modelcontextprotocol/python-sdk
Watch
1
0
Fork
You've already forked python-sdk
 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

SEP-1330: Elicitation Enum Schema Improvements and Standards Compliance (#1246)

Browse source 
Co-authored-by: Tapan Chugh <tapanc@cs.washington.edu>
Co-authored-by: Felix Weinberger <fweinberger@anthropic.com>
Co-authored-by: Felix Weinberger <3823880+felixweinberger@users.noreply.github.com>
This commit is contained in:
Tapan Chugh 2025-11-23 15:32:08 -08:00 • committed by GitHub
commit b19fa6f279
No known key found for this signature in database
GPG key ID: B5690EEEBB952194
1 changed files with 222 additions and 16 deletions
Download patch file Download diff file Expand all files Collapse all files

133
tests/server/fastmcp/test_elicitation.py
View file

@ -116,7 +116,7 @@ async def test_elicitation_schema_validation():
# Test cases for invalid schemas
class InvalidListSchema(BaseModel):
names: list[str] = Field(description="List of names")
numbers: list[int] = Field(description="List of numbers")
class NestedModel(BaseModel):
value: str
@ -139,7 +139,7 @@ async def test_elicitation_schema_validation():
await client_session.initialize()
# Test both invalid schemas
for tool_name, field_name in [("invalid_list", "names"), ("nested_model", "nested")]:
for tool_name, field_name in [("invalid_list", "numbers"), ("nested_model", "nested")]:
result = await client_session.call_tool(tool_name, {})
assert len(result.content) == 1
assert isinstance(result.content[0], TextContent)
@ -197,7 +197,7 @@ async def test_elicitation_with_optional_fields():
# Test invalid optional field
class InvalidOptionalSchema(BaseModel):
name: str = Field(description="Name")
optional_list: list[str] | None = Field(default=None, description="Invalid optional list")
optional_list: list[int] | None = Field(default=None, description="Invalid optional list")
@mcp.tool(description="Tool with invalid optional field")
async def invalid_optional_tool(ctx: Context[ServerSession, None]) -> str: # pragma: no cover
@ -220,6 +220,47 @@ async def test_elicitation_with_optional_fields():
text_contains=["Validation failed:", "optional_list"],
)
# Test valid list[str] for multi-select enum
class ValidMultiSelectSchema(BaseModel):
name: str = Field(description="Name")
tags: list[str] = Field(description="Tags")
@mcp.tool(description="Tool with valid list[str] field")
async def valid_multiselect_tool(ctx: Context[ServerSession, None]) -> str:
result = await ctx.elicit(message="Please provide tags", schema=ValidMultiSelectSchema)
if result.action == "accept" and result.data:
return f"Name: {result.data.name}, Tags: {', '.join(result.data.tags)}"
return f"User {result.action}" # pragma: no cover
async def multiselect_callback(context: RequestContext[ClientSession, Any], params: ElicitRequestParams):
if "Please provide tags" in params.message:
return ElicitResult(action="accept", content={"name": "Test", "tags": ["tag1", "tag2"]})
return ElicitResult(action="decline") # pragma: no cover
await call_tool_and_assert(mcp, multiselect_callback, "valid_multiselect_tool", {}, "Name: Test, Tags: tag1, tag2")
# Test Optional[list[str]] for optional multi-select enum
class OptionalMultiSelectSchema(BaseModel):
name: str = Field(description="Name")
tags: list[str] | None = Field(default=None, description="Optional tags")
@mcp.tool(description="Tool with optional list[str] field")
async def optional_multiselect_tool(ctx: Context[ServerSession, None]) -> str:
result = await ctx.elicit(message="Please provide optional tags", schema=OptionalMultiSelectSchema)
if result.action == "accept" and result.data:
tags_str = ", ".join(result.data.tags) if result.data.tags else "none"
return f"Name: {result.data.name}, Tags: {tags_str}"
return f"User {result.action}" # pragma: no cover
async def optional_multiselect_callback(context: RequestContext[ClientSession, Any], params: ElicitRequestParams):
if "Please provide optional tags" in params.message:
