How to Manage Documents and Contracts Across Google Drive, Box, Dropbox, and S3 with a Unified API
October 21, 2025
Most SaaS products rely on documents and contracts that live across multiple storage providers — Google Drive, Dropbox, OneDrive, Box, or S3. Managing these files consistently is difficult when every system has its own schema, authentication model, and permissions logic.
Unified.to simplifies file and contract management through a single unified API. This same architecture enables retrieval-augmented generation (RAG), where documents are indexed and retrieved at query time to ground AI responses in real contract and file content.
Your product can list, read, download, update, and replace documents across 25+ storage systems — without building or maintaining custom integrations for each vendor.
When to Use Docs & Contracts Management
With a unified API, you can:
- Centralize access to documents and contracts from multiple storage systems.
- Retrieve files and metadata for review, processing, or AI pipelines.
- Update or replace files while preserving links, permissions, and audit metadata.
- Sync downstream systems automatically when files are created, modified, or replaced.
- Power RAG-based contract search, clause extraction, and AI-driven Q&A across storage providers.
Normalized File Object
Unified.to provides a consistent schema for managing files across providers, based on the Unified File model:
| Object | Description | Key Fields |
|---|---|---|
file | A stored document or contract item | id, created_at, updated_at, name, description, parent_id, user_id, size, mime_type, permissions, download_url, data, version, web_url |
This model supports both structured document storage (e.g., Drive, Box) and object-based storage (e.g., S3), with optional passthrough for provider-specific metadata.
Supported Providers
Unified.to integrates with major storage systems, covering 25+ file and content management platforms, including:
- Google Drive
- Microsoft OneDrive / SharePoint
- Dropbox
- Box
- Amazon S3
See the full list of supported File Storage integrations.
Data Flow for Document & Contract Management
The flow for managing files across providers is consistent and secure:
- Connect — The customer authorizes their storage provider through Unified Connect, returning a secure
connection_id. - List — Retrieve documents, folders, and metadata from the connected source.
- Read or Download — Fetch files for review, AI processing, or compliance workflows using the normalized
download_url. - Update or Replace — Push new versions of files while maintaining consistent references and metadata.
- Monitor Changes — Subscribe to Unified's native or virtual webhooks to detect file edits, replacements, or permission updates in real time.
With Unified's unified schema and real-time delivery, your product can manage contracts and documents seamlessly — regardless of where they're stored.
Extending Document Management into a RAG Pipeline
To build semantic contract search or AI Q&A:
- Subscribe to file create and update webhooks.
- Fetch document content using the normalized
download_url. - Chunk large documents and generate embeddings.
- Store embeddings in your vector database with identifiers like
connection_id,file_id,updated_at, and optional permission metadata. - On user query, retrieve the top matching document segments before generating an answer. Unified Use Case RAG Pipelines
Unified handles ingestion and real-time updates across 25+ storage platforms; embeddings and vector storage remain in your infrastructure.
Note: File objects include explicit permissions metadata, which can be used to filter retrieval results by user or group access when building enterprise RAG experiences.
Why Product Teams Choose Unified.to
For PMs and engineers building document-driven or AI-powered products:
- One API, 350+ integrations — consistent CRUD and webhook behavior across storage systems.
- Real-time sync — keep your RAG index aligned with document edits and version changes.
- Secure by design — no cached or stored customer data; every request fetches live content.
- Extensible — passthrough metadata and permissions for provider-specific workflows.
- Store embeddings and vector indexes in your own infrastructure.
Centralize document and contract management across every provider with a single integration.
Start your free 30-day trial or book a demo to see how Unified.to can simplify your file workflows.