Build your first Primitive Function

# 1. Install the CLI and confirm it sees your account.
npm install -g @primitivedotdev/cli
primitive whoami

# 2. Scaffold a function project. Creates ./mail-to-crm/ with
#    handler.ts, package.json, build.mjs, tsconfig.json.
primitive functions:init mail-to-crm
cd mail-to-crm

# 3. Edit handler.ts. Paste the handler source from below over the
#    scaffolded body. It POSTs the inbound email to your CRM and
#    sends an acknowledgement back to the sender.

# 4. Install deps and build the single-file ESM bundle to ./dist/handler.js.
npm install
npm run build

# 5. Deploy. The response includes the function id; export it as FN_ID.
primitive functions:deploy --name mail-to-crm --file ./dist/handler.js
export FN_ID=<id-from-response>

# 6. Set CRM_API_KEY and redeploy in one call so the new secret lands
#    in the running handler immediately. PRIMITIVE_WEBHOOK_SECRET and
#    PRIMITIVE_API_KEY are managed for you by the runtime; you only
#    set the third-party secrets your handler needs.
primitive functions:set-secret --id $FN_ID --key CRM_API_KEY --value $CRM_API_KEY --redeploy

# 7. Send a test email through the real inbound MX path. --local-part
#    routes the test through a specific local-part if your handler
#    branches on it; omit for a random synthetic local-part.
primitive functions:test-function --id $FN_ID --local-part support

# 8. Inspect the inbound row your function received.
primitive emails:latest --limit 5

# 9. Inspect the outbound acknowledgement the function sent in response.
primitive sending:list-sent-emails --limit 5

# 10. Tail logs from the function to confirm the CRM call returned and
#     the reply was sent.
primitive functions:logs --id $FN_ID --tail

import {
  createPrimitiveClient,
  verifyWebhookSignature,
  WebhookVerificationError,
  PRIMITIVE_SIGNATURE_HEADER,
} from '@primitivedotdev/sdk/api';
import type { EmailReceivedEvent } from '@primitivedotdev/sdk';

interface Env {
  PRIMITIVE_WEBHOOK_SECRET: string;
  PRIMITIVE_API_KEY: string;
  CRM_API_KEY: string;
}

export default {
  async fetch(request: Request, env: Env): Promise<Response> {
    const rawBody = await request.text();
    try {
      await verifyWebhookSignature({
        rawBody,
        signatureHeader: request.headers.get(PRIMITIVE_SIGNATURE_HEADER) ?? '',
        secret: env.PRIMITIVE_WEBHOOK_SECRET,
      });
    } catch (e) {
      if (e instanceof WebhookVerificationError) {
        return new Response('invalid signature', { status: 401 });
      }
      throw e;
    }

    const event = JSON.parse(rawBody) as EmailReceivedEvent;
    if (event.event !== 'email.received') {
      return Response.json({ skipped: 'unhandled event type' });
    }

    const email = event.email;
    const bodyText =
      email.parsed.status === 'complete' ? email.parsed.body_text ?? '' : '';

    // POST the inbound to your CRM. Replace the host with your CRM's
    // real ticketing endpoint and adjust the body to match its schema.
    const crmRes = await fetch('https://api.your-crm.example.com/tickets', {
      method: 'POST',
      headers: {
        Authorization: `Bearer ${env.CRM_API_KEY}`,
        'content-type': 'application/json',
      },
      body: JSON.stringify({
        from: email.headers.from,
        subject: email.headers.subject ?? '(no subject)',
        body: bodyText,
      }),
    });

    if (!crmRes.ok) {
      const detail = await crmRes.text();
      console.error('crm error', crmRes.status, detail);
      return new Response('crm error', { status: 502 });
    }

    const { id: ticketId } = (await crmRes.json()) as { id: string };

    // Reply to the sender with a templated acknowledgement. The
    // idempotency key prevents duplicate replies if Primitive retries
    // the webhook delivery.
    const client = createPrimitiveClient({ apiKey: env.PRIMITIVE_API_KEY });
    await client.send(
      {
        from: 'support@your-domain.primitive.email',
        to: email.headers.from,
        subject: `Re: ${email.headers.subject ?? '(no subject)'}`,
        bodyText:
          `Thanks for reaching out. We've opened ticket ${ticketId} ` +
          'and someone will follow up shortly.',
      },
      { idempotencyKey: `${event.id}:ack` },
    );

    return Response.json({ ok: true, ticketId });
  },
};