This PR expands the dashboard with a guided endpoint import workflow, live section refresh on the home page, and more resilient YAML configuration loading.

README.md

@@ -27,6 +27,7 @@ Implemented so far:
 - Phase 12: automated test expansion for invalid and edge-case coverage
 - Phase 13: publish and deployment validation
 - Phase 14: GitHub Actions CI/CD and Dependabot automation
+- Post-v1: endpoint import flow with live probe, YAML preview, and diff comparison
 
 Not implemented yet:
 - Backlog items tracked for post-v1 work
@@ -70,6 +71,7 @@ The app uses locally bundled AdminLTE assets under [`src/ApiHealthDashboard/wwwr
 Current UI pages:
 - dashboard summary page: [`src/ApiHealthDashboard/Pages/Index.cshtml`](src/ApiHealthDashboard/Pages/Index.cshtml)
 - endpoint details page: [`src/ApiHealthDashboard/Pages/Endpoints/Details.cshtml`](src/ApiHealthDashboard/Pages/Endpoints/Details.cshtml)
+- endpoint import preview page: [`src/ApiHealthDashboard/Pages/Import.cshtml`](src/ApiHealthDashboard/Pages/Import.cshtml)
 
 ### YAML Configuration
 
@@ -183,10 +185,24 @@ Current dashboard behavior:
 - shows configured, enabled, disabled, and actively polling endpoint counts
 - highlights healthy, degraded, unhealthy, and unknown totals in summary cards
 - includes a client-side search field for filtering endpoint rows by name, id, status, or error text
+- refreshes the live dashboard section with same-origin timed GET requests instead of reloading the whole page
 - renders a live endpoint table with last check, duration, error summary, and manual refresh actions
 - surfaces degraded and unhealthy endpoints in an active issues panel for faster triage
 - shows a clearer empty state when no endpoints are configured
 
+### Endpoint Import Flow
+
+The app now includes an endpoint import preview flow for deriving YAML from a live API probe without writing files automatically.
+
+Current import behavior:
+- sends a live request using the entered URL, headers, timeout, and enabled/frequency settings
+- auto-suggests endpoint id and name when those fields are left blank
+- shows a soft warning when the chosen poll frequency is below the configured appsettings recommendation
+- parses discovered checks from the response and can optionally populate `includeChecks`
+- generates a normalized YAML snippet for manual copy into `dashboard.yaml` or a separate endpoint file
+- compares the generated YAML against the currently loaded config when an existing endpoint matches by id or URL
+- shows a diff preview plus a raw response preview for review before any manual save
+
 ### Endpoint Details
 
 The endpoint details page now acts as a diagnostic view for a single configured endpoint.
@@ -401,7 +417,6 @@ Test file:
 ## Future Plans
 
 These are planned enhancements after the current v1 path:
-- add an import flow that can derive YAML endpoint config from API request and response inspection, with preview and diff comparison before any manual save
 - add CLI execution with machine-readable output for automation and scripting scenarios
 - allow per-endpoint priority so important endpoints can be surfaced and scheduled differently
 - optionally allow email sending, either through direct SMTP configuration or by calling an external API

api-health-dashboard-build-checklist-v2.md

@@ -662,7 +662,6 @@ These should not block v1.
 - [ ] health status mini charts
 - [ ] SBOM generation
 - [ ] artifact signing
-- [ ] import YAML endpoint definitions from API endpoint request/response inspection with preview and diff comparison before manual save
 - [ ] CLI execution mode with machine-readable output
 - [ ] per-endpoint priority support
 - [ ] optional email sending via SMTP or an external API

api-health-dashboard-codex-requirements-v2.md

@@ -784,7 +784,6 @@ These are optional later improvements and should not block v1:
 - tag-based filtering
 - retry policy with backoff
 - readonly config viewer page
-- import YAML endpoint definitions from API endpoint request/response inspection with preview and diff comparison before manual file save
 - CLI execution mode with machine-readable output for automation workflows
 - per-endpoint priority for display and future scheduling behavior
 - optional email sending via directly configured SMTP or an external API integration

src/ApiHealthDashboard/Configuration/ConfigurationWarningState.cs

@@ -0,0 +1,13 @@
+namespace ApiHealthDashboard.Configuration;
+
+public sealed class ConfigurationWarningState
+{
+    public ConfigurationWarningState(IReadOnlyList<string> warnings)
+    {
+        Warnings = warnings;
+    }
+
+    public IReadOnlyList<string> Warnings { get; }
+
+    public bool HasWarnings => Warnings.Count > 0;
+}

src/ApiHealthDashboard/Configuration/DashboardConfigLoadResult.cs

@@ -0,0 +1,8 @@
+namespace ApiHealthDashboard.Configuration;
+
+public sealed class DashboardConfigLoadResult
+{
+    public required DashboardConfig Config { get; init; }
+
+    public IReadOnlyList<string> Warnings { get; init; } = [];
+}

src/ApiHealthDashboard/Configuration/IYamlConfigLoader.cs

@@ -2,5 +2,5 @@ namespace ApiHealthDashboard.Configuration;
 
 public interface IYamlConfigLoader
 {
-    DashboardConfig Load(string path);
+    DashboardConfigLoadResult Load(string path);
 }

src/ApiHealthDashboard/Configuration/ImportUiOptions.cs

@@ -0,0 +1,8 @@
+namespace ApiHealthDashboard.Configuration;
+
+public sealed class ImportUiOptions
+{
+    public const string SectionName = "Import";
+
+    public int MinimumRecommendedPollFrequencySeconds { get; set; } = 180;
+}

src/ApiHealthDashboard/Configuration/YamlConfigLoader.cs

@@ -18,12 +18,25 @@ public YamlConfigLoader(DashboardConfigValidator validator)
             .Build();
     }
 
