feat: add a2a server config; agent card generation

lib/crewai/src/crewai/a2a/config.py

@@ -5,18 +5,22 @@ This module is separate from experimental.a2a to avoid circular imports.
 
 from __future__ import annotations
 
-from typing import Annotated, Any, ClassVar, Literal
+from importlib.metadata import version
+from typing import Any, ClassVar, Literal
 
-from pydantic import (
+from a2a.types import (
-    BaseModel,
+    AgentCapabilities,
-    BeforeValidator,
+    AgentCardSignature,
-    ConfigDict,
+    AgentInterface,
-    Field,
+    AgentProvider,
-    HttpUrl,
+    AgentSkill,
-    TypeAdapter,
+    SecurityScheme,
 )
+from pydantic import BaseModel, ConfigDict, Field
+from typing_extensions import deprecated
 
 from crewai.a2a.auth.schemas import AuthScheme
+from crewai.a2a.types import TransportType, Url
 
 
 try:
@@ -25,25 +29,25 @@ except ImportError:
     UpdateConfig = Any  # type: ignore[misc,assignment]
 
 
-http_url_adapter = TypeAdapter(HttpUrl)
-
-Url = Annotated[
-    str,
-    BeforeValidator(
-        lambda value: str(http_url_adapter.validate_python(value, strict=True))
-    ),
-]
-
-
 def _get_default_update_config() -> UpdateConfig:
     from crewai.a2a.updates import StreamingConfig
 
     return StreamingConfig()
 
 
+@deprecated(
+    """
+    `crewai.a2a.config.A2AConfig` is deprecated and will be removed in v2.0.0,
+    use `crewai.a2a.config.A2AClientConfig` or `crewai.a2a.config.A2AServerConfig` instead.
+    """,
+    category=FutureWarning,
+)
 class A2AConfig(BaseModel):
     """Configuration for A2A protocol integration.
 
+    Deprecated:
+        Use A2AClientConfig instead. This class will be removed in a future version.
+
     Attributes:
         endpoint: A2A agent endpoint URL.
         auth: Authentication scheme.
@@ -87,3 +91,176 @@ class A2AConfig(BaseModel):
         default="JSONRPC",
         description="Specified mode of A2A transport protocol",
     )
+
+
+class A2AClientConfig(BaseModel):
+    """Configuration for connecting to remote A2A agents.
+
+    Attributes:
+        endpoint: A2A agent endpoint URL.
+        auth: Authentication scheme.
+        timeout: Request timeout in seconds.
+        max_turns: Maximum conversation turns with A2A agent.
+        response_model: Optional Pydantic model for structured A2A agent responses.
+        fail_fast: If True, raise error when agent unreachable; if False, skip and continue.
+        trust_remote_completion_status: If True, return A2A agent's result directly when completed.
+        updates: Update mechanism config.
+        accepted_output_modes: Media types the client can accept in responses.
+        supported_transports: Ordered list of transport protocols the client supports.
+        use_client_preference: Whether to prioritize client transport preferences over server.
+        extensions: Extension URIs the client supports.
+    """
+
+    model_config: ClassVar[ConfigDict] = ConfigDict(extra="forbid")
+
+    endpoint: Url = Field(description="A2A agent endpoint URL")
+    auth: AuthScheme | None = Field(
+        default=None,
+        description="Authentication scheme",
+    )
+    timeout: int = Field(default=120, description="Request timeout in seconds")
+    max_turns: int = Field(
+        default=10, description="Maximum conversation turns with A2A agent"
+    )
+    response_model: type[BaseModel] | None = Field(
+        default=None,
+        description="Optional Pydantic model for structured A2A agent responses",
+    )
+    fail_fast: bool = Field(
+        default=True,
+        description="If True, raise error when agent unreachable; if False, skip",
+    )
+    trust_remote_completion_status: bool = Field(
+        default=False,
+        description="If True, return A2A result directly when completed",
+    )
+    updates: UpdateConfig = Field(
+        default_factory=_get_default_update_config,
+        description="Update mechanism config",
+    )
+    accepted_output_modes: list[str] = Field(
+        default_factory=lambda: ["application/json"],
+        description="Media types the client can accept in responses",
+    )
+    supported_transports: list[str] = Field(
+        default_factory=lambda: ["JSONRPC"],
+        description="Ordered list of transport protocols the client supports",
+    )
+    use_client_preference: bool = Field(
+        default=False,
+        description="Whether to prioritize client transport preferences over server",
+    )
+    extensions: list[str] = Field(
+        default_factory=list,
+        description="Extension URIs the client supports",
+    )
+    transport_protocol: Literal["JSONRPC", "GRPC", "HTTP+JSON"] = Field(
+        default="JSONRPC",
+        description="Specified mode of A2A transport protocol",
+    )
+
+
+class A2AServerConfig(BaseModel):
+    """Configuration for exposing a Crew or Agent as an A2A server.
+
+    All fields correspond to A2A AgentCard fields. Fields like name, description,
+    and skills can be auto-derived from the Crew/Agent if not provided.
+
+    Attributes:
+        name: Human-readable name for the agent.
+        description: Human-readable description of the agent.
+        version: Version string for the agent card.
+        skills: List of agent skills/capabilities.
+        default_input_modes: Default supported input MIME types.
+        default_output_modes: Default supported output MIME types.
+        capabilities: Declaration of optional capabilities.
+        preferred_transport: Transport protocol for the preferred endpoint.
+        protocol_version: A2A protocol version this agent supports.
+        provider: Information about the agent's service provider.
+        documentation_url: URL to the agent's documentation.
+        icon_url: URL to an icon for the agent.
+        additional_interfaces: Additional supported interfaces.
+        security: Security requirement objects for all interactions.
+        security_schemes: Security schemes available to authorize requests.
+        supports_authenticated_extended_card: Whether agent provides extended card to authenticated users.
+        url: Preferred endpoint URL for the agent.
+        signatures: JSON Web Signatures for the AgentCard.
+    """
+
+    model_config: ClassVar[ConfigDict] = ConfigDict(extra="forbid")
+
+    name: str | None = Field(
+        default=None,
+        description="Human-readable name for the agent. Auto-derived from Crew/Agent if not provided.",
+    )
+    description: str | None = Field(
+        default=None,
+        description="Human-readable description of the agent. Auto-derived from Crew/Agent if not provided.",
+    )
+    version: str = Field(
+        default="1.0.0",
+        description="Version string for the agent card",
+    )
+    skills: list[AgentSkill] = Field(
+        default_factory=list,
+        description="List of agent skills. Auto-derived from tasks/tools if not provided.",
+    )
+    default_input_modes: list[str] = Field(
+        default_factory=lambda: ["text/plain", "application/json"],
+        description="Default supported input MIME types",
+    )
+    default_output_modes: list[str] = Field(
+        default_factory=lambda: ["text/plain", "application/json"],
+        description="Default supported output MIME types",
+    )
+    capabilities: AgentCapabilities = Field(
+        default_factory=lambda: AgentCapabilities(
+            streaming=True,
+            push_notifications=False,
+        ),
+        description="Declaration of optional capabilities supported by the agent",
+    )
+    preferred_transport: TransportType = Field(
+        default="JSONRPC",
+        description="Transport protocol for the preferred endpoint",
+    )
+    protocol_version: str = Field(
+        default_factory=lambda: version("a2a-sdk"),
+        description="A2A protocol version this agent supports",
+    )
+    provider: AgentProvider | None = Field(
+        default=None,
+        description="Information about the agent's service provider",
+    )
+    documentation_url: Url | None = Field(
+        default=None,
+        description="URL to the agent's documentation",
+    )
+    icon_url: Url | None = Field(
+        default=None,
+        description="URL to an icon for the agent",
+    )
+    additional_interfaces: list[AgentInterface] = Field(
+        default_factory=list,
+        description="Additional supported interfaces (transport and URL combinations)",
+    )
+    security: list[dict[str, list[str]]] = Field(
+        default_factory=list,
+        description="Security requirement objects for all agent interactions",
+    )
+    security_schemes: dict[str, SecurityScheme] = Field(
+        default_factory=dict,
+        description="Security schemes available to authorize requests",
+    )
+    supports_authenticated_extended_card: bool = Field(
+        default=False,
+        description="Whether agent provides extended card to authenticated users",
+    )
+    url: Url | None = Field(
+        default=None,
+        description="Preferred endpoint URL for the agent. Set at runtime if not provided.",
+    )
+    signatures: list[AgentCardSignature] = Field(
+        default_factory=list,
+        description="JSON Web Signatures for the AgentCard",
+    )

