Allow configuration of max payload size limit #1180

kevin-shelaga · 2025-12-29T13:56:45Z

No description provided.

Signed-off-by: kevin-shelaga <[email protected]>

Copilot

Pull request overview

This PR adds support for configuring the maximum payload size limit for A2A (Agent-to-Agent) requests across the kagent platform. The change addresses the hardcoded payload size limit in the a2a-python library (~7-8MB) by allowing users to specify custom limits through configuration.

Key Changes

Added max_payload_size configuration parameter to AgentConfig types in Python (ADK, LangGraph, CrewAI) and Go (v1alpha1, v1alpha2 APIs)
Implemented runtime patching mechanism (_patch_a2a_payload_limit) to override a2a-python's hardcoded payload size limits
Extended CLI and KAgentApp classes to accept and propagate max_payload_size configuration

Reviewed changes

Copilot reviewed 15 out of 15 changed files in this pull request and generated 10 comments.

Show a summary per file

File	Description
`python/packages/kagent-adk/src/kagent/adk/types.py`	Added `max_payload_size` field to AgentConfig with inline documentation
`python/packages/kagent-adk/src/kagent/adk/_a2a.py`	Implemented `_patch_a2a_payload_limit` function and integrated it into KAgentApp.build()
`python/packages/kagent-adk/src/kagent/adk/cli.py`	Updated CLI to pass max_payload_size from config to KAgentApp
`python/packages/kagent-langgraph/src/kagent/langgraph/_a2a.py`	Added payload patching support for LangGraph integration
`python/packages/kagent-langgraph/src/kagent/langgraph/_executor.py`	Reordered imports (langgraph imports moved after kagent.core imports)
`python/packages/kagent-crewai/src/kagent/crewai/_a2a.py`	Added payload patching support for CrewAI integration
`python/packages/kagent-crewai/src/kagent/crewai/_executor.py`	Minor whitespace cleanup (removed blank line)
`python/packages/kagent-core/src/kagent/core/tracing/_span_processor.py`	Reordered imports for consistency
`python/packages/kagent-adk/tests/unittests/test_agent_config.py`	Added comprehensive unit tests for AgentConfig with max_payload_size field
`python/packages/kagent-adk/tests/unittests/test_a2a_payload_size.py`	Added unit tests for the patching mechanism with various edge cases
`go/api/v1alpha2/agent_types.go`	Added MaxPayloadSize field to A2AConfig with Kubernetes quantity support
`go/api/v1alpha1/agent_types.go`	Added MaxPayloadSize field to A2AConfig for v1alpha1 API compatibility
`go/internal/adk/types.go`	Added MaxPayloadSize to AgentConfig struct and unmarshal logic
`go/internal/controller/translator/agent/adk_api_translator.go`	Implemented extraction and translation of maxPayloadSize from Agent CRD to AgentConfig
`go/internal/controller/translator/agent/testdata/inputs/agent_with_max_payload_size.yaml`	Added test case with maxPayloadSize configuration (50Mi)

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

Copilot · 2025-12-29T14:01:47Z

python/packages/kagent-crewai/src/kagent/crewai/_a2a.py

+        # Patch a2a-python's payload size limit if specified
+        if self.max_payload_size is not None:
+            _patch_a2a_payload_limit(self.max_payload_size)


The patching approach modifies a global module-level constant at runtime. In deployment scenarios where multiple KAgentApp instances might be created with different max_payload_size values (e.g., in tests or multi-tenant environments), the last value set will override previous ones, potentially causing unexpected behavior. Consider documenting this limitation or implementing the patch only once during module initialization if multiple instances are expected.

