Python: Add A2A server sample (#4528)

* Python: Add A2A server sample and fix client streaming bug Add a pure Python A2A server sample so testing the A2A client no longer requires running the .NET server. The server uses the a2a-sdk's A2AStarletteApplication with uvicorn and supports three agent types (invoice, policy, logistics) backed by AzureOpenAIResponsesClient. New files: - a2a_server.py: Main server entry point with CLI args - agent_executor.py: Bridges a2a-sdk AgentExecutor to Agent Framework - agent_definitions.py: Agent and AgentCard factory definitions - invoice_data.py: Mock invoice data and query tool functions - a2a_server.http: REST Client requests for testing Also fixes a streaming bug in agent_with_a2a.py where async with was used on ResponseStream which does not support the async context manager protocol. Changed to async for to match all other samples. Closes #4045 Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> * Address PR review: handle CancelledError and fix end_date filtering - Re-raise asyncio.CancelledError before the broad exception handler so cooperative cancellation is not swallowed. - Make end_date filter inclusive of the full day by comparing with < end + timedelta(days=1) instead of <= midnight. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> --------- Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
2026-06-16 21:04:09 +08:00 · 2026-03-10 00:00:49 +00:00
parent e2f0bc814e
commit ded32f3ff8
7 changed files with 709 additions and 25 deletions
@@ -0,0 +1,169 @@
+# 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 typing import TYPE_CHECKING
+
+from a2a.types import AgentCapabilities, AgentCard, AgentSkill
+from invoice_data import query_by_invoice_id, query_by_transaction_id, query_invoices
+
+if TYPE_CHECKING:
+    from agent_framework import Agent
+    from agent_framework.azure import AzureOpenAIResponsesClient
+
+
+# ---------------------------------------------------------------------------
+# 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: AzureOpenAIResponsesClient) -> Agent:
+    """Create an invoice agent backed by the given client with query tools."""
+    return client.as_agent(
+        name="InvoiceAgent",
+        instructions=INVOICE_INSTRUCTIONS,
+        tools=[query_invoices, query_by_transaction_id, query_by_invoice_id],
+    )
+
+
+def create_policy_agent(client: AzureOpenAIResponsesClient) -> Agent:
+    """Create a policy agent backed by the given client."""
+    return client.as_agent(
+        name="PolicyAgent",
+        instructions=POLICY_INSTRUCTIONS,
+    )
+
+
+def create_logistics_agent(client: AzureOpenAIResponsesClient) -> Agent:
+    """Create a logistics agent backed by the given client."""
+    return client.as_agent(
+        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.",
+        url=url,
+        version="1.0.0",
+        default_input_modes=["text"],
+        default_output_modes=["text"],
+        capabilities=_CAPABILITIES,
+        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.",
+        url=url,
+        version="1.0.0",
+        default_input_modes=["text"],
+        default_output_modes=["text"],
+        capabilities=_CAPABILITIES,
+        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.",
+        url=url,
+        version="1.0.0",
+        default_input_modes=["text"],
+        default_output_modes=["text"],
+        capabilities=_CAPABILITIES,
+        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,
+}