Custom instructions

Custom instructions let you define persistent preferences that shape how Le Chat responds across every conversation.

For teams, custom instructions help standardize how your organization interacts with Le Chat, so everyone gets responses tailored to shared conventions, terminology, and formatting requirements.

1. In the left-menu bar, click Intelligence then Instructions.
2. The Custom instructions pop-up opens.
3. Choose a Tone and enter your instructions: describe your role, output format, or any context you want Le Chat to assume.
4. Save your changes.

Your instructions take effect in all new conversations from that point on. Existing conversations aren't affected.

Custom instructions apply alongside other context sources, but their priority depends on the feature.

• Agents: when you activate an Agent, its instructions take precedence over your custom instructions. This lets you build Agents for specialized tasks without worrying about conflicts with your general preferences.
• Memories: Memories store facts and preferences that Le Chat picks up from your conversations over time. Custom instructions are set explicitly by you. Both apply together, but if they conflict, custom instructions take priority.
• Tools: custom instructions shape how Le Chat communicates with you, but they don't change how tools execute. For example, Code Interpreter still runs Python regardless of your language or formatting preferences.

A good custom instruction is short, specific, and tells Le Chat something it can't infer from your prompts alone.

Role and domain expertise

• "I'm a compliance officer at a European bank. Reference EU regulations (MiFID II, GDPR) when relevant."
• "I'm a software engineer working with Python and TypeScript. Tailor code examples accordingly."
• "When I ask about data, assume I'm working with PostgreSQL."

Output formatting

• "Structure all technical responses with Problem, Analysis, Solution, and Next Steps sections."
• "Always format financial figures with two decimal places and include the currency symbol."
• "Keep responses concise. Use bullet points instead of paragraphs."

Language and tone

• "Always respond in French unless I ask otherwise."
• "Respond in British English. Use formal tone for client-facing content, casual for internal notes."

Constraints

• "Don't include disclaimers or caveats unless I'm asking about medical, legal, or financial advice."
• "When generating code, always include error handling and type annotations."

Custom instructions work best when they're focused.

• Don't use them as a project brief. They're meant for persistent preferences, not task descriptions. For detailed briefs, use the conversation itself or Projects.
• Don't contradict your prompts. If your custom instruction says "always respond in French" but you ask questions in English and expect English answers, you'll get inconsistent results.
• Keep them concise. A few well-written sentences work better than multiple paragraphs. The more focused your instructions, the more reliably Le Chat follows them.

• Agents: create specialized configurations with their own instructions, tools, and Connectors.
• Memories: let Le Chat learn and recall context from your conversations automatically.
• Chat: start conversations where your custom instructions are applied.