Add session-specific visibility control via Context

examples/namespace_activation/README.md

@@ -0,0 +1,55 @@
+# Namespace Activation
+
+Demonstrates session-specific visibility control using tags to organize tools into namespaces that can be activated on demand.
+
+## Pattern
+
+1. Tag tools with namespaces: `@server.tool(tags={"namespace:finance"})`
+2. Globally disable namespaces: `server.disable(tags={"namespace:finance"})`
+3. Provide activation tools that call `ctx.enable_components(tags={"namespace:finance"})`
+
+Each session starts with only the activation tools visible. When a session calls an activation tool, that namespace becomes visible **only for that session**.
+
+## Run
+
+```bash
+# Server
+uv run python server.py
+
+# Client (in another terminal)
+uv run python client.py
+```
+
+## Example Output
+
+```
+Namespace Activation Demo
+
+╭─────────────────── Initial Tools ───────────────────╮
+│ activate_finance, activate_admin, deactivate_all    │
+╰─────────────────────────────────────────────────────╯
+
+→ Calling activate_finance()
+  Finance tools activated
+╭─────────────── After Activating Finance ────────────╮
+│ analyze_portfolio, get_market_data, execute_trade,  │
+│ activate_finance, activate_admin, deactivate_all    │
+╰─────────────────────────────────────────────────────╯
+
+→ Calling get_market_data(symbol='AAPL')
+  {'symbol': 'AAPL', 'price': 150.25, 'change': '+2.5%'}
+
+→ Calling activate_admin()
+  Admin tools activated
+╭────────────── After Activating Admin ───────────────╮
+│ analyze_portfolio, get_market_data, execute_trade,  │
+│ list_users, reset_user_password, activate_finance,  │
+│ activate_admin, deactivate_all                      │
+╰─────────────────────────────────────────────────────╯
+
+→ Calling deactivate_all()
+  All namespaces deactivated
+╭────────────── After Deactivating All ───────────────╮
+│ activate_finance, activate_admin, deactivate_all    │
+╰─────────────────────────────────────────────────────╯
+```

examples/namespace_activation/client.py

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+"""
+Namespace Activation Client
+
+Demonstrates how session-specific visibility works from the client perspective.
+"""
+
+import asyncio
+
+from rich import print
+from rich.panel import Panel
+
+from fastmcp import Client
+from server import server
+
+
+def show_tools(tools: list, title: str) -> None:
+    """Display available tools in a panel."""
+    tool_names = [f"[cyan]{t.name}[/]" for t in tools]
+    print(Panel(", ".join(tool_names) or "[dim]No tools[/]", title=title))
+
+
+async def main():
+    print("\n[bold]Namespace Activation Demo[/]\n")
+
+    async with Client(server) as client:
+        # Initially only activation tools are visible
+        tools = await client.list_tools()
+        show_tools(tools, "Initial Tools")
+
+        # Activate finance namespace
+        print("\n[yellow]→ Calling activate_finance()[/]")
+        result = await client.call_tool("activate_finance", {})
+        print(f"  [green]{result.data}[/]")
+
+        tools = await client.list_tools()
+        show_tools(tools, "After Activating Finance")
+
+        # Use a finance tool
+        print("\n[yellow]→ Calling get_market_data(symbol='AAPL')[/]")
+        result = await client.call_tool("get_market_data", {"symbol": "AAPL"})
+        print(f"  [green]{result.data}[/]")
+
+        # Activate admin namespace too
+        print("\n[yellow]→ Calling activate_admin()[/]")
+        result = await client.call_tool("activate_admin", {})
+        print(f"  [green]{result.data}[/]")
+
+        tools = await client.list_tools()
+        show_tools(tools, "After Activating Admin")
+
+        # Deactivate all - back to defaults
+        print("\n[yellow]→ Calling deactivate_all()[/]")
+        result = await client.call_tool("deactivate_all", {})
+        print(f"  [green]{result.data}[/]")
+
+        tools = await client.list_tools()
+        show_tools(tools, "After Deactivating All")
+
+
+if __name__ == "__main__":
+    asyncio.run(main())