Copilot · 2025-12-29T14:01:47Z

python/packages/kagent-langgraph/src/kagent/langgraph/_a2a.py

+def _patch_a2a_payload_limit(max_body_size: int):
+    """Attempt to patch a2a-python library's hardcoded payload size limit."""
+    try:
+        # Try different import paths for jsonrpc_app module
+        jsonrpc_app = None
+        import_paths = [
+            "a2a.server.apps.jsonrpc.jsonrpc_app",
+            "a2a.server.apps.jsonrpc_app",
+        ]
+        for path in import_paths:
+            try:
+                jsonrpc_app = __import__(path, fromlist=[""])
+                break
+            except ImportError:
+                continue
+
+        if jsonrpc_app is None:
+            logger.debug("Could not find a2a-python jsonrpc_app module to patch")
+            return
+
+        # Check if MAX_PAYLOAD_SIZE or similar constant exists
+        if hasattr(jsonrpc_app, "MAX_PAYLOAD_SIZE"):
+            jsonrpc_app.MAX_PAYLOAD_SIZE = max_body_size
+            logger.info(f"Patched a2a-python MAX_PAYLOAD_SIZE to {max_body_size} bytes")
+        # Also check for _MAX_PAYLOAD_SIZE or other variants
+        elif hasattr(jsonrpc_app, "_MAX_PAYLOAD_SIZE"):
+            jsonrpc_app._MAX_PAYLOAD_SIZE = max_body_size
+            logger.info(f"Patched a2a-python _MAX_PAYLOAD_SIZE to {max_body_size} bytes")
+        else:
+            logger.debug("Could not find MAX_PAYLOAD_SIZE constant in a2a-python jsonrpc_app")
+    except (ImportError, AttributeError) as e:
+        # If patching fails, log a debug message but continue
+        logger.debug(f"Could not patch a2a-python payload limit: {e}")


The _patch_a2a_payload_limit function is duplicated identically across three files: kagent-adk/_a2a.py, kagent-langgraph/_a2a.py, and kagent-crewai/_a2a.py. This code duplication makes maintenance more difficult, as any bug fixes or improvements would need to be applied in multiple places. Consider extracting this function to a shared module in kagent-core (e.g., kagent.core.a2a) and importing it from there instead.

Copilot · 2025-12-29T14:01:48Z

python/packages/kagent-crewai/src/kagent/crewai/_a2a.py

+def _patch_a2a_payload_limit(max_body_size: int):
+    """Attempt to patch a2a-python library's hardcoded payload size limit."""
+    try:
+        # Try different import paths for jsonrpc_app module
+        jsonrpc_app = None
+        import_paths = [
+            "a2a.server.apps.jsonrpc.jsonrpc_app",
+            "a2a.server.apps.jsonrpc_app",
+        ]
+        for path in import_paths:
+            try:
+                jsonrpc_app = __import__(path, fromlist=[""])
+                break
+            except ImportError:
+                continue
+
+        if jsonrpc_app is None:
+            logger.debug("Could not find a2a-python jsonrpc_app module to patch")
+            return
+
+        # Check if MAX_PAYLOAD_SIZE or similar constant exists
+        if hasattr(jsonrpc_app, "MAX_PAYLOAD_SIZE"):
+            jsonrpc_app.MAX_PAYLOAD_SIZE = max_body_size
+            logger.info(f"Patched a2a-python MAX_PAYLOAD_SIZE to {max_body_size} bytes")
+        # Also check for _MAX_PAYLOAD_SIZE or other variants
+        elif hasattr(jsonrpc_app, "_MAX_PAYLOAD_SIZE"):
+            jsonrpc_app._MAX_PAYLOAD_SIZE = max_body_size
+            logger.info(f"Patched a2a-python _MAX_PAYLOAD_SIZE to {max_body_size} bytes")
+        else:
+            logger.debug("Could not find MAX_PAYLOAD_SIZE constant in a2a-python jsonrpc_app")
+    except (ImportError, AttributeError) as e:
+        # If patching fails, log a debug message but continue
+        logger.debug(f"Could not patch a2a-python payload limit: {e}")


The _patch_a2a_payload_limit function is duplicated identically across three files: kagent-adk/_a2a.py, kagent-langgraph/_a2a.py, and kagent-crewai/_a2a.py. This code duplication makes maintenance more difficult, as any bug fixes or improvements would need to be applied in multiple places. Consider extracting this function to a shared module in kagent-core (e.g., kagent.core.a2a) and importing it from there instead.

