Outbound with consent

Outbound calling is gated. Your business must be verified and your account topped up with paid credit. Every call also passes the checks in Compliance.

Only call people who gave the consent your calls need. Larynth enforces its checks, but you are the caller and the legal responsibility stays with you.

All examples use fictional 555 numbers.

Create a contact

curl https://api-us.larynth.com/v1/contacts \
  -H "Authorization: Bearer $LARYNTH_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"e164": "+14155550142", "first_name": "Sam", "timezone": "America/Los_Angeles"}'

The timezone and region help the calling-hours check use the right local time.

Record consent with evidence

curl https://api-us.larynth.com/v1/compliance/consents \
  -H "Authorization: Bearer $LARYNTH_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "e164": "+14155550142",
    "kind": "express",
    "source": "web_form",
    "granted_at": "2026-11-01T15:04:00Z",
    "scope_type": "tenant",
    "evidence_text": "Checked the box agreeing to calls on the booking form."
  }'

A record needs evidence_ref or evidence_text. Set scope_type to campaign and add a scope_id to limit consent to one campaign.

Create a campaign

A campaign needs an agent, the numbers it may call from, a purpose, and calling windows in the contact’s local time.

curl https://api-us.larynth.com/v1/campaigns \
  -H "Authorization: Bearer $LARYNTH_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "name": "Appointment reminders",
    "assistant_id": "'"$ASSISTANT_ID"'",
    "number_ids": ["'"$NUMBER_ID"'"],
    "purpose": "informational",
    "amd_mode": "voicemail",
    "voicemail_message": "Hello, this is the clinic with a reminder. Please call us back.",
    "windows": [{"days": [1, 2, 3, 4, 5], "start_minute": 600, "end_minute": 1020}]
  }'

Days run from 0 for Sunday to 6 for Saturday. Minutes count from midnight, so 600 is 10:00 and 1020 is 17:00. Your windows can only narrow the legal calling hours, not widen them.

Enrol contacts

Add existing contacts with POST /v1/campaigns/{id}/contacts.To bring in many at once, upload a CSV with an e164 column to POST /v1/contacts/imports. Other columns become contact attributes. The upload needs an attestation of how consent was obtained, and a consent_kind and consent_source. Pass a campaign_id to enrol everyone imported. Check progress with GET /v1/contacts/imports/{id}.

Start the campaign

curl -X POST https://api-us.larynth.com/v1/campaigns/$CAMPAIGN_ID/start \
  -H "Authorization: Bearer $LARYNTH_API_KEY"

Each contact is checked before it dials. A contact that fails a check is skipped or held until the check can pass, for example until the calling window opens. Pause with POST /v1/campaigns/{id}/pause; active calls continue. Resume with .../resume.

Watch results

GET /v1/campaigns/{id}/stats returns counters: calls placed, answered, humans, machines and opt-outs. GET /v1/compliance/decisions shows why any contact was or was not dialed.

When someone asks to stop

Record it right away with POST /v1/compliance/revocations. The number joins your internal Do-Not-Call list and is not called again. The agent can also record an opt-out during a call with the opt_out tool.

Do-Not-Call lists

You bring your own Do-Not-Call registrations for outbound campaigns. Larynth also applies its own opt-out list to every account.

Retries

The campaign retry_policy sets the delay before retrying after no answer, busy, a failure or a left voicemail. A delay that is not set means no retry. max_attempts caps total tries per contact.

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Outbound with consent

When someone asks to stop

Do-Not-Call lists

Retries

​When someone asks to stop

​Do-Not-Call lists

​Retries

When someone asks to stop

Do-Not-Call lists

Retries