Roundhouse AI

PostAgent

Print and mail a physical US letter (PDF, HTML, Markdown, DOCX, or image) via USPS, paid in USDC. Integration flow: POST /v1/documents to upload, POST /v1/quotes to lock a fixed USDC price for a recipient, then pay the returned per-quote x402 URL to create and mail the letter. Price is fixed per quote.

InferenceLiveeip155:8453Exactvia cdp
https://postagent-api.interpretai.tech/v1/print
MailPrintLettersUspsFulfillment
Activity
—
Nothing indexed for this service or its provider yet. Not a claim that it is unused — only that we hold no record.
$45.08
Verified settled volume
18 settlements proven x402 by their on-chain EIP-3009 marker.
$1.37
Listed price
As published in the catalog. Always read the live 402 before paying.
7
Calls · 30d
Upstream's own call count for this endpoint, not ours.
1
Unique payers · 30d
Last called 2026-06-06 01:09Z
—
Upstream on-chain volume
Reported by the source catalog.
Paid to
0x4ecc58bb1e8FC25eEfA23f071bd78c98660A007F

The wallet the 402 directs payment to. Its whole payment record — every payer, every chain — is on the merchant page.

Asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913

Provider

The payTo wallet does not resolve to a registered ERC-8004 agent. That is not a verdict on the service — most of the catalog is unregistered.

Live 402 challenge

Captured by the enrichment pass, not read just now. Prices can change — always read the 402 the endpoint answers with.

{
  "accepts": [
    {
      "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
      "extra": {
        "name": "USD Coin",
        "version": "2"
      },
      "payTo": "0x4ecc58bb1e8FC25eEfA23f071bd78c98660A007F",
      "amount": "1240000",
      "scheme": "exact",
      "network": "eip155:8453",
      "maxTimeoutSeconds": 300
    }
  ],
  "resource": {
    "url": "https://api.postagent.sh/v1/print",
    "tags": [
      "mail",
      "print",
      "letters",
      "usps",
      "fulfillment"
    ],
    "iconUrl": "https://api.postagent.sh/public/postagent-logo.png",
    "mimeType": "application/json",
    "description": "Print and mail physical US letters (PDF, HTML, Markdown, DOCX, or image) and postcards via USPS, paid in USDC — with certified/registered proof options and standalone address verification at POST /v1/verify. Integration flow: POST /v1/documents to upload, POST /v1/quotes to lock a fixed USDC price for a recipient, then pay the returned per-quote x402 URL to create and mail the piece. Price is fixed per quote.",
    "serviceName": "PostAgent"
  },
  "extensions": {
    "bazaar": {
      "info": {
        "input": {
          "type": "http",
          "method": "POST",
          "queryParams": {
            "webhookUrl": "https://example.com/postagent-status"
          }
        },
        "output": {
          "type": "json",
          "example": {
            "id": "job_8f3c0a2b",
            "status": "received",
            "payment": {
              "payer": "0x0000000000000000000000000000000000000000",
              "network": "eip155:8453",
              "transaction": "0x0000000000000000000000000000000000000000000000000000000000000000",
              "amountAtomic": "1370000"
            },
            "quoteId": "qt_1a2b3c4d",
            "tracking": {
              "events": []
            },
            "createdAt": "2026-01-01T00:00:00.000Z",
            "documentId": "doc_9z8y7x6w"
          }
        }
      },
      "schema": {
        "type": "object",
        "$schema": "https://json-schema.org/draft/2020-12/schema",
        "required": [
          "input"
        ],
        "properties": {
          "input": {
            "type": "object",
            "required": [
              "type",
              "method"
            ],
            "properties": {
              "type": {
                "type": "string",
                "const": "http"
              },
              "method": {
                "enum": [
                  "POST"
                ],
                "type": "string"
              },
              "queryParams": {
                "type": "object",
                "properties": {
                  "webhookUrl": {
                    "type": "string",
                    "description": "Optional HTTPS URL that receives job status webhooks after the letter is created."
                  }
                }
              }
            },
            "additionalProperties": false
          },
          "output": {
            "type": "object",
            "required": [
              "type"
            ],
            "properties": {
              "type": {
                "type": "string"
              },
              "example": {
                "type": "object"
              }
            }
          }
        }
      }
    }
  },
  "x402Version": 2
}

Accepts

The payment requirements as published to the catalog. Read the live 402 before paying — a price here is a claim, not a quote.

