[WIP] Create model context protocol for MP's API

.gitignore

@@ -121,3 +121,4 @@ _autosummary
 
 uv.lock
 JANAF_*_data.json
+.gemini

mp_api/client/core/utils.py

@@ -1,5 +1,6 @@
 from __future__ import annotations
 
+import os
 import re
 from typing import TYPE_CHECKING, Literal
 
@@ -13,6 +14,8 @@
 if TYPE_CHECKING:
     from monty.json import MSONable
 
+_MAPI_SETTINGS = MAPIClientSettings()
+
 
 def _compare_emmet_ver(
     ref_version: str, op: Literal["==", ">", ">=", "<", "<="]
@@ -70,6 +73,25 @@ def _legacy_id_validation(id_list: list[str]) -> list[str]:
     return id_list
 
 
+def validate_api_key(api_key: str | None = None) -> str:
+    """Utility to find and pre-check validity of an API key."""
+    # SETTINGS tries to read API key from ~/.config/.pmgrc.yaml
+    api_key = api_key or os.getenv("MP_API_KEY")
+    if not api_key:
+        from pymatgen.core import SETTINGS
+
+        api_key = SETTINGS.get("PMG_MAPI_KEY")
+
+    if not api_key or len(api_key) != 32:
+        addendum = " Valid API keys are 32 characters." if api_key else ""
+        raise ValueError(
+            "Please obtain a valid API key from https://materialsproject.org/api "
+            f"and export it as an environment variable `MP_API_KEY`.{addendum}"
+        )
+
+    return api_key
+
+
 def validate_ids(id_list: list[str]):
     """Function to validate material and task IDs.
 
@@ -82,7 +104,7 @@ def validate_ids(id_list: list[str]):
     Returns:
         id_list: Returns original ID list if everything is formatted correctly.
     """
-    if len(id_list) > MAPIClientSettings().MAX_LIST_LENGTH:
+    if len(id_list) > _MAPI_SETTINGS.MAX_LIST_LENGTH:
         raise ValueError(
             "List of material/molecule IDs provided is too long. Consider removing the ID filter to automatically pull"
             " data for all IDs and filter locally."

mp_api/client/mprester.py

@@ -14,7 +14,7 @@
 from packaging import version
 from pymatgen.analysis.phase_diagram import PhaseDiagram
 from pymatgen.analysis.pourbaix_diagram import IonEntry
-from pymatgen.core import SETTINGS, Composition, Element, Structure
+from pymatgen.core import Composition, Element, Structure
 from pymatgen.core.ion import Ion
 from pymatgen.entries.computed_entries import ComputedStructureEntry
 from pymatgen.io.vasp import Chgcar
@@ -24,7 +24,12 @@
 from mp_api.client.core import BaseRester, MPRestError
 from mp_api.client.core._oxygen_evolution import OxygenEvolution
 from mp_api.client.core.settings import MAPIClientSettings
-from mp_api.client.core.utils import _compare_emmet_ver, load_json, validate_ids
+from mp_api.client.core.utils import (
+    _compare_emmet_ver,
+    load_json,
+    validate_api_key,
+    validate_ids,
+)
 from mp_api.client.routes import GeneralStoreRester, MessagesRester, UserSettingsRester
 from mp_api.client.routes.materials import (
     AbsorptionRester,
@@ -169,17 +174,7 @@ def __init__(
             mute_progress_bars:  Whether to mute progress bars.
 
         """
-        # SETTINGS tries to read API key from ~/.config/.pmgrc.yaml
-        api_key = api_key or os.getenv("MP_API_KEY") or SETTINGS.get("PMG_MAPI_KEY")
-
-        if api_key and len(api_key) != 32:
-            raise ValueError(
-                "Please use a new API key from https://materialsproject.org/api "
-                "Keys for the new API are 32 characters, whereas keys for the legacy "
-                "API are 16 characters."
-            )
-
-        self.api_key = api_key
+        self.api_key = validate_api_key(api_key)
         self.endpoint = endpoint or os.getenv(
             "MP_API_ENDPOINT", "https://api.materialsproject.org/"
         )

mp_api/mcp/__init__.py

@@ -0,0 +1 @@
+"""Get default MCP for Materials Project."""

mp_api/mcp/mp_mcp.py

@@ -0,0 +1,36 @@
+"""Define custom MCP tools for the Materials Project API."""
+from __future__ import annotations
+
+from urllib.parse import urljoin
+
+import httpx
+from fastmcp import FastMCP
+
+from mp_api.mcp.tools import MPMcpTools
+from mp_api.mcp.utils import _NeedsMPClient
+
+
+def get_mcp() -> FastMCP:
+    """MCP with finer depth of control over tool names."""
+    mp_mcp = FastMCP("Materials_Project_MCP")
+    mcp_tools = MPMcpTools()
+    for attr in {x for x in dir(mcp_tools) if x.startswith("get_")}:
+        mp_mcp.tool(getattr(mcp_tools, attr))
+
+    # Register tool to set the user's API key
+    mp_mcp.tool(mcp_tools.update_user_api_key)
+    return mp_mcp
+
+
+def get_bootstrap_mcp() -> FastMCP:
+    """Bootstrap an MP API MCP only from the OpenAPI spec."""
+    client = _NeedsMPClient().client
+
+    return FastMCP.from_openapi(
+        openapi_spec=httpx.get(urljoin(client.endpoint, "openapi.json")).json(),
+        client=httpx.AsyncClient(
+            base_url=client.endpoint,
+            headers={"x-api-key": client.api_key},
+        ),
+        name="MP_OpenAPI_MCP",
+    )

mp_api/mcp/server.py

@@ -0,0 +1,9 @@
+"""Run MCP."""
+from __future__ import annotations
+
+from mp_api.mcp.mp_mcp import get_mcp
+
+mcp = get_mcp()
+
+if __name__ == "__main__":
+    mcp.run()