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BimSpeed AI — Connect Claude, Codex, Antigravity to Revit

Connect AI lets the AI assistant you already use (Claude, Codex/ChatGPT, Antigravity…) read the model and run BimSpeed tools inside Revit: count elements, look up levels and grids, reinforce columns and beams, reinforce the whole model, create beam drawings… The connection uses the MCP standard (Model Context Protocol) and runs entirely on your computer. Revit 2024–2027 are supported.

Ribbon: BimSpeed.STR → BimSpeedAI panel → Connect AI.

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open the BimSpeed.STR tab; click Connect AI. Open a model first; the window connects to the model that is open.

Jump to: Claude Desktop · Claude Code · Codex · Antigravity · check the connection · example prompts · troubleshooting

Interface versions and language

The earlier walkthrough describes the newer Connect AI card layout on Revit 2027. The Revit 2024 installation 2026.10.23.2046 uses three tabs and an application dropdown instead of the Revit 2027 card layout. The tool UI is Vietnamese; Vietnamese dialog screenshots are omitted from this English page. See the version-specific mapping below.

Requirements​

  • BimSpeed with an active license; Revit 2024–2027 with a model open.
  • An AI app that supports local (stdio) MCP servers, signed in: Claude Desktop, Claude Code, Codex (app/CLI/VS Code), Google Antigravity, OpenCode, or another MCP app (Cursor, VS Code, Gemini CLI…).
  • ChatGPT on the web cannot read local configuration; use the Codex app (ChatGPT for Windows with Codex) or the Codex CLI.

1. Open the Connect AI window​

Click Connect AI. The window is modeless (Revit stays usable) and opens a local connection for this Revit session.

Status light, Revit version and connected model: amber = ready, waiting for an AI app; green = an AI app has called Revit; red = disconnected. Which AI app called last. AI permission for this session (Chỉ đọc = read only, Cho phép chỉnh sửa = allow edits, Nâng cao: chạy C# = advanced: run C#). Pick your AI app; each card shows whether it is set up. Thiết lập tự động (Set up automatically) writes the configuration for the selected app.

Card states:

StateMeaningWhat to do
Đã thiết lập (green, set up)The app's config has a bimspeed server pointing to the right bridgeNothing; go to step 3
Cấu hình cũ, cần thiết lập lại (orange, outdated)bimspeed exists but points to an old bridge that was removed, typically after BimSpeed updated an older installClick Set up automatically, then restart the AI app
Chưa thiết lập (not set up)The app is installed but has no bimspeed entryClick Set up automatically
Chưa thấy trên máy (not found)The app was not foundInstall it (the Open … button opens the download page)
Dán cấu hình thủ công (manual)Other MCP appsSee manual configuration

2. Choose the AI permission​

The permission applies to the current Revit session only and resets to read only every time Revit starts.

PermissionThe AI canUse it when
Read only (default)Read the model, count, look up, preview rebar and batches. Never changes the modelQuestions, checks, planning
Allow editsCreate/modify/delete elements with BimSpeed tools (rebar, columns, beams, floors, grids, drawings…). Each command is one Undo stepYou want the AI to actually model
Advanced: run C#Same, plus send_code_to_revit: the AI writes and runs Revit API C# code. Revit 2025+ onlyOnly when you control what is sent to the AI

If the AI reports "Chưa cấp quyền cho tool" (tool not permitted), change the permission and ask again; no restart is needed.

3. Set up your AI app​

Follow the 3 steps in the window. Each step's number turns into a green ✓ when done.

  1. Write the MCP configuration: click Set up automatically. BimSpeed adds a bimspeed server to the app's config file, keeps everything else and saves the previous file as *.bimspeed.bak.
  2. Restart the AI app: apps read MCP configuration at startup. If it is running, quit it completely and reopen it.
  3. Ask a test question: click Sao chép câu hỏi (copy question) and paste it into a new chat. The AI should answer with the open model's name.

the Claude Desktop card shows set up; step 1 is ticked and names the file that was changed; the message bar tells you the next step.

Version-specific bridge path

The R24 2026.10.23.2046 UI points to the bridge inside its installed version folder. Copy the path from that session and recheck it after an update. The stable-path mechanism below applies to the newer interface.

