Write the prompt and custom instructions

The Prompt tab holds the two texts you add to the assistant's prompt, Your users and Custom instructions, and the Web search switch. They apply to every chat user in the workspace.

Before you begin

Describe your users

The assistant reads Your users before every conversation and adapts its help and tone to it.

  1. In the portal, go to Faustine Chat and select Configuration.
  2. Under Assistant, select Prompt.
  3. In Your users, enter who talks to the assistant and what they do. Two sentences are enough, and a list of names is not needed. The field takes up to 2,000 characters.
  4. Select Save.

For example:

Account managers at Nimbus. They look up companies and contacts, keep deals up to date and answer questions about pricing.

Write custom instructions

Custom instructions are added to the assistant's prompt for every user. Use them for the language and tone of the answers, and for how to use your gateways, such as which connection to choose in a given case.

  1. On the same tab, enter the text in Custom instructions. The field takes up to 8,000 characters.
  2. Select Save instructions.

For example:

Answer in Spanish. Show amounts in euros. Before you change a deal, show its current stage and owner.

Both texts apply to the next message of every conversation, including the ones already open.

Custom instructions cannot turn off confirmation. An operation marked as requiring confirmation waits for the user whatever the instructions say, because the gateway refuses the call without the user's answer.

Turn web search on or off

Web search lets the assistant search the internet for information that is not in your gateways or your documents. It is on by default.

To change it, turn the Web search switch on or off on the same tab.

Web search uses Anthropic's web search tool. It is available when the chat runs on an Anthropic model through Anthropic or Vercel AI Gateway. Otherwise the switch is disabled, and the card says why. When the assistant uses a web page, the reply lists it under Sources.

Next steps

Last updated November 11, 2026