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Flux vs CELUS: From schematic and BOM to the whole device.

CELUS AI turns electronics requirements into reference schematics and BOMs for your ECAD tool. Flux is the alternative when you want an AI hardware engineer to design electronics, mechanical parts, and firmware together in one browser project.

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Flux editor: the AI engineer plans and delegates tasks while the 3D view shows the complete device: enclosure, circuit board, and wiring

What Flux and CELUS are

What Flux is

Flux is an AI hardware engineer for the complete device. It works across the schematic, board, mechanical parts, and firmware, then provides simulation, checks, and manufacturing files.

What CELUS is

CELUS is an AI electronics design platform. An assistant captures requirements step by step, and agents match trusted reference designs.[1]

CELUS produces a reference schematic and complete bill of materials with supply-chain data and alternatives. Teams can open the output in Altium, Cadence, Siemens, Fusion, or KiCad.[1]

What CELUS does

Requirements capture

An assistant captures design requirements question by question.[1]

Reference designs and BOMs

Agents match trusted reference designs and produce a reference schematic and complete BOM with supply-chain data and alternatives.[1]

Connected part catalogs

Component manufacturers can connect their catalogs so their parts are proposed during design.[1]

One AI hardware engineer for the whole device

CELUS starts at the front of electronics design. It captures requirements and matches reference designs. It then delivers a schematic and BOM to your ECAD tool. Flux brings electronics, mechanical design, and firmware together in one project. Its AI hardware engineer works across the board and mechanical parts, writes firmware for the board, and provides manufacturing files and orders.

An engineer holds a relay board in a blue 3D-printed enclosure
A complete Flux design, with electronics and mechanical parts.
Flux compared with CELUS
Feature Flux CELUS
Requirements and specification The AI engineer turns your idea into requirements and a product specification, and checks the design against them. An assistant captures requirements question by question.[1]
What it is AI hardware engineer with its own design tools AI electronics design platform.[1]
Where it runs In your web browser. Nothing to install. Your projects live in the cloud. Opens design outputs in Altium, Cadence, Siemens, Fusion, or KiCad.[1]
Who does the design work The Flux agent. Your engineers review and edit. An assistant captures requirements; agents match trusted reference designs.[1]
Schematic and parts Built in. Picks from 734,000+ public parts. Produces a reference schematic and complete BOM with supply-chain data and alternatives.[1]
Board layout and routing Built in Hands the reference schematic to an ECAD tool for board layout.[1]
Placement and routing The AI engineer places the parts and routes the board like an experienced designer. Your engineers review and edit. Board routing follows the reference schematic handoff to your ECAD tool.[1]
High-speed design The AI engineer plans DDR topology and timing budgets, routes differential pairs and length-matched buses, tunes length and skew, fans out BGAs with blind, buried, and microvias, and sets trace impedance from your stackup. It checks the routed board with S-parameters, TDR, eye diagrams, crosstalk analysis, and a signal integrity, power integrity, and EMC review. Your engineers review and edit. Not part of CELUS.[1]
Flex and rigid-flex boards Built in. Named stackups for rigid and flex areas, coverlay and stiffeners, hatched flex pours, bending lines with a folded 3D view and folded STEP files, flex design checks, and Gerber, ODB++, and IPC-2581 files. The AI engineer routes each area on its own layers. Schematic handoff to ECAD; no rigid-flex workflow in the cited page.[1]
Parts and sourcing 734,000+ public parts, with live prices and stock from distributors Component manufacturers connect catalogs so their parts can be proposed during design.[1]
Simulation and design rule checks SPICE, power delivery network, full-wave electromagnetic, signal integrity, thermal, and mechanical simulation, plus design rule checks Reference-design matching, not circuit simulation or PCB design rule checks.[1]
Firmware Writes firmware for the board it designed Not part of CELUS.[1]
Wiring harnesses Built in. Flux designs the wiring harnesses between the boards: connectors, pinouts, and wires, in the same project. Not part of CELUS.[1]
Manufacturing files Gerber, ODB++, IPC-2581, bill of materials, pick-and-place, and more; Flux can check the files before you order, including copper gaps, silkscreen, board outline, BOM, and pick-and-place files. Exports a BOM; PCB fabrication files are produced in your ECAD tool.[1]
Quotes and orders Quotes and orders for boards, 3D printing, CNC machining, and wire harnesses, from the project. Provides supply-chain data and component alternatives with the BOM.[1]
Import from other tools Imports complete projects from Altium, OrCAD and Allegro, KiCad, PADS and Xpedition, CADSTAR, Eagle, Fusion Electronics, EasyEDA, DipTrace, and SOLIDWORKS PCB. Flux imports Labcenter Proteus SDF netlists with Specctra board exports. IPC-2581 revision B and C files become board projects with reusable footprint parts. IDF 2.0 and 3.0 board files become board projects with the outline, cutouts, drilled and mounting holes, part placements, and 3D part heights. Starts from requirements, then hands native design outputs to Altium, Cadence, Siemens, Fusion, or KiCad.[1]
Versions, branches, and merges Full change history. The AI engineer forks a design into a second version, keeps both, and merges the changes that you pick. Not part of CELUS; version the exported design in your ECAD tool.[1]
Who reviews the work The whole team, in one live project in the browser: electrical, layout, mechanical, and firmware engineers Teams receive a reference schematic and BOM for their ECAD workflow.[1]
Product images, videos, and documents Product images, product videos, datasheets, and regulatory documents, made from the design in the project. Delivers engineering documents: a reference schematic and BOM.[1]
Price See current pricing No public price list. Contact CELUS for pricing.[1]
Plus the mechanical parts too
Mechanical CAD Built in, kernel agnostic. From an enclosure to a complete robot arm. Not part of CELUS.[1]
Mechanical simulation Finite-element stress, thermal, and airflow simulation Not part of CELUS.[1]
Mechanical manufacturing STEP, STL, and 3MF files, plus quotes for 3D printing, CNC machining, sheet metal, and laser cutting Not part of CELUS.[1]
CNC toolpaths and G-code The AI engineer writes the toolpaths, the G-code, a toolpath preview, and a setup sheet for the parts that it designed. Not part of CELUS.[1]