Every AI app points to the same bridge program: %LOCALAPPDATA%\BimSpeedAI\mcp-bridge\BimSpeedMcpBridge.exe. BimSpeed refreshes this copy whenever you open Connect AI, so the configuration survives BimSpeed auto-updates and you only set it up once. If an AI app is currently running the bridge, the new copy is installed the next time, after the AI app is closed.

Claude Desktop​

  • Set up automatically writes claude_desktop_config.json. The Microsoft Store build uses %LOCALAPPDATA%\Packages\Claude_pzs8sxrjxfjjc\LocalCache\Roaming\Claude\; the regular installer uses %APPDATA%\Claude\. BimSpeed picks the right file.
  • Restart: right-click the Claude icon in the system tray → Quit, then reopen. Closing the window with × is not enough.
  • Check: in the chat box open the tools menu and look for bimspeed. The first time the AI calls a tool Claude asks for permission: choose Allow.
  • Organization accounts (Team/Enterprise) may have local MCP servers disabled by an admin.

Claude Code​

  • Set up automatically writes ~/.claude.json (user scope, works in every folder).
  • Open Claude Code starts a terminal in %LOCALAPPDATA%\BimSpeedAI\claude-workspace, which contains a CLAUDE.md telling the AI to prefer BimSpeed tools.
  • Check: start a new claude session and type /mcp, or run:
claude mcp list
# bimspeed: C:\Users\<name>\AppData\Local\BimSpeedAI\mcp-bridge\BimSpeedMcpBridge.exe - ✔ Connected
  • The Claude Code extension for VS Code shares this configuration.

Codex (app, CLI, VS Code)​

  • Set up automatically adds an [mcp_servers.bimspeed] table to ~/.codex/config.toml (or %CODEX_HOME%\config.toml if you set that variable). The Codex app (ChatGPT/Codex for Windows), the Codex CLI and the Codex VS Code extension share this file.
  • It sets startup_timeout_sec = 30 (antivirus may scan the bridge on first run for longer than the default 10 s) and tool_timeout_sec = 110 for long rebar commands.
  • Restart: quit the Codex app, or start a new codex session. Type /mcp to see bimspeed.

Outdated: the file has bimspeed but it points to a bridge that no longer exists (configured by an older BimSpeed, before an auto-update); the file that will be fixed; click Set up automatically; the rest of config.toml is kept.

Check from the CLI:

codex mcp get bimspeed
# bimspeed
#   enabled: true
#   transport: stdio
#   command: C:\Users\<name>\AppData\Local\BimSpeedAI\mcp-bridge\BimSpeedMcpBridge.exe
#   startup_timeout_sec: 30
#   tool_timeout_sec: 110

Antigravity​

  • Set up automatically writes ~/.gemini/config/mcp_config.json, shared by Antigravity IDE and Antigravity CLI (2.x). If the older ~/.gemini/antigravity/mcp_config.json exists, both files are updated.
  • Reload: in Antigravity open the Agent panel → … → MCP Servers → Refresh, or restart the IDE.

pick Antigravity; the config file that will be written; Set up automatically. Steps 2 and 3 are only ticked once the selected app itself has called Revit.

OpenCode and other MCP apps​

  • OpenCode: Set up automatically writes an mcp.bimspeed block to ~/.config/opencode/opencode.json; start a new opencode session.
  • Other MCP apps (Cursor, Windsurf, VS Code Copilot, Gemini CLI…): choose Ứng dụng MCP khác (other MCP app) → Sao chép cấu hình (copy configuration) and paste it into the app's MCP file (see manual configuration).

4. Check the connection​

Send the test question (copied by the button), in English if you prefer:

Call the bimspeed connection_status tool and tell me which model, view and Revit version are connected.

green light; Claude Desktop called at … with the tool that ran; all steps ticked. If the AI answers with the right model, view and Revit version, you are connected.

Chẩn đoán kết nối (diagnose, bottom right) tests bridge → Revit without an AI app. If it reports that the bridge reaches Revit but the AI app still has no tools, the problem is on the AI app side: re-check step 1 and restart the app.

5. Example prompts​

Talk to the AI as you would assign work to a colleague. It picks the right tool; for anything that writes, select Allow edits first.

