chore: import upstream snapshot with attribution

python/samples/04-hosting/a2a/.env.example

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+# Azure AI Foundry Configuration (required for a2a_server.py and a2a_agent_as_function_tools.py)
+FOUNDRY_PROJECT_ENDPOINT=https://your-project.services.ai.azure.com/api/projects/your-project
+FOUNDRY_MODEL=gpt-4o
+
+# A2A Client Configuration (required for agent_with_a2a.py and a2a_agent_as_function_tools.py)
+# The function-tools flow uses http://localhost:5000/ in the sample docs/output.
+# Update this value if you start a different local A2A server instance on another port.
+A2A_AGENT_HOST=http://localhost:5000/

python/samples/04-hosting/a2a/README.md

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+# A2A Server Hosting Examples
+
+This sample demonstrates how to **host** Agent Framework agents as A2A-compliant servers using the [A2A (Agent2Agent) protocol](https://a2a-protocol.org/latest/).
+
+> **Looking for client samples?** See [`samples/02-agents/a2a/`](../../02-agents/a2a/) for consuming remote A2A agents.
+
+## Server Samples
+
+| Run this file | To... |
+|---------------|-------|
+| **[`a2a_server.py`](a2a_server.py)** | Host an Agent Framework agent as an A2A-compliant server (multi-agent). |
+| **[`agent_framework_to_a2a.py`](agent_framework_to_a2a.py)** | Minimal example: expose a single agent as an A2A server. |
+
+## Supporting Modules
+
+| File | Description |
+|------|-------------|
+| [`agent_definitions.py`](agent_definitions.py) | Agent and AgentCard factory definitions for invoice, policy, and logistics agents. |
+| [`invoice_data.py`](invoice_data.py) | Mock invoice data and tool functions for the invoice agent. |
+| [`a2a_server.http`](a2a_server.http) | REST Client requests for testing the server directly from VS Code. |
+
+## Environment Variables
+
+### Required (Server)
+- `FOUNDRY_PROJECT_ENDPOINT` — Your Azure AI Foundry project endpoint
+- `FOUNDRY_MODEL` — Model deployment name (e.g. `gpt-4o`)
+
+## Quick Start
+
+All commands below should be run from this directory:
+
+```powershell
+cd python/samples/04-hosting/a2a
+```
+
+### 0. Install Dependencies
+
+Copy `.env.example` to `.env` and fill in your values:
+
+```powershell
+copy .env.example .env
+```
+
+**Option A — pip (standard):**
+
+```powershell
+python -m venv .venv
+.venv\Scripts\Activate.ps1      # Windows
+# source .venv/bin/activate     # macOS / Linux
+pip install -r requirements.txt
+```
+
+**Option B — uv:**
+
+```powershell
+uv run python a2a_server.py --agent-type policy
+```
+
+### 1. Start the A2A Server
+
+> **Note (Option A — pip users):** Replace `uv run python` with `python` in all `uv run` commands below. `uv` is not required once the virtual environment is activated.
+
+Pick an agent type and start the server (each in its own terminal):
+
+```powershell
+uv run python a2a_server.py --agent-type invoice --port 5000
+uv run python a2a_server.py --agent-type policy --port 5001
+uv run python a2a_server.py --agent-type logistics --port 5002
+```
+
+You can run one agent or all three — each listens on its own port.
+
+### 2. Run a Client
+
+Once a server is running, use any of the client samples in [`samples/02-agents/a2a/`](../../02-agents/a2a/):
+
+```powershell
+cd python/samples/02-agents/a2a
+$env:A2A_AGENT_HOST = "http://localhost:5001/"
+uv run python agent_with_a2a.py
+```
+
+## Security considerations for multi-tenant hosting
+
+The default `a2a-sdk` task/push-config stores scope ownership by `user_name` only. **Any host that mounts tenant-bearing routes must pass a tenant-aware `owner_resolver`** to the stores, e.g.:
+
+```python
+from a2a.server.tasks import InMemoryTaskStore
+
+def resolve_tenant_user_scope(context):
+    # Derive tenant + user identity from your host's auth/session context.
+    return f"{context.tenant}:{context.user.user_name}"
+task_store = InMemoryTaskStore(owner_resolver=resolve_tenant_user_scope)
+```

