fleet-memory/hindsight-api/tests/test_mcp_endpoint_routing.py
DK09876 e798979733
Harden MCP server: fix routing, validation, and usage metering (#341)
* fix: move mental model usage metering into engine for MCP support

Mental model validation hooks (validate_mental_model_get, validate_mental_model_refresh)
were only called in REST HTTP handlers, not in the engine. MCP tools call engine methods
directly, so usage metering was skipped entirely for MCP mental model operations.

Moved pre-validation and post-completion hooks into memory_engine.py (matching the
retain/recall/reflect pattern) and removed the duplicate code from http.py.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* fix: remove double validation from create_mental_model and add internal checks

- Remove pre-validation from create_mental_model since callers always call
  submit_async_refresh_mental_model next (which validates), preventing
  double credit checks
- Add is_internal checks to mental model metering validators (matching
  the existing pattern for recall/reflect) so background worker tasks
  skip billing

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* fix: prevent 307 redirect on /mcp that breaks MCP tool discovery

Starlette's Mount class redirects /mcp to /mcp/ with a 307 Temporary
Redirect. Many MCP clients don't follow POST redirects, which causes
tool discovery to fail (0 tools discovered despite successful auth).

Add _MCPPathRewriteMiddleware that rewrites /mcp to /mcp/ at the ASGI
level before routing, preventing the redirect entirely. Both /mcp and
/mcp/ now work identically.

Add regression test test_mcp_no_trailing_slash_works to verify URLs
with and without trailing slashes discover tools correctly.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* harden MCP server for real-world usage

- Remove MCP_ENDPOINTS blocklist so banks named "sse"/"messages" route correctly
- Scope SSE body rewriting to text/event-stream responses only to prevent data corruption
- Add _validate_mental_model_inputs for name, source_query, max_tokens validation in MCP tools
- Improve "not found" error messages to include bank_id context
- Fix fragile tool count assertions (exact → minimum bounds)
- Add integration tests: tool execution, input validation, edge-case bank names
- Add unit tests for validation helper and tool-level validation

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* refactor: replace Mount + rewrite middleware with wrapping middleware

Starlette's Mount class redirects /mcp -> /mcp/ with 307, which MCP clients
don't follow. Previously we patched this with _MCPPathRewriteMiddleware.

Now MCPMiddleware wraps the FastAPI app directly via add_middleware, intercepting
/mcp* requests before they reach Starlette's router. No Mount means no redirect.

- Remove _MCPPathRewriteMiddleware (no longer needed)
- Remove app.mount() call
- Add prefix parameter to MCPMiddleware
- Use app.add_middleware() for proper Starlette integration
- Simplify path stripping (just remove prefix, no mount/root_path handling)
- Update routing test to match current behavior (no MCP_ENDPOINTS blocklist)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* fix: update stale docstring referencing removed _MCPPathRewriteMiddleware

