# Build an in-house legal platform with the Relex SDK | Relex

> Build your interface and workflows on existing legal matter and confidentiality foundations.

# Build an in-house legal platform with the Relex SDK

Build your interface and workflows on existing legal matter and confidentiality foundations.

## What you reuse

The SDK connects your application to Relex matters, parties, knowledge, ontology, drafts and billing APIs. Its Node.js, Python and Java bindings share the native protection implementation: seal identity fields and redact documents in your process before upload.

## What you still build

Your interface, sign-in experience, roles, workflow rules, deployment and professional review. Preserve tenant authorization and keep the PII password out of the server and agent. Billing or export can require a deliberate, limited identity disclosure. This is an application foundation, not a ready-made compliant firm.

## SDK, MCP or Marketplace?

Use the SDK to build a portal or in-house platform. Use MCP to connect a supported assistant to the same saved matter. Use Marketplace to publish an eligible firm profile or request professional help. The platform example runs against a mock by default; verify package access, service permissions and live behavior before launch.

[What is a legal workspace?](/guides/what-is-a-legal-workspace)[Build an in-house legal platform](/guides/build-in-house-legal-platform)[Join the agentic law firm marketplace](/guides/agentic-law-firm-marketplace)[Compare workspaces & benchmark](/compare)[Portable legal context](/guides/portable-legal-context)[SDK](/docs/legal-sdk)[MCP](/docs/connectors)[Security](/security)

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