---
title: "Choosing a product"
description: "Which Lacuna product fits your integration: certificates in the browser, cloud or on-premises signing, document workflows, or issuing certificates."
canonical: "https://docs.lacunasoftware.com/en-us/articles/welcome/choosing-a-product"
locale: "en"
product: "Welcome"
last_updated: "2026-10-12"
---

# Choosing a product

Start from what your application has to do. Each product links to its quick reference: install, configuration,
core operations, errors and samples on one page.

## Main products

| If your application needs to… | Use |
|---|---|
| Work with the user's certificates in the browser: list them, read them, sign with them on a web page | [Web PKI](https://docs.lacunasoftware.com/en-us/articles/web-pki/quick-reference) |
| Sign, validate and timestamp documents through a REST API, as a cloud service or on its own instance | [Rest PKI Core](https://docs.lacunasoftware.com/en-us/articles/rest-pki/core/quick-reference) |
| Sign on its own Windows or Linux servers, from a language other than .NET (Java, PHP, Python, Node.js, Ruby…) | [PKI Express](https://docs.lacunasoftware.com/en-us/articles/pki-express/quick-reference) |
| Sign, validate and handle certificates inside a .NET application | [PKI SDK](https://docs.lacunasoftware.com/en-us/articles/pki-sdk/quick-reference) |
| Send documents to people and collect their signatures, with a workflow | [Signer](https://docs.lacunasoftware.com/en-us/articles/signer/quick-reference) |
| Issue certificates: run its own certification authorities or a whole PKI | [Amplia](https://docs.lacunasoftware.com/en-us/articles/amplia/quick-reference) |

Already integrated with **Rest PKI** at pki.rest? It is a legacy product that still receives bug and security fixes; see its
[quick reference (legacy)](https://docs.lacunasoftware.com/en-us/articles/rest-pki/quick-reference). For a new cloud integration, use Rest PKI Core.

## Common combinations

- **Signatures on a web page with the user's certificate**: Web PKI does the part that must run in the browser, and a
  server-side product (Rest PKI Core, PKI SDK or PKI Express) does the rest. The [web signatures](https://docs.lacunasoftware.com/en-us/articles/pki-guide/web-signatures)
  article in the PKI guide explains the approaches.
- **Signatures with a key kept on the server**: no browser step. In .NET, the PKI guide recommends PKI SDK; see
  [server signatures](https://docs.lacunasoftware.com/en-us/articles/pki-guide/server-signatures).
- **Certificate login**: Web PKI in the browser and a server-side product to check the certificate; see
  [certificate authentication](https://docs.lacunasoftware.com/en-us/articles/pki-guide/cert-auth).

## Other products

| Product | What it does |
|---|---|
| [Amplia Reg](https://docs.lacunasoftware.com/en-us/articles/amplia-reg) | Registration authority for Amplia: confirms who the holder is before a certificate is issued |
| [PSC](https://docs.lacunasoftware.com/en-us/articles/psc) | Stores and manages cloud certificates, together with Amplia |
| [TSA](https://docs.lacunasoftware.com/en-us/articles/tsa) | Timestamp server (RFC 3161) |
| [GrantID](https://docs.lacunasoftware.com/en-us/articles/grant-id) | Single sign-on and multiple authentication factors for your applications |
| [Bulk Signer](https://docs.lacunasoftware.com/en-us/articles/bulk-signer) | On-premises service that signs files in bulk |
| [Scanner](https://docs.lacunasoftware.com/en-us/articles/scanner) | Adds document scanning to a web application |
| [Digiploma](https://docs.lacunasoftware.com/en-us/articles/digiploma) | Issues, registers and publishes digital diplomas following Portaria MEC 554/2019 |
| [TrustBridge](https://docs.lacunasoftware.com/en-us/articles/trustbridge) | Remote signatures with ICP-Brasil certificates held by people, on smart cards or USB tokens |

To hand these docs to an AI coding agent, see [Using these docs with AI agents](https://docs.lacunasoftware.com/en-us/articles/welcome/using-with-ai-agents).