diff --git a/CHANGELOG.md b/CHANGELOG.md
index 49765f849..3f19edaa1 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -16,6 +16,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Multi-window tab persistence dropped all but one tab on relaunch. Three save paths each wrote only the current window's tabs, racing the `willTerminate` aggregate save: `handleTabSelectionChange` (every time you switched tabs), the `mainWindowWillClose` notification observer, and the per-window `handleWindowWillClose` close path. On Cmd+Q, AppKit closes windows LIFO so the last writer left only the first-opened window's tab in the file. The tab-selection path now writes aggregated tabs from all windows of the connection. Per-window close-time saves no-op when the app is terminating, leaving the canonical `willTerminate` aggregate save intact. The `mainWindowWillClose` observer also routes through the aggregated save path.
 - Filter value autocomplete popover stole keyboard focus from the text field after the first keystroke when Full Keyboard Access was enabled (System Settings → Keyboard → Keyboard Navigation). The popover content used SwiftUI `Button` rows, which become focus targets under FKA, so SwiftUI auto-focused the first row when the popover appeared. Replaced the rows with `Text` + `.onTapGesture` (non-focusable) and marked the dropdown as `.focusable(false)`.
 - Toolbar database name was empty after relaunching with a connection that had no database configured but a last-used database restored via `selectDatabaseFromLastSession`. The window opened (and the toolbar resolved its initial name) before the post-connect actions populated `session.currentDatabase`, so the toolbar fell back to the empty `connection.database`. Sidebar and Cmd+K both worked because they read the session directly. The toolbar now re-syncs its database name on every `connectionStatusDidChange`, picking up the restored value once the session settles.
+- AI provider settings showed `unsupported URL` on Test Connection and Reload Models while editing a draft provider's endpoint. `AIProviderFactory` cached the created provider by `(id, apiKey)` only, so a debounced model fetch that fired during a momentarily empty endpoint (cleared before retyping) stashed a provider built with `endpoint = ""`. Subsequent calls under the same draft id returned that stale instance regardless of the now-correct endpoint, and `URL(string: "/v1/models")` was rejected with `URLError.unsupportedURL`. Cache invalidation only happened on save. The cache now compares the full `AIProviderConfig` along with `apiKey`, so any field change rebuilds the provider.
 
 ### Changed
 
diff --git a/TablePro/Core/AI/AIProviderFactory.swift b/TablePro/Core/AI/AIProviderFactory.swift
index 9c40f1c29..adf64e6e6 100644
--- a/TablePro/Core/AI/AIProviderFactory.swift
+++ b/TablePro/Core/AI/AIProviderFactory.swift
@@ -17,12 +17,12 @@ enum AIProviderFactory {
     }
 
     private static let cacheLock = OSAllocatedUnfairLock(
-        initialState: [UUID: (apiKey: String?, provider: AIProvider)]()
+        initialState: [UUID: (config: AIProviderConfig, apiKey: String?, provider: AIProvider)]()
     )
 
     static func createProvider(for config: AIProviderConfig, apiKey: String?) -> AIProvider {
         cacheLock.withLock { cache in
-            if let cached = cache[config.id], cached.apiKey == apiKey {
+            if let cached = cache[config.id], cached.apiKey == apiKey, cached.config == config {
                 return cached.provider
             }
             let provider: AIProvider
@@ -36,7 +36,7 @@ enum AIProviderFactory {
                     maxOutputTokens: config.maxOutputTokens
                 )
             }
-            cache[config.id] = (apiKey, provider)
+            cache[config.id] = (config, apiKey, provider)
             return provider
         }
     }
diff --git a/TableProTests/Core/AI/AIProviderFactoryCacheTests.swift b/TableProTests/Core/AI/AIProviderFactoryCacheTests.swift
new file mode 100644
index 000000000..783a6c2f2
--- /dev/null
+++ b/TableProTests/Core/AI/AIProviderFactoryCacheTests.swift
@@ -0,0 +1,175 @@
+//
+//  AIProviderFactoryCacheTests.swift
+//  TableProTests
+//
+//  Verifies AIProviderFactory.createProvider returns a fresh instance
+//  whenever any field of AIProviderConfig changes — not only id/apiKey.