Go from requirements to the complete device

Start a Flux project free and connect electronics, mechanical design, and firmware in one project.

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Board design, done by the AI engineer.

Routes like an experienced designer

Flux places the parts and routes the board like an experienced designer, and it respects your design intent and your layout rules.

Parts you can buy

Flux picks from 734,000+ public parts. It checks live prices and stock across distributors before it puts a part on the board.

Your layout rules

Flux checks every board against your layout rules and the capabilities of your fabricator.

Checks every datasheet

Flux reads the datasheet of every part and checks the design against its pinouts, ratings, and limits.

Bring your ECAD projects into Flux.

Import an existing ECAD project, then connect the electronics with mechanical parts and firmware in the same project.

Example request

“Connect the new schematic to the board, enclosure, and firmware.”

An engineer holds a board in a green enclosure
A complete Flux design, with electronics and mechanical parts.
  • Altium Altium Designer
  • Cadence OrCAD and Allegro
  • KiCad KiCad
  • Siemens PADS, Xpedition, and NX
  • Zuken CADSTAR
  • Autodesk Eagle and Fusion
  • EasyEDA EasyEDA
  • SolidWorks SolidWorks
  • CATIA CATIA
  • PTC Creo
  • Onshape Onshape

Bring your existing work

Import complete projects, part libraries, and 3D models. Schematics, parts, and placement come across, and routing from most formats.

Keep going with your AI engineer

Imported designs are ready to edit right away. Ask "move the USB cutout 3 cm left" or "make the enclosure tighter", and Flux does the work.

Get it manufactured

Flux hands you the files that your manufacturer needs: Gerber, ODB++, IPC-2581, bill of materials, and pick-and-place for the board, and STEP, STL, or 3MF for the mechanical parts.

