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MailPulse

PulseNetworkby PulseNetwork · Intelligence APIs, Data, AI Agents

Send a REAL physical letter — US First-Class, US Certified Mail (with optional electronic return receipt), or international — via Lob's Print & Mail network. ACTION API, not a data lookup: paying causes a real letter to be printed and mailed. Flow: free quote -> paid send -> optional status/tracking poll. Pay-per-call via x402 on Base.

communicationsfederated
Price per request
$0.0050
About

Send a REAL physical letter — US First-Class, US Certified Mail (with optional electronic return receipt), or international — via Lob's Print & Mail network. ACTION API, not a data lookup: paying causes a real letter to be printed and mailed. Flow: free quote -> paid send -> optional status/tracking poll. Pay-per-call via x402 on Base. Part of PulseNetwork, operated by The Aslan Group LLC. Apiosk indexes this federated listing and adds ref=apiosk for attribution; calls and x402 payments go directly to PulseNetwork.

Hosted by the provider

Apiosk lists this API but does not proxy it. Call the provider's URL directly and pay them over x402 — Apiosk never sits between you and the response.

Open provider →

ResourceDescription
https://mailpulse.theaslangroupllc.com/api/verify-address?ref=apiosk Verify a mailing address before sending physical mail through it. Wraps Lob's US and international address verification engines: standardizes the address, flags undeliverable/incomplete addresses, and returns a deliverability verdict. Run this before /api/quote and /api/letters to avoid paying to print and post a letter that will bounce. Open
https://mailpulse.theaslangroupllc.com/api/letters?ref=apiosk Send a real physical letter (US first-class, US certified, or international) via Lob's Print & Mail network. This is an ACTION endpoint, not a data lookup: it prints and mails a physical letter to the destination address once payment settles. Requires a quote_id from POST /api/quote (free) and a client_request_id for idempotency. The submitted "from" address is the sender of record. Open
https://mailpulse.theaslangroupllc.com/api/letters/{id}?ref=apiosk Check the status and tracking of a physical letter previously sent via POST /api/letters. Returns render status, expected delivery date, and (for certified mail) the USPS tracking number. Open
Technical Specs
Auth MethodNone (x402 payment proof only)
Response FormatJSON
Endpoints5
Endpoints
MethodPathDescriptionCost
GET /api/health Free liveness check. Reports whether the service is currently in test or live Lob mode.
Free default
 View details
POST /api/letters Send a real physical letter (US first-class, US certified, or international) via Lob's Print & Mail network. This is an ACTION endpoint, not a data lookup: it prints and mails a physical letter to the destination address once payment settles. Requires a quote_id from POST /api/quote (free) and a client_request_id for idempotency. The submitted "from" address is the sender of record.
$3.00 default
 View details
GET /api/letters/{id} Check the status and tracking of a physical letter previously sent via POST /api/letters. Returns render status, expected delivery date, and (for certified mail) the USPS tracking number.
$0.0050 default
 View details
POST /api/quote FREE — no x402 gate, no Lob call. Returns the exact fixed price for the requested service, a signed quote_id (HMAC, tamper-evident), and a 15-minute expiry. Copy the response's `order`, `quote_id`, `issued_at` and `amount_micro` verbatim into POST /api/letters.
Free default
 View details
POST /api/verify-address Verify a mailing address before sending physical mail through it. Wraps Lob's US and international address verification engines: standardizes the address, flags undeliverable/incomplete addresses, and returns a deliverability verdict. Run this before /api/quote and /api/letters to avoid paying to print and post a letter that will bounce.
$0.01 default
 View details
Endpoint documentation
GET/api/health
Free default
Description

Free liveness check. Reports whether the service is currently in test or live Lob mode.

Documentation

Liveness + current mode

Free liveness check. Reports whether the service is currently in test or live Lob mode.

**Price:** Free per call

Calls go directly to PulseNetwork. Paid routes use the live x402 challenge; Apiosk never rewrites payTo or settles the payment.

