> For the complete documentation index, see [llms.txt](https://docs.apryse.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.apryse.com/uwp/digital-signature.md). # Digital signature - [UWP Digital Signature Library](https://docs.apryse.com/uwp/digital-signature/signature.md): Sign PDF documents with ease using our built-in certificate parsing tool. Certify, verify, timestamp, and add Long Term Validation to your digital signatures effortlessly. Get started now! The Apryse - [Verify a signature in UWP](https://docs.apryse.com/uwp/digital-signature/signature/verify-pdf.md): We offer a higher-level document-based API for verifying signatures, as well as a lower-level per-signature API. Page includes code samples. - [Custom Signing in UWP](https://docs.apryse.com/uwp/digital-signature/signature/custom-signing.md): Discover how the Apryse custom signing API simplifies digital signature customization for documents. Integrate PDF-specific operations with ease using HSM tokens, cloud keystores, and more. Follow our - [Add a DocTimeStamp signature in UWP](https://docs.apryse.com/uwp/digital-signature/signature/dts.md): Set doctimestamp in PDF in UWP to add authenticity to the document. Learn how to add trusted certifictae using WebViewer. - [Embedded Timestamp Tokens with custom signing API in UWP](https://docs.apryse.com/uwp/digital-signature/signature/emb-tst.md): Elevate your digital signature security with custom signing API features. Learn how to create and insert secure timestamp tokens for PAdES-format signature conformance. Ensure verifiability with trust - [Add Long-Term Validation (LTV) information for a signature in UWP](https://docs.apryse.com/uwp/digital-signature/signature/ltv.md): Learn how to enable LTV to digital signature in PDF either signed internally or externally in {{language}}. - [Sign a PDF document in UWP](https://docs.apryse.com/uwp/digital-signature/sign-pdf.md): Learn how to digitally sign PDF files using the Apryse SDK. Ensure document authenticity with approval signatures and certificates. Get started now! The Apryse uwp SDK streamlines secure document proc - [Adding a certified signature field to a PDF in UWP](https://docs.apryse.com/uwp/digital-signature/certify-pdf.md): Learn how to add a certification signature field to a PDF document and digitally sign it with a full code sample. Find out about certifying PDF/A documents and ensuring PDF/A-2 compliance with the PDF - [Code samples for adding digital signatures to PDFs in UWP](https://docs.apryse.com/uwp/digital-signature/samples.md): Digitally sign PDF files with ease using this high-level API. Learn how to sign and certify documents effortlessly. Perfect for secure and efficient digital signatures. The Apryse uwp SDK streamlines - [API for digital signatures in UWP](https://docs.apryse.com/uwp/digital-signature/apis.md): Learn how to handle digital signatures in PDF documents using UWP with C#, VB, or JS. Explore pdftron.SDF.ISignatureHandler and pdftron.PDF.Annots.Widget classes. The Apryse uwp SDK streamlines secure --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation by asking a question. Perform an HTTP GET request on the following URL with the `ask` and `goal` query parameters: ``` GET https://docs.apryse.com/uwp/digital-signature.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is what the user is ultimately trying to achieve, the reason they need the answer. Sharing it helps GitBook give you a better, more relevant answer. A goal is most helpful when it describes the outcome the user wants rather than restating the question. For example, with `ask=how do I create an API token`, a goal like `automate deployments from our CI pipeline` lets GitBook tailor the answer to that use case. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.