BIM Open Toolkit stores a model as plain tables (BIM Open Schema, or BOS) and turns each question about those tables into a small graph you can inspect and run again. A person and an AI agent build the graph with the same four edits, so an agent's answer arrives with the steps that produced it.
124 node kinds48 sample graphsIFC and Revit in, Excel, Parquet, and DuckDB outMIT licence
Both demos run entirely in the page. Nothing is installed or uploaded.
BIM OpenViewer
Seven 3D demos over three real buildings
Colour Schependomlaan by category or storey, cut a plan at any floor with solid cut faces, pull the storeys apart, point at an element and read its properties, and see the DigitalHub and Duplex disciplines drawn together. Then embed the same viewer in three lines.
Open the viewer gallery
BIM OpenNotebook
Twelve NRC notebooks, no server
Each turn is a plain-language request and a reply with its tables, charts, 3D views, and the graph that computed them. Start with door compliance: 14 doors checked against an 850 mm minimum leaf width, 8 pass and 6 fail, then handed to the architect as BCF issues.
Open the NRC walkthrough
One graph system, shown to five kinds of people. Each context is a profile of node packs, a page that says who it is for, and a handful of sample graphs over openly licensed buildings. The same graphs run by hand in the editor and by Claude through the MCP servers. The plan is docs/proposals/demo-contexts.md.
A table and a chart, with the query that made them one click away. Door schedules, rooms per storey, missing widths, source lineage.
Today: nine query graphs and an Ask box in the DuckDB studio, over a private model. Next: the same over Schependomlaan and DigitalHub (TKT-165).
A model coloured, sectioned, exploded, or ghosted by a query result, in the same pane the editor uses.
Today: eight 3D graphs over the Duplex and a seven-recipe lab. Next: both over a public building, every recipe a graph (TKT-166).
Rules as graphs: verdict tables, the model coloured by verdict, and an evidence report that names every input by hash.
Today: one door-width check from IFC to verdicts, 3D, chart, and report. Next: three checks over a public building (TKT-167).
IFC, BOS, DuckDB, Parquet, CSV, and XLSX in and out. Nothing writes until Run, and the run record says what was written.
Today: readers for every format; writers wait on Run from the editor. Next: four conversion graphs that run (TKT-168).
A published paper's eight answers computed by graphs, each run pinned by content hash, and the IFC written back byte-exact.
Today: the NRC walkthrough and its page. Next: presented as one reproducibility demo (TKT-169).
The toolkit is being split into one repository per product. A product marked moving has its repository and README, but its code is still inside the toolkit at the path given.
Draws building models in the browser with three.js: hundreds of thousands of instances, per-object colour, sections, exploded layouts, and picking. Reads BOS, BFAST, GLB, GLTF, OBJ, and STL.
Split out 2026-10-03; 17 npm packages.
A session with an AI agent kept as a document. Every result keeps a snapshot, and one backed by a graph can be evaluated again to show whether it changed.
Split out 2026-10-04; the notebook and the 3D pane, in two npm packages.
The graph system: node packs over tables, a headless host that evaluates graphs and records runs, the web editor, and an MCP server so an agent edits the graph a person sees.
Moving in phase 5. Code in src/flow and bimopenflow/web.
BIM Open Schema and IFC in .NET: read and write BOS, load and mesh IFC, convert IFC to BOS and DuckDB, and edit property sets without changing any other byte of the file.
Moving in phase 4, under way. Code in src/data and apps/.
The hub and the analyst application: the studio, the node packs that know about buildings, the samples over real models, the headless checks, and the NRC research work.
Hub. Holds every product not yet split out; phase 7 makes it the single entry point.
The figure layer: charts, drawings coloured by data, and composed figures from result tables, for the notebook, the studio, and reports.
New on 2026-10-11, not split out. Brand, a brief, and a demo page of 34 figures; no library yet. Charts still come from Flow's viz package.
The specification: five dependency-free C# files that define the BOS tables (entities, parameters, relations, geometry) stored as Parquet. No reader, writer, or converter.
Separate from the start.
| Phase | Step | State |
|---|---|---|
| 0 | Clear stale ticket claims and stray files | Done |
| 1 | Take Gratify through deps/ instead of a submodule | Done |
| 2 | Split out the viewer | Done |
| 3 | Let the host and editor take node packs and panes from whoever composes them | Next |
| 4 | Move src/data to bim-open-data | Under way |
| 5 | Move the graph system to bim-open-flow | Not started |
| 6 | Move the notebook to bim-open-notebook | Not started |
| 7 | Make the toolkit the entry point; tag the first combination that passes every check | Not started |
A model enters as an IFC file, or as a BOS file exported from Revit. Each layer below builds on the ones under it; the bottom row is general libraries that know nothing about buildings.
Each repository lists what it needs in deps.json and reads it only from its own deps/ folder. node deps.mjs fills that folder with a link to a sibling checkout or a clone at the pinned commit, so one checkout never holds two copies of a repository.
Needs Windows, the .NET 8 SDK, Node.js 20.19 or 22.12 and later, and Git. This path ends at a table graph in the editor over committed sample tables; no private model is needed.
git clone --recursive https://github.com/ara3d/bim-open-toolkit
cd bim-open-toolkit
node deps.mjsnode scripts/preflight.mjs
npm ci --prefix bimopenflow/webnode scripts/start-bim-flow.mjs --profile tablesBuilds the host, starts it on port 5224 and the editor on 5310, and waits until both answer. Open http://127.0.0.1:5310/ and choose a sample analysis. --stop ends both.
The 3D, DuckDB, and Ask demos over the Snowdon Towers model need a private copy of that model; docs/START.md and docs/DEMOS.md list every demo and what it needs.