sequenceDiagram
participant UI as 𧩠McpServersSettings / ChatForm
participant chatStore as ποΈ chatStore
participant mcpStore as ποΈ mcpStore
participant mcpResStore as ποΈ mcpResourceStore
participant convStore as ποΈ conversationsStore
participant MCPSvc as βοΈ MCPService
participant LS as πΎ LocalStorage
participant ExtMCP as π External MCP Server
Note over mcpStore: State:<br/>isInitializing, error<br/>toolCount, connectedServers<br/>healthChecks (Map)<br/>connections (Map)<br/>toolsIndex (Map)<br/>serverConfigs (Map)
Note over mcpResStore: State:<br/>serverResources (Map)<br/>cachedResources (Map)<br/>subscriptions (Map)<br/>attachments[]
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Note over UI,ExtMCP: π INITIALIZATION (App Startup)
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UI->>mcpStore: ensureInitialized()
activate mcpStore
mcpStore->>LS: get(MCP_SERVERS_LOCALSTORAGE_KEY)
LS-->>mcpStore: MCPServerSettingsEntry[]
mcpStore->>mcpStore: parseServerSettings(servers)
Note right of mcpStore: Filter enabled servers<br/>Build MCPServerConfig objects<br/>Per-chat overrides checked via convStore
loop For each enabled server
mcpStore->>mcpStore: runHealthCheck(serverId)
mcpStore->>mcpStore: updateHealthCheck(id, CONNECTING)
mcpStore->>MCPSvc: connect(serverName, config, clientInfo, capabilities, onPhase)
activate MCPSvc
MCPSvc->>MCPSvc: createTransport(config)
Note right of MCPSvc: WebSocket / StreamableHTTP / SSE<br/>with optional CORS proxy
MCPSvc->>ExtMCP: Transport handshake
ExtMCP-->>MCPSvc: Connection established
MCPSvc->>ExtMCP: Initialize request
Note right of ExtMCP: Exchange capabilities<br/>Server info, protocol version
ExtMCP-->>MCPSvc: InitializeResult (serverInfo, capabilities)
MCPSvc->>ExtMCP: listTools()
ExtMCP-->>MCPSvc: Tool[]
MCPSvc-->>mcpStore: MCPConnection
deactivate MCPSvc
mcpStore->>mcpStore: connections.set(serverName, connection)
mcpStore->>mcpStore: indexTools(connection.tools, serverName)
Note right of mcpStore: toolsIndex.set(toolName, serverName)<br/>Handle name conflicts with prefixes
mcpStore->>mcpStore: updateHealthCheck(id, SUCCESS)
mcpStore->>mcpStore: _connectedServers.push(serverName)
alt Server supports resources
mcpStore->>MCPSvc: listAllResources(connection)
MCPSvc->>ExtMCP: listResources()
ExtMCP-->>MCPSvc: MCPResource[]
MCPSvc-->>mcpStore: resources
mcpStore->>MCPSvc: listAllResourceTemplates(connection)
MCPSvc->>ExtMCP: listResourceTemplates()
ExtMCP-->>MCPSvc: MCPResourceTemplate[]
MCPSvc-->>mcpStore: templates
mcpStore->>mcpResStore: setServerResources(serverName, resources, templates)
end
end
mcpStore->>mcpStore: _isInitializing = false
deactivate mcpStore
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Note over UI,ExtMCP: π§ TOOL EXECUTION (Chat with Tools)
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UI->>mcpStore: executeTool(mcpCall: MCPToolCall, signal?)