+//  Regression coverage for the bug where mid-edit endpoint changes were
+//  ignored because the cache key was just (id, apiKey).
+//
+
+import Foundation
+@testable import TablePro
+import Testing
+
+@Suite("AIProviderFactory cache")
+@MainActor
+struct AIProviderFactoryCacheTests {
+    private func makeConfig(
+        id: UUID,
+        type: AIProviderType = .openAI,
+        name: String = "Test",
+        model: String = "gpt-x",
+        endpoint: String = "https://api.openai.com",
+        maxOutputTokens: Int? = nil
+    ) -> AIProviderConfig {
+        AIProviderConfig(
+            id: id,
+            name: name,
+            type: type,
+            model: model,
+            endpoint: endpoint,
+            maxOutputTokens: maxOutputTokens
+        )
+    }
+
+    // MARK: - Cache hit
+
+    @Test("Identical config + apiKey returns the same cached instance")
+    func cacheHitReturnsSameInstance() {
+        let id = UUID()
+        defer { AIProviderFactory.invalidateCache(for: id) }
+        let config = makeConfig(id: id)
+        let first = AIProviderFactory.createProvider(for: config, apiKey: "k")
+        let second = AIProviderFactory.createProvider(for: config, apiKey: "k")
+        #expect(first === second)
+    }
+
+    // MARK: - Cache miss on config changes (the bug)
+
+    @Test("Endpoint change rebuilds the provider (the regression)")
+    func endpointChangeBypassesCache() {
+        let id = UUID()
+        defer { AIProviderFactory.invalidateCache(for: id) }
+        let original = makeConfig(id: id, endpoint: "https://api.openai.com")
+        let mutated = makeConfig(id: id, endpoint: "https://api.deepseek.com")
+        let first = AIProviderFactory.createProvider(for: original, apiKey: "k")
+        let second = AIProviderFactory.createProvider(for: mutated, apiKey: "k")
+        #expect(first !== second)
+    }
+
+    @Test("Model change rebuilds the provider")
+    func modelChangeBypassesCache() {
+        let id = UUID()
+        defer { AIProviderFactory.invalidateCache(for: id) }
+        let original = makeConfig(id: id, model: "gpt-4")
+        let mutated = makeConfig(id: id, model: "gpt-4o")
+        let first = AIProviderFactory.createProvider(for: original, apiKey: "k")
+        let second = AIProviderFactory.createProvider(for: mutated, apiKey: "k")
+        #expect(first !== second)
+    }
+
+    @Test("maxOutputTokens change rebuilds the provider")
+    func maxOutputTokensChangeBypassesCache() {
+        let id = UUID()
+        defer { AIProviderFactory.invalidateCache(for: id) }
+        let original = makeConfig(id: id, maxOutputTokens: nil)
+        let mutated = makeConfig(id: id, maxOutputTokens: 2_048)
+        let first = AIProviderFactory.createProvider(for: original, apiKey: "k")
+        let second = AIProviderFactory.createProvider(for: mutated, apiKey: "k")
+        #expect(first !== second)
+    }
+
+    @Test("Name change rebuilds the provider (full-config equality)")
+    func nameChangeBypassesCache() {
+        let id = UUID()
+        defer { AIProviderFactory.invalidateCache(for: id) }
+        let original = makeConfig(id: id, name: "A")
+        let mutated = makeConfig(id: id, name: "B")
+        let first = AIProviderFactory.createProvider(for: original, apiKey: "k")
+        let second = AIProviderFactory.createProvider(for: mutated, apiKey: "k")
+        #expect(first !== second)
+    }
+
+    @Test("apiKey change rebuilds the provider")
+    func apiKeyChangeBypassesCache() {
+        let id = UUID()