Pricing
Free default
Authentication

Free PulseNetwork route; no API key, wallet or payment required.

Links
External documentation ↗OpenAPI / Swagger ↗
POST/api/letters
$3.00 default
Description

Send a real physical letter (US first-class, US certified, or international) via Lob's Print & Mail network. This is an ACTION endpoint, not a data lookup: it prints and mails a physical letter to the destination address once payment settles. Requires a quote_id from POST /api/quote (free) and a client_request_id for idempotency. The submitted "from" address is the sender of record.

Documentation

Send a physical letter (THE paid action)

Prints and mails a real physical letter via Lob once payment settles. Requires a quote_id from POST /api/quote (recomputed and verified server-side; mismatched or expired quotes are rejected with 400 BEFORE payment is requested) and a client_request_id (8-128 chars) for idempotency — replaying the same client_request_id with the same order returns the original result without double-charging or double-sending. Price varies by service: standard $3.00, certified $12.00, certified_return_receipt $14.00, international $5.00 (see /pricing.md). Every order is capped at $25.00 total.

**Price:** $3 USDC per call

Calls go directly to PulseNetwork. Paid routes use the live x402 challenge; Apiosk never rewrites payTo or settles the payment.

Pricing
$3.00 default
Authentication

No account or API key. Pay PulseNetwork directly using the live x402 challenge. The challenge is authoritative for price, network, asset and payTo.

Request schema
{
  "properties": {
    "amount_micro": {
      "description": "From POST /api/quote, copied verbatim",
      "type": "string"
    },
    "client_request_id": {
      "description": "Unique per letter. Enables safe retries — replay returns the original result, never a duplicate send.",
      "maxLength": 128,
      "minLength": 8,
      "type": "string"
    },
    "content": {
      "description": "Identical to the quote",
      "type": "object"
    },
    "from": {
      "description": "Sender-of-record address — identical to the quote",
      "type": "object"
    },
    "issued_at": {
      "description": "From POST /api/quote, copied verbatim",
      "type": "string"
    },
    "pages_estimate": {
      "default": 1,
      "maximum": 6,
      "minimum": 1,
      "type": "integer"
    },
    "quote_id": {
      "description": "From POST /api/quote",
      "type": "string"
    },
    "service": {
      "enum": [
        "standard",
        "certified",
        "certified_return_receipt",
        "international"
      ],
      "type": "string"
    },
    "to": {
      "description": "Recipient address — identical to the quote",
      "type": "object"
    }
  },
  "required": [
    "quote_id",
    "issued_at",
    "amount_micro",
    "service",
    "to",
    "from",
    "content",
    "client_request_id"
  ],
  "type": "object"
}
Example request
{
  "amount_micro": "test",
  "client_request_id": "test",
  "content": {},
  "from": {},
  "issued_at": "test",
  "pages_estimate": 1,
  "quote_id": "test",
  "service": "standard",
  "to": {}
}
Links
External documentation ↗OpenAPI / Swagger ↗
GET/api/letters/{id}
$0.0050 default
Description

Check the status and tracking of a physical letter previously sent via POST /api/letters. Returns render status, expected delivery date, and (for certified mail) the USPS tracking number.

Documentation

Letter status / USPS tracking poll

Cheap status/tracking poll for a previously sent letter. Returns render status, expected delivery date, and (for certified mail) the USPS tracking number.

**Price:** $0.005 USDC per call

Calls go directly to PulseNetwork. Paid routes use the live x402 challenge; Apiosk never rewrites payTo or settles the payment.

Pricing
$0.0050 default
Authentication

No account or API key. Pay PulseNetwork directly using the live x402 challenge. The challenge is authoritative for price, network, asset and payTo.