activate mcpStore
mcpStore->>mcpStore: toolsIndex.get(mcpCall.function.name)
Note right of mcpStore: Resolve serverName from toolsIndex<br/>MCPToolCall = {id, type, function: {name, arguments}}
mcpStore->>mcpStore: acquireConnection()
Note right of mcpStore: activeFlowCount++<br/>Prevent shutdown during execution
mcpStore->>mcpStore: connection = connections.get(serverName)
mcpStore->>MCPSvc: callTool(connection, {name, arguments}, signal)
activate MCPSvc
MCPSvc->>MCPSvc: throwIfAborted(signal)
MCPSvc->>ExtMCP: callTool(name, arguments)
alt Tool execution success
ExtMCP-->>MCPSvc: ToolCallResult (content, isError)
MCPSvc->>MCPSvc: formatToolResult(result)
Note right of MCPSvc: Handle text, image (base64),<br/>embedded resource content
MCPSvc-->>mcpStore: ToolExecutionResult
else Tool execution error
ExtMCP-->>MCPSvc: Error
MCPSvc-->>mcpStore: throw Error
else Aborted
MCPSvc-->>mcpStore: throw AbortError
end
deactivate MCPSvc
mcpStore->>mcpStore: releaseConnection()
Note right of mcpStore: activeFlowCount--
mcpStore-->>UI: ToolExecutionResult
deactivate mcpStore
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Note over UI,ExtMCP: οΏ½ RESOURCE ATTACHMENT CONSUMPTION
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chatStore->>mcpStore: consumeResourceAttachmentsAsExtras()
activate mcpStore
mcpStore->>mcpResStore: getAttachments()
mcpResStore-->>mcpStore: MCPResourceAttachment[]
mcpStore->>mcpStore: Convert attachments to message extras
mcpStore->>mcpResStore: clearAttachments()
mcpStore-->>chatStore: MessageExtra[] (for user message)
deactivate mcpStore
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Note over UI,ExtMCP: οΏ½π PROMPT OPERATIONS
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UI->>mcpStore: getAllPrompts()
activate mcpStore
loop For each connected server with prompts capability
mcpStore->>MCPSvc: listPrompts(connection)
MCPSvc->>ExtMCP: listPrompts()
ExtMCP-->>MCPSvc: Prompt[]
MCPSvc-->>mcpStore: prompts
end
mcpStore-->>UI: MCPPromptInfo[] (with serverName)
deactivate mcpStore
UI->>mcpStore: getPrompt(serverName, promptName, args?)
activate mcpStore
mcpStore->>MCPSvc: getPrompt(connection, name, args)
MCPSvc->>ExtMCP: getPrompt({name, arguments})
ExtMCP-->>MCPSvc: GetPromptResult (messages)
MCPSvc-->>mcpStore: GetPromptResult
mcpStore-->>UI: GetPromptResult
deactivate mcpStore
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Note over UI,ExtMCP: π RESOURCE OPERATIONS
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UI->>mcpResStore: addAttachment(resourceInfo)
activate mcpResStore
mcpResStore->>mcpResStore: Create MCPResourceAttachment (loading: true)
mcpResStore-->>UI: attachment
UI->>mcpStore: readResource(serverName, uri)
activate mcpStore
mcpStore->>MCPSvc: readResource(connection, uri)
MCPSvc->>ExtMCP: readResource({uri})
ExtMCP-->>MCPSvc: MCPReadResourceResult (contents)
MCPSvc-->>mcpStore: contents
mcpStore-->>UI: MCPResourceContent[]
deactivate mcpStore
UI->>mcpResStore: updateAttachmentContent(attachmentId, content)
mcpResStore->>mcpResStore: cacheResourceContent(resource, content)
deactivate mcpResStore
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Note over UI,ExtMCP: π AUTO-RECONNECTION
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Note over mcpStore: On WebSocket close or connection error:
mcpStore->>mcpStore: autoReconnect(serverName, attempt)
activate mcpStore
mcpStore->>mcpStore: Calculate backoff delay
Note right of mcpStore: delay = min(30s, 1s * 2^attempt)
mcpStore->>mcpStore: Wait for delay
mcpStore->>mcpStore: reconnectServer(serverName)
alt Reconnection success
mcpStore->>mcpStore: updateHealthCheck(id, SUCCESS)
else Max attempts reached
mcpStore->>mcpStore: updateHealthCheck(id, ERROR)
end
deactivate mcpStore
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Note over UI,ExtMCP: π SHUTDOWN
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UI->>mcpStore: shutdown()
activate mcpStore
mcpStore->>mcpStore: Wait for activeFlowCount == 0
loop For each connection
mcpStore->>MCPSvc: disconnect(connection)
MCPSvc->>MCPSvc: transport.onclose = undefined
MCPSvc->>ExtMCP: close()
end
mcpStore->>mcpStore: connections.clear()
mcpStore->>mcpStore: toolsIndex.clear()
mcpStore->>mcpStore: _connectedServers = []
mcpStore->>mcpResStore: clear()
deactivate mcpStore
