> ## Documentation Index
> Fetch the complete documentation index at: https://www.truefoundry.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Agent Builder Moving to Trueforge & Agent APIs Deprecated — v0.172

> In v0.172, the TrueFoundry agent builder moves to the Trueforge portal and the older Agent APIs are deprecated. Migrate to Trueforge APIs by 15th Oct, 2026.

<Warning>
  **Applicable to:** Users who build or invoke agents with the TrueFoundry agent builder (the previous **Agents** sidebar section: Playground, Registry, and Sessions). If you do not use the agent builder, this change does not affect you.
</Warning>

## What Is Changing

The agent builder is moving out of the main TrueFoundry sidebar **Agents** section into a dedicated **Trueforge** portal. Open it from the sidebar under **TRUEFORGE → Build Agents**.

<Frame caption="Before: agent builder lived under Agents (Playground, Registry, Sessions) in the main sidebar">
  <img src="https://mintcdn.com/truefoundry/Z86dKK-nvZeluIjE/images/docs/change-announcements/agents-sidebar-before.png?fit=max&auto=format&n=Z86dKK-nvZeluIjE&q=85&s=97e9a0eafb41b8e77065a0718da8ed1d" alt="TrueFoundry sidebar with the Agents section highlighted, showing Playground, Registry, and Sessions" width="1024" height="490" data-path="images/docs/change-announcements/agents-sidebar-before.png" />
</Frame>

<Frame caption="After: open the agent builder from TRUEFORGE → Build Agents">
  <img src="https://mintcdn.com/truefoundry/Z86dKK-nvZeluIjE/images/docs/change-announcements/trueforge-build-agents-after.png?fit=max&auto=format&n=Z86dKK-nvZeluIjE&q=85&s=da450bb540f6f8dc287ba8d969adde1f" alt="TrueFoundry sidebar with the TRUEFORGE section highlighted, showing Build Agents with a New badge" width="1024" height="473" data-path="images/docs/change-announcements/trueforge-build-agents-after.png" />
</Frame>

Clicking **Build Agents** opens the Trueforge portal — the managed agent builder experience:

<Frame caption="Trueforge portal — the managed agent builder">
  <img src="https://mintcdn.com/truefoundry/Z86dKK-nvZeluIjE/images/docs/change-announcements/trueforge-portal.png?fit=max&auto=format&n=Z86dKK-nvZeluIjE&q=85&s=87eb07f843d8112a444ff8089e5b148e" alt="Trueforge portal showing New Chat, Build Agent, Agents, Sessions, and Schedules in the left navigation" width="1024" height="514" data-path="images/docs/change-announcements/trueforge-portal.png" />
</Frame>

Trueforge is powered by our open-source agent harness ([truefoundry/trueforge](https://github.com/truefoundry/trueforge)). TrueFoundry provides a managed version of that harness in the platform.

### Existing agents

Agents you built earlier with the agent builder are migrated automatically to Trueforge. Open **Build Agents** to find and continue working with them there.

### APIs

If you invoke agents via APIs, the older APIs continue to work until **15th October, 2026**. We recommend migrating to the [new Trueforge APIs](https://trueforge.dev/api/use-agent) as soon as possible.

## Why This Change

The agent builder is moving onto Trueforge so you get a dedicated portal for building and running agents, backed by the same open-source harness you can run yourself, with a managed experience on TrueFoundry.

## What You Need to Do

<Steps>
  <Step title="Use Build Agents in the sidebar">
    Go to **TRUEFORGE → Build Agents** instead of the previous **Agents** sidebar section (Playground, Registry, Sessions). Your existing agents appear in Trueforge after migration — no recreate step is required for agents built in the old builder.
  </Step>

  <Step title="Migrate to the new Trueforge APIs">
    Older agent APIs continue to work until **15th October, 2026**. Migrate to the [new Trueforge APIs](https://trueforge.dev/api/use-agent) as soon as possible.
  </Step>
</Steps>

## References

* [Trueforge (open source)](https://github.com/truefoundry/trueforge)
* [Use an agent — new APIs](https://trueforge.dev/api/use-agent)

***

If you have questions about the migration or run into anything unexpected, reach out to [**support@truefoundry.com**](mailto:support@truefoundry.com) — we're happy to help.