ipt-mcp

Name: ipt-mcp
Author: bimwright

ipt-mcp is an open-source (Apache-2.0) Model Context Protocol gateway that lets Claude Code — and any MCP-capable client — drive Autodesk Inventor 2022-2027 locally.

The agent speaks MCP over stdio. The server speaks NDJSON over a local authenticated transport (TCP or Named Pipe) to a per-version in-process Inventor add-in. The add-in marshals every command onto Inventor's STA thread and talks to the Inventor API.

Your model stays on your machine.

What ipt-mcp Is

Two processes, one local pipe:

Bimwright.Ipt.Server.exe — a .NET 8 MCP stdio server launched by Claude Code, Cursor, Cline, Codex, or another stdio MCP client. It has no Inventor reference; it only compiles the API-agnostic contract files, so it builds and runs on any machine with the .NET 8 SDK.
Bimwright.Ipt.Plugin.InvNN.dll — an ApplicationAddInServer add-in that loads inside Inventor.exe, runs a TCP or Named-Pipe listener, and executes commands on Inventor's main UI (STA) thread. One thin shell per Inventor year, all compiled from the same src/shared/** source glob.

Unlike Revit, Inventor has no ExternalEvent equivalent. The add-in marshals work onto the STA thread through a hidden message-only WinForms control (InventorStaDispatcher). See ARCHITECTURE.md for the full design.

Supported Inventor Versions

Inventor	Target framework	Transport	Notes
2022	`net48` (.NET Framework 4.8)	TCP	references `System.Windows.Forms` directly
2023	`net48` (.NET Framework 4.8)	TCP
2024	`net48` (.NET Framework 4.8)	TCP
2025	`net8.0-windows7.0`	Named Pipe	`UseWindowsForms`, `EnableDynamicLoading`
2026	`net8.0-windows7.0`	Named Pipe
2027	`net10.0-windows7.0`	Named Pipe	needs the .NET 10 SDK; honors `UseInventorAssemblyContext`

The MCP server is one process, unaffected by the Inventor version — it just forwards JSON envelopes.
TCP for 2022-2024 (net48 add-ins); Named Pipe for 2025-2027 — Named Pipe avoids the loopback-firewall prompt on modern Windows.
Inventor moved desktop add-in development off .NET Framework starting in 2025: .NET 8 for 2025/2026, .NET 10 for 2027. (.NET 8 add-ins remain binary-compatible on 2027, but net10 is the native target.)
Use 4-digit calendar years (2022..2027) everywhere — never legacy version codes.

Status: verified. Phases 1-3 are complete and green (58 MCP tools by default, or 59 with send_code; server + tests build with no Inventor installed), and the Inventor-API handlers have been exercised against a live Inventor session. As always, test against your own templates before trusting it on production models.

Install / Wire an MCP Client

Download the client setup ZIP from GitHub Releases. It includes a self-contained MCP server and Inventor add-in years compiled against real interop (see manifest.json). The v0.1.0 ZIP ships 2025 and 2027. Other years: build locally — do not ship SkipInventorReferenceCheck shape-only DLLs.

$tag = (Invoke-RestMethod https://api.github.com/repos/bimwright/ipt-mcp/releases/latest).tag_name
$zip = "$env:TEMP\IptMcp.Setup-$tag-win-x64.zip"
$dir = "$env:TEMP\IptMcp.Setup-$tag-win-x64"
Invoke-WebRequest "https://github.com/bimwright/ipt-mcp/releases/download/$tag/IptMcp.Setup-$tag-win-x64.zip" -OutFile $zip
Expand-Archive $zip -DestinationPath $dir -Force

powershell -ExecutionPolicy Bypass -File "$dir\install.ps1" -WhatIf
powershell -ExecutionPolicy Bypass -File "$dir\install.ps1"

Deploys %APPDATA%\Autodesk\ApplicationPlugins\Bimwright.Ipt.bundle\ and ipt-mcp.exe under %LOCALAPPDATA%\Bimwright\ipt-mcp\server\<version>\. Restart Inventor. Point your MCP client at that ipt-mcp.exe path. Pin a year with --target 2025 or BIMWRIGHT_INVENTOR_TARGET=2025.

Do not dotnet tool install -g Bimwright.Ipt.Server — that is not the supported client install.