+        defer { AIProviderFactory.invalidateCache(for: id) }
+        let config = makeConfig(id: id)
+        let first = AIProviderFactory.createProvider(for: config, apiKey: "old")
+        let second = AIProviderFactory.createProvider(for: config, apiKey: "new")
+        #expect(first !== second)
+    }
+
+    @Test("nil → non-nil apiKey transition rebuilds the provider")
+    func apiKeyNilToValueRebuilds() {
+        let id = UUID()
+        defer { AIProviderFactory.invalidateCache(for: id) }
+        let config = makeConfig(id: id)
+        let first = AIProviderFactory.createProvider(for: config, apiKey: nil)
+        let second = AIProviderFactory.createProvider(for: config, apiKey: "k")
+        #expect(first !== second)
+    }
+
+    // MARK: - Mid-edit scenario
+
+    @Test("Stale cached provider after empty-endpoint debounce is replaced when endpoint is finalized")
+    func midEditEndpointBecomesActive() {
+        let id = UUID()
+        defer { AIProviderFactory.invalidateCache(for: id) }
+        // Mimic the SwiftUI flow: scheduleFetchModels fires while user is mid-typing
+        // with an empty/partial endpoint, then again once the field is filled in.
+        let mid = makeConfig(id: id, endpoint: "")
+        let final = makeConfig(id: id, endpoint: "https://api.deepseek.com")
+        let staleProvider = AIProviderFactory.createProvider(for: mid, apiKey: "k")
+        let liveProvider = AIProviderFactory.createProvider(for: final, apiKey: "k")
+        #expect(staleProvider !== liveProvider)
+    }
+
+    // MARK: - Cache isolation by id
+
+    @Test("Different provider ids never share cached instances")
+    func differentIdsAreIndependent() {
+        let firstID = UUID()
+        let secondID = UUID()
+        defer {
+            AIProviderFactory.invalidateCache(for: firstID)
+            AIProviderFactory.invalidateCache(for: secondID)
+        }
+        let firstConfig = makeConfig(id: firstID)
+        let secondConfig = makeConfig(id: secondID)
+        let first = AIProviderFactory.createProvider(for: firstConfig, apiKey: "k")
+        let second = AIProviderFactory.createProvider(for: secondConfig, apiKey: "k")
+        #expect(first !== second)
+    }
+
+    // MARK: - Invalidation
+
+    @Test("invalidateCache(for:) forces the next call to rebuild")
+    func invalidateForIdRebuilds() {
+        let id = UUID()
+        defer { AIProviderFactory.invalidateCache(for: id) }
+        let config = makeConfig(id: id)
+        let first = AIProviderFactory.createProvider(for: config, apiKey: "k")
+        AIProviderFactory.invalidateCache(for: id)
+        let second = AIProviderFactory.createProvider(for: config, apiKey: "k")
+        #expect(first !== second)
+    }
+
+    @Test("invalidateCache(for:) only affects the targeted id")
+    func invalidateForIdLeavesOthersIntact() {
+        let targetID = UUID()
+        let bystanderID = UUID()
+        defer {
+            AIProviderFactory.invalidateCache(for: targetID)
+            AIProviderFactory.invalidateCache(for: bystanderID)
+        }
+        let target = makeConfig(id: targetID)
+        let bystander = makeConfig(id: bystanderID)
+        _ = AIProviderFactory.createProvider(for: target, apiKey: "k")
+        let bystanderFirst = AIProviderFactory.createProvider(for: bystander, apiKey: "k")
+        AIProviderFactory.invalidateCache(for: targetID)
+        let bystanderSecond = AIProviderFactory.createProvider(for: bystander, apiKey: "k")
+        #expect(bystanderFirst === bystanderSecond)
+    }
+}