See all file formats
Complete projects
Flux imports complete projects from Altium, Cadence OrCAD and Allegro, KiCad, Siemens PADS and Xpedition, Zuken CADSTAR, Eagle, Fusion Electronics, EasyEDA, DipTrace (XML export), and SOLIDWORKS PCB. Schematics, parts, connections, board outlines, and placement come across. Flux imports Labcenter Proteus SDF netlists with Specctra board exports. IPC-2581 revision B and C files become board projects with reusable footprint parts. IDF 2.0 and 3.0 board files become board projects with the outline, cutouts, drilled and mounting holes, part placements, and 3D part heights.
Part libraries
Altium, OrCAD, PADS, KiCad, Eagle, Fusion Electronics, EasyEDA, and DipTrace libraries, Allegro footprints, and JEP30 part models become Flux parts.
Mechanical files
STEP, STL, OBJ, 3MF, and glTF models, plus DXF board outlines.
Handoff to manufacturing and electronics tools
Gerber, ODB++, IPC-2581, IPC-D-356 test netlists, bill of materials, pick-and-place, EDIF netlists, GenCAD, and KiCad board files.
Handoff to mechanical design
The full board and its parts as STEP, compressed STEP, BREP, VRML, glTF, and STL models, plus DXF layer drawings. Enclosures and brackets that Flux designs export as STEP, STL, and 3MF, ready for your mechanical tools or a 3D printer.

Orchestration

One request. A whole team of AI engineers.

Hand Flux a complete product. The lead AI engineer splits it into workstreams, starts parallel threads across projects, manages them, and reports back.

Parallel threads

Each workstream runs in its own agent thread. The main board, the daughterboards, and the enclosure come together at the same time.

Across projects

The lead engineer starts work in other projects and tracks it all from one place.

Managed for you

It monitors every thread, steers work that goes off the brief, and collects the results.

You stay in control

Changes that move an interface or resize a board wait for your approval.

Example

A product with three daughterboards

Flux writes a brief for each board with its outline, mounting holes, connectors, and the enclosure openings they line up with. Each board gets its own project and its own AI engineer, and all three are designed in parallel. Flux then places the finished boards in the main assembly and measures clearances and connector alignment in millimeters.

Verification lab

Simulates and checks its own work before you build.

Flux doesn't stop at generating designs. The AI engineer simulates and checks its own work with professional-grade solvers, and it shows you the results.

Circuit simulation

SPICE simulation of analog, power, and mixed-signal circuits, with Monte Carlo, temperature sweep, and noise analysis, run and read by the AI engineer.

Electromagnetic simulation

Full-wave simulation of the routed board: signal integrity, power integrity, impedance, S-parameters, crosstalk, and antennas.

Design rule checks

Electrical and manufacturing rule checks on every schematic and board.

Datasheet checks

Reads the datasheet of every part and checks the design against its pinouts, ratings, and limits.

Thermal simulation

Flux runs PCB thermal analysis of the routed board at stated operating powers, plus heat and airflow simulation of the enclosure, before you build.

Fluid simulation

Airflow and cooling through the enclosure, so vents, fans, and heat sinks work before the first prototype.

Mechanical simulation

Finite-element stress analysis of brackets, enclosures, and mounts.

SPICE load step of a 3.3 V buck converter
SPICE load step of a 3.3 V buck converter
Thermal map of top and bottom copper
Thermal map of top and bottom copper
Stress analysis of an aluminum bracket
Stress analysis of an aluminum bracket
S-parameters of a USB data line, simulated on the routed board
S-parameters of a USB data line, simulated on the routed board

Sourcing

Picks parts you can buy today, at today's prices.

Flux connects directly to major electronics and mechanical parts distributors. The AI engineer picks chips, connectors, screws, and standoffs that are in stock, compares prices across distributors, and replaces parts that are at end of life before the product goes to production.

  • Digi-Key Digi-Key
  • LCSC LCSC
  • Mouser Mouser
  • Arrow Arrow
  • Verical Verical
  • TME TME
  • HQonline HQonline
  • McMaster-Carr McMaster-Carr
  • MISUMI MISUMI
  • JLCMC JLCMC

Manufacturing

Gets quotes from your fabricators as the design changes.

Flux gets quotes directly from the fabricators for circuit boards and assembly, 3D printing in plastic and metal, CNC machining, sheet metal, laser cutting, injection molding, casting, and wiring harnesses. The AI engineer compares price and lead time, checks the design against each fabricator's rules, keeps the quote current as the design changes, and places the order when you confirm.

Circuit boards and assembly

  • JLCPCB JLCPCB
  • PCBWay PCBWay
  • OSH Park OSH Park
  • AISLER AISLER

Mechanical parts

  • Craftcloud Craftcloud
  • JLC 3D printing JLC 3D printing
  • PCBWay 3D printing PCBWay 3D printing
  • Shapeways Shapeways
  • OSH Cut OSH Cut
  • SendCutSend SendCutSend

Cables and wiring harnesses

  • MiniProto MiniProto

One AI hardware engineer beyond schematic and BOM

Continue from requirements to a device

Flux starts with the product requirement and carries the work across electronics, mechanical design, and firmware.

