Unify AI provider selection across all features

Every LLM-backed feature (Post-Processing, Proofreading, Title
Generation, Property Filler) now reads from one CHAT_PROVIDERS
registry instead of 5 hand-duplicated provider lists, so they always
offer the exact same providers in the exact same order.

- Add Groq as a 5th chat-completion provider (was transcription-only
  despite its OpenAI-compatible API and an already-collected key).
- Provider dropdowns disable options with no API key configured
  (shown as e.g. "Anthropic (no API key)") instead of silently
  failing at runtime when picked.
- Collapse 3 byte-for-byte duplicated resolveProvider() methods
  (Proofreader, TitleGenerator, PropertyFiller) plus AudioHandler's
  getPostProcessingApiKey() into one resolveChatProvider() helper
  (src/ProviderResolver.ts).
- Fix Custom provider: previously Proofreading/Title/Property silently
  reused Post-Processing's postProcessingUrl with no visible field to
  set it. Renamed to a shared customApiUrl field with its own UI
  (createCustomProviderFields), now exposed on every tab that offers
  Custom, plus rows on the API Keys tab. Migrates old data.json values
  automatically.
- Update README settings reference and getting-started sections to
  match.

No behavior change for existing single-provider setups; migration
handles the postProcessingUrl -> customApiUrl rename transparently.

README.md

@@ -75,11 +75,15 @@ Open **Settings** → **NibbleAI** and add at least one API key:
 
 | Key | Used For |
 |-----|----------|
-| **Transcription API Key** | Whisper transcription (OpenAI, Groq, Azure) |
+| **Groq API Key** | Whisper transcription, and as a chat provider for proofreading/title/property/post-processing |
-| **OpenAI API Key** | Proofreading, title generation, property filling, post-processing *(recommended: OpenRouter)* |
+| **OpenAI API Key** | Whisper transcription, and as a chat provider for proofreading/title/property/post-processing |
-| **Anthropic API Key** | Post-processing with Claude models |
+| **Anthropic API Key** | Claude models for proofreading/title/property/post-processing |
+| **OpenRouter API Key** | Access to hundreds of models for proofreading/title/property/post-processing |
+| **Custom API Key + URL** | Any OpenAI-compatible endpoint (self-hosted, Azure, etc.) |
 
-> **Tip:** For proofreading, title generation, and property filling, an [OpenRouter](https://openrouter.ai/keys) API key with a free model like `google/gemini-2.5-flash-lite` costs nothing and works great.
+Every LLM-backed feature (Proofreading, Title Generation, Property Filler, Post-Processing) shows the same provider dropdown — pick any provider that has a key configured above.
+
+> **Tip:** An [OpenRouter](https://openrouter.ai/keys) API key with a free model like `google/gemini-2.5-flash-lite` costs nothing and works great across all four AI features.
 
 ### 2. Try the Features
 
@@ -172,13 +176,14 @@ Securely stored in your system keychain via Obsidian's SecretStorage. Never writ
 | Setting | Default | Description |
 |---------|---------|-------------|
 | Enable | Off | Clean up transcripts with an LLM |
-| Provider | Anthropic | Anthropic, OpenAI, or Custom |
+| Provider | Anthropic | Any configured provider: Anthropic, OpenAI, Groq, OpenRouter, or Custom |
 | Model | `claude-sonnet-4-20250514` | LLM for cleanup |
 | Auto-generate title | Off | Create filenames from content |
 
 ### Proofreading
 | Setting | Default | Description |
 |---------|---------|-------------|
+| Provider | OpenRouter | Any configured provider: Anthropic, OpenAI, Groq, OpenRouter, or Custom |
 | Model | `openai/gpt-4o-mini` | Model for proofreading |
 | Temperature | `0.2` | Lower = more consistent |
 | Max tokens | `2000` | Maximum response length |
@@ -187,12 +192,16 @@ Securely stored in your system keychain via Obsidian's SecretStorage. Never writ
 ### Title Generation
 | Setting | Default | Description |
 |---------|---------|-------------|
+| Provider | OpenRouter | Any configured provider: Anthropic, OpenAI, Groq, OpenRouter, or Custom |
+| Model | `openai/gpt-4o-mini` | Model for generating titles |
 | Mode | Rename file | Rename file or set frontmatter property |
 | Max title length | 8 words | Maximum words in generated title |
 