Developer: pwsh scripts/package-bundle.ps1 on a box with Inventor interop (skip years without SDK). Close Inventor before rebuilds.

Add-in discovery is automatic: each running add-in writes %LOCALAPPDATA%\Bimwright\ipt-mcp\inventor-<year>-<pid>.json. With more than one Inventor open, call inventor_list_available_targets then inventor_switch_target.

inventor_send_code stays off unless both server (--enable-send-code / BIMWRIGHT_INVENTOR_ENABLE_SEND_CODE=1) and plugin (BIMWRIGHT_INVENTOR_PLUGIN_ENABLE_SEND_CODE=1) opt in — see Safety.

Build & Develop

Autodesk Inventor binaries and the Inventor SDK are not redistributed in this repo (see Not Redistributed). Building the server and tests needs only the .NET 8 SDK; building a per-version add-in needs the matching SDK plus the Inventor interop reference assembly.

# Server + tests (server-only; NO Inventor required — works on any machine with the .NET 8 SDK):
dotnet build src/IptMcp.sln -c Debug
dotnet test  tests/Bimwright.Ipt.Tests -c Debug

# Legacy TFM compatibility check using the installed 2027 interop reference:
dotnet build src/plugin-inv24 -c Debug /p:InventorInteropDir="C:\Program Files\Common Files\Autodesk Shared\Extensions 2027\Framework\Interop"
dotnet build src/plugin-inv27 -c Debug   # real 2027 interop compile; needs the .NET 10 SDK

# A per-version add-in always needs an Inventor interop reference. For a legacy TFM compatibility
# check, point InventorInteropDir at an installed compatible interop; real release builds use the
# matching year's default path.

The server explicit-includes only shared/Contracts/* + shared/Security/* (+ ToolBaker), so it compiles with no Inventor SDK present.
Each add-in uses <Compile Include="..\shared\**\*.cs" /> to pull in everything, including the API-touching Infrastructure/Plugin/Handlers.
The default interop hint path is C:\Program Files\Common Files\Autodesk Shared\Extensions <year>\Framework\Interop\Autodesk.Inventor.Interop.dll.
Building add-in 2027 needs the .NET 10 SDK installed.
Close Inventor before deploying add-in DLLs it would otherwise lock.

Tool Surface

The full surface is 58 tools by default when all platform toolsets are enabled, or 59 tools when inventor_send_code is enabled (opt-in). Every MCP-facing name is prefixed inventor_. Tools are grouped into toolset classes; --toolsets sketch,feature and --read-only gate which ones register so weak models never see disabled tools.

Default-on toolsets: meta, query, document, parameters, properties, sketch, feature, export, assembly, assembly_query, toolbaker, toolbaker_write.
Off by default: code (the send_code escape hatch — opt-in only).

All length inputs are in mm, angles in degrees; the add-in converts to Inventor's internal centimetres/radians.

meta (3) — server-side target tools, never round-trip to the add-in; stay exposed under `--read-only`

Tool	Description
`inventor_list_available_targets`	List detected live Inventor add-in targets (year, pid, transport, active document).
`inventor_get_current_target`	Report the server's currently selected target, or `NO_TARGET` if none is live.
`inventor_switch_target`	Select the active target by descriptor id, Inventor year, process id, or pipe/session name. Server-side only.

query (3) — read-only document/health probes

Tool	Description
`inventor_health`	Probe the active add-in: inventor_year, process_id, whether a document is open, active document type.
`inventor_list_open_documents`	List all open documents: title, path, type, and which is active.
`inventor_get_document_info`	Get the active document's title, full path, and document type.

document (7) — document lifecycle (write)

Tool	Description
`inventor_new_part`	Create a new part document (.ipt); optional template path.
`inventor_new_assembly`	Create a new assembly document (.iam); optional template path.
`inventor_open_document`	Open an existing document from a full path and make it active.
`inventor_save_document`	Save the active document, or Save-As to a given path.
`inventor_close_document`	Close the active document; `save=true` saves first.
`inventor_set_units`	Set the active document's length unit (mm, cm, m, in, ft).
`inventor_set_material`	Assign a material to the active part by name.

parameters (4) — model & user parameters (write)

