What is Heliciel MCP?
Heliciel MCP is the official remote server for Heliciel, the propeller, wing and turbine design software from the French firm Mecaflux, which has made fluid-mechanics software since 2005. An AI client connects to https://mcp.heliciel.com/mcp over streamable HTTP with OAuth 2.0 and PKCE, and each pass gets its own private hosted copy of the Windows application, driven through its own interface. Results come from Heliciel's blade element momentum (BEM) solver, not from the model.
The server exposes 99 tools, 24 of them read-only, for sizing from a plain-language brief, off-design sweeps, RPM, blade-count and chord optimisation including a genetic search, cavitation checks per blade element, an interactive 3D viewer and exports to STL, IGES, OBJ, JSON blade sections and CSV. It handles aircraft, drone, marine and fan propellers, wind and hydro turbines including ducted Kaplan runners, and wings and hydrofoils. Access is sold as prepaid time passes. The GitHub repository holds the documentation, registry manifest and a Claude plugin under Apache-2.0; Heliciel itself is proprietary.
How to install Heliciel MCP
https://mcp.heliciel.com/mcpIs Heliciel MCP worth it?
Heliciel MCP fixes the failure that makes general chat models dangerous for blade design: asked for a propeller, they invent plausible numbers. Here every thrust, torque, efficiency and cavitation figure comes from a tool call into Mecaflux's own solver, and the server is built to refuse rather than guess. Missing inputs are asked for, values inherited from a loaded model are flagged as such, and a quantity that has not been computed comes back as unavailable with a reason, never as a zero.
The physics has stated edges. Performance is ideal: surfaces are treated as smooth, lift and drag come from XFOIL, and compressibility is ignored, so accuracy falls at transonic and supersonic tip speeds. There is no acoustic model; blade-passing frequencies and tip speed are reported, a dB(A) level is not. Off-design and reverse-engineering modes are less precise than a design at optimal twist, and the vendor's own advice is to test the build and not put anyone at risk on a computation alone.
Running the real Windows application per session is why the numbers match the desktop product, and also why it is slow. The first call can take up to two and a half minutes if an instance has to start, only one computation runs at a time, and optimisations longer than 120 seconds return a pending status that a second tool polls. The catalogue is large at 99 tools, and 67 carry MCP's destructive hint because they change the open project, though all of them act only on the session's own instance and call no third party.
Pricing is per day, not per month. A pass costs €36 for one day, falling to €18 a day for 10 days or more, and the countdown starts when you activate it, not at purchase. The free discovery pass gives 1 day and 60 minutes of computation by e-mail but leaves out file and table exports, which are the point for anyone making parts, and Mecaflux says its €294 desktop licence is the better deal from 17 days of use. On data, the privacy policy says the service sees tool calls, not your conversation, keeps a call log with parameters cut to 300 characters for 29 days, erases session folders when an instance is recycled, expires download links after 60 minutes and uses nothing for training.
Where it earns its place
A mechanical engineer at a drone start-up
Size propellers for an 8 kg quadcopter with a 150% thrust margin
Describe the airframe; the server searches the design RPM for the target thrust, reports thrust, torque and efficiency, then exports STL for a test print. A 4-day pass at €120 covers a sizing round and one revision.
An engineer at a small hydropower consultancy
Check a Kaplan runner for 5 m³/s and a 4 m net head before quoting
Ask for the design and its efficiency curve, read cavitation per blade element and Heliciel's own design alerts, then export IGES into CAD. A single €36 day suits a one-off quote check.
A marine engineering lecturer
Show students how blade count changes efficiency
Use the free discovery pass to compare 2 and 3 blades in the 3D viewer during a class; 60 minutes of computation covers a demonstration, though exports are not included.
Before you commit
- Setup
- In Claude or ChatGPT, install from the connectors or plugin directory; elsewhere add https://mcp.heliciel.com/mcp as a custom connector and paste the pass key on the OAuth consent screen. The first call can take up to two and a half minutes while an instance starts.
- Integrations
- Claude, ChatGPT, Le Chat, LM Studio, Cursor, VS Code and other clients with streamable HTTP and OAuth 2.0 with PKCE. A Claude plugin in the repository adds four skills. Exports are STL, IGES, OBJ, JSON blade sections and CSV.
- Data and privacy
- Hosted by Mecaflux on OVH in France. The service receives tool calls, not conversations; call logs with parameters truncated to 300 characters are kept for 29 days. Session folders are erased when the instance is recycled, download links expire after 60 minutes, and data is not used for training.
- Cost at scale
- €36 for one day, €30 a day for 2 to 4 days, €24 a day for 5 to 9 days, €18 a day from 10 days; prepaid, with no renewal. Mecaflux says the €294 desktop licence is cheaper from 17 days of use.
- Limits
- One computation at a time; optimisations past 120 seconds return a pending status to poll. Results are ideal, incompressible BEM with XFOIL polars; no noise model; off-design modes are less precise.
What’s good
- Every figure comes from Heliciel's BEM solver
- Refuses to invent missing inputs or uncomputed values
- STL, IGES and OBJ exports for printing and CAD
- Covers propellers, fans, wind and hydro turbines and hydrofoils
What’s not
- Paid time passes; the free pass has no exports
- First call can take up to 2.5 minutes
- No acoustic model; ideal, incompressible flow
- 99 tools weigh on the context window
Best for
Engineers, drone builders and small marine or hydro firms who need a computed, exportable blade design for one project without buying a desktop licence.
Heliciel MCP alternatives
Heliciel MCP: common questions
- Is Heliciel MCP worth it?
- Turns a chat model into a front end for a real propeller solver that refuses to guess, at a day-pass price that suits a project rather than a habit. We rate it 3.7 out of 5.
- How much does Heliciel MCP cost?
- Prepaid passes from €36 for one day down to €18 a day for 10 days or more; a free 1-day discovery pass includes 60 minutes of computation but no exports. Desktop licence €294.
- What are the downsides of Heliciel MCP?
- Paid time passes; the free pass has no exports; first call can take up to 2.5 minutes; no acoustic model; ideal, incompressible flow; 99 tools weigh on the context window.
- Who is Heliciel MCP best for?
- Engineers, drone builders and small marine or hydro firms who need a computed, exportable blade design for one project without buying a desktop licence.
- How much does Heliciel MCP cost for a team or in production?
- €36 for one day, €30 a day for 2 to 4 days, €24 a day for 5 to 9 days, €18 a day from 10 days; prepaid, with no renewal. Mecaflux says the €294 desktop licence is cheaper from 17 days of use.
- Is Heliciel MCP safe for company data?
- Hosted by Mecaflux on OVH in France. The service receives tool calls, not conversations; call logs with parameters truncated to 300 characters are kept for 29 days. Session folders are erased when the instance is recycled, download links expire after 60 minutes, and data is not used for training.
- What are the best Heliciel MCP alternatives?
- The closest alternatives we have reviewed are OpenSCAD MCP and SolidCraft.
Answers checked Nov 14, 2026.