Rosetta MCP Server README

Rosetta MCP Server

Author: Ariel J. Ben-Sasson

A Model Context Protocol (MCP) server that lets Cursor (or any MCP client) work with Rosetta, PyRosetta, and Biotite: run RosettaScripts, validate XML protocols, translate between Rosetta and Biotite, score structures, and query documentation -- all from your AI coding assistant.

What's new in v1.3.0 (vs v1.1.8 on npm)

New: Biotite integration

rosetta_to_biotite -- Find the Biotite equivalent of any Rosetta function with working example code (21 mappings covering structure I/O, SASA, RMSD, superimposition, secondary structure, contacts, hydrogen bonds, B-factors, angles, and more)
biotite_to_rosetta -- Reverse lookup: find the Rosetta equivalent of a Biotite function
translate_rosetta_script_to_biotite -- Translate entire RosettaScripts XML or PyRosetta code to Biotite Python. Design/optimization operations are flagged as Rosetta-only.
Fuzzy search with keyword aliases ("contacts", "binding energy", "surface area", "align", etc.)

Improved: XML to PyRosetta translator

37 element types supported (was 6): 11 movers, 9 filters, 10 selectors, 7 task operations
Full attribute handling: repeats, disable_design, cartesian, tolerance, threshold, distance, and more
Child element support: MoveMap (with Span), Reweight, ScoreFunction
Reports unrecognized elements so you know what needs manual work

Improved: Help and documentation

get_rosetta_help now accepts any topic: movers by name ("FastRelax"), concepts ("constraints", "docking"), or score functions ("ref2015") -- auto-fetches live docs from rosettacommons.org
search_rosetta_web_docs fallback: when DuckDuckGo is rate-limited, probes direct Rosetta docs URLs
get_cached_docs auto-caches: no need to call cache_cli_docs first
Expanded static help for score_functions, movers, filters, xml, and parameters

Improved: Scoring

pyrosetta_score: new per_residue option returns per-residue energy breakdown
scorefxn parameter now works (was ignored in v1.1.8)
Proper error messages for missing files instead of silent {}

Improved: Validation

validate_xml: new validate_against_schema option checks element names against the Rosetta XSD schema (catches typos like FastRleax)

MCP spec compliance fixes

tools/call responses now use correct { content: [{ type: "text", text }] } format
Tool errors return isError: true (not JSON-RPC errors)
Standard JSON-RPC error codes (-32601, -32700, -32603)
Removed false resources capability advertisement

Security fixes

User input no longer interpolated into Python code (uses env vars / stdin)
Temp files written to os.tmpdir() (not module directory)

Cleanup

Removed 3 redundant tools: list_functions (merged into get_rosetta_info), search_pyrosetta_wheels, cache_cli_docs (auto-cache in get_cached_docs)
Removed hardcoded personal paths
Fixed shadowed variables, async anti-patterns, dead code
18 tools (was 21), all with improved agent-oriented descriptions

Example: asking a naive question

This is what makes the MCP server powerful -- an AI agent can answer domain questions by calling the right tools automatically:

User asks in Cursor: "How do I relax my protein and what's the Biotite equivalent?"

The agent calls two MCP tools behind the scenes:

1. get_rosetta_help("FastRelax") returns 6000+ chars of live documentation:

FastRelax performs all-atom relaxation using the FastRelax protocol. Parameters include scorefxn, repeats, cartesian, disable_design, MoveMap configuration...

2. rosetta_to_biotite("FastRelax") returns:

config.json

{
  "found": true,
  "results": [{
    "rosetta": { "name": "FastRelax", "example": ["relax = FastRelax()", "relax.set_scorefxn(get_score_function('ref2015'))", "relax.apply(pose)"] },
    "biotite": null,
    "equivalence": "none_from_biotite",
    "notes": "Biotite does NOT perform structure optimization. These are Rosetta-specific capabilities."
  }]
}

The agent synthesizes: "FastRelax is Rosetta's all-atom relaxation protocol. Here's how to use it... Note: Biotite is analysis-only and has no equivalent -- you need PyRosetta for structure optimization."

Without the MCP, the agent would guess from training data and likely get parameter names or API signatures wrong.

