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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
$0.0000
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.

Base URL
https://gateway.apiosk.com/mailpulse
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.
$3.45 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.
$0.0057 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
$3.45 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
$3.45 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}
$0.0057 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
$0.0057 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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