python/samples/04-hosting/a2a/a2a_server.http

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+### Each A2A agent is available at a different host address
+@hostInvoice = http://localhost:5000
+@hostPolicy = http://localhost:5001
+@hostLogistics = http://localhost:5002
+
+### Query agent card for the invoice agent
+GET {{hostInvoice}}/.well-known/agent.json
+
+### Send a message to the invoice agent
+POST {{hostInvoice}}
+Content-Type: application/json
+
+{
+    "id": "1",
+    "jsonrpc": "2.0",
+    "method": "message/send",
+    "params": {
+        "message": {
+            "kind": "message",
+            "role": "user",
+            "messageId": "msg_1",
+            "parts": [
+                {
+                    "kind": "text",
+                    "text": "Show me all invoices for Contoso"
+                }
+            ]
+        }
+    }
+}
+
+### Query agent card for the policy agent
+GET {{hostPolicy}}/.well-known/agent.json
+
+### Send a message to the policy agent
+POST {{hostPolicy}}
+Content-Type: application/json
+
+{
+    "id": "2",
+    "jsonrpc": "2.0",
+    "method": "message/send",
+    "params": {
+        "message": {
+            "kind": "message",
+            "role": "user",
+            "messageId": "msg_2",
+            "parts": [
+                {
+                    "kind": "text",
+                    "text": "What is the policy for short shipments?"
+                }
+            ]
+        }
+    }
+}
+
+### Query agent card for the logistics agent
+GET {{hostLogistics}}/.well-known/agent.json
+
+### Send a message to the logistics agent
+POST {{hostLogistics}}
+Content-Type: application/json
+
+{
+    "id": "3",
+    "jsonrpc": "2.0",
+    "method": "message/send",
+    "params": {
+        "message": {
+            "kind": "message",
+            "role": "user",
+            "messageId": "msg_3",
+            "parts": [
+                {
+                    "kind": "text",
+                    "text": "What is the status for SHPMT-SAP-001?"
+                }
+            ]
+        }
+    }
+}

