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

# Build, test & deploy

> An end-to-end walkthrough of building, testing, and promoting a PolyAI agent through environments with Builder MCP.

The lifecycle below is where Builder MCP does more than a thin API wrapper: branches, variants, environments, and deployments are all first-class, so you can take an agent from an idea to production — and roll back — entirely from your MCP client. This is the flow to prompt your assistant through.

<Note>
  These steps map to tools in [Capabilities](/mcp/builder/capabilities). You don't call them by hand — describe the outcome you want and let the client chain the tool calls. Example prompts are shown throughout.
</Note>

## 1. Branch

Never edit a live agent directly. Create a [branch](/api-reference/agents/introduction) so your changes are isolated until you're ready to merge.

> "Create a branch of the Acme support agent called `greeting-update`."

## 2. Build

Edit the agent on the branch — behavior rules, knowledge base topics, connectors, and [variants](/knowledge/variants/introduction) for A/B experiments.

> "On that branch, update the greeting and add a knowledge base topic for refund policy."

## 3. Test

Use a [debug chat](/api-reference/data/introduction) session to exercise the branch before it goes anywhere. Inspect the resulting [conversation data](/api-reference/data/endpoint/list-conversations) to confirm the agent behaves as intended.

> "Start a debug chat against this branch and ask it about refunds. Show me the transcript."

## 4. Merge

Once the branch checks out, merge it back into the agent's main line.

> "Merge `greeting-update` back into the agent."

## 5. Deploy to staging

[Publish](/api-reference/agents/endpoint/deployments/publish-the-current-draft-to-an-environment) the current draft to a non-production environment first. Test again against staging with real routing.

> "Publish the current draft to staging."

## 6. Promote to production

When staging looks good, [promote](/api-reference/agents/endpoint/deployments/promote-a-deployment-to-the-next-environment) the deployment to production. Nothing reaches live callers until this step.

> "Promote the staging deployment to production."

## 7. Roll back if needed

Every deployment is versioned. If something regresses, [roll back](/api-reference/agents/endpoint/deployments/rollback-to-a-previous-deployment) to a previous deployment immediately.

> "Roll production back to the previous deployment."

## Why this matters

Most MCP servers stop at create-and-update. PolyAI's environments and deployment model mean the entire promotion path — draft → staging → production, with versioned rollback — runs through the same MCP client you build in. Combine it with [variants](/knowledge/variants/introduction) to test changes on a slice of traffic before a full promotion.

<Warning>
  Publishing and promotion affect live agents. Gate these behind explicit intent — see [Security & safe use](/mcp/builder/security#review-destructive-actions).
</Warning>