# Flux Chat: Ask, Plan, and Spec Your Device for Free Flux Chat is free. Ask questions about your device, weigh electronics and mechanical trade-offs, and write the spec inside your Flux project. Then build it in Agent mode. Written by [Matthias Wagner](https://www.flux.ai/natarius) Published Oct 2026 - 2 min read ![Flux Chat: Ask, Plan, and Spec Your Device for Free](https://www.flux.ai/p/assets/blogs/flux-chat-free-ask-plan-spec/main.webp) Every device starts with questions. What are the requirements? How big can the enclosure be? Which power architecture fits the battery? How does the board mount, and where do the connectors exit? The answers become the spec, and the spec decides how good the device will be. **Flux Chat** is where that work happens. Ask it about your device: the electronics, the mechanics, or how they fit together. Then turn the answers into a plan that the Flux agent can build. **Chat is free. It does not use your AI usage, and it is never billed.** ## Ask first, build second Chat is for the thinking before the work: - **Ask about the electronics.** "Explain how this board is powered and what limits the runtime." - **Ask about the mechanics.** "What wall thickness and mounting approach make sense for an IP67 enclosure around this board?" - **Read your documents.** "Summarize this datasheet and the mechanical drawing, and list what constrains the board outline." - **Weigh trade-offs.** "Compare a single-board design with a main board and a daughter board in this housing." - **Write the spec.** "Turn these notes into a device specification with electrical, mechanical, thermal, and manufacturing requirements." Chat reads your Flux project and your uploaded files. Its answers are about your device, not about a generic one. ## A better plan makes a better device A design agent can only be as good as the brief that it gets. A spec that you write in a separate chat tool and paste into a design tool loses the discussion that shaped it: why a connector moved, which clearance matters, and what the enclosure must survive. The agent sees *what* to build, but not *why*. When you plan in Flux Chat, the plan and its reasoning are already in the project. When you switch to **Agent** mode, the agent starts from the full picture. The result is a board and an enclosure that fit together. ## Chat and Agent: one project, two modes | | Chat | Agent | | --- | --- | --- | | Use it to | Ask, explain, plan, and write specs | Research parts, design the electronics and the mechanics, simulate, and export for manufacturing | | Project access | Reads the whole device | Reads and changes the whole device | | Cost | **Free** | Uses AI usage | Agent mode does the work. It selects parts, captures the schematic, lays out the PCB, designs the enclosure and the brackets, runs simulations, and generates manufacturing files. Chat and Agent share one project, so you can move between them at any time. Plan in Chat, build in Agent, and come back to Chat to review what changed. ## Try it Open a Flux project, select **Chat** in the composer, and ask about your device. Write the spec there. When the plan is ready, switch to **Agent** and build it. **Ask and plan for free in Chat. Build the whole device in Agent.** ## About the author [Matthias Wagner](https://www.flux.ai/natarius) Founder & CEO at Flux Matthias is the Founder and CEO of Flux, a hardware design platform that's revolutionizing how teams create and iterate on circuits. Find him on Flux [@natarius](https://www.flux.ai/natarius). Let’s start building Build your big idea together with Flux. All you need to do is describe what you want to make, or what problem you want to solve. Flux will work with you to make it a reality. ![Close-up photo of a PCB made with Flux, with an ESP32 module, buttons, and a microSD slot.](https://www.flux.ai/p/assets/blogs/miscellaneous/sidebar-cta-pcb.webp) [Try it Free](https://www.flux.ai/signup) ## Related Content [ ![Flux simulation of the 2.45 GHz antenna feed of a real RF board: the electric field map above the top copper, and S11 and S21 from 0.5 to 4 GHz with S11 at -33.7 dB at 2.45 GHz](https://www.flux.ai/p/assets/blogs/em-simulation-of-your-routed-board/main.webp) ### Electromagnetic Simulation of Your Routed Board, From the Flux Chat 8 Min Read](https://www.flux.ai/p/blog/em-simulation-of-your-routed-board)[ ![The Mini Muse in the Flux 3D View with X-Ray materials: the enclosure and the display, boards, wiring harness, and speaker inside it](https://www.flux.ai/p/assets/blogs/3d-view-collaborative-mcad/main.webp) ### Stop Sending STEP Files: Build the Whole Device Together, Live, in Flux 6 Min Read](https://www.flux.ai/p/blog/3d-view-collaborative-mcad)[ ![A wall of logos for services that the Flux agent can use with your API keys: Digi-Key, Mouser, Arrow, JLCPCB, PCBWay, Craftcloud, Shapeways, Golioth, Particle, nRF Cloud, Edge Impulse, Arena, OpenBOM, Duro, Octopart, SiliconExpert, NI SystemLink, and SimScale](https://www.flux.ai/p/assets/blogs/agent-secrets-any-web-api/main.webp) ### Your API Keys, Used Safely: How the Flux Agent Reaches Distributors, Manufacturers, and Any Web API 3 Min Read](https://www.flux.ai/p/blog/agent-secrets-any-web-api)[ ![Diagram of Flux Adaptive: the Flux agent sends hard design decisions to frontier models and routine work to fast, low-cost models, and runs independent tasks at the same time](https://www.flux.ai/p/assets/blogs/adaptive-agent-model/main.webp) ### Flux Adaptive: Frontier Performance at 30% Lower Cost 4 Min Read](https://www.flux.ai/p/blog/adaptive-agent-model)[ ![Work in progress in Flux: the main board of a smart thermostat is captured in the block diagram, while a side thread reviews the electrical design and Flux coordinates the tasks](https://www.flux.ai/p/assets/blogs/agent-teams-across-projects/main.webp) ### Flux Agents Work as a Team: Side Threads, Parallel Work, and Agents in Other Projects 5 Min Read](https://www.flux.ai/p/blog/agent-teams-across-projects)[ ![Hands measure a red circuit board with a caliper at the bench](https://www.flux.ai/p/assets/blogs/design-is-the-easy-part/main.webp) ### Design Is the Easy Part. Flux Is Built for the Rest. 6 Min Read](https://www.flux.ai/p/blog/design-is-the-easy-part) See All (6) ## Let’s start building. Let’s build your idea together. All you need to do is describe what you want to make, or what problem you want to solve. Flux will work with you to make it a reality. [Try it Free](https://www.flux.ai/signup) ![Close-up of a Flux-designed printed circuit board](https://www.flux.ai/p/assets/homepage-v2/mission-visual.webp)