Design the board and mechanical parts

The board and mechanical parts share one project. The AI hardware engineer can update both as the design changes.

Keep firmware with its hardware

Flux writes firmware for the board in the same project as the electronics and mechanical design.

Use parts with current data

Flux selects from 734,000+ public parts and shows live distributor pricing and stock.

Check beyond the schematic

Flux supports SPICE, electromagnetic, thermal, and mechanical simulation, along with design rule checks.

Prepare for manufacturing

Flux provides files and project-based quotes and orders for boards, mechanical parts, and wire assemblies.

One platform

And the mechanical parts and firmware too.

Flux is not a collection of disconnected CAD applications. It is one AI-native engineering platform where every discipline shares the same project, the same data, and the same AI engineer.

  1. Boards, enclosure, and mounts in one model

    Mechanical design

    Parametric enclosures, brackets, and mounts, fitted to the real board's mounting holes and connectors. Bring in your own STEP models. One parts library for the whole product: chips and connectors, devices that are not on the board, and mechanical hardware such as screws and standoffs.

  2. STM32 current-loop firmware that Flux wrote and compiled, in a syntax-highlighted code block

    Firmware

    Firmware for the board Flux designed, for example on Arm Cortex-M, RISC-V, AVR, or Pico, then built, analyzed, and unit tested.

A board in a purple 3D-printed enclosure on an electronics bench
A complete Flux design, with electronics and mechanical parts.

Model-agnostic AI

Your favorite AI models. Our engineering superpowers.

Flux pairs frontier AI models with a state-of-the-art agent harness built for CAD and EDA. The models bring reasoning. Flux brings the engineering tools, project context, and workflows that turn that reasoning into working hardware.

  • OpenAI
  • Anthropic
  • Google Gemini
  • More as they ship
Adaptive model selection

Frontier performance at 30% lower cost.

Adaptive splits every engineering job into tasks and gives each task to the model that does it best for the price. Hard design decisions go to frontier models. Routine work goes to fast, low-cost models. Independent tasks run in parallel, so complete devices come together faster. Your team works with one AI engineer, and Flux handles the delegation behind the scenes.

Frontier AI models

  • Reasoning
  • Planning
  • Language

Flux engineering harness

  • CAD and EDA tools
  • Project context
  • Simulation
  • Design rules

Working hardware

  • Schematics
  • Boards
  • Enclosures
  • Firmware
  • Fab files
  • Product videos

Every frontier model, one platform

Work with the frontier models your team already trusts, inside Flux.

Engineering superpowers built in

Every model gets Flux's specialized engineering tools, project context, and workflows.

Upgrade without migrating

When a better model ships, your team gets it without switching engineering platforms.

No single-vendor lock-in

Avoid depending on any one model provider for your engineering capacity.

The right model for every step

Adaptive matches each engineering step to the model that does it best, from deep design decisions to routine checks.

Your designs stay yours.

  • SOC 2-aligned cloud infrastructure
  • Single sign-on (SSO)
  • Project-level permissions
  • Inputs and outputs are always your IP
  • No training on customer data

Flux pricing

  • Explore

    For learning and evaluation, with light AI usage and unlimited manual editing.

  • Build

    For active hardware projects, with included AI usage and additional usage available.

  • Pro

    For larger projects and heavier AI usage, with hands-on support from experienced electrical engineers.

  • Teams

    For teams on shared projects, with pooled AI usage, member seats, and priority support.

Eligible individual plans include a free trial. Teams subscriptions start paid; trial and pricing terms depend on your current offer. See all plans

Not ready to pick a plan? Start for free

When to use which

Use CELUS when your team wants to capture requirements and create reference schematics and BOMs for ECAD. Choose Flux when the design continues into mechanical parts and firmware.

Questions

Give Flux your next requirement.

Explore individual plan offers, or book a demo with our team.

Start Free Trial Book a Demo

Sources

  1. CELUS: https://www.celus.io/
  2. About CELUS: https://www.celus.io/about