What you get (18 tools)

Discovery & Help

Tool	Description
`get_rosetta_info`	All available score functions, movers, filters, selectors, parameters
`get_rosetta_help`	Help for any topic -- accepts mover names, concepts, or score functions
`pyrosetta_introspect`	Live PyRosetta API search with docs and signatures

Documentation

Tool	Description
`search_rosetta_web_docs`	Search rosettacommons.org documentation
`get_rosetta_web_doc`	Fetch and read a specific docs page
`get_cached_docs`	Search cached CLI help (auto-caches on first use)

Execution & Scoring

Tool	Description
`run_rosetta_scripts`	Run a RosettaScripts XML protocol on a PDB
`pyrosetta_score`	Score a PDB with optional per-residue breakdown

Translation

Tool	Description
`xml_to_pyrosetta`	XML to PyRosetta Python (37 element types)
`rosetta_to_biotite`	Find Biotite equivalent of a Rosetta function
`biotite_to_rosetta`	Find Rosetta equivalent of a Biotite function
`translate_rosetta_script_to_biotite`	Translate full scripts from Rosetta to Biotite

Validation & Schema

Tool	Description
`validate_xml`	Check XML syntax + optional schema validation
`rosetta_scripts_schema`	Generate XSD schema and extract element names

Environment

Tool	Description
`python_env_info`	Python version and installed packages
`check_pyrosetta`	Verify PyRosetta is available
`install_pyrosetta_installer`	Auto-install PyRosetta (10-30 min)
`find_rosetta_scripts`	Locate the rosetta_scripts binary

Quick start

1. Install from npm

Terminal

npm install -g rosetta-mcp-server

2. Set up Python environment

server.ts

# Create a venv with PyRosetta and Biotite
uv venv ~/.venvs/rosetta-mcp
~/.venvs/rosetta-mcp/bin/pip install pyrosetta-installer biotite
~/.venvs/rosetta-mcp/bin/python -c "import pyrosetta_installer as I; I.install_pyrosetta()"

Or skip this step -- PyRosetta auto-installs on first use (takes 10-30 min).

3. Configure your MCP client

Cursor (~/.cursor/mcp.json):

config.json

{
  "mcpServers": {
    "rosetta": {
      "command": "rosetta-mcp-server",
      "args": [],
      "env": {
        "ROSETTA_BIN": "/path/to/rosetta_scripts.default.macosclangrelease",
        "PYTHON_BIN": "/path/to/.venvs/rosetta-mcp/bin/python"
      }
    }
  }
}

Claude Desktop (~/Library/Application Support/Claude/claude_desktop_config.json):

config.json

{
  "mcpServers": {
    "rosetta": {
      "command": "rosetta-mcp-server",
      "env": {
        "ROSETTA_BIN": "/path/to/rosetta_scripts.default.macosclangrelease",
        "PYTHON_BIN": "/path/to/.venvs/rosetta-mcp/bin/python"
      }
    }
  }
}

Environment variables:

Variable	Required	Description
`ROSETTA_BIN`	No	Path to `rosetta_scripts` binary or its directory. If not set, searches common paths and PATH.
`PYTHON_BIN`	No	Python interpreter with PyRosetta/Biotite. Defaults to `python3`.
`MCP_DEBUG`	No	Set to `1` for debug logging to stderr.

4. Restart your editor

Open Settings -> MCP. The "rosetta" server should appear green with 18 tools.

XML to PyRosetta translation example

Input XML:

xml

<ROSETTASCRIPTS>
  <SCOREFXNS>
    <ScoreFunction name="ref" weights="ref2015"/>
  </SCOREFXNS>
  <RESIDUE_SELECTORS>
    <Chain name="chainA" chains="A"/>
  </RESIDUE_SELECTORS>
  <MOVERS>
    <FastRelax name="relax" scorefxn="ref" repeats="5" cartesian="true"/>
  </MOVERS>
  <PROTOCOLS>
    <Add mover="relax"/>
  </PROTOCOLS>
</ROSETTASCRIPTS>