 ### Property Filler
 | Setting | Default | Description |
 |---------|---------|-------------|
+| Provider | OpenRouter | Any configured provider: Anthropic, OpenAI, Groq, OpenRouter, or Custom |
+| Model | `openai/gpt-4o-mini` | Model for generating property values |
 | Custom prompt | *(built-in)* | Template with `{property}` placeholder |
 | Overwrite existing | Off | Replace existing property values |
 
@@ -205,7 +214,8 @@ NibbleAI/
 ├── main.ts                          # Plugin entry point, commands, events
 ├── src/
 │   ├── SettingsManager.ts           # Settings + SecretStorage management
-│   ├── AIService.ts                 # Unified AI client (OpenAI + Anthropic)
+│   ├── AIService.ts                 # Unified AI client (OpenAI-compatible + Anthropic-native)
+│   ├── ProviderResolver.ts          # Shared provider → API key/endpoint resolution
 │   ├── ModelBrowser.ts              # OpenRouter model suggest modal
 │   ├── PostProcessor.ts             # LLM post-processing for transcripts
 │   ├── NibbleAISettingsTab.ts       # Settings UI

src/AIService.ts

@@ -5,7 +5,7 @@ export interface ChatCompletionOptions {
 	apiKey: string;
 	model: string;
 	endpoint?: string;
-	provider?: "anthropic" | "openai" | "openrouter" | "custom";
+	provider?: "anthropic" | "openai" | "openrouter" | "groq" | "custom";
 	temperature?: number;
 	maxTokens?: number;
 }

src/NibbleAISettingsTab.ts

@@ -3,9 +3,8 @@ import { App, PluginSettingTab, Setting, setIcon } from "obsidian";
 import {
 	SettingsManager,
 	PostProcessingProvider,
-	AIProvider,
 	TranscriptionProvider,
-	PROVIDER_URLS,
+	CHAT_PROVIDERS,
 	PROVIDER_DEFAULT_MODELS,
 } from "./SettingsManager";
 import { ModelSuggestModal } from "./ModelBrowser";
@@ -106,10 +105,14 @@ export class NibbleAISettingsTab extends PluginSettingTab {
 			text: "API keys are stored securely in your system keychain.",
 			cls: "setting-item-description",
 		});
+		containerEl.createEl("p", {
+			text: "Each AI feature below (Proofreading, Title Generation, Property Filler, Post-Processing) lets you pick which of these providers to use, provided its key is set here.",
+			cls: "setting-item-description",
+		});
 
 		this.createApiKeySetting(containerEl,
 			"Groq API Key",
-			"For Whisper transcription via Groq (groq.com)",
+			"For Whisper transcription and Groq chat models (groq.com)",
 			"gsk_...",
 			this.plugin.settings.groqApiKey,
 			async (value) => {
@@ -139,7 +142,7 @@ export class NibbleAISettingsTab extends PluginSettingTab {
 		);
 		this.createApiKeySetting(containerEl,
 			"OpenRouter API Key",
-			"For OpenRouter models — get one at openrouter.ai/keys. Used for proofreading, title generation, property filling, and post-processing.",
+			"For OpenRouter models — get one at openrouter.ai/keys.",
 			"sk-or-v1-...",
 			this.plugin.settings.openRouterApiKey,
 			async (value) => {
@@ -147,6 +150,26 @@ export class NibbleAISettingsTab extends PluginSettingTab {
 				await this.save();
 			}
 		);
+		this.createApiKeySetting(containerEl,
+			"Custom API Key",
+			"For a self-hosted or OpenAI-compatible endpoint not listed above",
+			"sk-...xxxx",
+			this.plugin.settings.customApiKey,
+			async (value) => {
+				this.plugin.settings.customApiKey = value;
+				await this.save();
+			}
+		);
+		this.createTextSetting(containerEl,
+			"Custom API URL",
+			"Chat completions endpoint for the custom provider",
+			"https://api.example.com/v1/chat/completions",
+			this.plugin.settings.customApiUrl,
+			async (value) => {
+				this.plugin.settings.customApiUrl = value;
+				await this.save();
+			}
+		);
 	}
 
