Overview
Every message you send in Trace is handled by one of three modes. Each mode has different capabilities, different levels of autonomy, and different guardrails. You can pick a mode explicitly using the mode selector in the chat panel, or let Trace’s classifier choose automatically based on your message.The Three Modes
How the Classifier Works
When you send a message without explicitly selecting a mode, Trace’s backend classifier analyzes your request and picks the appropriate mode:- Ask is selected for questions, explanations, comparisons, and anything that doesn’t require changing files. Examples: “What does this resistor do?”, “Compare LDO vs buck converter for my use case.”
- Agent is selected for direct, bounded edits. Examples: “Add a 100nF cap to U1 VDD”, “Route the power traces”, “Generate Gerbers.”
- Plan is selected for complex, multi-step tasks that benefit from research and user review before execution. Examples: “Design a USB-C PD charging circuit”, “Lay out this entire power supply section.”
When to Use Each Mode
Use Ask Mode when you want to learn or understand
- “How does this circuit work?”
- “What capacitor value do I need for this LDO’s output?”
- “Is there a better alternative to the STM32F103?”
- “Explain the DRC violation on net /VCC”
- “What’s the thermal resistance of this package?”
Use Agent Mode when you want the AI to make changes
- “Add a TVS diode on the USB data lines”
- “Change R3 to 4.7k”
- “Route the SPI bus traces”
- “Run DRC and fix any violations”
- “Generate Gerber and drill files”
Use Plan Mode when the task is complex
- “Design a 5V 3A buck converter with input protection”
- “Lay out the board with proper decoupling and power distribution”
- “Redesign the analog front-end for better noise performance”
- “Create a 4-layer stackup with controlled impedance for USB 2.0”
Mode Availability by Plan
New accounts receive a one-time grant of free agent credits (~$5, never expire, plus a small monthly top-up) that unlock Agent and Plan on the Free plan. Accounts on the legacy 14-day trial keep full access until the trial naturally expires.
When your monthly usage is exhausted, your credit balance reaches zero, or your free agent credits run out, Agent and Plan modes are disabled until the next billing cycle, credit purchase, or monthly free top-up. Ask mode always remains available.
Switching Modes
The mode selector is in the chat panel, next to the message input. Click it to choose a mode before sending your message. You can also switch modes mid-conversation. Starting in Ask mode to understand a circuit, then switching to Agent to make changes is a common workflow:- Ask: “How does the current limiting work on this LED driver?”
- Ask: “What happens if I increase R4 to 1k?”
- Agent: “Change R4 to 1k and add a test point on that net”
Next Steps
- Ask Mode — full guide to read-only AI analysis
- Agent Mode — full guide to AI-driven edits
- Plan Mode — full guide to multi-step planning workflows
- Using Prompts — tips for writing effective prompts in any mode
- Billing & Plans — plan limits and usage details

