OneSource Developer Documentation

Five surfaces, one API. Integrate OneSource enrichment and identity resolution via REST, CLI, MCP, Gateway, or Portal. All endpoints authenticated via api-key header. 1 credit per hit. Cache hits are free.

Get API Key Quick Start

Enrich Your First Contact

1. Get your API key from the dashboard. 2. POST to /v2/contact/enrich/email with an email address and api-key header. 3. Receive enriched contact data with a deterministic DID. Under 60 seconds to first enrichment.

Start here

Authentication

All endpoints require the api-key header. Generate keys from the OneSource Portal. Keys are scoped per tenant with configurable rate limits. Rate limit headers are included in every response.

Read guide

Three Onboarding Paths

REST API for developers building integrations. CLI for power users who live in the terminal (onesource auth login to start). MCP for AI-native workflows via Claude Desktop (8 tools including enrich_contact and enrich_company).

Choose your path

Ready to Build?

Get your API key and POST to /v2/contact/enrich/email to enrich your first contact. Free tier available for testing.

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