 	// ── Transcription Tab ──
@@ -328,29 +351,22 @@ export class NibbleAISettingsTab extends PluginSettingTab {
 			);
 
 		if (this.plugin.settings.postProcessing) {
-			this.createPostProcessingProviderSetting(containerEl);
+			this.createChatProviderSetting(containerEl,
+				"Select the LLM provider for cleaning up transcriptions",
+				this.plugin.settings.postProcessingProvider,
+				async (provider) => {
+					this.plugin.settings.postProcessingProvider = provider;
+					if (provider !== "custom") {
+						this.plugin.settings.postProcessingModel =
+							PROVIDER_DEFAULT_MODELS[provider];
+					}
+					await this.save();
+					this.display();
+				}
+			);
 
 			if (this.plugin.settings.postProcessingProvider === "custom") {
-				this.createTextSetting(containerEl,
+				this.createCustomProviderFields(containerEl);
-					"API URL",
-					"Custom endpoint for chat completions",
-					"https://api.example.com/v1/chat/completions",
-					this.plugin.settings.postProcessingUrl,
-					async (value) => {
-						this.plugin.settings.postProcessingUrl = value;
-						await this.save();
-					}
-				);
-				this.createApiKeySetting(containerEl,
-					"API Key",
-					"API key for the custom endpoint",
-					"sk-...xxxx",
-					this.plugin.settings.customApiKey,
-					async (value) => {
-						this.plugin.settings.customApiKey = value;
-						await this.save();
-					}
-				);
 			}
 
 			this.createModelSetting(containerEl,
@@ -424,15 +440,23 @@ export class NibbleAISettingsTab extends PluginSettingTab {
 			cls: "setting-item-description",
 		});
 
-		this.createProviderSetting(containerEl,
+		this.createChatProviderSetting(containerEl,
-			"Provider",
 			"Select the AI provider for proofreading",
 			this.plugin.settings.proofreadingProvider,
-			async (value) => {
+			async (provider) => {
-				this.plugin.settings.proofreadingProvider = value as AIProvider;
+				this.plugin.settings.proofreadingProvider = provider;
+				if (provider !== "custom") {
+					this.plugin.settings.proofreadingModel =
+						PROVIDER_DEFAULT_MODELS[provider];
+				}
 				await this.save();
+				this.display();
 			}
 		);
+
+		if (this.plugin.settings.proofreadingProvider === "custom") {
+			this.createCustomProviderFields(containerEl);
+		}
 		this.createModelSetting(containerEl,
 			"Model",
 			"Model for fixing punctuation and grammar",
@@ -508,15 +532,23 @@ export class NibbleAISettingsTab extends PluginSettingTab {
 			cls: "setting-item-description",
 		});
 
-		this.createProviderSetting(containerEl,
+		this.createChatProviderSetting(containerEl,
-			"Provider",
 			"Select the AI provider for title generation",
 			this.plugin.settings.titleGenProvider,
-			async (value) => {
+			async (provider) => {
-				this.plugin.settings.titleGenProvider = value as AIProvider;
+				this.plugin.settings.titleGenProvider = provider;
+				if (provider !== "custom") {
+					this.plugin.settings.titleGenModel =
+						PROVIDER_DEFAULT_MODELS[provider];
+				}
 				await this.save();
+				this.display();
 			}
 		);
+
+		if (this.plugin.settings.titleGenProvider === "custom") {
+			this.createCustomProviderFields(containerEl);
+		}
 		this.createModelSetting(containerEl,
 			"Model",
 			"Model for generating titles",
@@ -577,15 +609,23 @@ export class NibbleAISettingsTab extends PluginSettingTab {
 			cls: "setting-item-description",
 		});
 
-		this.createProviderSetting(containerEl,
+		this.createChatProviderSetting(containerEl,
-			"Provider",
 			"Select the AI provider for property generation",
 			this.plugin.settings.propertyGenProvider,
-			async (value) => {
+			async (provider) => {
-				this.plugin.settings.propertyGenProvider = value as AIProvider;
+				this.plugin.settings.propertyGenProvider = provider;
+				if (provider !== "custom") {
+					this.plugin.settings.propertyGenModel =
+						PROVIDER_DEFAULT_MODELS[provider];
+				}
 				await this.save();
+				this.display();
 			}
 		);
+
+		if (this.plugin.settings.propertyGenProvider === "custom") {
+			this.createCustomProviderFields(containerEl);
+		}
 		this.createModelSetting(containerEl,
 			"Model",
 			"Model for generating property values",
@@ -748,30 +788,53 @@ export class NibbleAISettingsTab extends PluginSettingTab {
 		infoEl.style.flex = "1 1 100%";
 	}
 
