The browser loop is project, input, run, log. The same loop is available over MCP (Model Context Protocol): an HTTP interface that lets a language-model client call named tools instead of clicking the UI.
What the server does
Tools cover list/create project, write input.lammps, submit,
poll, and read stdout.txt. Authentication is a personal access
token (qmd_…) or OAuth 2.1 with PKCE. There is no anonymous
path; a missing credential returns HTTP 401.
It is the same account, credits, containers, and 1 / 2 / 4 CPU cores as the app. GPU (KOKKOS, NVIDIA L4) remains Pro-only, same as in the browser. Movies stay in the app; MCP returns text logs and dump excerpts.
Why
A large fraction of LAMMPS wall-clock on a laptop is typing, waiting, and fetching the log. An agent can do that once it has a credential and a short tool list. You still write the physics. The client does not invent a force field.
Setup
-
In the app, open Account.
Create an API token. Copy the
qmd_…secret (shown once). -
Point the client at
https://api.quickmdsim.com/mcpwithAuthorization: Bearer qmd_…. Grok-style connectors that require OAuth: client idquickmdsim-mcp, blank secret, PKCE only. Endpoints are on the MCP docs. -
Ask the client to call
whoami, create a project, write a small input, and submit.
Config snippets for Hermes, Claude, and Cursor are on quickmdsim.com/docs/mcp.
A first job
A 10-step Lennard-Jones quench is enough to test the pipe. Overwrite the
stub input.lammps, submit_job, poll
get_job until status_label is done,
then read_output on stdout.txt for the LAMMPS
banner.
Multi-file jobs match the app: write the potential
(Al99.eam.alloy, a data.lammps topology file,
whatever pair_coeff names) into the same project. Do not mark
the data file as the primary input.
Limits
- A token sees only that account.
- Revoke it on Account; the next call is 401.
- Email must be verified. Credits must be present.
- Free is 1 CPU core. Paid CPU can pass
vcpus2 or 4.
Docs: quickmdsim.com/docs/mcp. App: Account.