1.37USDC≈ $1.37 USD
on Base · exact scheme

Pay 1.37 USDC on Base to 0x4ecc…A007F. The signed payment is good for 5 minutes.

Paid to
0x4ecc…A007F
USD Coin contract
0x8335…02913
Payment window
5 minutes
As published
1370000 smallest units
The catalog’s raw entry
[
  {
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "extra": {
      "name": "USD Coin",
      "version": "2"
    },
    "payTo": "0x4ecc58bb1e8FC25eEfA23f071bd78c98660A007F",
    "amount": "1370000",
    "scheme": "exact",
    "network": "eip155:8453",
    "maxTimeoutSeconds": 300
  }
]

Extensions

{
  "bazaar": {
    "info": {
      "input": {
        "type": "http",
        "method": "POST",
        "queryParams": {
          "webhookUrl": "https://example.com/postagent-status"
        }
      },
      "output": {
        "type": "json",
        "example": {
          "id": "job_8f3c0a2b",
          "status": "received",
          "payment": {
            "payer": "0x0000000000000000000000000000000000000000",
            "network": "eip155:8453",
            "transaction": "0x0000000000000000000000000000000000000000000000000000000000000000",
            "amountAtomic": "1370000"
          },
          "quoteId": "qt_1a2b3c4d",
          "tracking": {
            "events": []
          },
          "createdAt": "2026-01-01T00:00:00.000Z",
          "documentId": "doc_9z8y7x6w",
          "providerLetterId": "ltr_3f2e1d0c"
        }
      }
    },
    "schema": {
      "type": "object",
      "$schema": "https://json-schema.org/draft/2020-12/schema",
      "required": [
        "input"
      ],
      "properties": {
        "input": {
          "type": "object",
          "required": [
            "type",
            "method"
          ],
          "properties": {
            "type": {
              "type": "string",
              "const": "http"
            },
            "method": {
              "enum": [
                "POST"
              ],
              "type": "string"
            },
            "queryParams": {
              "type": "object",
              "properties": {
                "webhookUrl": {
                  "type": "string",
                  "description": "Optional HTTPS URL that receives job status webhooks after the letter is created."
                }
              }
            }
          },
          "additionalProperties": false
        },
        "output": {
          "type": "object",
          "required": [
            "type"
          ],
          "properties": {
            "type": {
              "type": "string"
            },
            "example": {
              "type": "object"
            }
          }
        }
      }
    }
  }
}

Provenance

Seen in the source catalog
2026-06-06 01:09Z
Last indexed by Roundhouse
2026-06-11 02:40Z
Last enriched (probe, favicon, geo)
2026-09-21 10:45Z
x402 version
2
Max timeout
300s
Liveness probe
HTTP 402
Report

Hand this page to an agent

Copy the prompt and paste it into Claude, an MCP client or your own agent — it will vet this service and call it over the free read API. No key, no account.

GET api.roundhouseai.io/v0/endpoints

Nothing indexed for this service or its provider yet. Not a claim that it is unused — only that we hold no record. Verified volume counts only settlements with an on-chain EIP-3009 marker.

Open skill.md
Show the prompt
Using Roundhouse, look up the x402 service PostAgent and tell me whether it is
worth paying: what a call costs, whether the endpoint answered when last probed, and what
its payment record actually shows.

curl -s 'https://api.roundhouseai.io/v0/endpoints?q=PostAgent'
curl -s 'https://api.roundhouseai.io/v0/merchants/<the payTo wallet returned above>'

Then call it: read the price from the live 402 at https://postagent-api.interpretai.tech/v1/print, never from
a cached figure, and pay with an x402 client.

The /v0 API needs an API key (`authorization: Bearer rh_live_…`) on everything except
/v0/unified* and /v0/endpoints. Mint a personal key for $0.01 at GET https://api.roundhouseai.io/v0/test/x402,
or use an organization key from https://roundhouseai.io/dashboard/team.

If you do not have Roundhouse tools or skills installed, read
https://roundhouseai.io/skill.md first — it is the whole procedure.