GoalExample prompt
Model overviewShow model statistics by category and by level.
LookupList level 2 beams without rebar, with their sizes.
Column rebarI have 4 columns selected; reinforce them with the default settings.
Beam run rebarAnalyze the beam run on grid B level 2, preview 3Ø18 top, 3Ø20 bottom, Ø8 stirrups at 100/200, then create it.
Whole modelPreview reinforcing all beams and columns on level 3, skipping elements that already have rebar.
DrawingsCreate a beam drawing for that run on sheet BD-01 with the A3 title block.
ModelingCreate a 5×4 grid at 6 m spacing, levels at 0 and 3.6 m, and 300×300 columns at the intersections.

The AI uses the values you give; anything else comes from your current BimSpeed settings. The AI does not design structural reinforcement for you; review the results before issuing drawings.

Tool catalog​

The Danh mục tool (tool catalog) tab lists the 43 tools the AI can call, searchable by name, group or purpose. Each tool shows its description, parameters, result and an example input (the copy button puts the use case and example on the clipboard for the AI).

search; tools by group; parameter details. send_code_to_revit exists on Revit 2025 and later only.

Whole-model rebar​

The Thép toàn model (whole-model rebar) tab reinforces beams and columns in bulk without going through an AI (the AI can do the same with start_rebar_batch).

  1. Choose the elements (beams and columns / beams / columns), the scope (whole model / active view / selection) and the level (empty = all levels).
  2. Enter diameters and spacings to override; empty fields use your current BimSpeed settings.
  3. Xem trước phạm vi (preview scope) counts what will be reinforced and skipped → Bắt đầu đặt thép (start, requires Allow edits). Progress and created/error/skipped counts refresh every 2 s; Dừng sau cấu kiện hiện tại stops safely after the current element; Xuất báo cáo JSON saves per-element results.

Each element runs independently: a failing element is rolled back, finished ones are kept, Undo works per element. Beams need a 3D view to be open. The batch does not splice bars across spans or storeys, does not create sheets and skips linked models.

Advanced: manual configuration and several Revit sessions​

Expand Nâng cao: cấu hình thủ công, ghim phiên Revit (advanced) at the bottom of the connection tab.

alternative command for the selected app; pin this Revit session; configuration to paste by hand, already in the app's format; copy configuration, copy bridge path, open the app's official guide.

Sample configuration (replace <name> with your Windows user name):

Claude Desktop, Claude Code, Antigravity, Cursor, Gemini CLI
{
  "mcpServers": {
    "bimspeed": {
      "command": "C:\\Users\\<name>\\AppData\\Local\\BimSpeedAI\\mcp-bridge\\BimSpeedMcpBridge.exe",
      "args": []
    }
  }
}
Codex — ~/.codex/config.toml
[mcp_servers.bimspeed]
command = "C:\\Users\\<name>\\AppData\\Local\\BimSpeedAI\\mcp-bridge\\BimSpeedMcpBridge.exe"
args = []
startup_timeout_sec = 30
tool_timeout_sec = 110

Or use each app's command:

claude mcp add --scope user bimspeed -- "$env:LOCALAPPDATA\BimSpeedAI\mcp-bridge\BimSpeedMcpBridge.exe"
codex mcp add bimspeed -- "$env:LOCALAPPDATA\BimSpeedAI\mcp-bridge\BimSpeedMcpBridge.exe"

Several Revit sessions: without pinning, the AI uses the only Revit session that has Connect AI open. With two or more, the AI reports "Đang mở 2 phiên Revit…" (2 Revit sessions open). In the session you want, tick pin this Revit session → Set up automatically → restart the AI app. A pinned configuration contains the Revit process ID, so set it up again every time Revit restarts; unpin and set up again when you are done.

Restarting Revit while the AI app stays open: the bridge reconnects to the new session if exactly one session is open on the same model. If a different model is open, the AI reports that the previous session closed; restart the AI app to connect to the new model. This keeps write commands from landing in the wrong model.