-	private createProviderSetting(
+	/**
+	 * Shared provider dropdown for every LLM-backed feature (Post-Processing,
+	 * Proofreading, Title Generation, Property Filler). Reads from the single
+	 * CHAT_PROVIDERS registry so all four features always offer the exact
+	 * same providers, and disables any provider whose API key isn't set yet.
+	 */
+	private createChatProviderSetting(
 		containerEl: HTMLElement,
-		name: string,
 		desc: string,
-		value: string,
+		currentProvider: PostProcessingProvider,
-		onChange: (value: string) => Promise<void>
+		onChange: (provider: PostProcessingProvider) => Promise<void>
 	): void {
-		const providers: Record<string, string> = {
+		const configured = new Set(
-			openrouter: "OpenRouter",
+			CHAT_PROVIDERS.filter((p) => !!this.plugin.settings[p.apiKeyField]).map(
-			openai: "OpenAI",
+				(p) => p.id
-			anthropic: "Anthropic",
+			)
-			custom: "Custom",
+		);
-		};
 
 		new Setting(containerEl)
-			.setName(name)
+			.setName("Provider")
 			.setDesc(desc)
 			.addDropdown((dropdown) => {
-				for (const [val, label] of Object.entries(providers)) {
+				for (const p of CHAT_PROVIDERS) {
-					dropdown.addOption(val, label);
+					dropdown.addOption(
+						p.id,
+						configured.has(p.id) ? p.label : `${p.label} (no API key)`
+					);
+				}
+				dropdown.setValue(currentProvider || "openrouter");
+				dropdown.onChange(async (value) => {
+					await onChange(value as PostProcessingProvider);
+				});
+				for (const p of CHAT_PROVIDERS) {
+					if (configured.has(p.id)) continue;
+					const optionEl = dropdown.selectEl.querySelector(
+						`option[value="${p.id}"]`
+					) as HTMLOptionElement | null;
+					if (optionEl) optionEl.disabled = true;
 				}
-				dropdown.setValue(value || "openrouter");
-				dropdown.onChange(async (val) => await onChange(val));
 			});
+
+		if (configured.size === 0) {
+			containerEl.createEl("p", {
+				text: "⚠️ No AI provider configured yet — add an API key in the API Keys tab.",
+				cls: "setting-item-description",
+			});
+		}
 	}
 
 	private createModelSetting(
@@ -860,36 +923,35 @@ export class NibbleAISettingsTab extends PluginSettingTab {
 		);
 	}
 
-	private createPostProcessingProviderSetting(containerEl: HTMLElement): void {
+	/**
-		const providers: Record<PostProcessingProvider, string> = {
+	 * Custom endpoint + key fields, shown whenever a feature's provider is
-			anthropic: "Anthropic",
+	 * set to "Custom". This slot is shared across all four AI features.
-			openai: "OpenAI",
+	 */
-			openrouter: "OpenRouter",
+	private createCustomProviderFields(containerEl: HTMLElement): void {
-			custom: "Custom",
+		containerEl.createEl("p", {
-		};
+			text: "Custom provider connection \u2014 shared across Post-Processing, Proofreading, Title Generation, and Property Filler.",
-
+			cls: "setting-item-description",
-		new Setting(containerEl)
+		});
-			.setName("Provider")
+		this.createTextSetting(containerEl,
-			.setDesc("Select the LLM provider")
+			"Custom API URL",
-			.addDropdown((dropdown) => {
+			"OpenAI-compatible chat completions endpoint",
-				for (const [value, label] of Object.entries(providers)) {
+			"https://api.example.com/v1/chat/completions",
-					dropdown.addOption(value, label);
+			this.plugin.settings.customApiUrl,
-				}
+			async (value) => {
-				dropdown
+				this.plugin.settings.customApiUrl = value;
-					.setValue(this.plugin.settings.postProcessingProvider)
+				await this.save();
-					.onChange(async (value) => {
+			}
-						const provider = value as PostProcessingProvider;
+		);
-						this.plugin.settings.postProcessingProvider = provider;
+		this.createApiKeySetting(containerEl,
-						if (provider !== "custom") {
+			"Custom API Key",
-							this.plugin.settings.postProcessingUrl =
+			"API key for the custom endpoint",
-								PROVIDER_URLS[provider];
+			"sk-...xxxx",
-							this.plugin.settings.postProcessingModel =
+			this.plugin.settings.customApiKey,
-								PROVIDER_DEFAULT_MODELS[provider];
+			async (value) => {
-						}
+				this.plugin.settings.customApiKey = value;
-						await this.save();
+				await this.save();
-						this.display();
+			}
-					});
+		);
-			});
 	}
 