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
2026-02-11 10:41:20 +01:00

280 lines
13 KiB
Python

"""Integration test for MCP endpoint routing.
This test verifies that /mcp/ and /mcp/{bank_id}/ expose different tool sets,
and that URLs with or without trailing slashes both work (no 307 redirect).
"""
import httpx
import pytest
from mcp.client.session import ClientSession
from mcp.client.streamable_http import streamable_http_client
@pytest.mark.asyncio
async def test_mcp_endpoint_routing_integration(memory):
"""Test that multi-bank and single-bank endpoints expose different tools using StreamableHTTP.
This is a regression test for issue #317 where /mcp/{bank_id}/ was incorrectly
exposing all tools (including list_banks) and bank_id parameters.
"""
from hindsight_api.api import create_app
# Create app with MCP enabled
app = create_app(memory, mcp_api_enabled=True, initialize_memory=False)
# Use the app's lifespan context to properly initialize MCP servers
async with app.router.lifespan_context(app):
# Create an HTTPX client that routes to our ASGI app
from httpx import ASGITransport
async with httpx.AsyncClient(transport=ASGITransport(app=app), base_url="http://test") as http_client:
# Test 1: Multi-bank endpoint /mcp/
async with streamable_http_client("http://test/mcp/", http_client=http_client) as (
read_stream,
write_stream,
_,
):
async with ClientSession(read_stream, write_stream) as session:
await session.initialize()
multi_result = await session.list_tools()
multi_tools = {t.name for t in multi_result.tools}
# Multi-bank should have all tools including bank management and mental models
assert "retain" in multi_tools
assert "recall" in multi_tools
assert "reflect" in multi_tools
assert "list_banks" in multi_tools, "Multi-bank should expose list_banks"
assert "create_bank" in multi_tools, "Multi-bank should expose create_bank"
assert "list_mental_models" in multi_tools, "Multi-bank should expose list_mental_models"
assert "create_mental_model" in multi_tools, "Multi-bank should expose create_mental_model"
assert "get_mental_model" in multi_tools, "Multi-bank should expose get_mental_model"
assert "update_mental_model" in multi_tools, "Multi-bank should expose update_mental_model"
assert "delete_mental_model" in multi_tools, "Multi-bank should expose delete_mental_model"
assert "refresh_mental_model" in multi_tools, "Multi-bank should expose refresh_mental_model"
# Multi-bank retain should have bank_id parameter
retain_tool = next((t for t in multi_result.tools if t.name == "retain"), None)
assert retain_tool is not None
multi_params = set(retain_tool.inputSchema.get("properties", {}).keys())
assert "bank_id" in multi_params, "Multi-bank retain should have bank_id parameter"
# Test 2: Single-bank endpoint /mcp/test-bank/
async with streamable_http_client("http://test/mcp/test-bank/", http_client=http_client) as (
read_stream,
write_stream,
_,
):
async with ClientSession(read_stream, write_stream) as session:
await session.initialize()
single_result = await session.list_tools()
single_tools = {t.name for t in single_result.tools}
# Single-bank should have scoped tools including mental models (no bank management)
assert "retain" in single_tools
assert "recall" in single_tools
assert "reflect" in single_tools
assert "list_mental_models" in single_tools, "Single-bank should expose list_mental_models"
assert "create_mental_model" in single_tools, "Single-bank should expose create_mental_model"
assert "list_banks" not in single_tools, "Single-bank should NOT expose list_banks"
assert "create_bank" not in single_tools, "Single-bank should NOT expose create_bank"
# Single-bank retain should NOT have bank_id parameter
retain_tool = next((t for t in single_result.tools if t.name == "retain"), None)
assert retain_tool is not None
single_params = set(retain_tool.inputSchema.get("properties", {}).keys())
assert "bank_id" not in single_params, "Single-bank retain should NOT have bank_id parameter"
@pytest.mark.asyncio
async def test_mcp_no_trailing_slash_works(memory):
"""Test that /mcp (no trailing slash) discovers tools without 307 redirect.
Starlette's Mount class redirects /mcp to /mcp/ with a 307 Temporary Redirect.
Many MCP clients don't follow POST redirects, causing 0 tools to be discovered.
MCPMiddleware wraps the app directly (no Mount), so the redirect never happens.
"""
from hindsight_api.api import create_app
app = create_app(memory, mcp_api_enabled=True, initialize_memory=False)
async with app.router.lifespan_context(app):
from httpx import ASGITransport
async with httpx.AsyncClient(transport=ASGITransport(app=app), base_url="http://test") as http_client:
# /mcp (no slash) should work the same as /mcp/
async with streamable_http_client("http://test/mcp", http_client=http_client) as (
read_stream,
write_stream,
_,
):
async with ClientSession(read_stream, write_stream) as session:
await session.initialize()
result = await session.list_tools()
tools = {t.name for t in result.tools}
assert len(tools) >= 11, f"Expected at least 11 tools from /mcp, got {len(tools)}: {tools}"
assert "retain" in tools
assert "recall" in tools
assert "list_banks" in tools
# /mcp/my-bank (single-bank, no slash) should also work
async with streamable_http_client("http://test/mcp/my-bank", http_client=http_client) as (
