Installation
# API client only (zero dependencies)
go get github.com/formepdf/forme-go
# Local rendering with component DSL (adds wazero)
go get github.com/formepdf/forme-go/templates
Hosted API
The API client uses only the Go standard library. Create templates in the dashboard, then render them with data:package main
import (
"os"
forme "github.com/formepdf/forme-go"
)
func main() {
client := forme.New(os.Getenv("FORME_API_KEY"))
pdf, err := client.Render("invoice", map[string]any{
"customer": "Acme Corp",
"items": []map[string]any{
{"name": "Widget", "qty": 5, "price": 49},
},
"total": 245,
})
if err != nil {
panic(err)
}
os.WriteFile("invoice.pdf", pdf, 0644)
}
Client options
client := forme.New(apiKey,
forme.WithBaseURL("https://custom-api.example.com"),
forme.WithHTTPClient(&http.Client{Timeout: 30 * time.Second}),
)
Methods
| Method | Description | Returns |
|---|---|---|
Render(slug, data) | Synchronous render | ([]byte, error) |
RenderWithOptions(slug, data, opts) | Render with options | ([]byte, error) |
RenderS3(slug, data, s3Opts) | Render and upload to S3 | (*S3Result, error) |
RenderAsync(slug, data, asyncOpts) | Start async render job | (*AsyncResult, error) |
GetJob(jobID) | Poll async job status | (*JobResult, error) |
Merge(pdfs) | Merge multiple PDFs | ([]byte, error) |
Certify(pdfBytes, certPem, keyPem, opts) | Certify a PDF with X.509 certificate | ([]byte, error) |
Redact(pdfBytes, opts) | Redact regions/patterns from a PDF | ([]byte, error) |
Extract(pdfBytes) | Extract embedded data | (map[string]any, error) |
Error handling
pdf, err := client.Render("invoice", data)
if err != nil {
var fErr *forme.FormeError
if errors.As(err, &fErr) {
fmt.Printf("API error %d: %s\n", fErr.Status, fErr.Message)
}
}
Native templates
Build documents in Go code using a component DSL that mirrors the JSX API. Renders locally via the WASM engine — no network calls.package main
import (
"os"
t "github.com/formepdf/forme-go/templates"
)
func main() {
doc := t.Document(
t.Page(
t.View(
t.Text("Invoice #001", t.Style{FontSize: 24, FontWeight: "bold"}),
t.Text("Acme Corp", t.Style{FontSize: 14, Color: "#666"}),
).Style(t.Style{FlexDirection: "column", Gap: 8}),
t.Table(
t.Row(t.Cell(t.Text("Item")), t.Cell(t.Text("Price"))).Header(true),
t.Row(t.Cell(t.Text("Widget")), t.Cell(t.Text("$50.00"))),
t.Row(t.Cell(t.Text("Gadget")), t.Cell(t.Text("$100.00"))),
).Columns([]t.Column{{Width: "1fr"}, {Width: 100.0}}),
),
).Title("Invoice #001")
pdf, err := doc.Render()
if err != nil {
panic(err)
}
os.WriteFile("invoice.pdf", pdf, 0644)
}
Components
| Constructor | Description | Chainable methods |
|---|---|---|
Document(children...) | Root container | .Title(), .Author(), .Subject(), .Lang(), .DefaultStyle(), .Fonts(), .Tagged(), .PdfA(), .PdfUA(), .FlattenForms(), .SetCertification() |
Page(children...) | Page container | .Size(), .Margin() |
View(children...) | Flex/grid container | .Style(), .Wrap(), .Bookmark(), .Href() |
Text(content, style?) | Text element | .Style(), .Href(), .Children() |
Image(src) | Image element | .Width(), .Height(), .Style(), .Href(), .Alt() |
Table(children...) | Table with auto-repeating headers | .Columns(), .Style() |
Row(children...) | Table row | .Header(), .Style() |
Cell(children...) | Table cell | .ColSpan(), .RowSpan(), .Style() |
QRCode(data) | Vector QR code | .Size(), .Color(), .Style() |
Barcode(data) | 1D barcode | .Format(), .Width(), .Height(), .Color(), .Style() |
BarChart(data) | Bar chart | .Width(), .Height(), .Color(), .Title(), .Style() |
LineChart(series, labels) | Line chart | .Width(), .Height(), .ShowPoints(), .Title(), .Style() |
PieChart(data) | Pie/donut chart | .Width(), .Height(), .Donut(), .Title(), .Style() |
TextField(name) | Fillable text field | .Value(), .Placeholder(), .FontSize(), .Multiline(), .Style() |
Checkbox(name) | Fillable checkbox | .Checked(), .Style() |
Dropdown(name, options) | Fillable dropdown | .Value(), .Style() |
RadioButton(name, value) | Radio button | .Checked(), .Style() |
PageBreak() | Force page break | — |
Watermark(text) | Rotated watermark | .FontSize(), .Color(), .Angle(), .Style() |
Building the WASM binary
Local rendering requires the Forme WASM binary:cd packages/go-sdk/templates
bash build_wasm.sh
go test -tags forme_wasm ./...
Hosted vs native
| Hosted API | Native templates | |
|---|---|---|
| Dependencies | Zero (stdlib only) | wazero (~10MB WASM) |
| Templates | Pre-uploaded via dashboard | Built in Go code |
| Network | Requires API call | Fully offline |
| Use case | Dynamic data + stored templates | Full control, CI/CD, testing |