lib/crewai/src/crewai/a2a/types.py

@@ -1,7 +1,17 @@
 """Type definitions for A2A protocol message parts."""
 
-from typing import Any, Literal, Protocol, TypedDict, runtime_checkable
+from __future__ import annotations
 
+from typing import (
+    Annotated,
+    Any,
+    Literal,
+    Protocol,
+    TypedDict,
+    runtime_checkable,
+)
+
+from pydantic import BeforeValidator, HttpUrl, TypeAdapter
 from typing_extensions import NotRequired
 
 from crewai.a2a.updates import (
@@ -15,6 +25,18 @@ from crewai.a2a.updates import (
 )
 
 
+TransportType = Literal["JSONRPC", "GRPC", "HTTP+JSON"]
+
+http_url_adapter: TypeAdapter[HttpUrl] = TypeAdapter(HttpUrl)
+
+Url = Annotated[
+    str,
+    BeforeValidator(
+        lambda value: str(http_url_adapter.validate_python(value, strict=True))
+    ),
+]
+
+
 @runtime_checkable
 class AgentResponseProtocol(Protocol):
     """Protocol for the dynamically created AgentResponse model."""

lib/crewai/src/crewai/a2a/utils/__init__.py

@@ -0,0 +1 @@
+"""A2A utility modules for client operations."""

