Design document layouts in the template editor, send your data to the API, and receive PDFs. Upload Excel or Word templates to output Excel, Word or CSV as well.
Building document generation and delivery into your application creates ongoing development and operational overhead. DocRelay removes these challenges in one service.
Challenge
Generating PDFs requires building, operating, and scaling servers that run headless browsers or LibreOffice.
How DocRelay solves it
Issue documents through an API alone. No rendering infrastructure to build or operate.
Challenge
Implementing and maintaining Japanese fonts, line-breaking rules, page breaks, and line items that span pages takes significant effort.
How DocRelay solves it
A typesetting engine for Japanese business documents is built in.
Challenge
Even minor layout changes require modifying and releasing the application.
How DocRelay solves it
Edit and publish in the template editor; changes take effect immediately.
Challenge
Asynchronous processing and storage, delivery, and deletion of generated files must be built separately.
How DocRelay solves it
Batch issuance, webhook notifications on completion, expiring URLs, and automatic deletion by retention period are included.
Challenge
Generated files keep accumulating, increasing storage capacity, cost, and deletion overhead.
How DocRelay solves it
Set a retention period per issuance; files are deleted automatically when it ends. No capacity to manage.
Challenge
It is difficult to prove after the fact that an issued document has not been altered.
How DocRelay solves it
Verify authenticity with a tamper-detection log that applies blockchain technology and published daily hashes.
Call POST /v1/renders with the template name, output format and data. If the document is ready within the wait time, it is returned immediately; otherwise you receive an ID and a webhook on completion. Test environment API keys use the latest version, including drafts. Production API keys use the published version.
Node.js
Python
PHP
Ruby
Go
RESTNothing to run on your side
const res = await fetch('https://api.docrelay.jp/v1/renders', {
method: 'POST',
headers: {
Authorization: `Bearer ${process.env.DOCRELAY_API_KEY}`,
'Content-Type': 'application/json',
'Idempotency-Key': 'inv_88',
},
body: JSON.stringify({
template: 'invoice',
format: 'pdf',
data: { customer: { name: 'Acme Inc.' }, total: 128000 },
wait: 10,
link: { expires_in: 86400 },
}),
})
// 200 + expiring URL within wait seconds; otherwise 202 and a DocRelay webhook on completionimport os
import requests
res = requests.post(
"https://api.docrelay.jp/v1/renders",
headers={
"Authorization": f"Bearer {os.environ['DOCRELAY_API_KEY']}",
"Idempotency-Key": "inv_88",
},
json={
"template": "invoice",
"format": "pdf",
"data": {"customer": {"name": "Acme Inc."}, "total": 128000},
"wait": 10,
"link": {"expires_in": 86400},
},
)
# 200 + expiring URL within wait seconds; otherwise 202 and a DocRelay webhook on completion$ch = curl_init('https://api.docrelay.jp/v1/renders');
curl_setopt_array($ch, [
CURLOPT_POST => true,
CURLOPT_RETURNTRANSFER => true,
CURLOPT_HTTPHEADER => [
'Authorization: Bearer ' . getenv('DOCRELAY_API_KEY'),
'Content-Type: application/json',
'Idempotency-Key: inv_88',
],
CURLOPT_POSTFIELDS => json_encode([
'template' => 'invoice',
'format' => 'pdf',
'data' => ['customer' => ['name' => 'Acme Inc.'], 'total' => 128000],
'wait' => 10,
'link' => ['expires_in' => 86400],
]),
]);
$res = curl_exec($ch);
// 200 + expiring URL within wait seconds; otherwise 202 and a DocRelay webhook on completionrequire "net/http"
require "json"
res = Net::HTTP.post(
URI("https://api.docrelay.jp/v1/renders"),
{
template: "invoice",
format: "pdf",
data: { customer: { name: "Acme Inc." }, total: 128000 },
wait: 10,
link: { expires_in: 86400 },
}.to_json,
"Authorization" => "Bearer #{ENV.fetch('DOCRELAY_API_KEY')}",
"Content-Type" => "application/json",
"Idempotency-Key" => "inv_88",
)
# 200 + expiring URL within wait seconds; otherwise 202 and a DocRelay webhook on completionbody, _ := json.Marshal(map[string]any{
"template": "invoice",
"format": "pdf",
"data": map[string]any{"customer": map[string]any{"name": "Acme Inc."}, "total": 128000},