 	private async createAudioDeviceSetting(containerEl: HTMLElement): Promise<void> {

src/ProviderResolver.ts

@@ -0,0 +1,27 @@
+import { CHAT_PROVIDERS, PROVIDER_URLS, PluginSettings, PostProcessingProvider } from "./SettingsManager";
+
+export interface ResolvedChatProvider {
+	apiKey: string;
+	endpoint: string;
+	provider: PostProcessingProvider;
+}
+
+/**
+ * Resolves the API key + endpoint for a chat-completion provider selection.
+ * Shared by every AI feature that talks to an LLM (Post-Processing,
+ * Proofreading, Title Generation, Property Filler) so they all treat
+ * providers — including "no key configured" — identically.
+ */
+export function resolveChatProvider(
+	settings: PluginSettings,
+	provider: PostProcessingProvider
+): ResolvedChatProvider | null {
+	const info = CHAT_PROVIDERS.find((p) => p.id === provider);
+	if (!info) return null;
+
+	const apiKey = settings[info.apiKeyField];
+	const endpoint = provider === "custom" ? settings.customApiUrl : PROVIDER_URLS[provider];
+
+	if (!apiKey || !endpoint) return null;
+	return { apiKey, endpoint, provider };
+}

src/SettingsManager.ts

@@ -1,6 +1,6 @@
 import { Plugin } from "obsidian";
 
-const SECRET_IDS: Record<keyof ApiKeysSettings, string> = {
+const SECRET_IDS: Partial<Record<keyof ApiKeysSettings, string>> = {
 	groqApiKey: "groq-api-key",
 	openAiApiKey: "openai-api-key",
 	anthropicApiKey: "anthropic-api-key",
@@ -8,7 +8,7 @@ const SECRET_IDS: Record<keyof ApiKeysSettings, string> = {
 	openRouterApiKey: "openrouter-api-key",
 };
 
-export type PostProcessingProvider = "anthropic" | "openai" | "openrouter" | "custom";
+export type PostProcessingProvider = "anthropic" | "openai" | "openrouter" | "groq" | "custom";
 
 export type AIProvider = PostProcessingProvider;
 
@@ -16,6 +16,7 @@ export const PROVIDER_URLS: Record<PostProcessingProvider, string> = {
 	anthropic: "https://api.anthropic.com/v1/messages",
 	openai: "https://api.openai.com/v1/chat/completions",
 	openrouter: "https://openrouter.ai/api/v1/chat/completions",
+	groq: "https://api.groq.com/openai/v1/chat/completions",
 	custom: "",
 };
 
@@ -23,9 +24,30 @@ export const PROVIDER_DEFAULT_MODELS: Record<PostProcessingProvider, string> = {
 	anthropic: "claude-sonnet-4-20250514",
 	openai: "gpt-4o-mini",
 	openrouter: "openai/gpt-4o-mini",
+	groq: "llama-3.3-70b-versatile",
 	custom: "",
 };
 
+export interface ChatProviderInfo {
+	id: PostProcessingProvider;
+	label: string;
+	apiKeyField: keyof ApiKeysSettings;
+}
+
+/**
+ * Single source of truth for which chat-completion providers exist and which
+ * API key each one uses. UI dropdowns and provider resolution both read from
+ * this list so every AI feature (Post-Processing, Proofreading, Title
+ * Generation, Property Filler) offers the exact same providers.
+ */
+export const CHAT_PROVIDERS: ChatProviderInfo[] = [
+	{ id: "anthropic", label: "Anthropic", apiKeyField: "anthropicApiKey" },
+	{ id: "openai", label: "OpenAI", apiKeyField: "openAiApiKey" },
+	{ id: "groq", label: "Groq", apiKeyField: "groqApiKey" },
+	{ id: "openrouter", label: "OpenRouter", apiKeyField: "openRouterApiKey" },
+	{ id: "custom", label: "Custom", apiKeyField: "customApiKey" },
+];
+
 export type TranscriptionProvider = "groq" | "openai" | "azure" | "custom";
 
