DUOLEXX API

Bilingual documents via API — straight from your systems.

Generate, fill and sign legally sound documents programmatically. A clean, versioned REST API with API-key authentication — ideal for PropTech, HR and LegalTech workflows.

Request an API key See the MCP server

Built for developers

Versioned REST API

Stable endpoints under /v1 with clear JSON — no surprises on updates.

API-key authentication

Per-project keys, rate limits and quotas instead of fragile session logic.

Self-discovery catalog

Document types, countries, required fields and language pairs are available as JSON.

Bilingual PDF & signature

The same engine as the web: authoritative language + translation, electronic signature included.

Core endpoints

GET/v1/document-types

List all document types, countries and required fields.

POST/v1/documents

Create a document from type, country, language pair and answers.

PATCH/v1/documents/{id}

Update answers and recompute the preview.

POST/v1/documents/{id}/pdf

Render the finished bilingual PDF.

POST/v1/documents/{id}/signature-request

Trigger the counterparty's signature via link.

Example: create a document

curl -X POST https://duolexx.com/api/v1/documents \
  -H "Authorization: Bearer $DUOLEXX_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: 3f9a…" \
  -d {
    "type": "intl-nda",
    "legalLanguage": "en",
    "translationLanguage": "de",
    "answers": { "partyA": "…", "partyB": "…", "purpose": "…" }
  }

Access

The API is part of DUOLEXX Pro — with an included quota, usage-based beyond it. Request an API key and get started.

Request an API key