C# / .NET SDK

Installation

Targets net8.0. Install with `dotnet add package RelayPDF`. Source is github.com/timspell1/relaypdf-dotnet.

dotnet add package RelayPDF

Quick start

apiKey is required. Load RELAYPDF_API_KEY from the environment.

using RelayPDF;

var client = new RelayPDF.RelayPDF(Environment.GetEnvironmentVariable("RELAYPDF_API_KEY")!);
var pdf = await client.Pdf.FromHtmlAsync(
    "<h1>Invoice #1042</h1><p>Total: $1,200.00</p>",
    extra: new() { ["filename"] = "invoice.pdf" }
);
pdf.Save("invoice.pdf");

Errors and webhooks

Failures throw RelayPDFException. Webhook.Verify checks RelayPDF-Signature against the raw body.

try {
    await client.Pdf.FromUrlAsync("https://example.com");
} catch (RelayPDFException err) {
    Console.WriteLine($"{err.Status} {err.Code} {err.Message} {err.RetryAfter}");
}

var ok = Webhook.Verify(
    Environment.GetEnvironmentVariable("RELAYPDF_WEBHOOK_SECRET")!,
    rawBody,
    signatureHeader
);

SDK reference

Pass extra dictionaries for REST camelCase fields. File bytes are Base64-encoded automatically.

Document platform release support

The release adds ocr, pdfa, crop, resize, repair, optimize, attachments, extract-images, redact, compress, image-convert, and email processing. Every official SDK exposes process / ProcessAsync plus files.upload, files.delete, billingUsage / billing_usage, and billingLimits / billing_limits. Availability requires the matching released package. Older published versions may not contain these methods.

See /docs/files, /docs/billing, and each operation guide for field names and limits.

For safe retries, use URL or async output with Idempotency-Key. Per-request caps use X-RelayPDF-Max-Charge-Microdollars (integer millionths of USD). Billing APIs preserve microdollar precision; legacy account millicent fields are not the complete precise balance.

Native OCR with a per-job cap

Requires RelayPDF 0.1.2 or a compatible newer release. Replace the example URL with your own publicly accessible scan. The 40000-microdollar cap authorizes at most $0.04; it is not a price estimate. Reuse the idempotency key only for retries of the same request.

client.Files.UploadAsync / DeleteAsync; client.BillingUsageAsync / BillingLimitsAsync

Files and billing APIs do not require a separate client. See /docs/files, /docs/billing, and /docs/idempotency for ownership, precision, and retry behavior.

using var client = new global::RelayPDF.RelayPDF(
    Environment.GetEnvironmentVariable(
        "RELAYPDF_API_KEY")!
);
var job = await client.ProcessAsync("ocr", new() {
    ["url"] = "https://example.com/scan.pdf",
    ["response"] = "async",
}, new() {
    ["idempotencyKey"] = "scan-001",
    ["maxChargeMicrodollars"] = 40000,
});