What Agent Mode Does
Agent mode is the primary working mode in Trace. When you ask the AI to make a change — add a component, route a trace, fix a DRC violation, generate manufacturing files — it executes the change directly on your design files.
The AI can:
- Read your schematic and PCB files
- Make targeted edits (add/remove/modify components, connections, traces)
- Run ERC and DRC checks
- Generate Gerber, drill, and position files
- Search for symbols and footprints
- Take screenshots for visual analysis
- Create matched length groups
- Annotate reference designators
- Route traces (quick routing or advanced cloud layout)
Every edit is versioned automatically. If you don’t like a change, click undo on the message and you’re back to where you started.
When to Use Agent Mode
Agent mode is best for bounded, concrete tasks:
| Good for Agent Mode | Better suited for Plan Mode |
|---|
| ”Add a 100nF cap between VDD and GND on U1" | "Design a complete power supply section" |
| "Route the SPI bus" | "Lay out the entire board from scratch" |
| "Fix the DRC violation on net /CLK" | "Redesign the analog front-end for better noise" |
| "Generate Gerbers and drill files" | "Create a 4-layer stackup with impedance control" |
| "Change R3 from 10k to 4.7k" | "Optimize all resistor values for this LED driver” |
How It Works
When you send a message in Agent mode, the following happens:
- Your message goes to the backend with your conversation history and project context.
- The AI reasons about what to do — you see thinking blocks stream in real-time.
- Tool calls dispatch — the AI requests actions like “read this file” or “write this component.” These execute locally on your machine.
- Results return — your app sends tool results back. The AI continues with that information.
- Changes sync — after all edits, the
.trace_sch converts to .kicad_sch and your editor reloads.
The Activity Feed
As the AI works, you see an interleaved activity timeline in the chat:
- Status messages — Friendly updates like “Reading schematic…”, “Adding component…”, “Running ERC…”
- Thinking blocks — The AI’s reasoning process, collapsible for review
- Text responses — Explanations of what was done and why
- Tool activity — Which files are being read or modified
This gives you full visibility into what the AI is doing at every step.
Tools execute locally on your machine — your design files never leave your computer. The server only sees tool results (e.g., “file written successfully” or “DRC found 3 violations”).
| Tool | What it does |
|---|
read_file | Read a schematic, PCB, or project file |
write | Create or overwrite a file |
search_replace | Make targeted edits using exact string matching |
grep | Search for patterns across project files |
list_dir | List files and directories |
delete_trace_file | Delete a file (with confirmation) |
| Tool | What it does |
|---|
run_erc | Run Electrical Rule Check |
run_drc | Run Design Rule Check |
take_snapshot | Capture a visual screenshot for analysis |
annotate_schematic | Auto-annotate reference designators |
autoroute | Run the autorouter (quick or advanced engine) |
match_lengths | Create matched length groups for high-speed buses |
generate_gerbers | Generate manufacturing Gerber files |
generate_drill_files | Generate Excellon drill files |
| Tool | What it does |
|---|
search_web | Find datasheets, reference designs, application notes |
search_parts_nexar | Query distributors for availability and pricing |
parse_datasheet | Extract structured data from PDF datasheets |
search_symbols / search_footprints | Find library components by description |
Multi-Tab Parallel Execution
Each chat tab is an independent execution unit. You can:
- Run Agent mode in one tab while asking questions in another
- Have two Agent tabs making edits to different parts of the design simultaneously
- Start a long routing task in one tab and continue working in another
Tabs don’t interfere with each other — each has its own streaming state, conversation history, and backend client. File-level locking prevents conflicts when two tabs try to edit the same file.
Versioning and Undo
Every edit the AI makes is automatically versioned:
- Local history — git commits in
.history/ (works offline)
- Cloud sync — saved to Trace’s backend for cross-device access
- Per-message undo — click the undo button on any assistant message to restore the state before that message’s edits
Rolling back is non-destructive — it creates a new version, so you can always go forward again. See Version History for details.
Optimistic Concurrency
When the AI edits a file, it uses a hash-based safety mechanism:
- Read the file + compute a hash
- Make the edit
- Before writing, verify the hash hasn’t changed (nobody else modified the file)
- If the hash matches, write succeeds. If not, the AI retries with the updated content.
This prevents data loss when you and the AI (or two AI tabs) edit the same file around the same time.
Extended Thinking
For complex Agent tasks, the AI shows its reasoning in collapsible thinking blocks:
- How it’s analyzing your design
- What tradeoffs it’s considering
- Why it chose a particular approach
- What constraints it’s working around
Thinking blocks auto-collapse as the AI moves to the next step. Click to expand and read the full reasoning.
Extended thinking uses a 10,000-token budget per reasoning step. This allows deep analysis of complex design decisions even in Agent mode — you don’t need Plan mode just to get thoughtful reasoning.
Todo Tracking in Agent Mode
For multi-step Agent tasks, the AI may create a todo checklist to organize its approach:
- The todo widget appears in the chat panel
- Items update in real-time as the AI completes each step
- You can see exactly where the AI is in the process
This happens automatically for complex requests — you don’t need to ask for it.
Example Prompts
Adding Components
Add TVS diodes (PESD5V0S2BT) on the USB D+ and D- lines for ESD protection.
Place them close to the USB connector.
Modifying Values
Change all bulk decoupling caps on the power rail from 10uF to 22uF.
Keep the same 0805 package.
Routing
Route the I2C bus (SDA, SCL) with 0.2mm traces.
Keep them parallel and add 4.7k pull-ups to 3.3V if not already present.
Validation
Run DRC on the board. For any clearance violations, increase the
trace spacing to meet the minimum. Don't move any components.
Manufacturing
Generate Gerber files, drill files, and pick-and-place position file.
Package everything into a ZIP ready for JLCPCB submission.
Research + Edit
Check if the ADS1115IDGSR is in stock at LCSC. If yes, add it to
the schematic with proper decoupling and I2C pull-ups connected to
the STM32's I2C1 peripheral.
Tips for Effective Agent Mode Usage
- Be specific about what you want changed. “Fix it” is vague. “Change R4 to 4.7k because the LED current is too high” gives the AI clear intent.
- One task per message for precision. For complex changes, break them into steps. This makes undo granular — you can roll back one step without losing others.
- Attach context when relevant. Drag a datasheet into the chat if you want the AI to implement a specific reference circuit.
- Let the AI run checks. After edits, ask “Run ERC” or “Run DRC” to validate. The AI can then fix any issues it introduced.
- Use multi-tab for parallel work. Route traces in one tab while reviewing the schematic in another.
Limitations
- Agent mode requires the desktop application (files must be local)
- Not available on the Free plan (Ask mode is free; Agent requires Pro/Ultra/On-Demand)
- Complex multi-step tasks may produce better results in Plan Mode where the AI researches and plans before executing
- PCB version rollback is limited — version restore is fully implemented in the schematic editor but has reduced functionality in PCBnew
Next Steps
