Changelog

Actions API: Readable names

Names of call transfer, post-call SMS, in-call SMS, and WhatsApp actions are now saved exactly as you type them, up to 64 characters, through both the Actions API and the app.

Agents API: Updated Get an agent response

The Get an agent response now includes these fields:

• knowledge_base_id
• agent.greeting_message_mode
• agent.greeting_message_human_talk_timeout
• agent.suppression_level
• agent.redact_pii
• agent.voice_style, now returned as a decimal instead of 0

Improved performance in Logs search

Searching your logs is now much faster, including in high-volume workspaces.

• Call logs: The Phone Number filter now only finds exact matches, so results load instantly. Enter the full number, including the country code.
• Webhook logs: Search by a full Call ID, webhook log ID, or action ID for instant results.

Extended list of transfer failure reasons

Failed transfers now report more specific failure reasons:

• number_not_found
• number_incomplete
• destination_unavailable
• rejected_by_destination
• transfer_blocked_by_carrier
• carrier_unavailable
• routing_loop
• media_negotiation_failed
• transfer_method_unsupported

Find every state, reason, and SIP code in the transfer outcome states reference.

Prompt Reuse metric

Prompt Reuse is a new metric in Analytics that shows the health of your agent’s prompt. It measures how much of the prompt the AI model reused instead of reading it again.

Use it to understand why some agents respond faster than others: the more of its prompt an agent reuses, the lower its latency in the call.

Learn more about Prompt Reuse.

Run simulations from the agent editor

You can now create and run test suites without leaving the agent editor. Change a prompt, rerun the suite, and see what passed or failed right next to the agent.

Emails

Your agent can now send an email once the call ends. Attach a Post-Call Email action to any agent and pick who should receive it.

Synthflow TTS for multilingual agents

Agents set to Multilingual can now use Synthflow TTS as their voice model or fallback. One voice covers the whole conversation, including when the caller switches language mid-call.

Custom action response time

Call details now shows the response time of every custom action. Open a call, check the Actions tab, and find the slow endpoint behind a long silence.

Call quality metrics on every call

The Telephony tab now reports call quality for every call, so you can rule out the network without pulling a PCAP. The same measurements are on the Calls endpoints.

Auto-overage for subaccounts

Parent accounts now control whether a subaccount can call past its included minutes. Turn on Auto-overage and the extra minutes are billed to your account at your per-minute rate.

200 voices for Synthflow TTS

Synthflow TTS now offers 200 voices instead of 12, so you can match a voice to your brand instead of settling for the closest fit. Filter the Voice selector by accent, gender, or language, and play a preview before you assign one. Voices already on your agents are unchanged.

Time to human on warm transfers

Warm transfers that connect now record human_connected_at, the moment the caller actually reached a person, not just when the transfer started. See transfer timestamps.

New transfer outcome states

A transfer that reaches a phone menu, a voicemail greeting, or a busy line now reports that instead of a generic timeout. If you match on outcome state, add the values from the full list of transfer outcome states.

Action execution timeline in webhooks

A transfer that retried three times used to show up as one attempt in the post-call webhook. The new action execution timeline lists every attempt and the number each one dialed.

Use the new Synthflow app

The new Synthflow app runs at app.synthflow.ai, with faster page loads and more responsive navigation. Turn it on for your workspace from Early Access.

The guide covers what changes and the current known issues.