lib/crewai/src/crewai/a2a/utils/agent_card.py

@@ -0,0 +1,399 @@
+"""AgentCard utilities for A2A client and server operations."""
+
+from __future__ import annotations
+
+import asyncio
+from collections.abc import MutableMapping
+from functools import lru_cache
+import time
+from types import MethodType
+from typing import TYPE_CHECKING
+
+from a2a.client.errors import A2AClientHTTPError
+from a2a.types import AgentCapabilities, AgentCard, AgentSkill
+from aiocache import cached  # type: ignore[import-untyped]
+from aiocache.serializers import PickleSerializer  # type: ignore[import-untyped]
+import httpx
+
+from crewai.a2a.auth.schemas import APIKeyAuth, HTTPDigestAuth
+from crewai.a2a.auth.utils import (
+    _auth_store,
+    configure_auth_client,
+    retry_on_401,
+)
+from crewai.a2a.config import A2AServerConfig
+from crewai.crew import Crew
+
+
+if TYPE_CHECKING:
+    from crewai.a2a.auth.schemas import AuthScheme
+    from crewai.agent import Agent
+    from crewai.task import Task
+
+
+def _get_server_config(agent: Agent) -> A2AServerConfig | None:
+    """Get A2AServerConfig from an agent's a2a configuration.
+
+    Args:
+        agent: The Agent instance to check.
+
+    Returns:
+        A2AServerConfig if present, None otherwise.
+    """
+    if agent.a2a is None:
+        return None
+    if isinstance(agent.a2a, A2AServerConfig):
+        return agent.a2a
+    if isinstance(agent.a2a, list):
+        for config in agent.a2a:
+            if isinstance(config, A2AServerConfig):
+                return config
+    return None
+
+
+def fetch_agent_card(
+    endpoint: str,
+    auth: AuthScheme | None = None,
+    timeout: int = 30,
+    use_cache: bool = True,
+    cache_ttl: int = 300,
+) -> AgentCard:
+    """Fetch AgentCard from an A2A endpoint with optional caching.
+
+    Args:
+        endpoint: A2A agent endpoint URL (AgentCard URL).
+        auth: Optional AuthScheme for authentication.
+        timeout: Request timeout in seconds.
+        use_cache: Whether to use caching (default True).
+        cache_ttl: Cache TTL in seconds (default 300 = 5 minutes).
+
+    Returns:
+        AgentCard object with agent capabilities and skills.
+
+    Raises:
+        httpx.HTTPStatusError: If the request fails.
+        A2AClientHTTPError: If authentication fails.
+    """
+    if use_cache:
+        if auth:
+            auth_data = auth.model_dump_json(
+                exclude={
+                    "_access_token",
+                    "_token_expires_at",
+                    "_refresh_token",
+                    "_authorization_callback",
+                }
+            )
+            auth_hash = hash((type(auth).__name__, auth_data))
+        else:
+            auth_hash = 0
+        _auth_store[auth_hash] = auth
+        ttl_hash = int(time.time() // cache_ttl)
+        return _fetch_agent_card_cached(endpoint, auth_hash, timeout, ttl_hash)
+
+    loop = asyncio.new_event_loop()
+    asyncio.set_event_loop(loop)
+    try:
+        return loop.run_until_complete(
+            afetch_agent_card(endpoint=endpoint, auth=auth, timeout=timeout)
+        )
+    finally:
+        loop.close()
+
+
+async def afetch_agent_card(
+    endpoint: str,
+    auth: AuthScheme | None = None,
+    timeout: int = 30,
+    use_cache: bool = True,
+) -> AgentCard:
+    """Fetch AgentCard from an A2A endpoint asynchronously.
+
+    Native async implementation. Use this when running in an async context.
+
+    Args:
+        endpoint: A2A agent endpoint URL (AgentCard URL).
+        auth: Optional AuthScheme for authentication.
+        timeout: Request timeout in seconds.
+        use_cache: Whether to use caching (default True).
+
+    Returns:
+        AgentCard object with agent capabilities and skills.
+
+    Raises:
+        httpx.HTTPStatusError: If the request fails.
+        A2AClientHTTPError: If authentication fails.
+    """
+    if use_cache:
+        if auth:
+            auth_data = auth.model_dump_json(
+                exclude={
+                    "_access_token",
+                    "_token_expires_at",
+                    "_refresh_token",
+                    "_authorization_callback",
+                }
+            )
+            auth_hash = hash((type(auth).__name__, auth_data))
+        else:
+            auth_hash = 0
+        _auth_store[auth_hash] = auth
+        agent_card: AgentCard = await _afetch_agent_card_cached(
+            endpoint, auth_hash, timeout
+        )
+        return agent_card
+
+    return await _afetch_agent_card_impl(endpoint=endpoint, auth=auth, timeout=timeout)
+
+
+@lru_cache()
+def _fetch_agent_card_cached(
+    endpoint: str,
+    auth_hash: int,
+    timeout: int,
+    _ttl_hash: int,
+) -> AgentCard:
+    """Cached sync version of fetch_agent_card."""
+    auth = _auth_store.get(auth_hash)
+
+    loop = asyncio.new_event_loop()
+    asyncio.set_event_loop(loop)
+    try:
+        return loop.run_until_complete(
+            _afetch_agent_card_impl(endpoint=endpoint, auth=auth, timeout=timeout)
+        )
+    finally:
+        loop.close()
+
+
+@cached(ttl=300, serializer=PickleSerializer())  # type: ignore[untyped-decorator]
+async def _afetch_agent_card_cached(
+    endpoint: str,
+    auth_hash: int,
+    timeout: int,
+) -> AgentCard:
+    """Cached async implementation of AgentCard fetching."""
+    auth = _auth_store.get(auth_hash)
+    return await _afetch_agent_card_impl(endpoint=endpoint, auth=auth, timeout=timeout)
+
+
+async def _afetch_agent_card_impl(
+    endpoint: str,
+    auth: AuthScheme | None,
+    timeout: int,
+) -> AgentCard:
+    """Internal async implementation of AgentCard fetching."""
+    if "/.well-known/agent-card.json" in endpoint:
+        base_url = endpoint.replace("/.well-known/agent-card.json", "")
+        agent_card_path = "/.well-known/agent-card.json"
+    else:
+        url_parts = endpoint.split("/", 3)
+        base_url = f"{url_parts[0]}//{url_parts[2]}"
+        agent_card_path = f"/{url_parts[3]}" if len(url_parts) > 3 else "/"
+
+    headers: MutableMapping[str, str] = {}
+    if auth:
+        async with httpx.AsyncClient(timeout=timeout) as temp_auth_client:
+            if isinstance(auth, (HTTPDigestAuth, APIKeyAuth)):
+                configure_auth_client(auth, temp_auth_client)
+            headers = await auth.apply_auth(temp_auth_client, {})
+
+    async with httpx.AsyncClient(timeout=timeout, headers=headers) as temp_client:
+        if auth and isinstance(auth, (HTTPDigestAuth, APIKeyAuth)):
+            configure_auth_client(auth, temp_client)
+
+        agent_card_url = f"{base_url}{agent_card_path}"
+
+        async def _fetch_agent_card_request() -> httpx.Response:
+            return await temp_client.get(agent_card_url)
+
+        try:
+            response = await retry_on_401(
+                request_func=_fetch_agent_card_request,
+                auth_scheme=auth,
+                client=temp_client,
+                headers=temp_client.headers,
+                max_retries=2,
+            )
+            response.raise_for_status()
+
+            return AgentCard.model_validate(response.json())
+
+        except httpx.HTTPStatusError as e:
+            if e.response.status_code == 401:
+                error_details = ["Authentication failed"]
+                www_auth = e.response.headers.get("WWW-Authenticate")
+                if www_auth:
+                    error_details.append(f"WWW-Authenticate: {www_auth}")
+                if not auth:
+                    error_details.append("No auth scheme provided")
+                msg = " | ".join(error_details)
+                raise A2AClientHTTPError(401, msg) from e
+            raise
+
+
+def _task_to_skill(task: Task) -> AgentSkill:
+    """Convert a CrewAI Task to an A2A AgentSkill.
+
+    Args:
+        task: The CrewAI Task to convert.
+
+    Returns:
+        AgentSkill representing the task's capability.
+    """
+    task_name = task.name or task.description[:50]
+    task_id = task_name.lower().replace(" ", "_")
+
+    tags: list[str] = []
+    if task.agent:
+        tags.append(task.agent.role.lower().replace(" ", "-"))
+
+    return AgentSkill(
+        id=task_id,
+        name=task_name,
+        description=task.description,
+        tags=tags,
+        examples=[task.expected_output] if task.expected_output else None,
+    )
+
+
+def _tool_to_skill(tool_name: str, tool_description: str) -> AgentSkill:
+    """Convert an Agent's tool to an A2A AgentSkill.
+
+    Args:
+        tool_name: Name of the tool.
+        tool_description: Description of what the tool does.
+
+    Returns:
+        AgentSkill representing the tool's capability.
+    """
+    tool_id = tool_name.lower().replace(" ", "_")
+
+    return AgentSkill(
+        id=tool_id,
+        name=tool_name,
+        description=tool_description,
+        tags=[tool_name.lower().replace(" ", "-")],
+    )
+
+
+def _crew_to_agent_card(crew: Crew, url: str) -> AgentCard:
+    """Generate an A2A AgentCard from a Crew instance.
+
+    Args:
+        crew: The Crew instance to generate a card for.
+        url: The base URL where this crew will be exposed.
+
+    Returns:
+        AgentCard describing the crew's capabilities.
+    """
+    crew_name = getattr(crew, "name", None) or crew.__class__.__name__
+
+    description_parts: list[str] = []
+    crew_description = getattr(crew, "description", None)
+    if crew_description:
+        description_parts.append(crew_description)
+    else:
+        agent_roles = [agent.role for agent in crew.agents]
+        description_parts.append(
+            f"A crew of {len(crew.agents)} agents: {', '.join(agent_roles)}"
+        )
+
+    skills = [_task_to_skill(task) for task in crew.tasks]
+
+    return AgentCard(
+        name=crew_name,
+        description=" ".join(description_parts),
+        url=url,
+        version="1.0.0",
+        capabilities=AgentCapabilities(
+            streaming=True,
+            push_notifications=True,
+        ),
+        default_input_modes=["text/plain", "application/json"],
+        default_output_modes=["text/plain", "application/json"],
+        skills=skills,
+    )
+
+
+def _agent_to_agent_card(agent: Agent, url: str) -> AgentCard:
+    """Generate an A2A AgentCard from an Agent instance.
+
+    Uses A2AServerConfig values when available, falling back to agent properties.
+
+    Args:
+        agent: The Agent instance to generate a card for.
+        url: The base URL where this agent will be exposed.
+
+    Returns:
+        AgentCard describing the agent's capabilities.
+    """
+    server_config = _get_server_config(agent) or A2AServerConfig()
+
+    name = server_config.name or agent.role
+
+    description_parts = [agent.goal]
+    if agent.backstory:
+        description_parts.append(agent.backstory)
+    description = server_config.description or " ".join(description_parts)
+
+    skills: list[AgentSkill] = (
+        server_config.skills.copy() if server_config.skills else []
+    )
+
+    if not skills:
+        if agent.tools:
+            for tool in agent.tools:
+                tool_name = getattr(tool, "name", None) or tool.__class__.__name__
+                tool_desc = getattr(tool, "description", None) or f"Tool: {tool_name}"
+                skills.append(_tool_to_skill(tool_name, tool_desc))
+
+        if not skills:
+            skills.append(
+                AgentSkill(
+                    id=agent.role.lower().replace(" ", "_"),
+                    name=agent.role,
+                    description=agent.goal,
+                    tags=[agent.role.lower().replace(" ", "-")],
+                )
+            )
+
+    return AgentCard(
+        name=name,
+        description=description,
+        url=server_config.url or url,
+        version=server_config.version,
+        capabilities=server_config.capabilities,
+        default_input_modes=server_config.default_input_modes,
+        default_output_modes=server_config.default_output_modes,
+        skills=skills,
+        protocol_version=server_config.protocol_version,
+        provider=server_config.provider,
+        documentation_url=server_config.documentation_url,
+        icon_url=server_config.icon_url,
+        additional_interfaces=server_config.additional_interfaces,
+        security=server_config.security,
+        security_schemes=server_config.security_schemes,
+        supports_authenticated_extended_card=server_config.supports_authenticated_extended_card,
+        signatures=server_config.signatures,
+    )
+
+
+def inject_a2a_server_methods(agent: Agent) -> None:
+    """Inject A2A server methods onto an Agent instance.
+
+    Adds a `to_agent_card(url: str) -> AgentCard` method to the agent
+    that generates an A2A-compliant AgentCard.
+
+    Only injects if the agent has an A2AServerConfig.
+
+    Args:
+        agent: The Agent instance to inject methods onto.
+    """
+    if _get_server_config(agent) is None:
+        return
+
+    def _to_agent_card(self: Agent, url: str) -> AgentCard:
+        return _agent_to_agent_card(self, url)
+
+    object.__setattr__(agent, "to_agent_card", MethodType(_to_agent_card, agent))

lib/crewai/src/crewai/a2a/utils/delegation.py

@@ -1,16 +1,14 @@
-"""Utility functions for A2A (Agent-to-Agent) protocol delegation."""
+"""A2A delegation utilities for executing tasks on remote agents."""
 
