Upload template
01Detect variables, check the address window, and keep legal copy out of deploy cycles.
Sendaway 
European letter delivery without postal plumbing
Turn Word templates, spreadsheets, and PDFs into real delivered letters with one clean API. The API handles validation, rendering, provider handoff, and status tracking so product teams can ship mail like software.
Send letters from the data you already have
Follow the document until it becomes mail.
The important handoffs stay visible: validate the template, attach rows, render through the API, and dispatch a tracked letter without hiding the messy parts in glue code.
Map source data
02CSV, XLS, and XLSX rows become stable IDs with explicit template and address mappings.
Render and queue
03Call one letter endpoint for rendered templates, or hand over a finished PDF.
Send letter
04Provider dispatch and status lookup stay tied to the same token-scoped job.
A developer API that behaves like a product
One action per endpoint, scoped by API key.
Upload templates, attach sources, render PDFs, send letters, and check jobs through plain JSON and multipart endpoints. Errors are structured, status lookups are explicit, and sandbox servers use the same request shape as live delivery.
Clear auth: Bearer API keys scope every request.
Clear failures: one JSON error format with useful messages.
Clear modes: production and sandbox are server settings, not separate client code paths.
letter-job.ts
const response = await fetch("/v1/letters/from-template", {
method: "POST",
headers: {
"Content-Type": "application/json",
"Authorization": `Bearer ${process.env.SENDAWAY_API_KEY}`
},
body: JSON.stringify({
templateId: "invoice-reminder",
sourceId: "customers-june",
rowIds: ["row-1042", "row-1043"],
options: {
printColor: "bw",
printSides: "duplex",
deliverySpeed: "standard"
}
})
});
const job = await response.json(); letter job created, rendered, and queued for provider dispatch
OpenAPI, raw schema, and developer guide
Documentation for every site you run.
Multisite API docs let sandbox, production, and customer-specific deployments expose the right OpenAPI UI, raw schema, and long-form developer documentation without changing the integration model.
/docs
Sandbox api.sandbox.sendaway.local
Production api.sendaway.local
Customer site api.eu-west.customer.tld
Planning calculator
See how cheap a letter run can be before you wire the API.
This estimate mirrors Sendaway's built-in planning table: base print and postage, international uplift, optional color, simplex, express, and tracking additions. Final provider invoices can differ.
Total estimate EUR 0.00
Average EUR 0.00
Domestic 0
International 0