Troubleshooting​

SymptomCauseFix
The AI app shows no bimspeed tools / Connection closed / Failed to connectThe AI app was not restarted, or its configuration was created by an older BimSpeed and points into the plugin folder, which is renamed by auto-updatesOpen Connect AI: if the card says outdated, click Set up automatically, then quit and reopen the AI app
Chưa có phiên Revit sẵn sàng (no Revit session ready)Connect AI was not opened in Revit, or it was disconnectedOpen a model → Connect AI. If disconnected, click Bật lại kết nối (reconnect)
Đang mở 2 phiên Revit…Several Revit sessions have Connect AI openClose the extra ones, or pin a session
Phiên Revit đã kết nối (…) không còn mở (connected session closed)Revit was closed or reopened on another modelReopen that model and click Connect AI, or restart the AI app
Chưa cấp quyền cho tool (tool not permitted)Permission is read onlyChoose Allow edits (or Advanced)
Model đang mở khác model đã kết nối (different model)You switched model after connectingClick Connect AI again on the target model
Revit chưa nhận yêu cầu / timeoutRevit has a dialog open or is busyClose the dialog, wait, retry. For write commands already sent, check the model before asking the AI to run them again
needs_selectionThe tool works on the selectionSelect elements in Revit and ask again
Codex says the server timed out on startupAntivirus scanning the bridge on first runSet up again (writes startup_timeout_sec = 30), or exclude %LOCALAPPDATA%\BimSpeedAI\mcp-bridge
Set up automatically cannot writeThe config file is broken, or declares bimspeed inlineFix the file using the sample configuration; BimSpeed never overwrites a file it cannot read

Security​

  • The Revit bridge listens on 127.0.0.1 and checks a random session token. A local process with a valid token can call it; this does not authenticate the caller's Windows account. Keep connection details and tokens private. Your chosen AI client may still send selected content to its AI provider; loopback describes the Revit bridge only.
  • Model data the AI reads through tools is sent to the AI provider like any chat content. Follow your company's project confidentiality rules.
  • The default is read only, and it resets every time Revit starts. Ngắt kết nối (disconnect) blocks all requests immediately.

Revit 2024 three-tab layout​

Installation 2026.10.23.2046 / Revit 2024 uses Kết nối (Connection), Danh mục MCP tools (Catalogue), and Thép toàn model (Whole-model reinforcement). The setup button is Thiết lập kết nối and an application dropdown replaces the cards described above. The actual dialog remains Vietnamese; no English-localized dialog capture is claimed.

Visible Vietnamese labelMeaning and operation
Quyền trong phiên nàyRead only / allow edits / advanced C#. Read only is the default; change access deliberately for the intended action.
Chọn ứng dụng AIChanges the setup instructions and example configuration. Selecting an app does not install its MCP entry or confirm connectivity.
Ghim đúng phiên Revit nàyTargets this process when several Revit instances are open. Recheck the target after restarting Revit.
Cấu hình thủ công / copy pasteDisplays bridge configuration, not design parameters.
Thiết lập kết nốiWrites/merges supported application configuration; some choices copy instructions for manual setup. Read the reported destination and restart the AI app.
Sao chép cấu hình / đường dẫn bridge / câu lệnh thửCopies text to the clipboard; it does not send a request or run a Revit tool.
Hướng dẫn chính thức / Mở ứng dụng / terminalOpens external documentation or an application. A ready status alone does not confirm an AI client connection.
Chẩn đoán bridge → RevitChecks the local communication path and displays diagnostics; it is not a reinforcement result.
Ngắt kết nốiStops the session local server. Reopen Connect AI to reconnect. Closing the window with X differs from Disconnect.
Danh mục MCP toolsSearch filters names/groups/use cases. Select a tool to read its inputs, outputs and example; copying the example does not execute it.

For Thép toàn model, select both / beam / column, scope project / activeview / selection, and Level (enter the Project Browser Level name; blank means all levels). The skip-existing checkbox excludes hosts recognized as already reinforced. Beam fields are top/bottom main diameter, stirrup diameter and end/midspan spacing a1/a2, all in mm. Column Cx/Cy are bar counts; main diameter is in mm. Blank fields inherit existing settings; zero is not an instruction to preserve settings. Advanced JSON takes priority over the input fields, so resolve conflicts before running.

Xem trước phạm vi previews eligible hosts without creating rebar. Bắt đầu đặt thép creates rebar and needs edit permission. Dừng sau cấu kiện hiện tại stops after the current host. Xuất toàn bộ kết quả saves a JSON report, not an RVT. A failed host is rolled back while completed hosts remain. Inspect per-host results and actual Rebar Properties before saving the RVT. The local UI inspection does not establish a successful reinforcement batch or external AI service call.