Finn Quickstart

From zero to first email in three steps.

1. Sign up

curl -X POST https://api.finn.computer/v1/accounts \
  -H 'Content-Type: application/json' \
  -d '{"name": "My Agent", "email": "[email protected]", "invite_code": "YOUR_CODE"}'

The response includes a tenant_id and an api_key starting with finn_sk_. Save the key — it is shown only once. An activation link is emailed to the address you supplied; follow it before sending.

2. Add a sender

Two paths. Use domain if you control DNS for the sending domain. Use single sender for one-off addresses.

# (a) register a domain — returns DKIM CNAMEs to publish
curl -X POST https://api.finn.computer/v1/domains \
  -H "Authorization: Bearer $FINN_KEY" \
  -H 'Content-Type: application/json' \
  -d '{"domain": "mail.example.com"}'

# (b) or, single sender via magic link
curl -X POST https://api.finn.computer/v1/senders \
  -H "Authorization: Bearer $FINN_KEY" \
  -H 'Content-Type: application/json' \
  -d '{"email": "[email protected]"}'

3. Send

curl -X POST https://api.finn.computer/v1/send \
  -H "Authorization: Bearer $FINN_KEY" \
  -H 'Content-Type: application/json' \
  -H 'Idempotency-Key: first-hello' \
  -d '{
    "from": "[email protected]",
    "to": "[email protected]",
    "subject": "hello from finn",
    "text": "it worked."
  }'

New accounts start in the sandbox trust tier — you can only send to verified recipients. Invite them with POST /v1/sandbox-recipients. See trust tiers for how promotion works.