Can you validate and standardize all their shipping addresses so we know they'll actually receive their packages?”
Confirm ZIP code and city match
“I just received a new customer signup with address '456 Oak Ave, Denver, CO 80202'. Can you verify that ZIP code is correct for Denver and the address will actually receive mail?”
Technical details
Endpoint
GEThttps://postagent-api.interpretai.tech/v1/verifyWhen to prefer
Choose this endpoint when you need per-call, pay-as-you-go postal address verification with CASS standardization for US addresses or international validation for non-US addresses, especially in agentic workflows that already handle x402 micropayments in USDC. Ideal for validating addresses before triggering physical mail delivery (e.g. via the sibling print-and-mail endpoint on the same platform). Prefer this over bulk address validation APIs when individual address checks are needed on-demand without a subscription.
Side effects
- Missing or invalid X-PAYMENT header returns 402 with payment challenge
- Malformed address object (missing required fields like line1) returns 400 bad request
- Unsupported country code or unrecognized address format returns validation error
- Non-deliverable address returns a response indicating undeliverable status rather than an error
- Network timeout or service unavailability returns 5xx error
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| inputrequired | object | |
| output | object |
Tags
x402
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