Copilot · 2025-12-29T14:01:48Z

python/packages/kagent-adk/src/kagent/adk/_a2a.py

+def _patch_a2a_payload_limit(max_body_size: int):
+    """Attempt to patch a2a-python library's hardcoded payload size limit."""
+    try:
+        # Try different import paths for jsonrpc_app module
+        jsonrpc_app = None
+        import_paths = [
+            "a2a.server.apps.jsonrpc.jsonrpc_app",
+            "a2a.server.apps.jsonrpc_app",
+        ]
+        for path in import_paths:
+            try:
+                jsonrpc_app = __import__(path, fromlist=[""])
+                break
+            except ImportError:
+                continue
+
+        if jsonrpc_app is None:
+            logger.debug("Could not find a2a-python jsonrpc_app module to patch")
+            return
+
+        # Check if MAX_PAYLOAD_SIZE or similar constant exists
+        if hasattr(jsonrpc_app, "MAX_PAYLOAD_SIZE"):
+            jsonrpc_app.MAX_PAYLOAD_SIZE = max_body_size
+            logger.info(f"Patched a2a-python MAX_PAYLOAD_SIZE to {max_body_size} bytes")
+        # Also check for _MAX_PAYLOAD_SIZE or other variants
+        elif hasattr(jsonrpc_app, "_MAX_PAYLOAD_SIZE"):
+            jsonrpc_app._MAX_PAYLOAD_SIZE = max_body_size
+            logger.info(f"Patched a2a-python _MAX_PAYLOAD_SIZE to {max_body_size} bytes")
+        else:
+            logger.debug("Could not find MAX_PAYLOAD_SIZE constant in a2a-python jsonrpc_app")
+    except (ImportError, AttributeError) as e:
+        # If patching fails, log a debug message but continue
+        logger.debug(f"Could not patch a2a-python payload limit: {e}")


The _patch_a2a_payload_limit function is duplicated identically across three files: kagent-adk/_a2a.py, kagent-langgraph/_a2a.py, and kagent-crewai/_a2a.py. This code duplication makes maintenance more difficult, as any bug fixes or improvements would need to be applied in multiple places. Consider extracting this function to a shared module in kagent-core (e.g., kagent.core.a2a) and importing it from there instead.

Copilot · 2025-12-29T14:01:48Z

python/packages/kagent-adk/src/kagent/adk/types.py

    sse_tools: list[SseMcpServerConfig] | None = None  # SSE MCP tools
    remote_agents: list[RemoteAgentConfig] | None = None  # remote agents
    execute_code: bool | None = None
+    max_payload_size: int | None = None  # Maximum payload size in bytes for A2A requests


The max_payload_size parameter lacks input validation. Negative or zero values could be passed and would be used to patch the a2a-python library, potentially causing unexpected behavior. Consider adding validation to ensure the value is positive (e.g., max_payload_size > 0) or documenting the acceptable range.

Copilot · 2025-12-29T14:01:48Z

go/internal/controller/translator/agent/adk_api_translator.go


+	// Extract maxPayloadSize from A2AConfig if present
+	if agent.Spec.Declarative.A2AConfig != nil && agent.Spec.Declarative.A2AConfig.MaxPayloadSize != nil {
+		maxPayloadSizeBytes := agent.Spec.Declarative.A2AConfig.MaxPayloadSize.Value()


The extracted maxPayloadSizeBytes value is not validated before being assigned to the config. While Kubernetes resource.Quantity parsing handles invalid formats, it can accept negative values (e.g., "-10Mi"). Consider adding validation to ensure the value is positive before assigning it to cfg.MaxPayloadSize.

Suggested change

maxPayloadSizeBytes := agent.Spec.Declarative.A2AConfig.MaxPayloadSize.Value()

maxPayloadSizeBytes := agent.Spec.Declarative.A2AConfig.MaxPayloadSize.Value()

if maxPayloadSizeBytes <= 0 {

return nil, nil, nil, fmt.Errorf("invalid maxPayloadSize: must be positive, got %d", maxPayloadSizeBytes)

}

Copilot · 2025-12-29T14:01:49Z

python/packages/kagent-langgraph/src/kagent/langgraph/_a2a.py

+        # Patch a2a-python's payload size limit if specified
+        if self.max_payload_size is not None:
+            _patch_a2a_payload_limit(self.max_payload_size)


The patching approach modifies a global module-level constant at runtime. In deployment scenarios where multiple KAgentApp instances might be created with different max_payload_size values (e.g., in tests or multi-tenant environments), the last value set will override previous ones, potentially causing unexpected behavior. Consider documenting this limitation or implementing the patch only once during module initialization if multiple instances are expected.