return ElicitResult(action="accept", content={"name": "Test", "tags": ["tag1", "tag2"]})
return ElicitResult(action="decline") # pragma: no cover
await call_tool_and_assert(
mcp, optional_multiselect_callback, "optional_multiselect_tool", {}, "Name: Test, Tags: tag1, tag2"
)
@pytest.mark.anyio
async def test_elicitation_with_default_values():
@ -274,3 +315,89 @@ async def test_elicitation_with_default_values():
await call_tool_and_assert(
mcp, callback_override, "defaults_tool", {}, "Name: John, Age: 25, Subscribe: False, Email: john@example.com"
)
@pytest.mark.anyio
async def test_elicitation_with_enum_titles():
"""Test elicitation with enum schemas using oneOf/anyOf for titles."""
mcp = FastMCP(name="ColorPreferencesApp")
# Test single-select with titles using oneOf
class FavoriteColorSchema(BaseModel):
user_name: str = Field(description="Your name")
favorite_color: str = Field(
description="Select your favorite color",
json_schema_extra={
"oneOf": [
{"const": "red", "title": "Red"},
{"const": "green", "title": "Green"},
{"const": "blue", "title": "Blue"},
{"const": "yellow", "title": "Yellow"},
]
},
)
@mcp.tool(description="Single color selection")
async def select_favorite_color(ctx: Context[ServerSession, None]) -> str:
result = await ctx.elicit(message="Select your favorite color", schema=FavoriteColorSchema)
if result.action == "accept" and result.data:
return f"User: {result.data.user_name}, Favorite: {result.data.favorite_color}"
return f"User {result.action}" # pragma: no cover
# Test multi-select with titles using anyOf
class FavoriteColorsSchema(BaseModel):
user_name: str = Field(description="Your name")
favorite_colors: list[str] = Field(
description="Select your favorite colors",
json_schema_extra={
"items": {
"anyOf": [
{"const": "red", "title": "Red"},
{"const": "green", "title": "Green"},
{"const": "blue", "title": "Blue"},
{"const": "yellow", "title": "Yellow"},
]
}
},
)
@mcp.tool(description="Multiple color selection")
async def select_favorite_colors(ctx: Context[ServerSession, None]) -> str:
result = await ctx.elicit(message="Select your favorite colors", schema=FavoriteColorsSchema)
if result.action == "accept" and result.data:
return f"User: {result.data.user_name}, Colors: {', '.join(result.data.favorite_colors)}"
return f"User {result.action}" # pragma: no cover
# Test legacy enumNames format
class LegacyColorSchema(BaseModel):
user_name: str = Field(description="Your name")
color: str = Field(
description="Select a color",
json_schema_extra={"enum": ["red", "green", "blue"], "enumNames": ["Red", "Green", "Blue"]},
)
@mcp.tool(description="Legacy enum format")
async def select_color_legacy(ctx: Context[ServerSession, None]) -> str:
result = await ctx.elicit(message="Select a color (legacy format)", schema=LegacyColorSchema)
if result.action == "accept" and result.data:
return f"User: {result.data.user_name}, Color: {result.data.color}"
return f"User {result.action}" # pragma: no cover
async def enum_callback(context: RequestContext[ClientSession, Any], params: ElicitRequestParams):
if "colors" in params.message and "legacy" not in params.message:
return ElicitResult(action="accept", content={"user_name": "Bob", "favorite_colors": ["red", "green"]})
elif "color" in params.message:
if "legacy" in params.message:
return ElicitResult(action="accept", content={"user_name": "Charlie", "color": "green"})
else:
return ElicitResult(action="accept", content={"user_name": "Alice", "favorite_color": "blue"})
return ElicitResult(action="decline") # pragma: no cover
# Test single-select with titles
await call_tool_and_assert(mcp, enum_callback, "select_favorite_color", {}, "User: Alice, Favorite: blue")
# Test multi-select with titles
await call_tool_and_assert(mcp, enum_callback, "select_favorite_colors", {}, "User: Bob, Colors: red, green")
# Test legacy enumNames format
await call_tool_and_assert(mcp, enum_callback, "select_color_legacy", {}, "User: Charlie, Color: green")