python/samples/04-hosting/a2a/a2a_server.py

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+# Copyright (c) Microsoft. All rights reserved.
+
+import argparse
+import os
+import sys
+
+import uvicorn
+from a2a.server.request_handlers import DefaultRequestHandler
+from a2a.server.routes import create_agent_card_routes, create_jsonrpc_routes
+from a2a.server.tasks import InMemoryTaskStore
+from agent_definitions import AGENT_CARD_FACTORIES, AGENT_FACTORIES  # pyrefly: ignore[missing-import]
+from agent_framework.a2a import A2AExecutor
+from agent_framework.foundry import FoundryChatClient
+from azure.identity import AzureCliCredential
+from dotenv import load_dotenv
+from starlette.applications import Starlette
+
+# Load environment variables from .env file
+load_dotenv()
+
+"""
+A2A Server Sample — Host an Agent Framework agent as an A2A endpoint
+
+This sample creates a Python-based A2A-compliant server that wraps an Agent
+Framework agent.  The server uses the a2a-sdk's Starlette application to handle
+JSON-RPC requests and serves the AgentCard at /.well-known/agent.json.
+
+Three agent types are available:
+  - invoice   — Answers invoice queries using mock data and function tools.
+  - policy    — Returns a fixed policy response.
+  - logistics — Returns a fixed logistics response.
+
+Usage:
+  uv run python a2a_server.py --agent-type policy --port 5001
+  uv run python a2a_server.py --agent-type invoice --port 5000
+  uv run python a2a_server.py --agent-type logistics --port 5002
+
+Environment variables:
+  FOUNDRY_PROJECT_ENDPOINT              — Your Azure AI Foundry project endpoint
+  FOUNDRY_MODEL — Model deployment name (e.g. gpt-4o)
+"""
+
+
+def parse_args() -> argparse.Namespace:
+    parser = argparse.ArgumentParser(description="A2A Agent Server")
+    parser.add_argument(
+        "--agent-type",
+        choices=["invoice", "policy", "logistics"],
+        default="policy",
+        help="Type of agent to host (default: policy)",
+    )
+    parser.add_argument(
+        "--host",
+        default="localhost",
+        help="Host to bind to (default: localhost)",
+    )
+    parser.add_argument(
+        "--port",
+        type=int,
+        default=5001,
+        help="Port to listen on (default: 5001)",
+    )
+    return parser.parse_args()
+
+
+def main() -> None:
+    args = parse_args()
+
+    # Validate environment
+    project_endpoint = os.getenv("FOUNDRY_PROJECT_ENDPOINT")
+    model = os.getenv("FOUNDRY_MODEL")
+
+    if not project_endpoint:
+        print("Error: FOUNDRY_PROJECT_ENDPOINT environment variable is not set.")
+        sys.exit(1)
+    if not model:
+        print("Error: FOUNDRY_MODEL environment variable is not set.")
+        sys.exit(1)
+
+    # Create the LLM client
+    credential = AzureCliCredential()
+    client = FoundryChatClient(
+        project_endpoint=project_endpoint,
+        model=model,
+        credential=credential,
+    )
+
+    # Create the Agent Framework agent for the chosen type
+    agent_factory = AGENT_FACTORIES[args.agent_type]
+    agent = agent_factory(client)
+
+    # Build the A2A server components
+    url = f"http://{args.host}:{args.port}/"
+    agent_card = AGENT_CARD_FACTORIES[args.agent_type](url)
+    executor = A2AExecutor(agent, stream=True)
+    task_store = InMemoryTaskStore()
+    request_handler = DefaultRequestHandler(
+        agent_executor=executor,
+        task_store=task_store,
+        agent_card=agent_card,
+    )
+
+    app = Starlette(
+        routes=[
+            *create_agent_card_routes(agent_card),
+            *create_jsonrpc_routes(request_handler, "/"),
+        ]
+    )
+
+    print(f"Starting A2A server: {agent_card.name}")
+    print(f"  Agent type : {args.agent_type}")
+    print(f"  Listening  : {url}")
+    print(f"  Agent card : {url}.well-known/agent.json")
+    print()
+
+    uvicorn.run(
+        app,
+        host=args.host,
+        port=args.port,
+    )
+
+
+if __name__ == "__main__":
+    main()