Copilot · 2025-12-29T14:01:49Z

python/packages/kagent-adk/src/kagent/adk/_a2a.py

+        # Patch a2a-python's payload size limit if specified
+        if self.max_payload_size is not None:
+            _patch_a2a_payload_limit(self.max_payload_size)


The patching approach modifies a global module-level constant at runtime. In deployment scenarios where multiple KAgentApp instances might be created with different max_payload_size values (e.g., in tests or multi-tenant environments), the last value set will override previous ones, potentially causing unexpected behavior. Consider documenting this limitation or implementing the patch only once during module initialization if multiple instances are expected.

Copilot · 2025-12-29T14:01:49Z

python/packages/kagent-adk/tests/unittests/test_a2a_payload_size.py

+import pytest
+


Import of 'pytest' is not used.

Suggested change

import pytest

Copilot · 2025-12-29T14:01:50Z

python/packages/kagent-adk/tests/unittests/test_agent_config.py

+import pytest
+


Import of 'pytest' is not used.

Suggested change

import pytest

Signed-off-by: kevin-shelaga <[email protected]>

… into payload-limit Signed-off-by: kevin-shelaga <[email protected]>

kevin-shelaga added 2 commits December 29, 2025 08:55

Allow configuration of max payload size for a2a

164c023

Signed-off-by: kevin-shelaga <[email protected]>

lint format

c868ecc

Signed-off-by: kevin-shelaga <[email protected]>

Copilot AI review requested due to automatic review settings December 29, 2025 13:56

kevin-shelaga requested review from EItanya, ilackarms, peterj and yuval-k as code owners December 29, 2025 13:56

Copilot started reviewing on behalf of kevin-shelaga December 29, 2025 13:57 View session

Copilot AI reviewed Dec 29, 2025

View reviewed changes

kevin-shelaga added 3 commits December 29, 2025 09:48

Address copilot comments

84a572f

Address copilot comments

8385e02

Signed-off-by: kevin-shelaga <[email protected]>

Merge branch 'payload-limit' of https://github.com/kevin-shelaga/kagent…

7c55825

… into payload-limit Signed-off-by: kevin-shelaga <[email protected]>

kevin-shelaga force-pushed the payload-limit branch from a032212 to 7c55825 Compare December 29, 2025 14:52

kevin-shelaga closed this Dec 29, 2025

kevin-shelaga deleted the payload-limit branch December 29, 2025 14:54

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Uh oh!

Allow configuration of max payload size limit #1180

Allow configuration of max payload size limit #1180

kevin-shelaga commented Dec 29, 2025

Uh oh!

Copilot AI left a comment

Uh oh!

Copilot AI Dec 29, 2025

Uh oh!

Copilot AI Dec 29, 2025

Uh oh!

Copilot AI Dec 29, 2025

Uh oh!

Copilot AI Dec 29, 2025

Uh oh!

Copilot AI Dec 29, 2025

Uh oh!

Copilot AI Dec 29, 2025

Uh oh!

Copilot AI Dec 29, 2025

Uh oh!

Copilot AI Dec 29, 2025

Uh oh!

Copilot AI Dec 29, 2025

Uh oh!

Copilot AI Dec 29, 2025

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

1 participant

Allow configuration of max payload size limit #1180

Allow configuration of max payload size limit #1180

Conversation

kevin-shelaga commented Dec 29, 2025

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Pull request overview

Key Changes

Reviewed changes

Uh oh!

Copilot AI Dec 29, 2025

Choose a reason for hiding this comment

Uh oh!

Copilot AI Dec 29, 2025

Choose a reason for hiding this comment

Uh oh!

Copilot AI Dec 29, 2025

Choose a reason for hiding this comment

Uh oh!

Copilot AI Dec 29, 2025

Choose a reason for hiding this comment

Uh oh!

Copilot AI Dec 29, 2025

Choose a reason for hiding this comment

Uh oh!

Copilot AI Dec 29, 2025

Choose a reason for hiding this comment

Uh oh!

Copilot AI Dec 29, 2025

Choose a reason for hiding this comment

Uh oh!

Copilot AI Dec 29, 2025

Choose a reason for hiding this comment

Uh oh!

Copilot AI Dec 29, 2025

Choose a reason for hiding this comment

Uh oh!

Copilot AI Dec 29, 2025

Choose a reason for hiding this comment

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

1 participant