Model across four layers
Work through operational, system, logical and physical architecture. Each layer has a method guide. You map logical architecture to physical components; Spine records the mapping and checks its consequences.
Spine / Evaluation Edition
One model.
Four layers.
Connected decisions.
Free to evaluate
Spine turns what your team knows into one governed architecture model of your product, organized in four layers: operational, system, logical and physical. Start from the documents you already have, or from a short structured brief for something new.
No account. No sign-up. No procurement.
The Arcadia method
- 01
Operational
The needs and activities around your system.
- 02
System
What the system must do.
- 03
Logical
How functions and responsibilities connect.
- 04
Physical
Your mapping to physical components.
Windows is available from the Microsoft Store. The Mac download is available from the public release page. Free to evaluate; evaluation, not production use. No Spine account is required; connecting an AI assistant requires your own provider account.
01 / What Spine does
Make the architecture
easier to inspect.
Your own AI assistant proposes changes. Spine’s deterministic validation checks them against the method’s rules, explains rejected changes, and records the model’s history.
Bring your starting point
Import requirements through ReqIF. Register PDF, Word (.docx), Excel (.xlsx) and PowerPoint (.pptx) documents for your assistant to work from. Older .doc, .xls and .ppt formats aren’t supported.
Or start something new from a Seed. For a new feature or component, fill in a Feature Seed or Component Seed: a short structured form that says what it must do, how it is used, what could go wrong and who is responsible. Your AI proposes all four layers from it, through the gate, and Spine reports which of thirteen design categories, from interfaces and diagnostics to safety and cybersecurity, the model still lacks.
Build your first modelSee the connections
Explore architecture diagrams, trace relationships and inspect what depends on a proposed change. View the Architecture Document in Spine and save it as a PDF.
Trace and review changes
Keep a recorded change history, review model changes and examine their impact. Engineering judgment and design authority remain with the engineer.
Work with your own AI
Connect an external assistant that supports MCP tools, using your own provider account. Claude Code has been tested on macOS and Windows; other MCP assistants are not verified.
Prepare for a DFMEA
Export the design description as two files and import results into your model. The DFMEA itself is a separate service run by BIG Intelligence.
Explore the DFMEA serviceSee the example DFMEAEngineering support, with clear limits.
Spine is not certified under a functional-safety standard and is not a means of compliance. Verified, named human-only sign-off is not a shipped capability of the Evaluation Edition. HARA, TARA, SOTIF and DVP&R are coming soon for Nexus, the automotive edition; no release dates are announced. These capabilities and convergence are not included in the desktop download.
02 / Start with an example
Explore a model
before connecting AI.
Example: electric power steering
The built-in example contains 521 elements across all four Arcadia layers. Opening it creates your own editable copy of a generic electric power steering model, so you can explore diagrams, trace relationships and inspect the Architecture Document.
See the failure modes, causes, candidate trouble codes and open items in the DFMEA we ran on this example.
Download example DFMEA (PDF)Illustrative example, not a safety case.
The electric power steering example is licensed CC BY 4.0. Built by BIG Intelligence from NHTSA, Functional Safety Assessment of a Generic Electric Power Steering System, DOT HS 812 575 (2018), a US government public-domain report. Its requirements are illustrative and not NHTSA's official position.
03 / Installation & availability
Spine for your desktop.
Free to evaluate. No account. No sign-up. No procurement. Evaluate on your own designs on your own machine. Never send us proprietary or confidential material. The Evaluation Edition is for evaluation, not production use. Get the Windows edition from the Microsoft Store below. Download the Mac edition from the public release page below. Review the Spine Evaluation License and Privacy notice before installing.
Windows
From the
Microsoft Store.
64-bit Windows 10, version 1607 or later.
Microsoft Store listing: Spine-MBSE, published by Big Intelligence AI, LLC, the company behind BIG Intelligence. Installation and updates are handled by the Store.
Get Spine for Windows · Microsoft StoremacOS
Built for
Apple silicon.
macOS 15 (Sequoia) or later. Apple silicon (M1 or newer); no Intel build.
The release is provided as a disk image. Open the .dmg and drag Spine into Applications. Launch it from Applications; it needs to live there to update.
Download Spine for MacSpine is not available in the EU/EEA.
The Windows download is available from the Microsoft Store. The Mac download is available from the public release page. The Spine Evaluation License and Privacy notice are available to review now.
Planning production use?
A separate written agreement with BIG Intelligence is required. Please start with a conversation and don’t send proprietary or confidential designs by email.
04 / Getting started
Your assistant.
A connected model.
After installing Spine, connect your own MCP-capable assistant. Spine doesn’t include an AI assistant or provide an AI-provider key.
- 01
Use your own AI account
Install Claude Code and sign in to your own account. What your assistant reads is handled under your agreement with its provider. Evaluate on your own designs on your own machine. Never send us proprietary or confidential material.
- 02
Create a project in Spine
Choose New. Spine prepares the assistant connection in the project folder.
- 03
Open the project in Claude Code
Open a terminal in that project’s folder and run
claude. Review the requested connection and approve thembseserver if you want to connect it. - 04
Check the connection
Ask Claude what tools it has. Names beginning with
mbse_indicate the connection. Start by asking it to describe your model back to you. - 05
Build your first model
Start from your existing requirements or documents, or fill in a Seed for something new. Follow the guide below and download the Seed forms.
Explore with care.
Evaluate on your own designs on your own machine. Never send us proprietary or confidential material. Before connecting an external AI assistant, review what it can read and its provider’s data-handling terms. The Evaluation Edition does not provide a confidential upload channel.
05 / Build your first model
Build your first model.
Start from the documents you already have, or from a short structured brief for something new.
Requirements you already have
Import a ReqIF export from DOORS, Polarion, Codebeamer or Jama. The requirements land through the same gate as everything else.
Your documents
Register PDF, Word (.docx), Excel (.xlsx) and PowerPoint (.pptx) files for your AI to work from. Older .doc, .xls and .ppt files aren't read.
Something new: a Seed
Fill in a Feature Seed for a new feature, or a Component Seed for a part you buy or build as a unit: a short structured form that says what it must do, how it is used, what could go wrong and who is responsible. Plain language, no modelling terms.
New feature
Feature Seed
Read the PDF; fill in the Markdown file and hand it to your AI.
Part you buy or build
Component Seed
Read the PDF; fill in the Markdown file and hand it to your AI.
Using a seed form
- 01
Download the form.
Read the PDF; fill in the
.mdfile. - 02
Fill it in.
Replace each
___in plain language. You don't need modelling terms. Answer every required field, even briefly: the model can only be as complete as the form. - 03
Save it in your Spine project folder,
for example as
seeds/feature-seed-door-opener.md. - 04
Ask your AI to build the model from it,
for example: “Build the model from seeds/feature-seed-door-opener.md.” Your AI proposes the four layers, Spine's gate checks every step, and everything lands for your review.
- 05
See what's still missing.
Spine reports which of thirteen design categories, from interfaces and diagnostics to safety and cybersecurity, the model has nothing for yet. Fill those gaps next. In this release, a category you mark as not applicable is still listed as missing.
See an example first.
Not sure what a finished model looks like? Open “Example: electric power steering” from Spine's first screen before you start. Illustrative example, not a safety case.