python/samples/04-hosting/a2a/agent_definitions.py

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+# Copyright (c) Microsoft. All rights reserved.
+
+"""Agent definitions and AgentCard factories for the A2A server sample.
+
+Provides factory functions to create Agent Framework agents and A2A
+AgentCards for the invoice, policy, and logistics agent types.
+"""
+
+from __future__ import annotations
+
+from a2a.types import AgentCapabilities, AgentCard, AgentInterface, AgentSkill
+from agent_framework import Agent
+from agent_framework.foundry import FoundryChatClient
+from invoice_data import query_by_invoice_id, query_by_transaction_id, query_invoices  # pyrefly: ignore[missing-import]
+
+# ---------------------------------------------------------------------------
+# Agent instructions
+# ---------------------------------------------------------------------------
+
+INVOICE_INSTRUCTIONS = "You specialize in handling queries related to invoices."
+
+POLICY_INSTRUCTIONS = """\
+You specialize in handling queries related to policies and customer communications.
+
+Always reply with exactly this text:
+
+Policy: Short Shipment Dispute Handling Policy V2.1
+
+Summary: "For short shipments reported by customers, first verify internal shipment records
+(SAP) and physical logistics scan data (BigQuery). If discrepancy is confirmed and logistics data
+shows fewer items packed than invoiced, issue a credit for the missing items. Document the
+resolution in SAP CRM and notify the customer via email within 2 business days, referencing the
+original invoice and the credit memo number. Use the 'Formal Credit Notification' email
+template."
+"""
+
+LOGISTICS_INSTRUCTIONS = """\
+You specialize in handling queries related to logistics.
+
+Always reply with exactly:
+
+Shipment number: SHPMT-SAP-001
+Item: TSHIRT-RED-L
+Quantity: 900
+"""
+
+# ---------------------------------------------------------------------------
+# Agent factories
+# ---------------------------------------------------------------------------
+
+
+def create_invoice_agent(client: FoundryChatClient) -> Agent:
+    """Create an invoice agent backed by the given client with query tools."""
+    return Agent(
+        client=client,
+        name="InvoiceAgent",
+        instructions=INVOICE_INSTRUCTIONS,
+        tools=[query_invoices, query_by_transaction_id, query_by_invoice_id],
+    )
+
+
+def create_policy_agent(client: FoundryChatClient) -> Agent:
+    """Create a policy agent backed by the given client."""
+    return Agent(
+        client=client,
+        name="PolicyAgent",
+        instructions=POLICY_INSTRUCTIONS,
+    )
+
+
+def create_logistics_agent(client: FoundryChatClient) -> Agent:
+    """Create a logistics agent backed by the given client."""
+    return Agent(
+        client=client,
+        name="LogisticsAgent",
+        instructions=LOGISTICS_INSTRUCTIONS,
+    )
+
+
+# ---------------------------------------------------------------------------
+# AgentCard factories
+# ---------------------------------------------------------------------------
+
+_CAPABILITIES = AgentCapabilities(streaming=True, push_notifications=False)
+
+
+def get_invoice_agent_card(url: str) -> AgentCard:
+    """Return an A2A AgentCard for the invoice agent."""
+    return AgentCard(
+        name="InvoiceAgent",
+        description="Handles requests relating to invoices.",
+        version="1.0.0",
+        default_input_modes=["text"],
+        default_output_modes=["text"],
+        capabilities=_CAPABILITIES,
+        supported_interfaces=[AgentInterface(url=url, protocol_binding="JSONRPC")],
+        skills=[
+            AgentSkill(
+                id="id_invoice_agent",
+                name="InvoiceQuery",
+                description="Handles requests relating to invoices.",
+                tags=["invoice", "agent-framework"],
+                examples=["List the latest invoices for Contoso."],
+            ),
+        ],
+    )
+
+
+def get_policy_agent_card(url: str) -> AgentCard:
+    """Return an A2A AgentCard for the policy agent."""
+    return AgentCard(
+        name="PolicyAgent",
+        description="Handles requests relating to policies and customer communications.",
+        version="1.0.0",
+        default_input_modes=["text"],
+        default_output_modes=["text"],
+        capabilities=_CAPABILITIES,
+        supported_interfaces=[AgentInterface(url=url, protocol_binding="JSONRPC")],
+        skills=[
+            AgentSkill(
+                id="id_policy_agent",
+                name="PolicyAgent",
+                description="Handles requests relating to policies and customer communications.",
+                tags=["policy", "agent-framework"],
+                examples=["What is the policy for short shipments?"],
+            ),
+        ],
+    )
+
+
+def get_logistics_agent_card(url: str) -> AgentCard:
+    """Return an A2A AgentCard for the logistics agent."""
+    return AgentCard(
+        name="LogisticsAgent",
+        description="Handles requests relating to logistics.",
+        version="1.0.0",
+        default_input_modes=["text"],
+        default_output_modes=["text"],
+        capabilities=_CAPABILITIES,
+        supported_interfaces=[AgentInterface(url=url, protocol_binding="JSONRPC")],
+        skills=[
+            AgentSkill(
+                id="id_logistics_agent",
+                name="LogisticsQuery",
+                description="Handles requests relating to logistics.",
+                tags=["logistics", "agent-framework"],
+                examples=["What is the status for SHPMT-SAP-001"],
+            ),
+        ],
+    )
+
+
+# ---------------------------------------------------------------------------
+# Lookup helpers
+# ---------------------------------------------------------------------------
+
+AGENT_FACTORIES = {
+    "invoice": create_invoice_agent,
+    "policy": create_policy_agent,
+    "logistics": create_logistics_agent,
+}
+
+AGENT_CARD_FACTORIES = {
+    "invoice": get_invoice_agent_card,
+    "policy": get_policy_agent_card,
+    "logistics": get_logistics_agent_card,
+}

