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# 2.2025

> February 2025 release notes.

The **February 2025** PolyAI Agent Studio release introduces new tools for Knowledge versioning, function latency control, and improved conversation review.

Expand the items for details:

#### View Knowledge differences between versions

You can now use the [Environments & versions](/agent-studio/deployments/compare-versions) tab to compare two [Knowledge](/agent-studio/knowledge/fa-qs/fa-qs) versions
side-by-side and track modifications across the **sandbox, pre-release, and live** environments.

Versions are displayed as **split diffs**.

* ** Additions** mean a new Knowledge entry.
* ** Deletions** means a Knowledge entry has been deleted.
* ** Edits** is the symbol applied to any existing but altered Knowledge entry.

![kb-diff](/_fern-files/_img/6688b4c92c0e2f1d918929fafc55bb8331cceb58d13e05e9cd4a01a8804fb3b2.webp)

* Quickly identify additions, deletions, and changes between Knowledge versions.
* Easily attribute changes to their authors.

Visit the [Environments & versions](/agent-studio/deployments/compare-versions) page for more details.

#### Manage function latency

Improve the experience for users when a function takes longer than expected by playing filler utterances during the delay.

![latency-control](/_fern-files/_img/2f85fc64be5afaffb1a3982636357f76da9ed75592f7db34716da2c38fcfa3a7.webp)

**How it works:**

* Set up **delay responses** that play while a function is still processing.
* Define the **initial delay** before the first filler utterance is played.
* Configure the **interval** between utterances to control pacing.
* Specify the **expected length** of each utterance for smoother timing.

This feature ensures that users receive real-time feedback instead of silence, making interactions feel more natural. It's useful for scenarios like **booking confirmations** or **data lookups**, where a response takes a few seconds.

Visit the [Function delay control](/agent-studio/tools/delay-control) page for more details.

#### Upload audio to replace cached items

Upload pre-recorded audio directly from the **audio management resource** in Agent Studio.

![audio-upload](/_fern-files/_img/ebb5b9559cce564af8b46fe1f64577339ba681424c0249c0b2609b7f6b449975.webp)

**Key benefits:**

* Easily replace TTS with high-quality voice actor recordings.
* Improve voice consistency across different agent responses.
* Initial release supports single file uploads. Bulk upload functionality is planned for a future release.

#### Reference variants in Knowledge

Reference variant attributes dynamically within Knowledge responses.

![variants](/_fern-files/_img/3d3f4193d0d2e96e371b1b4c957a3dd8bf44ce5fc48dd30e38e89011754fa705.webp)

**How it works:**

* Add variant attributes by typing `/` or selecting the `+` icon in content fields.
* Reference existing attributes or create new ones dynamically.
* Personalize responses by encoding structured variant data.

#### Managing transition functions in a flow

Transition functions are now managed centrally within the flow editor.

![transition-functions](/_fern-files/_img/197d6e2c85c9ae0dbaa50721ce0c45ccbcf55591fa9d676ae3b3cd8bf25ec5e8.webp)

**Key benefits:**

* Prevents accidental deletions when modifying flows.
* Enables reusing, duplicating, and managing transition functions from a single interface.
* Streamlines agent configuration and debugging.

Visit the [flows](/agent-studio/flows/overview) page for more details.

#### Conversation review annotations

Users can now annotate user conversation turns for:

* **Missed topics**
* **Incorrect ASR transcriptions**

Agent conversation turns can be annotated for **wrong information**.

![review-annotations](/_fern-files/_img/b45258121a6de6acdce6c01e5223d7c633c7fb5935eef380a7fb795a767f8f37.webp)

#### Handoff SIP configuration

You can now configure handoff using SIP, with [INVITE](https://datatracker.ietf.org/doc/html/rfc3261#section-13.3.1), [REFER](https://www.ietf.org/rfc/rfc3515.txt), or [BYE](https://www.rfc-editor.org/rfc/rfc3261.html).
You can also add [SIP headers](https://www.iana.org/assignments/sip-parameters/sip-parameters.xhtml) to the handoff template.

![sip-handoff](/_fern-files/_img/834566d24da93d22f75c8700bbe6836dad422beb32b72e9c93f3fa97250a7be7.webp)

**How it works:**

* The default handoff method is set to REFER.
* You can adjust this to other methods according to the specific needs of your projects.
* You can add SIP headers to the handoff.

Visit the [call handoff](/agent-studio/voice/handoffs) page for more details.

#### Enterprise overview dashboard

A new **Enterprise overview dashboard** provides key operational insights and is the new homepage of a project.

![enterprise-dashboard](/_fern-files/_img/a321f01ab0530fa1adcdbaf35accce07a91c5ef46f24e2c6ff11bc3d234281fa.webp)

**Key benefits:**

* Monitor total calls, call duration, words generated, and key metrics.
* Improve oversight of agent performance and containment rates.
* Can be configured to work alongside custom dashboards for deeper analytics.