When a customer asks an investing assistant a question, they judge more than the answer. They notice whether it sounds like their bank, whether it uses familiar product language, whether it gives the right amount of detail, and whether the interface feels native to the app they already trust.

That is why brand and tone are not just finishing touches. In wealth and investing, tone is part of the product boundary. It helps the user understand what the assistant can do, what it cannot do, when it is being educational, when it is using portfolio data, and when a human should be involved.

Charlie is built to be configured around the institution. The name, tone, language, topic scope, answer length, supported tools, visual treatment, and deployment model can all be adapted. If Charlie is embedded through the SDK, the experience can be fully white-label and shaped in detail inside the bank's own product. If Charlie is used through API or MCP, the bank can keep more of its own interface while using Charlie as the investing intelligence layer behind it.

For clarity, we left the UI (tools and resources consulted) in English.

Tone is configuration, not a single prompt

A prompt can say "be professional and friendly". That is not enough for a regulated investing product.

A real brand and tone setup needs to define how the assistant behaves across many moments: a calm portfolio explanation, a market-news question, an empty-portfolio onboarding flow, an order step, a blocked request, a missing-data state, a support handoff, and a long educational answer for someone who asks for more detail.

This is also where brand, UX, and compliance meet. The FCA Consumer Duty puts strong emphasis on clear, timely, accessible information and on tailoring communications to customers' financial literacy. ESMA's guidance on AI in investment services reminds firms that AI does not remove MiFID II obligations, including acting in the client's best interest. So the question is not only "does this sound on brand?" It is also "does this help the customer understand the right thing at the right time?"

What should be editable

The useful standard is simple: if the investor can see it, hear it, read it, click it, misunderstand it, or infer it from the conversation, it should be configurable.

And the editable surface should not stop at text.

Formality is not one slider

Formality is often treated as one setting. In practice, it is a group of decisions.

A financial institution might want Charlie to sound very precise when explaining risk, warmer when helping a beginner understand an empty portfolio, and short and factual when an order flow is in progress. Another institution might prefer a more coaching style throughout the journey, but still require strict language around suitability, execution, and portfolio losses.

Here is the same idea in a few different styles.

That level of detail matters because different answers carry different risk. A welcome message can be light. A portfolio-loss explanation should be calm and factual. An order step should be exact. A blocked advice request should be kind, firm, and useful.

White-label should mean the full surface is yours

With Charlie, you can go two ways:

• Use the full SDK if you want deep control over the full experience,

• or use our widget library if you prefer to build more through APIs.

In both cases, the UI is highly editable in detail, so it can match the bank’s design system far beyond a simple logo swap.

Our library includes ready-made widgets for Flutter, HTML/CSS and React, with Swift and native Android coming soon. We keep that library continuously updated, so teams can move faster without losing control over the look and feel.

Tone should change by moment

A strong tone system does not force every answer into the same shape. It gives each situation the right default.

This is where many generic assistants feel wrong inside a bank. They can be fluent, but they do not naturally know when to become shorter, more formal, more careful, or more explicit. Charlie's per-bank configuration layer is there to make those decisions part of the product setup.