# Swap agents

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This is the official documentation of the `@forestadmin/agent` Node.js agent.
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When agents start, Forest Admin knows which project and environment they are linked to thanks to the `envSecret` configuration key.

By bringing the old configuration to your newly generated codebase, you will link this new codebase to your existing environment (eg. Production).

Notably:

* `authSecret` so that issued authentication tokens stay valid.
* `envSecret` to change the project and environment the agent is linked to.
* `prefix` and `port` so that the new agent is mounted on the same URL as the old one.

Your project will then be migrated to the new agent, and you can delete both:

* The old agent code from your source tree
* The temporary environment that you created.