Generated PyRosetta code:

server.ts

import pyrosetta
from pyrosetta import pose_from_pdb
from pyrosetta.rosetta.core.scoring import get_score_function
from pyrosetta.rosetta.core.select.residue_selector import *
from pyrosetta.rosetta.protocols.relax import *

pyrosetta.init("-mute all")

pose = pose_from_pdb("your_protein.pdb")

# Residue Selectors
chainSelector = ChainSelector()
chainSelector.set_chain_strings("A")

# Movers
fastRelax = FastRelax()
fastRelax.set_scorefxn(get_score_function("ref"))
fastRelax.set_default_repeats(5)
fastRelax.cartesian(True)

sfxn = get_score_function("ref2015")

# Apply movers
fastRelax.apply(pose)

pose.dump_pdb("output.pdb")
score = pose.energies().total_energy()
print(f"Final score: {score}")

Rosetta <-> Biotite mapping coverage

Category	Rosetta	Biotite	Equivalence
Structure I/O	`pose_from_pdb`	`PDBFile.read`	Full
Structure I/O	`pose.dump_pdb`	`PDBFile.write`	Full
Structure I/O	`pose_from_file` (CIF)	`CIFFile.read`	Full
Surface Analysis	`SasaMetric`	`biotite.structure.sasa`	Full
Alignment	`SuperimposeMover`	`biotite.structure.superimpose`	Full
RMSD	`all_atom_rmsd`	`biotite.structure.rmsd`	Full
Secondary Structure	`DsspMover`	`annotate_sse`	Partial
Sequence	`pose.sequence()`	`get_residues`	Full
Distance	`AtomPairConstraint`	`biotite.structure.distance`	Full
Angles	`pose.phi/psi/omega`	`biotite.structure.dihedral`	Full
Interface	`InterfaceAnalyzerMover`	`sasa` + selection	Partial
Database	`rcsb.pose_from_rcsb`	`rcsb.fetch`	Full
Selection	`ChainSelector` etc.	numpy boolean indexing	Full
Contacts	distance matrices	`CellList`	Partial
Ramachandran	`pose.phi/psi`	`dihedral_backbone`	Partial
H-bonds	`HBondSet`	`biotite.structure.hbond`	Partial
B-factors	`pdb_info().bfactor`	`AtomArray.b_factor`	Full
Center of Mass	`center_of_mass`	`mass_center`	Full
Scoring	`ScoreFunction`	None	Rosetta only
Optimization	`FastRelax`	None	Rosetta only
Design	`FastDesign`	None	Rosetta only

Troubleshooting

Server shows red in Cursor: Restart Cursor. Use absolute path in config (e.g., /opt/homebrew/bin/rosetta-mcp-server). Ensure Node 14+ and Python 3.8+.
run_rosetta_scripts fails: Verify ROSETTA_BIN points to a valid binary. Try "$ROSETTA_BIN" -help.
PyRosetta tools say "not available": Install via pip install pyrosetta-installer then run the installer, or let the MCP server auto-install on first use.
Biotite tools return no results: Install Biotite in the same Python env: pip install biotite
get_rosetta_help returns "No detailed help": Try the exact Rosetta class name (e.g., "FastRelax" not "relax"). The tool resolves common aliases but may miss unusual names.

Verify from the command line

server.ts

# Check version
echo '{"jsonrpc":"2.0","id":1,"method":"initialize","params":{"protocolVersion":"2024-11-05"}}' | rosetta-mcp-server 2>/dev/null | python3 -c "import sys,json; print(json.loads(sys.stdin.readline())['result']['serverInfo'])"

# List all tools
echo '{"jsonrpc":"2.0","id":1,"method":"tools/list","params":{}}' | rosetta-mcp-server 2>/dev/null | python3 -c "import sys,json; [print(t['name']) for t in json.loads(sys.stdin.readline())['result']['tools']]"

Development

Code

rosetta-mcp-server/
├── rosetta_mcp_wrapper.js   # Node MCP server (protocol + all 18 tools)
├── rosetta_mcp_server.py    # Python helper (static Rosetta data)
├── install_pyrosetta.js     # Standalone PyRosetta installer
├── package.json             # npm package config
└── README.md

License and attribution

MIT for this repository
Rosetta/PyRosetta: see RosettaCommons licenses; commercial use requires the appropriate license
Biotite: BSD 3-Clause license