 from __future__ import annotations
 
 import asyncio
 from collections.abc import AsyncIterator, MutableMapping
 from contextlib import asynccontextmanager
-from functools import lru_cache
-import time
 from typing import TYPE_CHECKING, Any, Literal
 import uuid
 
-from a2a.client import A2AClientHTTPError, Client, ClientConfig, ClientFactory
+from a2a.client import Client, ClientConfig, ClientFactory
 from a2a.types import (
     AgentCard,
     Message,
@@ -19,19 +17,15 @@ from a2a.types import (
     Role,
     TextPart,
 )
-from aiocache import cached  # type: ignore[import-untyped]
-from aiocache.serializers import PickleSerializer  # type: ignore[import-untyped]
 import httpx
-from pydantic import BaseModel, Field, create_model
+from pydantic import BaseModel
 
 from crewai.a2a.auth.schemas import APIKeyAuth, HTTPDigestAuth
 from crewai.a2a.auth.utils import (
     _auth_store,
     configure_auth_client,
-    retry_on_401,
     validate_auth_against_agent_card,
 )
-from crewai.a2a.config import A2AConfig
 from crewai.a2a.task_helpers import TaskStateResult
 from crewai.a2a.types import (
     HANDLER_REGISTRY,
@@ -45,6 +39,7 @@ from crewai.a2a.updates import (
     StreamingHandler,
     UpdateConfig,
 )
+from crewai.a2a.utils.agent_card import _afetch_agent_card_cached
 from crewai.events.event_bus import crewai_event_bus
 from crewai.events.types.a2a_events import (
     A2AConversationStartedEvent,
@@ -52,7 +47,6 @@ from crewai.events.types.a2a_events import (
     A2ADelegationStartedEvent,
     A2AMessageSentEvent,
 )
-from crewai.types.utils import create_literals_from_strings
 
 
 if TYPE_CHECKING:
@@ -75,187 +69,6 @@ def get_handler(config: UpdateConfig | None) -> HandlerType:
     return HANDLER_REGISTRY.get(type(config), StreamingHandler)
 
 
-@lru_cache()
-def _fetch_agent_card_cached(
-    endpoint: str,
-    auth_hash: int,
-    timeout: int,
-    _ttl_hash: int,
-) -> AgentCard:
-    """Cached sync version of fetch_agent_card."""
-    auth = _auth_store.get(auth_hash)
-
-    loop = asyncio.new_event_loop()
-    asyncio.set_event_loop(loop)
-    try:
-        return loop.run_until_complete(
-            _afetch_agent_card_impl(endpoint=endpoint, auth=auth, timeout=timeout)
-        )
-    finally:
-        loop.close()
-
-
-def fetch_agent_card(
-    endpoint: str,
-    auth: AuthScheme | None = None,
-    timeout: int = 30,
-    use_cache: bool = True,
-    cache_ttl: int = 300,
-) -> AgentCard:
-    """Fetch AgentCard from an A2A endpoint with optional caching.
-
-    Args:
-        endpoint: A2A agent endpoint URL (AgentCard URL)
-        auth: Optional AuthScheme for authentication
-        timeout: Request timeout in seconds
-        use_cache: Whether to use caching (default True)
-        cache_ttl: Cache TTL in seconds (default 300 = 5 minutes)
-
-    Returns:
-        AgentCard object with agent capabilities and skills
-
-    Raises:
-        httpx.HTTPStatusError: If the request fails
-        A2AClientHTTPError: If authentication fails
-    """
-    if use_cache:
-        if auth:
-            auth_data = auth.model_dump_json(
-                exclude={
-                    "_access_token",
-                    "_token_expires_at",
-                    "_refresh_token",
-                    "_authorization_callback",
-                }
-            )
-            auth_hash = hash((type(auth).__name__, auth_data))
-        else:
-            auth_hash = 0
-        _auth_store[auth_hash] = auth
-        ttl_hash = int(time.time() // cache_ttl)
-        return _fetch_agent_card_cached(endpoint, auth_hash, timeout, ttl_hash)
-
-    loop = asyncio.new_event_loop()
-    asyncio.set_event_loop(loop)
-    try:
-        return loop.run_until_complete(
-            afetch_agent_card(endpoint=endpoint, auth=auth, timeout=timeout)
-        )
-    finally:
-        loop.close()
-
-
-async def afetch_agent_card(
-    endpoint: str,
-    auth: AuthScheme | None = None,
-    timeout: int = 30,
-    use_cache: bool = True,
-) -> AgentCard:
-    """Fetch AgentCard from an A2A endpoint asynchronously.
-
-    Native async implementation. Use this when running in an async context.
-
-    Args:
-        endpoint: A2A agent endpoint URL (AgentCard URL).
-        auth: Optional AuthScheme for authentication.
-        timeout: Request timeout in seconds.
-        use_cache: Whether to use caching (default True).
-
-    Returns:
-        AgentCard object with agent capabilities and skills.
-
-    Raises:
-        httpx.HTTPStatusError: If the request fails.
-        A2AClientHTTPError: If authentication fails.
-    """
-    if use_cache:
-        if auth:
-            auth_data = auth.model_dump_json(
-                exclude={
-                    "_access_token",
-                    "_token_expires_at",
-                    "_refresh_token",
-                    "_authorization_callback",
-                }
-            )
-            auth_hash = hash((type(auth).__name__, auth_data))
-        else:
-            auth_hash = 0
-        _auth_store[auth_hash] = auth
-        agent_card: AgentCard = await _afetch_agent_card_cached(
-            endpoint, auth_hash, timeout
-        )
-        return agent_card
-
-    return await _afetch_agent_card_impl(endpoint=endpoint, auth=auth, timeout=timeout)
-
-
-@cached(ttl=300, serializer=PickleSerializer())  # type: ignore[untyped-decorator]
-async def _afetch_agent_card_cached(
-    endpoint: str,
-    auth_hash: int,
-    timeout: int,
-) -> AgentCard:
-    """Cached async implementation of AgentCard fetching."""
-    auth = _auth_store.get(auth_hash)
-    return await _afetch_agent_card_impl(endpoint=endpoint, auth=auth, timeout=timeout)
-
-
-async def _afetch_agent_card_impl(
-    endpoint: str,
-    auth: AuthScheme | None,
-    timeout: int,
-) -> AgentCard:
-    """Internal async implementation of AgentCard fetching."""
-    if "/.well-known/agent-card.json" in endpoint:
-        base_url = endpoint.replace("/.well-known/agent-card.json", "")
-        agent_card_path = "/.well-known/agent-card.json"
-    else:
-        url_parts = endpoint.split("/", 3)
-        base_url = f"{url_parts[0]}//{url_parts[2]}"
-        agent_card_path = f"/{url_parts[3]}" if len(url_parts) > 3 else "/"
-
-    headers: MutableMapping[str, str] = {}
-    if auth:
-        async with httpx.AsyncClient(timeout=timeout) as temp_auth_client:
-            if isinstance(auth, (HTTPDigestAuth, APIKeyAuth)):
-                configure_auth_client(auth, temp_auth_client)
-            headers = await auth.apply_auth(temp_auth_client, {})
-
-    async with httpx.AsyncClient(timeout=timeout, headers=headers) as temp_client:
-        if auth and isinstance(auth, (HTTPDigestAuth, APIKeyAuth)):
-            configure_auth_client(auth, temp_client)
-
-        agent_card_url = f"{base_url}{agent_card_path}"
-
-        async def _fetch_agent_card_request() -> httpx.Response:
-            return await temp_client.get(agent_card_url)
-
-        try:
-            response = await retry_on_401(
-                request_func=_fetch_agent_card_request,
-                auth_scheme=auth,
-                client=temp_client,
-                headers=temp_client.headers,
-                max_retries=2,
-            )
-            response.raise_for_status()
-
-            return AgentCard.model_validate(response.json())
-
-        except httpx.HTTPStatusError as e:
-            if e.response.status_code == 401:
-                error_details = ["Authentication failed"]
-                www_auth = e.response.headers.get("WWW-Authenticate")
-                if www_auth:
-                    error_details.append(f"WWW-Authenticate: {www_auth}")
-                if not auth:
-                    error_details.append("No auth scheme provided")
-                msg = " | ".join(error_details)
-                raise A2AClientHTTPError(401, msg) from e
-            raise
-
-
 def execute_a2a_delegation(
     endpoint: str,
     transport_protocol: Literal["JSONRPC", "GRPC", "HTTP+JSON"],
@@ -644,19 +457,18 @@ async def _create_a2a_client(
     """Create and configure an A2A client.
 