-    public DashboardConfig Load(string path)
+    public DashboardConfigLoadResult Load(string path)
     {
         ArgumentException.ThrowIfNullOrWhiteSpace(path);
 
+        if (!File.Exists(path))
+        {
+            return new DashboardConfigLoadResult
+            {
+                Config = new DashboardConfig(),
+                Warnings =
+                [
+                    $"Dashboard configuration file '{path}' was not found. The dashboard started with no configured endpoints."
+                ]
+            };
+        }
+
         var dashboardConfig = DeserializeDashboardConfig(path);
         Normalize(dashboardConfig);
+        var warnings = new List<string>();
 
         var mergedConfig = new DashboardConfig
         {
@@ -39,6 +52,12 @@ public DashboardConfig Load(string path)
         foreach (var endpointFilePath in dashboardConfig.EndpointFiles)
         {
             var resolvedEndpointFilePath = ResolveConfigPath(endpointFilePath, dashboardDirectory);
+            if (!File.Exists(resolvedEndpointFilePath))
+            {
+                warnings.Add($"Endpoint configuration file '{resolvedEndpointFilePath}' was not found. It was skipped.");
+                continue;
+            }
+
             var fileEndpoints = LoadEndpointsFromFile(resolvedEndpointFilePath);
             mergedConfig.Endpoints.AddRange(fileEndpoints);
         }
@@ -51,7 +70,11 @@ public DashboardConfig Load(string path)
             throw new DashboardConfigurationException(path, errors);
         }
 
-        return mergedConfig;
+        return new DashboardConfigLoadResult
+        {
+            Config = mergedConfig,
+            Warnings = warnings
+        };
     }
 
     private DashboardConfig DeserializeDashboardConfig(string path)

src/ApiHealthDashboard/Formatting/DisplayValueFormatter.cs

@@ -0,0 +1,27 @@
+using System.Collections;
+using System.Text.Json;
+
+namespace ApiHealthDashboard.Formatting;
+
+public static class DisplayValueFormatter
+{
+    public static string Format(object? value)
+    {
+        return value switch
+        {
+            null => "(null)",
+            string text when string.IsNullOrWhiteSpace(text) => "(empty)",
+            string text => text,
+            IEnumerable values => FormatEnumerable(values),
+            _ => JsonSerializer.Serialize(value)
+        };
+    }
+
+    private static string FormatEnumerable(IEnumerable values)
+    {
+        var items = values.Cast<object?>().ToList();
+        return items.Count == 0
+            ? "(empty)"
+            : JsonSerializer.Serialize(items);
+    }
+}

src/ApiHealthDashboard/Pages/Endpoints/Details.cshtml.cs

@@ -1,5 +1,6 @@
 using ApiHealthDashboard.Configuration;
 using ApiHealthDashboard.Domain;
+using ApiHealthDashboard.Formatting;
 using ApiHealthDashboard.Scheduling;
 using ApiHealthDashboard.State;
 using Microsoft.AspNetCore.Mvc;
@@ -234,7 +235,7 @@ public static EndpointDetailsViewModel From(
                 DegradedCheckCount = flattenedNodes.Count(static node => node.Status == "Degraded"),
                 UnhealthyCheckCount = flattenedNodes.Count(static node => node.Status == "Unhealthy"),
                 UnknownCheckCount = flattenedNodes.Count(static node => node.Status is not ("Healthy" or "Degraded" or "Unhealthy")),
-                RawPayload = showRawPayload ? state?.Snapshot?.RawPayload : null,
+                RawPayload = showRawPayload ? FormatPayloadPreview(state?.Snapshot?.RawPayload) : null,
                 ShowRawPayload = showRawPayload
             };
         }
@@ -285,13 +286,30 @@ private static string BuildStatusSummary(bool enabled, bool isPolling, string st
 
         private static string FormatMetadataValue(object? value)
         {
-            return value switch
+            return DisplayValueFormatter.Format(value);
+        }
+
+        private static string? FormatPayloadPreview(string? rawPayload)
+        {
+            if (string.IsNullOrWhiteSpace(rawPayload))
             {
-                null => "(null)",
-                string text when string.IsNullOrWhiteSpace(text) => "(empty)",
-                string text => text,
-                _ => JsonSerializer.Serialize(value)
-            };
+                return rawPayload;
+            }
+
+            try
+            {
+                using var document = JsonDocument.Parse(rawPayload);
+                return JsonSerializer.Serialize(
+                    document.RootElement,
+                    new JsonSerializerOptions
+                    {
+                        WriteIndented = true
+                    });
+            }
+            catch (JsonException)
+            {
+                return rawPayload;
+            }
         }
 
         private static string ToBadgeClass(string status)