 export const TRANSCRIPTION_PROVIDER_URLS: Record<TranscriptionProvider, string> = {
@@ -42,6 +64,7 @@ export interface ApiKeysSettings {
 	openAiApiKey: string;
 	anthropicApiKey: string;
 	customApiKey: string;
+	customApiUrl: string;
 	openRouterApiKey: string;
 }
 
@@ -74,7 +97,6 @@ export interface OutputSettings {
 export interface PostProcessingSettings {
 	postProcessing: boolean;
 	postProcessingProvider: PostProcessingProvider;
-	postProcessingUrl: string;
 	postProcessingModel: string;
 	postProcessingPrompt: string;
 	autoGenerateTitle: boolean;
@@ -128,6 +150,7 @@ export const DEFAULT_API_KEYS: ApiKeysSettings = {
 	openAiApiKey: "",
 	anthropicApiKey: "",
 	customApiKey: "",
+	customApiUrl: "",
 	openRouterApiKey: "",
 };
 
@@ -160,7 +183,6 @@ export const DEFAULT_OUTPUT: OutputSettings = {
 export const DEFAULT_POST_PROCESSING: PostProcessingSettings = {
 	postProcessing: false,
 	postProcessingProvider: "anthropic",
-	postProcessingUrl: "https://api.anthropic.com/v1/messages",
 	postProcessingModel: "claude-sonnet-4-20250514",
 	postProcessingPrompt:
 		'You are a transcription editor. Clean up the following voice transcription: fix grammar, remove filler words (um, uh, like) and repetitions, and improve readability. Format the text in markdown. If there are action items or to-dos, format them as task lists with "[ ]". Preserve the original meaning and language. Return only the polished text, nothing else.',
@@ -274,19 +296,31 @@ export class SettingsManager {
 
 	private migratePostProcessingProvider(settings: PluginSettings): boolean {
 		if (settings.postProcessingProvider) return false;
+		const legacyUrl = (settings as PluginSettings & { postProcessingUrl?: string })
+			.postProcessingUrl;
+		if (!legacyUrl) return false;
 
 		for (const [provider, url] of Object.entries(PROVIDER_URLS)) {
-			if (url && settings.postProcessingUrl === url) {
+			if (url && legacyUrl === url) {
-				settings.postProcessingProvider =
+				settings.postProcessingProvider = provider as PostProcessingProvider;
-					provider as PostProcessingProvider;
 				return true;
 			}
 		}
-		if (settings.postProcessingUrl) {
+		settings.postProcessingProvider = "custom";
-			settings.postProcessingProvider = "custom";
+		return true;
-			return true;
+	}
-		}
+
-		return false;
+	private migrateCustomApiUrl(settings: PluginSettings): boolean {
+		// One-time migration: the old `postProcessingUrl` field is now the
+		// shared `customApiUrl` used by every feature's "Custom" provider.
+		if (settings.customApiUrl) return false;
+		const legacyUrl = (settings as PluginSettings & { postProcessingUrl?: string })
+			.postProcessingUrl;
+		if (!legacyUrl) return false;
+		if (Object.values(PROVIDER_URLS).includes(legacyUrl)) return false;
+
+		settings.customApiUrl = legacyUrl;
+		return true;
 	}
 
 	async loadSettings(): Promise<PluginSettings> {
@@ -300,6 +334,10 @@ export class SettingsManager {
 			await this.plugin.saveData(settings);
 		}
 
+		if (this.migrateCustomApiUrl(settings)) {
+			await this.plugin.saveData(settings);
+		}
+
 		if (this.migrateKeysFromDataJson(settings)) {
 			await this.plugin.saveData(settings);
 		}

src/proofreading/Proofreader.ts

@@ -1,6 +1,6 @@
 import { Editor, Notice } from "obsidian";
 import { AIService } from "../AIService";
-import { AIProvider, PROVIDER_URLS } from "../SettingsManager";
+import { resolveChatProvider } from "../ProviderResolver";
 import NibbleAI from "main";
 
 export class Proofreader {
@@ -10,33 +10,6 @@ export class Proofreader {
 		this.plugin = plugin;
 	}
 