     Args:
-        agent_card: The A2A agent card
+        agent_card: The A2A agent card.
-        transport_protocol: Transport protocol to use
+        transport_protocol: Transport protocol to use.
-        timeout: Request timeout in seconds
+        timeout: Request timeout in seconds.
-        headers: HTTP headers (already with auth applied)
+        headers: HTTP headers (already with auth applied).
-        streaming: Enable streaming responses
+        streaming: Enable streaming responses.
-        auth: Optional AuthScheme for client configuration
+        auth: Optional AuthScheme for client configuration.
-        use_polling: Enable polling mode
+        use_polling: Enable polling mode.
-        push_notification_config: Optional push notification config to include in requests
+        push_notification_config: Optional push notification config.
 
     Yields:
-        Configured A2A client instance
+        Configured A2A client instance.
     """
-
     async with httpx.AsyncClient(
         timeout=timeout,
         headers=headers,
@@ -687,78 +499,3 @@ async def _create_a2a_client(
         factory = ClientFactory(config)
         client = factory.create(agent_card)
         yield client
-
-
-def create_agent_response_model(agent_ids: tuple[str, ...]) -> type[BaseModel]:
-    """Create a dynamic AgentResponse model with Literal types for agent IDs.
-
-    Args:
-        agent_ids: List of available A2A agent IDs
-
-    Returns:
-        Dynamically created Pydantic model with Literal-constrained a2a_ids field
-    """
-
-    DynamicLiteral = create_literals_from_strings(agent_ids)  # noqa: N806
-
-    return create_model(
-        "AgentResponse",
-        a2a_ids=(
-            tuple[DynamicLiteral, ...],  # type: ignore[valid-type]
-            Field(
-                default_factory=tuple,
-                max_length=len(agent_ids),
-                description="A2A agent IDs to delegate to.",
-            ),
-        ),
-        message=(
-            str,
-            Field(
-                description="The message content. If is_a2a=true, this is sent to the A2A agent. If is_a2a=false, this is your final answer ending the conversation."
-            ),
-        ),
-        is_a2a=(
-            bool,
-            Field(
-                description="Set to false when the remote agent has answered your question - extract their answer and return it as your final message. Set to true ONLY if you need to ask a NEW, DIFFERENT question. NEVER repeat the same request - if the conversation history shows the agent already answered, set is_a2a=false immediately."
-            ),
-        ),
-        __base__=BaseModel,
-    )
-
-
-def extract_a2a_agent_ids_from_config(
-    a2a_config: list[A2AConfig] | A2AConfig | None,
-) -> tuple[list[A2AConfig], tuple[str, ...]]:
-    """Extract A2A agent IDs from A2A configuration.
-
-    Args:
-        a2a_config: A2A configuration
-
-    Returns:
-        List of A2A agent IDs
-    """
-    if a2a_config is None:
-        return [], ()
-
-    if isinstance(a2a_config, A2AConfig):
-        a2a_agents = [a2a_config]
-    else:
-        a2a_agents = a2a_config
-    return a2a_agents, tuple(config.endpoint for config in a2a_agents)
-
-
-def get_a2a_agents_and_response_model(
-    a2a_config: list[A2AConfig] | A2AConfig | None,
-) -> tuple[list[A2AConfig], type[BaseModel]]:
-    """Get A2A agent IDs and response model.
-
-    Args:
-        a2a_config: A2A configuration
-
-    Returns:
-        Tuple of A2A agent IDs and response model
-    """
-    a2a_agents, agent_ids = extract_a2a_agent_ids_from_config(a2a_config=a2a_config)
-
-    return a2a_agents, create_agent_response_model(agent_ids)

