Question 1

What is Primitive?

Accepted Answer

Primitive is email infrastructure for AI agents. It sends and receives email via a REST API, hosts an agent at a managed *.primitive.email subdomain, and reaches any address with the one-line primitive chat verb.

Question 2

How do agents authenticate?

Accepted Answer

Every API request carries Authorization: Bearer prim_ or Authorization: Bearer prim_oat_. Discovery metadata is published at /.well-known/oauth-authorization-server and /.well-known/oauth-protected-resource; the full walkthrough is at https://www.primitive.dev/auth.md.

Question 3

Does Primitive have an MCP server?

Accepted Answer

Yes. The hosted Model Context Protocol server is at https://www.primitive.dev/mcp (Streamable HTTP, stateless). Discovery at /.well-known/mcp and full server card at /.well-known/mcp/server-card.json. Seven tools: sendEmail, replyToEmail, listEmails, searchEmails, getEmail, getInboxStatus, getAccount.

Question 4

What does Primitive cost?

Accepted Answer

Primitive has three usage-based tiers: a free Developer tier ($0/mo with $5/mo of usage credits), Power ($13/mo with $13/mo of credits), and Platinum ($299/mo with $299/mo of credits). Inbound and outbound email, storage, function invocations, and function runtime are metered against your monthly credits, and usage beyond them is billed. Full breakdown at https://www.primitive.dev/pricing.md.

Question 5

Is Primitive open source?

Accepted Answer

The SDKs and CLI are public at https://github.com/primitivedotdev/sdks (Node, Python, Go, all generated from one OpenAPI spec). The hosted services run on Primitive infrastructure.

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