-	private resolveProvider(): { apiKey: string; endpoint: string; provider: AIProvider } | null {
-		const provider = this.plugin.settings.proofreadingProvider || "openrouter";
-		let apiKey = "";
-		let endpoint = PROVIDER_URLS[provider] || "";
-
-		switch (provider) {
-			case "openai":
-				apiKey = this.plugin.settings.openAiApiKey;
-				break;
-			case "anthropic":
-				apiKey = this.plugin.settings.anthropicApiKey;
-				break;
-			case "openrouter":
-				apiKey = this.plugin.settings.openRouterApiKey;
-				break;
-			case "custom":
-				apiKey = this.plugin.settings.customApiKey;
-				endpoint = this.plugin.settings.postProcessingUrl || "";
-				break;
-		}
-
-		if (!apiKey) return null;
-		if (!endpoint) return null;
-
-		return { apiKey, endpoint, provider };
-	}
-
 	async fixSelection(editor: Editor): Promise<void> {
 		const selection = editor.getSelection();
 		if (!selection || selection.trim().length === 0) {
@@ -44,7 +17,10 @@ export class Proofreader {
 			return;
 		}
 
-		const config = this.resolveProvider();
+		const config = resolveChatProvider(
+			this.plugin.settings,
+			this.plugin.settings.proofreadingProvider || "openrouter"
+		);
 		if (!config) {
 			new Notice(
 				"⚠️ No API key for selected provider. Check Settings \u2192 NibbleAI \u2192 API Keys."

src/property/PropertyFiller.ts

@@ -1,6 +1,6 @@
 import { Notice, MarkdownView, Modal, App, Setting, TFile } from "obsidian";
 import { AIService } from "../AIService";
-import { AIProvider, PROVIDER_URLS } from "../SettingsManager";
+import { resolveChatProvider } from "../ProviderResolver";
 import NibbleAI from "main";
 
 class PropertyPromptModal extends Modal {
@@ -80,31 +80,6 @@ export class PropertyFiller {
 		this.plugin = plugin;
 	}
 
-	private resolveProvider(): { apiKey: string; endpoint: string; provider: AIProvider } | null {
-		const provider = this.plugin.settings.propertyGenProvider || "openrouter";
-		let apiKey = "";
-		let endpoint = PROVIDER_URLS[provider] || "";
-
-		switch (provider) {
-			case "openai":
-				apiKey = this.plugin.settings.openAiApiKey;
-				break;
-			case "anthropic":
-				apiKey = this.plugin.settings.anthropicApiKey;
-				break;
-			case "openrouter":
-				apiKey = this.plugin.settings.openRouterApiKey;
-				break;
-			case "custom":
-				apiKey = this.plugin.settings.customApiKey;
-				endpoint = this.plugin.settings.postProcessingUrl || "";
-				break;
-		}
-
-		if (!apiKey || !endpoint) return null;
-		return { apiKey, endpoint, provider };
-	}
-
 	async fillProperty(): Promise<void> {
 		new PropertyPromptModal(
 			this.plugin.app,
@@ -139,7 +114,10 @@ export class PropertyFiller {
 			return;
 		}
 
-		const config = this.resolveProvider();
+		const config = resolveChatProvider(
+			this.plugin.settings,
+			this.plugin.settings.propertyGenProvider || "openrouter"
+		);
 		if (!config) {
 			new Notice(
 				"⚠️ No API key for selected provider. Check Settings \u2192 NibbleAI \u2192 API Keys."

src/title/TitleGenerator.ts

@@ -1,6 +1,6 @@
 import { Notice, TFile, MarkdownView } from "obsidian";
 import { AIService } from "../AIService";
-import { AIProvider, PROVIDER_URLS } from "../SettingsManager";
+import { resolveChatProvider } from "../ProviderResolver";
 import NibbleAI from "main";
 
 export class TitleGenerator {
@@ -10,31 +10,6 @@ export class TitleGenerator {
 		this.plugin = plugin;
 	}
 
