feat(client): add session persistence and restoration support #426
Conversation
WalkthroughThe changes introduce functionality for exporting and importing the internal state of the Changes
Suggested labels
Suggested reviewers
Warning There were issues while running some tools. Please review the errors and either fix the tool's configuration or disable the tool if it's a critical failure. 🔧 golangci-lint (1.64.8)Error: you are using a configuration file for golangci-lint v2 with golangci-lint v1: please use golangci-lint v2 ✨ Finishing Touches
Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out. 🪧 TipsChatThere are 3 ways to chat with CodeRabbit:
SupportNeed help? Create a ticket on our support page for assistance with any issues or questions. Note: Be mindful of the bot's finite context window. It's strongly recommended to break down tasks such as reading entire modules into smaller chunks. For a focused discussion, use review comments to chat about specific files and their changes, instead of using the PR comments. CodeRabbit Commands (Invoked using PR comments)
Other keywords and placeholders
CodeRabbit Configuration File (
|
![coderabbitai[bot]](https://avatars.githubusercontent.com/in/347564?s=60&v=4){kind=small}
There was a problem hiding this comment.
Actionable comments posted: 0
🧹 Nitpick comments (2)
www/docs/pages/clients/basics.mdx (1)
332-332: Fix grammar issue.A comma is needed after "call" for proper sentence structure.
-`ImportState()` re-hydrates those values. After a successful call the +`ImportState()` re-hydrates those values. After a successful call, theclient/client.go (1)
204-227: Solid state import implementation with room for enhanced validation.The method includes proper validation for critical scenarios and safely restores all state fields. Consider adding validation for capability consistency between export and import contexts.
Consider adding validation to ensure the imported capabilities are compatible:
func (c *Client) ImportState(ctx context.Context, state *mcp.ClientState) error { if state == nil { return fmt.Errorf("state cannot be nil") } if c.transport == nil { return fmt.Errorf("transport is not initialized") } if state.Initialized && state.RequestID < 0 { return fmt.Errorf("invalid state: initialized client must have non-negative request ID") } + + // Validate that we're not importing state with incompatible protocol requirements + if state.Initialized && len(c.clientCapabilities.Experimental) > 0 { + // Could add capability compatibility checks here if needed + } c.initialized = state.Initialized c.requestID.Store(state.RequestID) c.clientCapabilities = state.ClientCapabilities c.serverCapabilities = state.ServerCapabilities c.setTransportSessionID(state.SessionID) return nil }
📜 Review details
Configuration used: CodeRabbit UI
Review profile: CHILL
Plan: Pro
📒 Files selected for processing (5)
client/client.go(1 hunks)client/client_test.go(1 hunks)client/transport/streamable_http.go(1 hunks)mcp/types.go(1 hunks)www/docs/pages/clients/basics.mdx(1 hunks)
🧰 Additional context used
🪛 LanguageTool
www/docs/pages/clients/basics.mdx
[typographical] ~332-~332: It appears that a comma is missing.
Context: ...rates those values. After a successful call the restored client can immediately iss...
(DURING_THAT_TIME_COMMA)
🔇 Additional comments (6)
mcp/types.go (1)
1045-1062: Clean and well-designed state structure.The
ClientStatestruct is well-implemented with appropriate field types, clear documentation, and proper JSON serialization tags. The design effectively captures all necessary client state for persistence and restoration.client/transport/streamable_http.go (1)
517-520: Simple and correct implementation.The
SetSessionIdmethod is implemented correctly using atomic storage for thread safety, maintaining consistency with the existingGetSessionIdmethod.www/docs/pages/clients/basics.mdx (1)
300-334: Excellent documentation for the new feature.The documentation clearly explains the state persistence functionality with practical examples and details about what data is captured. This will help users understand when and how to use this feature effectively.
client/client_test.go (1)
11-79: Comprehensive test coverage for state restoration.The test effectively validates the complete state persistence workflow, including proper state progression after restoration. The test structure is clean and includes appropriate error handling and cleanup.
client/client.go (2)
174-189: Well-implemented state export functionality.The
ExportStatemethod correctly captures all necessary client state using thread-safe atomic operations. The implementation is clean and follows the documented contract.
191-202: Good encapsulation of transport-specific functionality.The helper methods properly handle the optional nature of session IDs by checking the transport type and safely handling cases where session IDs aren't supported.
Description
This feature adds client session persistence and restoration support, which is useful for environments where entire client instances cannot be persisted, such as within Temporal activities.
Key points:
ExportState()andImportState()methods onclient.Clientmcp.ClientStatetypeSetSessionId()helper on Streamable HTTP transportTestStateRestorationType of Change
Checklist
Additional Information
This was created to address the requirement of restoring the session ID for Playwright MCP, which necessitates the same session ID for uninterrupted access to the same browser instance.
Summary by CodeRabbit