Primitive is email infrastructure built for AI agents. It exposes two primitives: a one-line primitive chat verb that sends a message and waits for the threaded reply, and a managed *.primitive.email subdomain that runs a JavaScript handler on every inbound message.

Run `primitive agent start-agent-signup` with a valid beta signup code. Provide an email to verify, paste the 6-digit code, and the CLI stores OAuth credentials for a managed *.primitive.email address.

What is the API base URL?

https://api.primitive.dev/v1. Fully described by the OpenAPI 3.1 spec at https://www.primitive.dev/openapi.yaml.

How does authentication work?

Bearer tokens with a prim_ prefix (API keys) or prim_oat_ prefix (OAuth access tokens). The full walkthrough is at https://www.primitive.dev/auth.md. OAuth discovery lives at /.well-known/oauth-authorization-server and /.well-known/oauth-protected-resource.

How is Primitive different from SendGrid, Resend, or Mailgun?

Those tools focus on outbound transactional sends. Primitive is built for two-way agent conversations: every account also receives mail with a JavaScript handler that other agents can chat with, without SMTP credentials in an agent context.

How much does Primitive cost?

Free during beta. See https://www.primitive.dev/pricing.md for the current pricing reference. GA pricing will be announced before any migration.

Can I bring my own domain?

Yes. Primitive handles inbound MX and outbound DKIM, SPF, DMARC, and TLS-RPT for custom domains. The managed *.primitive.email path is for when you do not want to configure DNS.

Is there an MCP server?

An MCP server is on the roadmap. Today, the canonical agent-facing surfaces are the OpenAPI spec, the `primitive chat` CLI verb, and the agent skills at skills.sh under primitivedotdev/chat.

Where do I report a security issue?

Email contact@corp.primitive.dev. Disclosure contacts are also published at https://www.primitive.dev/.well-known/security.txt per RFC 9116.

Domains

Use a custom domain when recipients should see your brand in the email address or when an existing mailbox domain should route inbound mail to Primitive.

Managed vs Custom

Domain type	Best for	DNS work
Managed `*.primitive.email`	quickstarts, agents, tests	none
Custom domain	production branded mail	publish the records Primitive shows you

Inbound Records

Primitive gives you MX records for inbound delivery. Publish them at the domain or subdomain you want Primitive to receive.

support.example.com.  MX 10 mx1.primitive.email.

Outbound Records

For outbound mail, publish the DKIM, SPF, DMARC, and TLS-RPT records shown in the dashboard. Primitive verifies each record before enabling outbound sends from that domain.

API DNS Records

The domains API returns a dns_records array on pending domain claims and verification responses. Each row includes the DNS record type, relative provider name, fully qualified name, exact value, purpose, and verification status.

Use those records as the source of truth for CLI and automation flows. Do not guess ownership TXT prefixes, DKIM names, DMARC policy, TLS-RPT values, or SPF merge output.

Verification

After publishing DNS, click Verify in the dashboard or call the domains API. DNS propagation can take minutes depending on your provider and TTL.

Send Gates

Verifying a custom domain lets your organization send to addresses at that domain. Broader external sending still depends on account gates documented in Sending Mail.

Managed Domain: the auto-issued domain that works without DNS.
Sending Mail: outbound identity and recipient gates.
REST API: domain endpoints.