lib/crewai/src/crewai/a2a/utils/response_model.py

@@ -0,0 +1,97 @@
+"""Response model utilities for A2A agent interactions."""
+
+from __future__ import annotations
+
+from typing import TypeAlias
+
+from pydantic import BaseModel, Field, create_model
+
+from crewai.a2a.config import A2AClientConfig, A2AConfig, A2AServerConfig
+from crewai.types.utils import create_literals_from_strings
+
+
+A2AConfigTypes: TypeAlias = A2AConfig | A2AServerConfig | A2AClientConfig
+A2AClientConfigTypes: TypeAlias = A2AConfig | A2AClientConfig
+
+
+def create_agent_response_model(agent_ids: tuple[str, ...]) -> type[BaseModel]:
+    """Create a dynamic AgentResponse model with Literal types for agent IDs.
+
+    Args:
+        agent_ids: List of available A2A agent IDs.
+
+    Returns:
+        Dynamically created Pydantic model with Literal-constrained a2a_ids field.
+    """
+    DynamicLiteral = create_literals_from_strings(agent_ids)  # noqa: N806
+
+    return create_model(
+        "AgentResponse",
+        a2a_ids=(
+            tuple[DynamicLiteral, ...],  # type: ignore[valid-type]
+            Field(
+                default_factory=tuple,
+                max_length=len(agent_ids),
+                description="A2A agent IDs to delegate to.",
+            ),
+        ),
+        message=(
+            str,
+            Field(
+                description="The message content. If is_a2a=true, this is sent to the A2A agent. If is_a2a=false, this is your final answer ending the conversation."
+            ),
+        ),
+        is_a2a=(
+            bool,
+            Field(
+                description="Set to false when the remote agent has answered your question - extract their answer and return it as your final message. Set to true ONLY if you need to ask a NEW, DIFFERENT question. NEVER repeat the same request - if the conversation history shows the agent already answered, set is_a2a=false immediately."
+            ),
+        ),
+        __base__=BaseModel,
+    )
+
+
+def extract_a2a_agent_ids_from_config(
+    a2a_config: list[A2AConfigTypes] | A2AConfigTypes | None,
+) -> tuple[list[A2AClientConfigTypes], tuple[str, ...]]:
+    """Extract A2A agent IDs from A2A configuration.
+
+    Filters out A2AServerConfig since it doesn't have an endpoint for delegation.
+
+    Args:
+        a2a_config: A2A configuration (any type).
+
+    Returns:
+        Tuple of client A2A configs list and agent endpoint IDs.
+    """
+    if a2a_config is None:
+        return [], ()
+
+    configs: list[A2AConfigTypes]
+    if isinstance(a2a_config, (A2AConfig, A2AClientConfig, A2AServerConfig)):
+        configs = [a2a_config]
+    else:
+        configs = a2a_config
+
+    # Filter to only client configs (those with endpoint)
+    client_configs: list[A2AClientConfigTypes] = [
+        config for config in configs if isinstance(config, (A2AConfig, A2AClientConfig))
+    ]
+
+    return client_configs, tuple(config.endpoint for config in client_configs)
+
+
+def get_a2a_agents_and_response_model(
+    a2a_config: list[A2AConfigTypes] | A2AConfigTypes | None,
+) -> tuple[list[A2AClientConfigTypes], type[BaseModel]]:
+    """Get A2A agent configs and response model.
+
+    Args:
+        a2a_config: A2A configuration (any type).
+
+    Returns:
+        Tuple of client A2A configs and response model.
+    """
+    a2a_agents, agent_ids = extract_a2a_agent_ids_from_config(a2a_config=a2a_config)
+
+    return a2a_agents, create_agent_response_model(agent_ids)

lib/crewai/src/crewai/a2a/wrapper.py

@@ -15,7 +15,7 @@ from typing import TYPE_CHECKING, Any
 from a2a.types import Role, TaskState
 from pydantic import BaseModel, ValidationError
 
-from crewai.a2a.config import A2AConfig
+from crewai.a2a.config import A2AClientConfig, A2AConfig
 from crewai.a2a.extensions.base import ExtensionRegistry
 from crewai.a2a.task_helpers import TaskStateResult
 from crewai.a2a.templates import (
@@ -26,13 +26,16 @@ from crewai.a2a.templates import (
     UNAVAILABLE_AGENTS_NOTICE_TEMPLATE,
 )
 from crewai.a2a.types import AgentResponseProtocol
-from crewai.a2a.utils import (
+from crewai.a2a.utils.agent_card import (
-    aexecute_a2a_delegation,
     afetch_agent_card,
-    execute_a2a_delegation,
     fetch_agent_card,
-    get_a2a_agents_and_response_model,
+    inject_a2a_server_methods,
 )
+from crewai.a2a.utils.delegation import (
+    aexecute_a2a_delegation,
+    execute_a2a_delegation,
+)
+from crewai.a2a.utils.response_model import get_a2a_agents_and_response_model
 from crewai.events.event_bus import crewai_event_bus
 from crewai.events.types.a2a_events import (
     A2AConversationCompletedEvent,
@@ -122,10 +125,12 @@ def wrap_agent_with_a2a_instance(
         agent, "aexecute_task", MethodType(aexecute_task_with_a2a, agent)
     )
 
+    inject_a2a_server_methods(agent)
+
 
 def _fetch_card_from_config(
-    config: A2AConfig,
+    config: A2AConfig | A2AClientConfig,
-) -> tuple[A2AConfig, AgentCard | Exception]:
+) -> tuple[A2AConfig | A2AClientConfig, AgentCard | Exception]:
     """Fetch agent card from A2A config.
 
     Args:
@@ -146,7 +151,7 @@ def _fetch_card_from_config(
 
 
 def _fetch_agent_cards_concurrently(
-    a2a_agents: list[A2AConfig],
+    a2a_agents: list[A2AConfig | A2AClientConfig],
 ) -> tuple[dict[str, AgentCard], dict[str, str]]:
     """Fetch agent cards concurrently for multiple A2A agents.
 
@@ -181,7 +186,7 @@ def _fetch_agent_cards_concurrently(
 
 def _execute_task_with_a2a(
     self: Agent,
-    a2a_agents: list[A2AConfig],
+    a2a_agents: list[A2AConfig | A2AClientConfig],
     original_fn: Callable[..., str],
     task: Task,
     agent_response_model: type[BaseModel],
@@ -270,7 +275,7 @@ def _execute_task_with_a2a(
 
 
 def _augment_prompt_with_a2a(
-    a2a_agents: list[A2AConfig],
+    a2a_agents: list[A2AConfig | A2AClientConfig],
     task_description: str,
     agent_cards: dict[str, AgentCard],
     conversation_history: list[Message] | None = None,
@@ -523,11 +528,11 @@ def _prepare_delegation_context(
     task: Task,
     original_task_description: str | None,
 ) -> tuple[
-    list[A2AConfig],
+    list[A2AConfig | A2AClientConfig],
     type[BaseModel],
     str,
     str,
-    A2AConfig,
+    A2AConfig | A2AClientConfig,
     str | None,
     str | None,
     dict[str, Any] | None,
@@ -591,7 +596,7 @@ def _handle_task_completion(
     task: Task,
     task_id_config: str | None,
     reference_task_ids: list[str],
-    agent_config: A2AConfig,
+    agent_config: A2AConfig | A2AClientConfig,
     turn_num: int,
 ) -> tuple[str | None, str | None, list[str]]:
     """Handle task completion state including reference task updates.
@@ -631,7 +636,7 @@ def _handle_agent_response_and_continue(
     a2a_result: TaskStateResult,
     agent_id: str,
     agent_cards: dict[str, AgentCard] | None,
-    a2a_agents: list[A2AConfig],
+    a2a_agents: list[A2AConfig | A2AClientConfig],
     original_task_description: str,
     conversation_history: list[Message],
     turn_num: int,
@@ -868,8 +873,8 @@ def _delegate_to_a2a(
 
 
 async def _afetch_card_from_config(
-    config: A2AConfig,
+    config: A2AConfig | A2AClientConfig,
-) -> tuple[A2AConfig, AgentCard | Exception]:
+) -> tuple[A2AConfig | A2AClientConfig, AgentCard | Exception]:
     """Fetch agent card from A2A config asynchronously."""
     try:
         card = await afetch_agent_card(
@@ -883,7 +888,7 @@ async def _afetch_card_from_config(
 
 
 async def _afetch_agent_cards_concurrently(
-    a2a_agents: list[A2AConfig],
+    a2a_agents: list[A2AConfig | A2AClientConfig],
 ) -> tuple[dict[str, AgentCard], dict[str, str]]:
     """Fetch agent cards concurrently for multiple A2A agents using asyncio."""
     agent_cards: dict[str, AgentCard] = {}
@@ -908,7 +913,7 @@ async def _afetch_agent_cards_concurrently(
 
 async def _aexecute_task_with_a2a(
     self: Agent,
-    a2a_agents: list[A2AConfig],
+    a2a_agents: list[A2AConfig | A2AClientConfig],
     original_fn: Callable[..., Coroutine[Any, Any, str]],
     task: Task,
     agent_response_model: type[BaseModel],
@@ -987,7 +992,7 @@ async def _ahandle_agent_response_and_continue(
     a2a_result: TaskStateResult,
     agent_id: str,
     agent_cards: dict[str, AgentCard] | None,
-    a2a_agents: list[A2AConfig],
+    a2a_agents: list[A2AConfig | A2AClientConfig],
     original_task_description: str,
     conversation_history: list[Message],
     turn_num: int,

lib/crewai/src/crewai/agent/core.py

@@ -17,7 +17,7 @@ from urllib.parse import urlparse
 from pydantic import BaseModel, Field, InstanceOf, PrivateAttr, model_validator
 from typing_extensions import Self
 