Tool	Description
`inventor_list_parameters`	List parameters (model + user): name, expression, value, unit, kind.
`inventor_get_parameter`	Get one parameter by name: expression, value, unit.
`inventor_set_parameter`	Set an existing parameter's expression/value, then update the document.
`inventor_create_parameter`	Create a new user parameter (name, expression, unit).

properties (3) — iProperties & mass properties (write)

Tool	Description
`inventor_get_iproperty`	Get an iProperty value by property-set and property name.
`inventor_set_iproperty`	Set an iProperty value.
`inventor_get_mass_properties`	Mass (g), volume (mm³), surface area (mm²), centre of mass, bounding box.

sketch (9) — 2D sketch geometry & constraints (write)

Tool	Description
`inventor_create_sketch`	Create a 2D sketch on a plane (XY/XZ/YZ or a face/work-plane reference).
`inventor_project_geometry`	Project model edges/vertices (by edge ids) into the active sketch.
`inventor_draw_line`	Draw a sketch line from (x1,y1) to (x2,y2).
`inventor_draw_circle`	Draw a sketch circle from centre + radius.
`inventor_draw_rectangle`	Draw a two-point sketch rectangle.
`inventor_draw_arc`	Draw a sketch arc (centre, radius, start/end angle).
`inventor_add_sketch_dimension`	Add a driving dimension constraint to a sketch entity.
`inventor_add_sketch_constraint`	Add a geometric constraint (coincident, parallel, tangent, …).
`inventor_close_sketch`	Finish editing a sketch (exit sketch edit mode).

feature (9) — solid & work features (write)

Tool	Description
`inventor_extrude`	Extrude a named sketch (distance, join/cut/intersect, direction).
`inventor_revolve`	Revolve a named sketch about an axis (angle, operation).
`inventor_fillet`	Add a constant-radius edge fillet over model edges.
`inventor_chamfer`	Add an equal-distance edge chamfer over model edges.
`inventor_create_work_plane`	Create a work plane (offset, three_points, or tangent).
`inventor_create_work_axis`	Create a work axis (two_points, edge, plane_intersection, normal_to_face_through_point).
`inventor_hole`	Drilled/counterbore/countersink holes on a deterministically-selected planar face; optional tapped-thread metadata.
`inventor_circular_pattern`	Circular-pattern part features around a named axis (count over an angle).
`inventor_rectangular_pattern`	Rectangular-pattern part features along one or two named axes.

export (6) — view capture & geometry export (write)

Tool	Description
`inventor_capture_view`	Capture the active view as a bounded base64 PNG, or write to an output path.
`inventor_export_step`	Export the active part/assembly to STEP (.stp/.step).
`inventor_export_stl`	Export the active part/assembly to STL (.stl).
`inventor_export_dxf`	Export a 2D DXF; must declare source (`sketch` or `flat_pattern`).
`inventor_view_fit`	Zoom-fit the active view to the model extents (run before capture).
`inventor_set_view_orientation`	Set a standard camera orientation (iso/front/top/…) for multi-angle captures.

Export paths must be absolute and under an allowed output root (user profile or temp).

assembly (3, write) — compose assemblies via relationships, not coordinates

Tool	Description
`inventor_place_occurrence`	Place a component (.ipt/.iam) into the active assembly; optional initial pose + grounded.
`inventor_add_constraint`	Constrain two named refs (mate/flush/insert/angle); response carries `health` — always check it.
`inventor_create_imate`	Author a named iMate on the active part using a deterministic face selector.

assembly_query (5, read-only) — numeric self-check battery; survives `--read-only`

Tool	Description
`inventor_list_interfaces`	List named interfaces (iMates, work features, origin geometry) of the doc or one occurrence.
`inventor_check_interference`	Run interference analysis; returns pair count and total/per-pair volumes.
`inventor_measure_min_distance`	Minimum 3D distance (mm) between two occurrences or named refs.
`inventor_get_assembly_bom`	BOM + occurrence tree with grounded flag and translation/rotation degrees of freedom.
`inventor_list_constraints`	Read back every constraint with type, `health`, suppressed flag and the two occurrence names.

code (1) — opt-in escape hatch (OFF by default)