python/samples/04-hosting/a2a/agent_framework_to_a2a.py

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+# Copyright (c) Microsoft. All rights reserved.
+
+import uvicorn
+from a2a.server.request_handlers import DefaultRequestHandler
+from a2a.server.routes import create_agent_card_routes, create_jsonrpc_routes
+from a2a.server.tasks import InMemoryTaskStore
+from a2a.types import (
+    AgentCapabilities,
+    AgentCard,
+    AgentInterface,
+    AgentSkill,
+)
+from agent_framework import Agent
+from agent_framework.a2a import A2AExecutor
+from agent_framework.openai import OpenAIChatClient
+from dotenv import load_dotenv
+from starlette.applications import Starlette
+
+load_dotenv()
+
+if __name__ == "__main__":
+    # --8<-- [start:AgentSkill]
+    flight_skill = AgentSkill(
+        id="Flight_Booking",
+        name="Flight Booking",
+        description="Search and book flights across Europe.",
+        tags=["flights", "travel", "europe"],
+        examples=[],
+    )
+    hotel_skill = AgentSkill(
+        id="Hotel_Booking",
+        name="Hotel Booking",
+        description="Search and book hotels across Europe.",
+        tags=["hotels", "travel", "accommodation"],
+        examples=[],
+    )
+    # --8<-- [end:AgentSkill]
+
+    # --8<-- [start:AgentCard]
+    # This will be the public-facing agent card
+    public_agent_card = AgentCard(
+        name="Europe Travel Agent",
+        description="A helpful Europe Travel Agent that can help users search and book flights and hotels across Europe.",
+        version="1.0.0",
+        default_input_modes=["text"],
+        default_output_modes=["text"],
+        capabilities=AgentCapabilities(streaming=True),
+        supported_interfaces=[AgentInterface(url="http://localhost:9999/", protocol_binding="JSONRPC")],
+        skills=[flight_skill, hotel_skill],
+    )
+    # --8<-- [end:AgentCard]
+
+    agent = Agent(
+        client=OpenAIChatClient(),
+        name="Europe Travel Agent",
+        instructions="You are a helpful Europe Travel Agent. You can help users search and book flights and hotels across Europe.",
+    )
+
+    request_handler = DefaultRequestHandler(
+        agent_executor=A2AExecutor(agent),
+        task_store=InMemoryTaskStore(),
+        agent_card=public_agent_card,
+    )
+
+    server = Starlette(
+        routes=[
+            *create_agent_card_routes(public_agent_card),
+            *create_jsonrpc_routes(request_handler, "/"),
+        ]
+    )
+
+    uvicorn.run(server, host="0.0.0.0", port=9999)