Parameters
{
  "properties": {
    "id": {
      "description": "Lob letter id returned by POST /api/letters",
      "pattern": "^ltr_[a-zA-Z0-9]+$",
      "required": true,
      "type": "string",
      "x-parameter-location": "path"
    }
  },
  "required": [
    "id"
  ],
  "type": "object"
}
Links
External documentation ↗OpenAPI / Swagger ↗
POST/api/quote
Free default
Description

FREE — no x402 gate, no Lob call. Returns the exact fixed price for the requested service, a signed quote_id (HMAC, tamper-evident), and a 15-minute expiry. Copy the response's `order`, `quote_id`, `issued_at` and `amount_micro` verbatim into POST /api/letters.

Documentation

Free price quote for a letter

FREE — no x402 gate, no Lob call. Returns the exact fixed price for the requested service, a signed quote_id (HMAC, tamper-evident), and a 15-minute expiry. Copy the response's order, quote_id, issued_at and amount_micro verbatim into POST /api/letters.

**Price:** Free per call

Calls go directly to PulseNetwork. Paid routes use the live x402 challenge; Apiosk never rewrites payTo or settles the payment.

Pricing
Free default
Authentication

Free PulseNetwork route; no API key, wallet or payment required.

Request schema
{
  "properties": {
    "content": {
      "description": "{ html: string } or { file_url: string } — exactly one",
      "type": "object"
    },
    "from": {
      "description": "Sender-of-record address",
      "type": "object"
    },
    "pages_estimate": {
      "default": 1,
      "maximum": 6,
      "minimum": 1,
      "type": "integer"
    },
    "service": {
      "enum": [
        "standard",
        "certified",
        "certified_return_receipt",
        "international"
      ],
      "type": "string"
    },
    "to": {
      "description": "Recipient address",
      "type": "object"
    }
  },
  "required": [
    "service",
    "to",
    "from",
    "content"
  ],
  "type": "object"
}
Example request
{
  "content": {},
  "from": {},
  "pages_estimate": 1,
  "service": "standard",
  "to": {}
}
Links
External documentation ↗OpenAPI / Swagger ↗
POST/api/verify-address
$0.01 default
Description

Verify a mailing address before sending physical mail through it. Wraps Lob's US and international address verification engines: standardizes the address, flags undeliverable/incomplete addresses, and returns a deliverability verdict. Run this before /api/quote and /api/letters to avoid paying to print and post a letter that will bounce.

Documentation

Verify a mailing address (US + international)

Deliverability check before you pay to print. Wraps Lob's US Address Verification (USPS CASS-based) and international address verification. Returns a deliverability verdict and a standardized address. Run this before /api/quote and /api/letters to reduce the risk of paying to mail an undeliverable address.

**Price:** $0.01 USDC per call

Calls go directly to PulseNetwork. Paid routes use the live x402 challenge; Apiosk never rewrites payTo or settles the payment.

Pricing
$0.01 default
Authentication

No account or API key. Pay PulseNetwork directly using the live x402 challenge. The challenge is authoritative for price, network, asset and payTo.

Request schema
{
  "properties": {
    "address": {
      "properties": {
        "address_city": {
          "type": "string"
        },
        "address_country": {
          "description": "ISO 3166-1 alpha-2, default US",
          "type": "string"
        },
        "address_line1": {
          "type": "string"
        },
        "address_line2": {
          "type": "string"
        },
        "address_state": {
          "type": "string"
        },
        "address_zip": {
          "type": "string"
        },
        "company": {
          "type": "string"
        },
        "name": {
          "type": "string"
        }
      },
      "required": [
        "address_line1"
      ],
      "type": "object"
    }
  },
  "required": [
    "address"
  ],
  "type": "object"
}
Example request
{
  "address": {
    "address_city": "test",
    "address_country": "test",
    "address_line1": "test",
    "address_line2": "test",
    "address_state": "test",
    "address_zip": "test",
    "company": "test",
    "name": "test"
  }
}
Links
External documentation ↗OpenAPI / Swagger ↗
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