Tool	Description
`inventor_send_code`	Dangerous, opt-in only. Execute a C# snippet in-process against `Inventor.Application`. Disabled unless both server and add-in opt in (else `SEND_CODE_DISABLED`); banned APIs (file/process/network/environment) are rejected.

toolbaker (3, read-only) — operate purely on the server-side bake database

Tool	Description
`inventor_list_baked_tools`	List all verified, compiled, registered baked tools.
`inventor_list_bake_suggestions`	List active ToolBaker suggestions from recurrent workflows.
`inventor_create_bake_issue_draft`	Create a GitHub issue draft for a suggestion (without submitting).

toolbaker_write (3, write) — run baked tools and manage the suggestion lifecycle

Tool	Description
`inventor_run_baked_tool`	Execute a registered baked tool by name with JSON parameters.
`inventor_accept_bake_suggestion`	Accept a suggestion: validate + compile + apply + persist as a baked tool.
`inventor_dismiss_bake_suggestion`	Dismiss or snooze an active suggestion.

Safety

Short version: your model stays on your machine, and write/dangerous tools are gated.

Read-only mode. --read-only (or BIMWRIGHT_INVENTOR_READ_ONLY=1) removes every write-capable toolset (document, parameters, properties, sketch, feature, export, assembly, code, toolbaker_write) but keeps meta + query + assembly_query + read-only toolbaker, and keeps inventor_switch_target exposed. The server sends read-only mode in each command envelope; the add-in also honors BIMWRIGHT_INVENTOR_PLUGIN_READ_ONLY=1 / BIMWRIGHT_INVENTOR_READ_ONLY=1. A write command under enforced read-only returns READ_ONLY.
send_code two-sided opt-in. inventor_send_code is disabled by default. It is exposed only when both gates are set: the server with --enable-send-code (or BIMWRIGHT_INVENTOR_ENABLE_SEND_CODE=1) and the add-in process with BIMWRIGHT_INVENTOR_PLUGIN_ENABLE_SEND_CODE=1. Otherwise the dispatcher returns SEND_CODE_DISABLED. Banned APIs (file/process/network/environment) are rejected.
Local, authenticated transport. TCP binds loopback; Named Pipe is local-machine scoped. Each per-session descriptor carries a random auth token, but MCP meta tools never return it.
Sanitized errors. Error messages returned to the model are sanitized to avoid leaking absolute paths/secrets.
ToolBaker controls. ToolBaker is enabled by default. It can be completely disabled by passing the --disable-toolbaker CLI flag or setting BIMWRIGHT_INVENTOR_ENABLE_TOOLBAKER=0.
Allowed export paths. File export tools validate that output_path points to a safe folder (within User Profile or Temp directory). You can define an additional allowed root folder by setting the BIMWRIGHT_INVENTOR_EXPORT_ROOT environment variable.

ToolBaker turns repeated local workflows into personal, verified tools: suggestions surface through inventor_list_bake_suggestions, you explicitly accept one with inventor_accept_bake_suggestion (validate → compile → apply → persist), and accepted tools become callable through inventor_list_baked_tools / inventor_run_baked_tool. The bake database and audit log live locally under %LOCALAPPDATA%\Bimwright\ipt-mcp\baked\. See docs/toolbaker.md and SECURITY.md.

Not Redistributed

This project does not redistribute Autodesk Inventor binaries or the Inventor SDK / interop DLLs. The shipped server and unit tests build and run with no Inventor present. Building the per-version add-ins requires a local Inventor installation or the matching interop reference assemblies (Autodesk.Inventor.Interop.dll), supplied via the default Autodesk shared-extensions path or an explicit /p:InventorInteropDir=... MSBuild property. Running the gateway against Inventor requires a licensed Inventor install.

The bimwright family

Hand-forged MCP gateways for the AEC toolchain — one architecture, predictable / auditable / reversible:

rvt-mcp — Autodesk® Revit®
dwg-mcp — Autodesk® AutoCAD®
nwd-mcp — Autodesk® Navisworks®
ipt-mcp — Autodesk® Inventor®
bim-wiki — Vietnamese-first BIM knowledge base

License

Apache-2.0. See LICENSE.

Inventor and Autodesk are registered trademarks of Autodesk, Inc. bimwright is an independent open-source project and is not affiliated with, sponsored by, or endorsed by Autodesk, Inc.