-from crewai.a2a.config import A2AConfig
+from crewai.a2a.config import A2AClientConfig, A2AConfig, A2AServerConfig
 from crewai.agent.utils import (
     ahandle_knowledge_retrieval,
     apply_training_data,
@@ -73,7 +73,7 @@ from crewai.utilities.constants import TRAINED_AGENTS_DATA_FILE, TRAINING_DATA_F
 from crewai.utilities.converter import Converter
 from crewai.utilities.guardrail_types import GuardrailType
 from crewai.utilities.llm_utils import create_llm
-from crewai.utilities.prompts import Prompts
+from crewai.utilities.prompts import Prompts, StandardPromptResult, SystemPromptResult
 from crewai.utilities.token_counter_callback import TokenCalcHandler
 from crewai.utilities.training_handler import CrewTrainingHandler
 
@@ -218,9 +218,18 @@ class Agent(BaseAgent):
     guardrail_max_retries: int = Field(
         default=3, description="Maximum number of retries when guardrail fails"
     )
-    a2a: list[A2AConfig] | A2AConfig | None = Field(
+    a2a: (
+        list[A2AConfig | A2AServerConfig | A2AClientConfig]
+        | A2AConfig
+        | A2AServerConfig
+        | A2AClientConfig
+        | None
+    ) = Field(
         default=None,
-        description="A2A (Agent-to-Agent) configuration for delegating tasks to remote agents. Can be a single A2AConfig or a dict mapping agent IDs to configs.",
+        description="""
+        A2A (Agent-to-Agent) configuration for delegating tasks to remote agents.
+        Can be a single A2AConfig/A2AClientConfig/A2AServerConfig, or a list of any number of A2AConfig/A2AClientConfig with a single A2AServerConfig.
+        """,
     )
     executor_class: type[CrewAgentExecutor] | type[CrewAgentExecutorFlow] = Field(
         default=CrewAgentExecutor,
@@ -733,7 +742,7 @@ class Agent(BaseAgent):
         if self.agent_executor is not None:
             self._update_executor_parameters(
                 task=task,
-                tools=parsed_tools,
+                tools=parsed_tools,  # type: ignore[arg-type]
                 raw_tools=raw_tools,
                 prompt=prompt,
                 stop_words=stop_words,
@@ -742,7 +751,7 @@ class Agent(BaseAgent):
         else:
             self.agent_executor = self.executor_class(
                 llm=cast(BaseLLM, self.llm),
-                task=task,
+                task=task,  # type: ignore[arg-type]
                 i18n=self.i18n,
                 agent=self,
                 crew=self.crew,
@@ -765,11 +774,11 @@ class Agent(BaseAgent):
     def _update_executor_parameters(
         self,
         task: Task | None,
-        tools: list,
+        tools: list[BaseTool],
         raw_tools: list[BaseTool],
-        prompt: dict,
+        prompt: SystemPromptResult | StandardPromptResult,
         stop_words: list[str],
-        rpm_limit_fn: Callable | None,
+        rpm_limit_fn: Callable | None,  # type: ignore[type-arg]
     ) -> None:
         """Update executor parameters without recreating instance.
 

