pi-revit

Native Revit tools for Pi — ask about, query, script, and modify the open Autodesk Revit model from your terminal.

You: how many levels in the model?
Pi:  calls get_model_overview → "There are 14 levels in the Revit model."

You: select all structural columns
Pi:  get_elements → manage_selection → "Selected 222 structural columns."

You: rename level 'L1' to 'Ground Floor'
Pi:  calls set_parameters → "Done — Level 'L1' is now 'Ground Floor'."

How it works

Pi terminal session
   │  native tools (registered by the pi-revit extension)
   ▼
localhost HTTP bridge          ← per-start token; connection info in %APPDATA%\RevitBridge\
   │
   ▼
headless Revit add-in          ← no ribbon, no panels; just a bridge
   │  ExternalEvent queue (Revit API thread)
   ▼
Revit API                      ← reads run directly; writes run in one named transaction

The extension discovers its tools from the bridge at startup (/reload re-discovers), so the tool list always matches what the add-in serves. Everything between Pi and Revit is local-machine only; note that Pi sends conversation context and tool results to your selected LLM provider, like any Pi session.

Requirements

• Windows 10/11
• Autodesk Revit 2025, 2026, or 2027
• .NET SDK matching your Revit: .NET 8 for Revit 2025/2026, .NET 10 for Revit 2027
• Node.js 20.3+
• Pi coding agent: npm install -g --ignore-scripts @earendil-works/pi-coding-agent

Install

One-command install

Close Revit, then in PowerShell:

npx.cmd -y pi-revit

This installs the Pi package, builds and deploys the Revit bridge add-in, creates the Documents\pi-revit workspace, and installs the global pi-revit command.

Start Revit (click Always Load on the unsigned add-in prompt once) and open any project. No panel or ribbon appears — the add-in is headless.

Manual npm install

Use this if you prefer to run each step yourself:

# 1. Install the Pi package from npm. This registers the pi-revit extension and skill.
pi install npm:pi-revit

# 2. Go to the installed package folder.
cd "$env:USERPROFILE\.pi\agent\npm\node_modules\pi-revit"

# 3. Build + deploy the Revit add-in (RevitBridge.dll + the Roslyn DLLs for execute_csharp).
npm.cmd run deploy

# 4. Create the workspace and global pi-revit command.
npm.cmd run setup

For a non-default Revit install location, use the PowerShell deploy script directly and pass -RevitVersion / -RevitApiPath, e.g.:

powershell -ExecutionPolicy Bypass -File scripts\deploy.ps1 -RevitVersion 2027 -RevitApiPath "D:\Autodesk\Revit 2027"

Source install

Use this if you want to run directly from the GitHub checkout instead of the npm package:

git clone https://github.com/Triavision-ai/pi-revit.git
cd pi-revit
powershell -ExecutionPolicy Bypass -File scripts\deploy.ps1
pi install ./
powershell -ExecutionPolicy Bypass -File scripts\setup-workspace.ps1

Use it

Open any terminal — PowerShell, CMD, or Windows Terminal — and type:

pi-revit

That's all. Pi starts with the Revit tools ready:

> give me a model overview
> how many doors per level?
> select all structural columns

How this works: the setup step placed a small pi-revit command in the same folder as the pi command itself. That folder is on your system PATH — which is exactly why every terminal finds pi-revit, with no extra configuration. When you run it, it switches to your workspace at Documents\pi-revit and starts Pi there, so your conventions file (AGENTS.md) loads automatically and all Revit session history lives in one predictable place (pi-revit -c continues the last session). The Revit tools themselves are installed globally in Pi, and the extension discovers them live from the bridge inside Revit each time a session starts.

Per model, automatically: files sort themselves. Exports land in Documents\pi-revit\Models\<model title>\exports — the add-in derives the folder from the document being exported, so even a session that touches many models files every output under the right one, with no naming decision from you or the AI. Each model folder carries a model.txt recording the model's GUID and file path, so two models that share a title stay distinguishable.

Plain pi from any folder also works; pi-revit just adds the right working folder on top.

Tools

| Tool | What it does | |---|---| | ping | Is the bridge reachable? Revit version | | get_model_overview | Project info, units, levels, grids, category counts — call first | | get_elements | Query/count elements of any category: parameter filters, pagination | | get_element_details | Parameter values, location, bounding box, materials per element | | get_element_types | Element types / family symbols, optional placed-instance counts | | manage_selection | Get/set/clear the selection, zoom, temporary isolate | | set_parameters | Bulk parameter writes + rename anything (one transaction per batch) | | search_api_docs | Search the offline Revit API docs (works with no document open) | | execute_csharp | Run a C# script in one auto-managed transaction — the escape hatch | | capture_view | PNG snapshot of a view to a temp file (read the returned path to see it) | | export_documents | PDF/DWG/PNG/IFC export of sheets and views — auto-sorted into Models\<model>\exports | | get_model_health | Warnings grouped + worksets, phases, design options audit |

Limitations — read before using on real projects

• Write tools are unrestricted by design. set_parameters and execute_csharp modify the open model directly — there is no confirmation prompt and no sandbox. Writes run in named transactions, undoable with Ctrl+Z in Revit (execute_csharp rolls back entirely on any error; set_parameters commits partial successes and reports each failure), but the model is yours to protect: test on copies, keep backups, read the result's failed lists.
• The add-in multi-targets .NET 8 (Revit 2025/2026) and .NET 10 (Revit 2027); deploy.ps1 auto-detects the Revit versions you have installed and builds only the matching framework(s), so you only need the SDK for the Revit you run. Verified on Revit 2025 and 2027.
• One Revit instance at a time is discoverable (last started wins).
• A tool call that outlives its timeout is abandoned client-side but may still complete inside Revit — verify model state before re-issuing a write.
• Long-running scripts cannot be interrupted mid-execution (Revit's API is single-threaded); the execute_csharp budget is 120s.

Uninstall

npm install

Close Revit, then in PowerShell — from any folder outside the installed package (Windows cannot delete a folder your shell is standing in):

powershell -ExecutionPolicy Bypass -File "$env:USERPROFILE\.pi\agent\npm\node_modules\pi-revit\scripts\uninstall.ps1"

Source install

Close Revit, then in PowerShell from the GitHub checkout:

powershell -ExecutionPolicy Bypass -File scripts\uninstall.ps1

This removes the Revit bridge add-in (every installed Revit version), the global pi-revit command, the bridge runtime folder (%APPDATA%\RevitBridge\), and the Pi package registration (it tries both the npm and the source-install form, so no extra pi remove is needed for either install kind). Your workspace at Documents\pi-revit (notes + session history) is preserved — add -RemoveWorkspace to delete it too, or -RevitVersion 2026 to target a single Revit version. Pi itself is left installed; remove it with npm uninstall -g @earendil-works/pi-coding-agent if you want.