python/samples/04-hosting/a2a/invoice_data.py

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+# Copyright (c) Microsoft. All rights reserved.
+
+"""Mock invoice data and tool functions for the A2A server sample.
+
+Provides mock invoice data and query tools for the A2A server sample,
+enabling invoice-related queries through the A2A protocol.
+"""
+
+import json
+import random
+from dataclasses import dataclass, field
+from datetime import datetime, timedelta, timezone
+from typing import Annotated
+
+from agent_framework import tool
+from pydantic import Field
+
+
+@dataclass
+class Product:
+    """A product line item on an invoice."""
+
+    name: str
+    quantity: int
+    price_per_unit: float
+
+    @property
+    def total_price(self) -> float:
+        return self.quantity * self.price_per_unit
+
+    def to_dict(self) -> dict:
+        return {
+            "name": self.name,
+            "quantity": self.quantity,
+            "price_per_unit": self.price_per_unit,
+            "total_price": self.total_price,
+        }
+
+
+@dataclass
+class Invoice:
+    """An invoice record with products."""
+
+    transaction_id: str
+    invoice_id: str
+    company_name: str
+    invoice_date: datetime
+    products: list[Product] = field(default_factory=list)
+
+    @property
+    def total_invoice_price(self) -> float:
+        return sum(p.total_price for p in self.products)
+
+    def to_dict(self) -> dict:
+        return {
+            "transaction_id": self.transaction_id,
+            "invoice_id": self.invoice_id,
+            "company_name": self.company_name,
+            "invoice_date": self.invoice_date.strftime("%Y-%m-%d"),
+            "products": [p.to_dict() for p in self.products],
+            "total_invoice_price": self.total_invoice_price,
+        }
+
+
+def _random_date_within_last_two_months() -> datetime:
+    end_date = datetime.now(timezone.utc)
+    start_date = end_date - timedelta(days=60)
+    random_days = random.randint(0, 60)
+    return start_date + timedelta(days=random_days)
+
+
+def _build_invoices() -> list[Invoice]:
+    """Build 10 mock invoices."""
+    return [
+        Invoice(
+            "TICKET-XYZ987",
+            "INV789",
+            "Contoso",
+            _random_date_within_last_two_months(),
+            [
+                Product("T-Shirts", 150, 10.00),
+                Product("Hats", 200, 15.00),
+                Product("Glasses", 300, 5.00),
+            ],
+        ),
+        Invoice(
+            "TICKET-XYZ111",
+            "INV111",
+            "XStore",
+            _random_date_within_last_two_months(),
+            [
+                Product("T-Shirts", 2500, 12.00),
+                Product("Hats", 1500, 8.00),
+                Product("Glasses", 200, 20.00),
+            ],
+        ),
+        Invoice(
+            "TICKET-XYZ222",
+            "INV222",
+            "Cymbal Direct",
+            _random_date_within_last_two_months(),
+            [
+                Product("T-Shirts", 1200, 14.00),
+                Product("Hats", 800, 7.00),
+                Product("Glasses", 500, 25.00),
+            ],
+        ),
+        Invoice(
+            "TICKET-XYZ333",
+            "INV333",
+            "Contoso",
+            _random_date_within_last_two_months(),
+            [
+                Product("T-Shirts", 400, 11.00),
+                Product("Hats", 600, 15.00),
+                Product("Glasses", 700, 5.00),
+            ],
+        ),
+        Invoice(
+            "TICKET-XYZ444",
+            "INV444",
+            "XStore",
+            _random_date_within_last_two_months(),
+            [
+                Product("T-Shirts", 800, 10.00),
+                Product("Hats", 500, 18.00),
+                Product("Glasses", 300, 22.00),
+            ],
+        ),
+        Invoice(
+            "TICKET-XYZ555",
+            "INV555",
+            "Cymbal Direct",
+            _random_date_within_last_two_months(),
+            [
+                Product("T-Shirts", 1100, 9.00),
+                Product("Hats", 900, 12.00),
+                Product("Glasses", 1200, 15.00),
+            ],
+        ),
+        Invoice(
