BIMO MCP connects a compatible AI agent to Autodesk Revit through the local BIMO MCP Host. An agent can discover connected Revit sessions, inspect model context, and use the BIMO tools exposed by the current runtime. Operations that require arbitrary Python use a separate BIMO approval step.
Open the control surface at BIMO > Interact > AI Agent Access.
The current AI Agent Access flow is available in Revit 2024-2027 and the setup dialog does not require an open document.
Quick start with Codex
BIMO includes a built-in Codex setup through its local STDIO connector. Recommended setup:
Start Revit with BIMO Toolbar installed.
Open BIMO > Interact > AI Agent Access.
Select Enable AI Agent Access and confirm the persistent access choice.
Open Manage MCP client connections.
Select Configure Codex.
Fully restart Codex.
In a new agent conversation, ask it to check the available Revit sessions.
After configuration, Codex uses the installed BIMO connector. You do not need to manually store a bearer credential in the Codex configuration.
If Revit is closed, the MCP connection can still be available while the Revit session list is empty.
What AI Agent Access shows
The status dialog helps you verify:
whether the local BIMO MCP Host is available;
whether AI Agent Access is enabled for Revit;
whether the current Revit session is connected;
the local MCP endpoint;
whether Host starts at Windows sign-in;
whether unsafe Python is locally enabled;
whether the current license passes the access check required for unsafe Python.
The secret MCP credential is not displayed in the status view.
Manage the connection
Enable AI Agent Access
On first enable, BIMO asks you to confirm the persistent behavior. After confirmation, BIMO can start the local Host when needed and register the current and future Revit sessions for AI-agent access.
Disable AI Agent Access disconnects the bridge for the current session and keeps future Revit sessions disconnected. This option does not control the separate Windows sign-in startup setting for Host.
Manage MCP client connections
The dialog provides these actions:
Configure Codex - add or refresh the BIMO-owned Codex connection;
Remove Codex integration - remove only the connection owned by BIMO;
Copy generic MCP connection configuration - copy a URL and Authorization header for another MCP client.
Treat the copied generic configuration as a secret. Do not post it in issues, logs, repositories, or chat, and clear the clipboard after configuring the intended client.
Manage Bimo.McpHost
This area controls the local background process. You can:
enable or disable BIMO MCP Host startup at Windows sign-in;
restart Host gracefully.
Windows sign-in startup is independent from AI Agent Access and is not required for the normal Revit workflow.
Rotate MCP client credential
Rotation invalidates old MCP client credentials and creates replacements. Restart connected AI clients after rotation. For Codex, fully restarting the application is normally sufficient.
How BIMO MCP works
The local execution path is:
Host runs in the current Windows user session and connects MCP clients to running Revit instances. Revit API execution stays inside the BIMO add-in and uses the Revit-safe execution path.
By default, the MCP Host binds to the computer loopback interface rather than an externally reachable network address.
What an agent can do
Available capabilities depend on the installed BIMO version and the MCP tools exposed by that runtime. A typical workflow can include:
discover running Revit sessions;
select the intended project;
inspect the active document and view context;
analyze model data;
run an available BIMO tool or an approved Python operation;
verify the result after execution.
For model-changing operations, it is good practice to ask the agent to explain the intended changes before execution.
Python execution and approvals
Arbitrary Python is treated as an unsafe capability. It requires all of the following:
Allow unsafe Agent Python execution enabled in BIMO Settings;
a valid paid BIMO license under the current access check;
BIMO approval for the exact request.
Approval inside the AI client does not replace BIMO approval. If the code, document, or another material part of the request changes, BIMO may require a new approval.
Connect another MCP client
For another compatible MCP client, open Manage MCP client connections and select Copy generic MCP connection configuration.
BIMO copies the local endpoint and Authorization header. Paste them only into the intended client's configuration. Actual compatibility can depend on that client's MCP implementation and its ability to reach Windows localhost.
For Codex, the built-in Configure Codex flow is preferred over generic manual setup because it avoids persisting the bearer credential in config.toml.
If Codex stops connecting
Try these steps in order:
Confirm that BIMO is installed and AI Agent Access is enabled.
Open AI Agent Access and check Host status.
Run Manage Bimo.McpHost > Restart Bimo.McpHost.
Run Manage MCP client connections > Configure Codex again.
Fully close and restart Codex.
If you manually edited the BIMO block in %USERPROFILE%\.codex\config.toml, BIMO may no longer treat it as an owned configuration and will not automatically overwrite it. In that case, remove or disable only [mcp_servers.bimo], then run Configure Codex again.
Close Codex completely before repairing, upgrading, or uninstalling BIMO.
Important limitations
The current AI Agent Access flow targets Revit 2024-2027.
Capabilities of a specific AI client depend on its MCP implementation.
BIMO MCP does not make arbitrary model edits automatically safe or replace normal Revit project safeguards.
For important changes, review the agent's proposed plan and verify the resulting model state.