"wait": 10,
"link": map[string]any{"expires_in": 86400},
})
req, _ := http.NewRequest("POST", "https://api.docrelay.jp/v1/renders", bytes.NewReader(body))
req.Header.Set("Authorization", "Bearer "+os.Getenv("DOCRELAY_API_KEY"))
req.Header.Set("Content-Type", "application/json")
req.Header.Set("Idempotency-Key", "inv_88")
res, err := http.DefaultClient.Do(req)
// 200 + expiring URL within wait seconds; otherwise 202 and a DocRelay webhook on completioncurl https://api.docrelay.jp/v1/renders \
-H "Authorization: Bearer $DOCRELAY_API_KEY" \
-H "Content-Type: application/json" \
-H "Idempotency-Key: inv_88" \
-d '{
"template": "invoice",
"format": "pdf",
"data": { "customer": { "name": "Acme Inc." }, "total": 128000 },
"wait": 10,
"link": { "expires_in": 86400 }
}'
# 200 + expiring URL within wait seconds; otherwise 202 and a DocRelay webhook on completionDesign a layout in the template editor, or upload your existing Excel and Word files as templates. With MCP support, AI assistants such as Claude can also create templates and issue documents.
In the template editor, place text, lines, rectangles, images, line-item tables and body text, and set merge fields such as {{customer.name}}. Line-item tables continue across pages as rows grow, and body text flows onto the following pages. You can also upload Excel or Word files that contain merge fields.
Templates from the template editor output PDF, Excel templates output Excel or CSV, and Word templates output Word. Batch issuance returns a zip or a single merged PDF.
Callers do not need to switch between synchronous and asynchronous handling based on processing time, and you choose how documents are delivered.
Documents that finish quickly are returned in the response. Longer jobs are accepted with an ID, and a webhook (render.succeeded) is sent on completion.
Share issued documents with expiring URLs, with an optional download limit. Within the retention period, you can retrieve them again through the API.
Compared with generating PDFs inside the application, issuing through the DocRelay API returned documents in less time.
| Document | Generated in the application (pdf-lib) | DocRelay (API, round trip) |
|---|---|---|
| 20-page policy document (PDF) | 0.9 s | 0.25 s |
| Amendment comparison table (PDF, A4 landscape, 40 rows) | 0.35 s | 0.15 s |
Our measurements, October 2026.
Set a retention period for each issuance; documents are deleted once it ends. Issuance records are kept in a tamper-evident form.
Issued documents are deleted when the retention period you set (24 hours by default) ends. After deletion, only the record, including the hash, size and file name, and the tamper-evident log are kept.
The hash of each issued document is chained to the previous entry, and a daily hash is published. The data you merge is never recorded. You can verify that a document is unchanged since it was issued.
From monthly invoices to bundled policy PDFs, amendment comparison tables and per-site reports. Every image here is a document issued with DocRelay (company and personal names are fictitious).
Merge each customer’s data and issue a PDF. Issue hundreds at month end in one batch and receive them as a zip or a single PDF.
Flow policy text into pages with a watermark and page numbers. Merge multiple policies into one PDF; the tamper-evident log verifies that it is unchanged since it was issued.
Place the old and new articles side by side in a landscape A4 table and mark the changes with color and underline. Long articles wrap within cells and continue across pages.
Merge the shift table, notes and signature images to issue one report per site. It is returned immediately and can be shared with your client through an expiring URL.
Monthly plans based on document volume, retention and projects. Early access is open ahead of launch.
For evaluation and small projects
$0/ mo
Join early accessFor light, recurring issuance
$19/ mo
Join early accessThe standard plan for production
$69/ mo
Join early accessFor high volume and SSO
$269/ mo
Join early accessMonthly volume, retention and rate limits set to match your scale.
We are preparing for launch. Pre-register and we will notify you when the service becomes available.