+            "TICKET-XYZ666",
+            "INV666",
+            "Contoso",
+            _random_date_within_last_two_months(),
+            [
+                Product("T-Shirts", 2500, 8.00),
+                Product("Hats", 1200, 10.00),
+                Product("Glasses", 1000, 6.00),
+            ],
+        ),
+        Invoice(
+            "TICKET-XYZ777",
+            "INV777",
+            "XStore",
+            _random_date_within_last_two_months(),
+            [
+                Product("T-Shirts", 1900, 13.00),
+                Product("Hats", 1300, 16.00),
+                Product("Glasses", 800, 19.00),
+            ],
+        ),
+        Invoice(
+            "TICKET-XYZ888",
+            "INV888",
+            "Cymbal Direct",
+            _random_date_within_last_two_months(),
+            [
+                Product("T-Shirts", 2200, 11.00),
+                Product("Hats", 1700, 8.50),
+                Product("Glasses", 600, 21.00),
+            ],
+        ),
+        Invoice(
+            "TICKET-XYZ999",
+            "INV999",
+            "Contoso",
+            _random_date_within_last_two_months(),
+            [
+                Product("T-Shirts", 1400, 10.50),
+                Product("Hats", 1100, 9.00),
+                Product("Glasses", 950, 12.00),
+            ],
+        ),
+    ]
+
+
+# Module-level singleton so dates are stable for the lifetime of the server
+INVOICES = _build_invoices()
+
+
+@tool(approval_mode="never_require")
+def query_invoices(
+    company_name: Annotated[str, Field(description="The company name to filter invoices by.")],
+    start_date: Annotated[str | None, Field(description="Optional start date (YYYY-MM-DD) to filter invoices.")] = None,
+    end_date: Annotated[str | None, Field(description="Optional end date (YYYY-MM-DD) to filter invoices.")] = None,
+) -> str:
+    """Retrieves invoices for the specified company and optionally within the specified time range."""
+    results = [i for i in INVOICES if i.company_name.lower() == company_name.lower()]
+
+    if start_date:
+        start = datetime.strptime(start_date, "%Y-%m-%d").replace(tzinfo=timezone.utc)
+        results = [i for i in results if i.invoice_date >= start]
+
+    if end_date:
+        end = datetime.strptime(end_date, "%Y-%m-%d").replace(tzinfo=timezone.utc) + timedelta(days=1)
+        results = [i for i in results if i.invoice_date < end]
+
+    return json.dumps([i.to_dict() for i in results], indent=2)
+
+
+@tool(approval_mode="never_require")
+def query_by_transaction_id(
+    transaction_id: Annotated[str, Field(description="The transaction ID to look up (e.g. TICKET-XYZ987).")],
+) -> str:
+    """Retrieves invoice using the transaction id."""
+    results = [i for i in INVOICES if i.transaction_id.lower() == transaction_id.lower()]
+    return json.dumps([i.to_dict() for i in results], indent=2)
+
+
+@tool(approval_mode="never_require")
+def query_by_invoice_id(
+    invoice_id: Annotated[str, Field(description="The invoice ID to look up (e.g. INV789).")],
+) -> str:
+    """Retrieves invoice using the invoice id."""
+    results = [i for i in INVOICES if i.invoice_id.lower() == invoice_id.lower()]
+    return json.dumps([i.to_dict() for i in results], indent=2)

python/samples/04-hosting/a2a/requirements.txt

@@ -0,0 +1,23 @@
+# Agent Framework packages
+# To use the deployed version, uncomment the lines below and comment out the local installation lines
+# agent-framework-a2a
+# agent-framework-foundry
+
+# Local installation (for development and testing)
+# Each package must be listed explicitly because pip doesn't resolve uv workspace sources.
+# Without explicit entries, pip would fetch transitive dependencies from PyPI instead of local source.
+-e ../../../packages/core  # Core framework - base dependency for all packages
+-e ../../../packages/foundry  # Foundry support - dependency for FoundryChatClient in a2a_server.py
+-e ../../../packages/a2a  # A2A integration - provides A2AAgent and a2a-sdk
+
+# Azure authentication
+azure-identity
+
+# A2A server runtime
+uvicorn
+
+# HTTP client used by A2A client samples
+httpx
+
+# Environment variable loading
+python-dotenv