-	private resolveProvider(): { apiKey: string; endpoint: string; provider: AIProvider } | null {
-		const provider = this.plugin.settings.titleGenProvider || "openrouter";
-		let apiKey = "";
-		let endpoint = PROVIDER_URLS[provider] || "";
-
-		switch (provider) {
-			case "openai":
-				apiKey = this.plugin.settings.openAiApiKey;
-				break;
-			case "anthropic":
-				apiKey = this.plugin.settings.anthropicApiKey;
-				break;
-			case "openrouter":
-				apiKey = this.plugin.settings.openRouterApiKey;
-				break;
-			case "custom":
-				apiKey = this.plugin.settings.customApiKey;
-				endpoint = this.plugin.settings.postProcessingUrl || "";
-				break;
-		}
-
-		if (!apiKey || !endpoint) return null;
-		return { apiKey, endpoint, provider };
-	}
-
 	async generateTitle(): Promise<void> {
 		const activeView =
 			this.plugin.app.workspace.getActiveViewOfType(MarkdownView);
@@ -55,7 +30,10 @@ export class TitleGenerator {
 			return;
 		}
 
-		const config = this.resolveProvider();
+		const config = resolveChatProvider(
+			this.plugin.settings,
+			this.plugin.settings.titleGenProvider || "openrouter"
+		);
 		if (!config) {
 			new Notice(
 				"⚠️ No API key for selected provider. Check Settings \u2192 NibbleAI \u2192 API Keys."

src/transcription/AudioHandler.ts

@@ -8,6 +8,7 @@ import {
 	resolveTemplate,
 } from "./utils";
 import { PostProcessor } from "../PostProcessor";
+import { resolveChatProvider } from "../ProviderResolver";
 
 export class AudioHandler {
 	private plugin: NibbleAI;
@@ -16,19 +17,6 @@ export class AudioHandler {
 		this.plugin = plugin;
 	}
 
-	private getPostProcessingApiKey(): string {
-		switch (this.plugin.settings.postProcessingProvider) {
-			case "anthropic":
-				return this.plugin.settings.anthropicApiKey;
-			case "openai":
-				return this.plugin.settings.openAiApiKey;
-			case "openrouter":
-				return this.plugin.settings.openRouterApiKey;
-			case "custom":
-				return this.plugin.settings.customApiKey;
-		}
-	}
-
 	private getTranscriptionUrl(): string {
 		switch (this.plugin.settings.transcriptionProvider) {
 			case "groq":
@@ -173,8 +161,11 @@ export class AudioHandler {
 
 			// Post-process with LLM if enabled
 			if (this.plugin.settings.postProcessing) {
-				const ppApiKey = this.getPostProcessingApiKey();
+				const resolved = resolveChatProvider(
-				if (!ppApiKey) {
+					this.plugin.settings,
+					this.plugin.settings.postProcessingProvider
+				);
+				if (!resolved) {
 					new Notice(
 						"✘ Add your post-processing API key in settings"
 					);
@@ -185,10 +176,10 @@ export class AudioHandler {
 						new Notice("Post-processing...");
 					}
 					const processor = new PostProcessor({
-						apiKey: ppApiKey,
+						apiKey: resolved.apiKey,
 						model: this.plugin.settings.postProcessingModel,
-						url: this.plugin.settings.postProcessingUrl,
+						url: resolved.endpoint,
-						provider: this.plugin.settings.postProcessingProvider,
+						provider: resolved.provider,
 					});
 					finalText = await processor.process(
 						originalText,
@@ -209,14 +200,17 @@ export class AudioHandler {
 				this.plugin.settings.autoGenerateTitle &&
 				this.plugin.settings.createNoteFile
 			) {
-				const ppApiKey = this.getPostProcessingApiKey();
+				const resolved = resolveChatProvider(
-				if (ppApiKey) {
+					this.plugin.settings,
+					this.plugin.settings.postProcessingProvider
+				);
+				if (resolved) {
 					try {
 						const processor = new PostProcessor({
-							apiKey: ppApiKey,
+							apiKey: resolved.apiKey,
 							model: this.plugin.settings.postProcessingModel,
-							url: this.plugin.settings.postProcessingUrl,
+							url: resolved.endpoint,
-							provider: this.plugin.settings.postProcessingProvider,
+							provider: resolved.provider,
 						});
 						const title = await processor.process(
 							finalText,