lib/crewai/tests/a2a/utils/test_agent_card.py

@@ -0,0 +1,325 @@
+"""Tests for A2A agent card utilities."""
+
+from __future__ import annotations
+
+from a2a.types import AgentCard, AgentSkill
+
+from crewai import Agent
+from crewai.a2a.config import A2AClientConfig, A2AServerConfig
+from crewai.a2a.utils.agent_card import inject_a2a_server_methods
+
+
+class TestInjectA2AServerMethods:
+    """Tests for inject_a2a_server_methods function."""
+
+    def test_agent_with_server_config_gets_to_agent_card_method(self) -> None:
+        """Agent with A2AServerConfig should have to_agent_card method injected."""
+        agent = Agent(
+            role="Test Agent",
+            goal="Test goal",
+            backstory="Test backstory",
+            a2a=A2AServerConfig(),
+        )
+
+        assert hasattr(agent, "to_agent_card")
+        assert callable(agent.to_agent_card)
+
+    def test_agent_without_server_config_no_injection(self) -> None:
+        """Agent without A2AServerConfig should not get to_agent_card method."""
+        agent = Agent(
+            role="Test Agent",
+            goal="Test goal",
+            backstory="Test backstory",
+            a2a=A2AClientConfig(endpoint="http://example.com"),
+        )
+
+        assert not hasattr(agent, "to_agent_card")
+
+    def test_agent_without_a2a_no_injection(self) -> None:
+        """Agent without any a2a config should not get to_agent_card method."""
+        agent = Agent(
+            role="Test Agent",
+            goal="Test goal",
+            backstory="Test backstory",
+        )
+
+        assert not hasattr(agent, "to_agent_card")
+
+    def test_agent_with_mixed_configs_gets_injection(self) -> None:
+        """Agent with list containing A2AServerConfig should get to_agent_card."""
+        agent = Agent(
+            role="Test Agent",
+            goal="Test goal",
+            backstory="Test backstory",
+            a2a=[
+                A2AClientConfig(endpoint="http://example.com"),
+                A2AServerConfig(name="My Agent"),
+            ],
+        )
+
+        assert hasattr(agent, "to_agent_card")
+        assert callable(agent.to_agent_card)
+
+    def test_manual_injection_on_plain_agent(self) -> None:
+        """inject_a2a_server_methods should work when called manually."""
+        agent = Agent(
+            role="Test Agent",
+            goal="Test goal",
+            backstory="Test backstory",
+        )
+        # Manually set server config and inject
+        object.__setattr__(agent, "a2a", A2AServerConfig())
+        inject_a2a_server_methods(agent)
+
+        assert hasattr(agent, "to_agent_card")
+        assert callable(agent.to_agent_card)
+
+
+class TestToAgentCard:
+    """Tests for the injected to_agent_card method."""
+
+    def test_returns_agent_card(self) -> None:
+        """to_agent_card should return an AgentCard instance."""
+        agent = Agent(
+            role="Test Agent",
+            goal="Test goal",
+            backstory="Test backstory",
+            a2a=A2AServerConfig(),
+        )
+
+        card = agent.to_agent_card("http://localhost:8000")
+
+        assert isinstance(card, AgentCard)
+
+    def test_uses_agent_role_as_name(self) -> None:
+        """AgentCard name should default to agent role."""
+        agent = Agent(
+            role="Data Analyst",
+            goal="Analyze data",
+            backstory="Expert analyst",
+            a2a=A2AServerConfig(),
+        )
+
+        card = agent.to_agent_card("http://localhost:8000")
+
+        assert card.name == "Data Analyst"
+
+    def test_uses_server_config_name(self) -> None:
+        """AgentCard name should prefer A2AServerConfig.name over role."""
+        agent = Agent(
+            role="Data Analyst",
+            goal="Analyze data",
+            backstory="Expert analyst",
+            a2a=A2AServerConfig(name="Custom Agent Name"),
+        )
+
+        card = agent.to_agent_card("http://localhost:8000")
+
+        assert card.name == "Custom Agent Name"
+
+    def test_uses_goal_as_description(self) -> None:
+        """AgentCard description should include agent goal."""
+        agent = Agent(
+            role="Test Agent",
+            goal="Accomplish important tasks",
+            backstory="Has extensive experience",
+            a2a=A2AServerConfig(),
+        )
+
+        card = agent.to_agent_card("http://localhost:8000")
+
+        assert "Accomplish important tasks" in card.description
+
+    def test_uses_server_config_description(self) -> None:
+        """AgentCard description should prefer A2AServerConfig.description."""
+        agent = Agent(
+            role="Test Agent",
+            goal="Accomplish important tasks",
+            backstory="Has extensive experience",
+            a2a=A2AServerConfig(description="Custom description"),
+        )
+
+        card = agent.to_agent_card("http://localhost:8000")
+
+        assert card.description == "Custom description"
+
+    def test_uses_provided_url(self) -> None:
+        """AgentCard url should use the provided URL."""
+        agent = Agent(
+            role="Test Agent",
+            goal="Test goal",
+            backstory="Test backstory",
+            a2a=A2AServerConfig(),
+        )
+
+        card = agent.to_agent_card("http://my-server.com:9000")
+
+        assert card.url == "http://my-server.com:9000"
+
+    def test_uses_server_config_url(self) -> None:
+        """AgentCard url should prefer A2AServerConfig.url over provided URL."""
+        agent = Agent(
+            role="Test Agent",
+            goal="Test goal",
+            backstory="Test backstory",
+            a2a=A2AServerConfig(url="http://configured-url.com"),
+        )
+
+        card = agent.to_agent_card("http://fallback-url.com")
+
+        assert card.url == "http://configured-url.com/"
+
+    def test_generates_default_skill(self) -> None:
+        """AgentCard should have at least one skill based on agent role."""
+        agent = Agent(
+            role="Research Assistant",
+            goal="Help with research",
+            backstory="Skilled researcher",
+            a2a=A2AServerConfig(),
+        )
+
+        card = agent.to_agent_card("http://localhost:8000")
+
+        assert len(card.skills) >= 1
+        skill = card.skills[0]
+        assert skill.name == "Research Assistant"
+        assert skill.description == "Help with research"
+
+    def test_uses_server_config_skills(self) -> None:
+        """AgentCard skills should prefer A2AServerConfig.skills."""
+        custom_skill = AgentSkill(
+            id="custom-skill",
+            name="Custom Skill",
+            description="A custom skill",
+            tags=["custom"],
+        )
+        agent = Agent(
+            role="Test Agent",
+            goal="Test goal",
+            backstory="Test backstory",
+            a2a=A2AServerConfig(skills=[custom_skill]),
+        )
+
+        card = agent.to_agent_card("http://localhost:8000")
+
+        assert len(card.skills) == 1
+        assert card.skills[0].id == "custom-skill"
+        assert card.skills[0].name == "Custom Skill"
+
+    def test_includes_custom_version(self) -> None:
+        """AgentCard should include version from A2AServerConfig."""
+        agent = Agent(
+            role="Test Agent",
+            goal="Test goal",
+            backstory="Test backstory",
+            a2a=A2AServerConfig(version="2.0.0"),
+        )
+
+        card = agent.to_agent_card("http://localhost:8000")
+
+        assert card.version == "2.0.0"
+
+    def test_default_version(self) -> None:
+        """AgentCard should have default version 1.0.0."""
+        agent = Agent(
+            role="Test Agent",
+            goal="Test goal",
+            backstory="Test backstory",
+            a2a=A2AServerConfig(),
+        )
+
+        card = agent.to_agent_card("http://localhost:8000")
+
+        assert card.version == "1.0.0"
+
+
+class TestAgentCardJsonStructure:
+    """Tests for the JSON structure of AgentCard."""
+
+    def test_json_has_required_fields(self) -> None:
+        """AgentCard JSON should contain all required A2A protocol fields."""
+        agent = Agent(
+            role="Test Agent",
+            goal="Test goal",
+            backstory="Test backstory",
+            a2a=A2AServerConfig(),
+        )
+
+        card = agent.to_agent_card("http://localhost:8000")
+        json_data = card.model_dump()
+
+        assert "name" in json_data
+        assert "description" in json_data
+        assert "url" in json_data
+        assert "version" in json_data
+        assert "skills" in json_data
+        assert "capabilities" in json_data
+        assert "defaultInputModes" in json_data
+        assert "defaultOutputModes" in json_data
+
+    def test_json_skills_structure(self) -> None:
+        """Each skill in JSON should have required fields."""
+        agent = Agent(
+            role="Test Agent",
+            goal="Test goal",
+            backstory="Test backstory",
+            a2a=A2AServerConfig(),
+        )
+
+        card = agent.to_agent_card("http://localhost:8000")
+        json_data = card.model_dump()
+
+        assert len(json_data["skills"]) >= 1
+        skill = json_data["skills"][0]
+        assert "id" in skill
+        assert "name" in skill
+        assert "description" in skill
+        assert "tags" in skill
+
+    def test_json_capabilities_structure(self) -> None:
+        """Capabilities in JSON should have expected fields."""
+        agent = Agent(
+            role="Test Agent",
+            goal="Test goal",
+            backstory="Test backstory",
+            a2a=A2AServerConfig(),
+        )
+
+        card = agent.to_agent_card("http://localhost:8000")
+        json_data = card.model_dump()
+
+        capabilities = json_data["capabilities"]
+        assert "streaming" in capabilities
+        assert "pushNotifications" in capabilities
+
+    def test_json_serializable(self) -> None:
+        """AgentCard should be JSON serializable."""
+        agent = Agent(
+            role="Test Agent",
+            goal="Test goal",
+            backstory="Test backstory",
+            a2a=A2AServerConfig(),
+        )
+
+        card = agent.to_agent_card("http://localhost:8000")
+        json_str = card.model_dump_json()
+
+        assert isinstance(json_str, str)
+        assert "Test Agent" in json_str
+        assert "http://localhost:8000" in json_str
+
+    def test_json_excludes_none_values(self) -> None:
+        """AgentCard JSON with exclude_none should omit None fields."""
+        agent = Agent(
+            role="Test Agent",
+            goal="Test goal",
+            backstory="Test backstory",
+            a2a=A2AServerConfig(),
+        )
+
+        card = agent.to_agent_card("http://localhost:8000")
+        json_data = card.model_dump(exclude_none=True)
+
+        assert "provider" not in json_data
+        assert "documentationUrl" not in json_data
+        assert "iconUrl" not in json_data

pyproject.toml

@@ -117,7 +117,7 @@ show_error_codes = true
 warn_unused_ignores = true
 python_version = "3.12"
 exclude = "(?x)(^lib/crewai/src/crewai/cli/templates/ | ^lib/crewai/tests/ | ^lib/crewai-tools/tests/)"
-plugins = ["pydantic.mypy", "crewai.mypy"]
+plugins = ["pydantic.mypy"]
 
 
 [tool.bandit]