read_stream,
write_stream,
_,
):
async with ClientSession(read_stream, write_stream) as session:
await session.initialize()
result = await session.list_tools()
tools = {t.name for t in result.tools}
assert "retain" in tools
assert "list_banks" not in tools, "Single-bank /mcp/my-bank should NOT expose list_banks"
@pytest.mark.asyncio
async def test_mcp_tool_execution_through_client(memory):
"""Test that tools can be called (not just discovered) through the MCP client.
This verifies the full pipeline: HTTP → middleware → FastMCP → tool → engine → response.
Previous tests only checked tool discovery (list_tools), not actual execution.
"""
from httpx import ASGITransport
from hindsight_api.api import create_app
app = create_app(memory, mcp_api_enabled=True, initialize_memory=False)
async with app.router.lifespan_context(app):
async with httpx.AsyncClient(transport=ASGITransport(app=app), base_url="http://test") as http_client:
async with streamable_http_client("http://test/mcp/", http_client=http_client) as (
read_stream,
write_stream,
_,
):
async with ClientSession(read_stream, write_stream) as session:
await session.initialize()
# Execute list_banks tool
result = await session.call_tool("list_banks", arguments={})
assert result is not None
assert len(result.content) > 0
# The result text should be valid JSON with a "banks" key
import json
response_text = result.content[0].text
parsed = json.loads(response_text)
assert "banks" in parsed
@pytest.mark.asyncio
async def test_mcp_mental_model_validation_through_client(memory):
"""Test that input validation works through the real MCP transport.
Verifies that invalid inputs return error messages without crashing,
and that the engine is never called with invalid data.
"""
from httpx import ASGITransport
from hindsight_api.api import create_app
app = create_app(memory, mcp_api_enabled=True, initialize_memory=False)
async with app.router.lifespan_context(app):
async with httpx.AsyncClient(transport=ASGITransport(app=app), base_url="http://test") as http_client:
async with streamable_http_client("http://test/mcp/", http_client=http_client) as (
read_stream,
write_stream,
_,
):
async with ClientSession(read_stream, write_stream) as session:
await session.initialize()
# Test: empty name should return validation error
import json
result = await session.call_tool(
"create_mental_model",
arguments={"name": "", "source_query": "test query"},
)
assert result is not None
parsed = json.loads(result.content[0].text)
assert "error" in parsed
assert "name cannot be empty" in parsed["error"]
# Test: max_tokens out of range should return validation error
result = await session.call_tool(
"create_mental_model",
arguments={"name": "Test", "source_query": "test query", "max_tokens": 0},
)
parsed = json.loads(result.content[0].text)
assert "error" in parsed
assert "max_tokens must be between 256 and 8192" in parsed["error"]
@pytest.mark.asyncio
async def test_mcp_bank_named_sse_routes_to_single_bank(memory):
"""Test that a bank named 'sse' routes to single-bank mode.
Regression test: the old MCP_ENDPOINTS blocklist prevented banks named 'sse'
or 'messages' from being accessed via path routing. They fell through to
multi-bank mode instead.
"""
from httpx import ASGITransport
from hindsight_api.api import create_app
app = create_app(memory, mcp_api_enabled=True, initialize_memory=False)
async with app.router.lifespan_context(app):
async with httpx.AsyncClient(transport=ASGITransport(app=app), base_url="http://test") as http_client:
async with streamable_http_client("http://test/mcp/sse/", http_client=http_client) as (
read_stream,
write_stream,
_,
):
async with ClientSession(read_stream, write_stream) as session:
await session.initialize()
result = await session.list_tools()
tools = {t.name for t in result.tools}
# Should be single-bank mode (no bank management tools)
assert "retain" in tools
assert "recall" in tools
assert "list_banks" not in tools, "Bank 'sse' should route to single-bank mode"
assert "create_bank" not in tools
# retain should NOT have bank_id parameter (single-bank mode)
retain_tool = next(t for t in result.tools if t.name == "retain")
params = set(retain_tool.inputSchema.get("properties", {}).keys())
assert "bank_id" not in params
@pytest.mark.asyncio
async def test_mcp_bank_named_messages_routes_to_single_bank(memory):
"""Test that a bank named 'messages' routes to single-bank mode.
Same regression test as test_mcp_bank_named_sse_routes_to_single_bank but for 'messages'.
"""
from httpx import ASGITransport
from hindsight_api.api import create_app
app = create_app(memory, mcp_api_enabled=True, initialize_memory=False)
async with app.router.lifespan_context(app):
async with httpx.AsyncClient(transport=ASGITransport(app=app), base_url="http://test") as http_client:
async with streamable_http_client("http://test/mcp/messages/", http_client=http_client) as (
read_stream,
write_stream,
_,
):
async with ClientSession(read_stream, write_stream) as session:
await session.initialize()
result = await session.list_tools()
tools = {t.name for t in result.tools}
assert "retain" in tools
assert "list_banks" not in tools, "Bank 'messages' should route to single-bank mode"