examples/namespace_activation/server.py

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+"""
+Namespace Activation Server
+
+Tools are organized into namespaces using tags, globally disabled by default,
+and selectively enabled per-session via activation tools.
+"""
+
+from fastmcp import FastMCP
+from fastmcp.server.context import Context
+
+server = FastMCP("Multi-Domain Assistant")
+
+
+# Finance namespace
+@server.tool(tags={"namespace:finance"})
+def analyze_portfolio(symbols: list[str]) -> str:
+    """Analyze a portfolio of stock symbols."""
+    return f"Portfolio analysis for: {', '.join(symbols)}"
+
+
+@server.tool(tags={"namespace:finance"})
+def get_market_data(symbol: str) -> dict:
+    """Get current market data for a symbol."""
+    return {"symbol": symbol, "price": 150.25, "change": "+2.5%"}
+
+
+@server.tool(tags={"namespace:finance"})
+def execute_trade(symbol: str, quantity: int, side: str) -> str:
+    """Execute a trade (simulated)."""
+    return f"Executed {side} order: {quantity} shares of {symbol}"
+
+
+# Admin namespace
+@server.tool(tags={"namespace:admin"})
+def list_users() -> list[str]:
+    """List all system users."""
+    return ["alice", "bob", "charlie"]
+
+
+@server.tool(tags={"namespace:admin"})
+def reset_user_password(username: str) -> str:
+    """Reset a user's password (simulated)."""
+    return f"Password reset for {username}"
+
+
+# Activation tools - always visible
+@server.tool
+async def activate_finance(ctx: Context) -> str:
+    """Activate finance tools for this session."""
+    await ctx.enable_components(tags={"namespace:finance"})
+    return "Finance tools activated"
+
+
+@server.tool
+async def activate_admin(ctx: Context) -> str:
+    """Activate admin tools for this session."""
+    await ctx.enable_components(tags={"namespace:admin"})
+    return "Admin tools activated"
+
+
+@server.tool
+async def deactivate_all(ctx: Context) -> str:
+    """Deactivate all namespaces, returning to defaults."""
+    await ctx.reset_components()
+    return "All namespaces deactivated"
+
+
+# Globally disable namespace tools by default
+server.disable(tags={"namespace:finance", "namespace:admin"})
+
+
+if __name__ == "__main__":
+    server.run()

loq.toml

@@ -28,7 +28,7 @@ max_lines = 1899
 
 [[rules]]
 path = "tests/server/middleware/test_middleware.py"
-max_lines = 1250
+max_lines = 1070
 
 [[rules]]
 path = "src/fastmcp/server/context.py"
@@ -40,7 +40,7 @@ max_lines = 1748
 
 [[rules]]
 path = "tests/server/test_mount.py"
-max_lines = 1560
+max_lines = 1545
 
 [[rules]]
 path = "tests/utilities/test_inspect.py"
@@ -60,15 +60,15 @@ max_lines = 3250
 
 [[rules]]
 path = "tests/tools/test_tool.py"
-max_lines = 2250
+max_lines = 2026
 
 [[rules]]
 path = "tests/client/test_elicitation.py"
 max_lines = 1132
 
 [[rules]]
 path = "src/fastmcp/client/client.py"
-max_lines = 2000
+max_lines = 1885
 
 [[rules]]
 path = "tests/utilities/test_json_schema_type.py"
@@ -95,9 +95,9 @@ path = "tests/server/auth/test_jwt_provider.py"
 max_lines = 1101
 
 [[rules]]
-path = "docs/servers/tools.mdx"
-max_lines = 1200
+path = "src/fastmcp/server/providers/local_provider.py"
+max_lines = 1187
 
 [[rules]]
-path = "docs/changelog.mdx"
-max_lines = 2280
+path = "tests/server/test_versioning.py"
+max_lines = 1235