Output handling

The Go SDK gives you four ways to handle a rendered PDF: in-memory []byte, a streaming io.ReadCloser, a write-to-disk helper, or a stored document on the server. Pick the one that matches how your code consumes the output.

In-memory (Render.PDF)

pdf, err := client.Render.PDF(ctx, polipage.RenderInput{
  Project:  "billing",
  Template: "invoice",
  Data:     map[string]any{"invoiceNumber": "INV-001"},
})
// pdf: []byte — write, upload, return as-is.

Best for documents that fit comfortably in process memory.

Streaming (Render.PDFStream)

For large PDFs or piping straight to an HTTP response or object store, use Render.PDFStream and let the SDK keep memory bounded. The caller MUST close the returned io.ReadCloser.

body, err := client.Render.PDFStream(ctx, polipage.RenderInput{
  Project:  "billing",
  Template: "invoice",
  Data:     map[string]any{"invoiceNumber": "INV-001"},
})
if err != nil {
  return err
}
defer body.Close()
// io.Copy(w, body) — pipe to an HTTP response, an S3 upload, or any io.Writer.

Write to file (RenderToFile)

The top-level RenderToFile helper streams bytes directly to disk with bounded memory. Parent directories are created automatically.

err := polipage.RenderToFile(
  ctx,
  client,
  polipage.RenderInput{Project: "billing", Template: "invoice", Data: map[string]any{}},
  "./out.pdf",
)

Server-side storage (Render.Document)

When you want the PDF to live on Poli Page’s servers (for later download, preview, or thumbnails), use Render.Document. It returns a *DocumentDescriptor with DocumentID, PresignedPDFURL, and a DownloadPDF method.

doc, err := client.Render.Document(ctx, polipage.RenderInput{
  Project:  "billing",
  Template: "invoice",
  Data:     map[string]any{"invoiceNumber": "INV-001"},
})
if err != nil {
  return err
}
pdf, err := doc.DownloadPDF(ctx)

PresignedPDFURL has a 15-minute TTL. If it expires, call client.Documents.Get(ctx, documentID) to refresh.

Example

package main

import (
  "context"
  "os"

  "github.com/poli-page/sdk-go"
  "github.com/poli-page/sdk-go/option"
)

func main() {
  ctx := context.Background()
  client := polipage.NewClient(option.WithAPIKey(os.Getenv("POLI_PAGE_API_KEY")))

  if err := polipage.RenderToFile(
    ctx,
    client,
    polipage.RenderInput{
      Project:  "billing",
      Template: "invoice",
      Data:     map[string]any{"invoiceNumber": "INV-001", "total": 1280},
    },
    "./invoices/INV-001.pdf",
  ); err != nil {
    panic(err)
  }
}

See also

• Cancellation
• Retries and idempotency