Function validateFlow

packages/agentflow/src/core/validation/flowValidation.ts:12–83

(nodes: FlowNode[], edges: FlowEdge[], availableNodes?: NodeDataSchema[])

 * Validate the flow structure
 */
export function validateFlow(nodes: FlowNode[], edges: FlowEdge[], availableNodes?: NodeDataSchema[]): ValidationResult {
    const errors: ValidationError[] = []

    // Check for empty flow
    if (nodes.length === 0) {
        errors.push({
            message: 'Flow is empty - add at least one node',
            type: 'error'
        })
        return { valid: false, errors }
    }

    // Check for start node
    const startNode = nodes.find((n) => n.data.name === 'startAgentflow')
    if (!startNode) {
        errors.push({
            message: 'Flow must have a start node',
            type: 'error'
        })
    }

    // Check for multiple start nodes
    const startNodes = nodes.filter((n) => n.data.name === 'startAgentflow')
    if (startNodes.length > 1) {
        errors.push({
            message: 'Flow can only have one start node',
            type: 'error'
        })
    }

    // Check for disconnected nodes (matching server-side pattern)
    const connectedNodes = new Set<string>()
    edges.forEach((edge) => {
        connectedNodes.add(edge.source)
        connectedNodes.add(edge.target)
    })

    const nonStickyNodes = nodes.filter((n) => n.data.name !== 'stickyNoteAgentflow')
    nonStickyNodes.forEach((node) => {
        if (!connectedNodes.has(node.id)) {
            errors.push({
                nodeId: node.id,
                message: 'This node is not connected to anything',
                type: 'warning'
            })
        }
    })

    // Check for cycles (should be handled during connection, but double-check)
    const hasCycle = detectCycle(nodes, edges)
    if (hasCycle) {
        errors.push({
            message: 'Flow contains a cycle - this may cause infinite loops',
            type: 'error'
        })
    }

    // Validate each node's inputs