Add varied messaging experiments

src/ai/openrouter.ts

@@ -256,6 +256,7 @@ ${this.config.openrouter.imageAnalysisPrompt}`;
     attractivenessScore: number | null = null,
     postFlair?: string | null,
     toneGuidance?: string,
+    recentMessages: readonly string[] = [],
   ): Promise<string> {
     try {
       this.logger.debug('Generating message...');
@@ -277,16 +278,7 @@ ${this.config.openrouter.imageAnalysisPrompt}`;
         prompt += `\n\n${toneGuidance}`;
       }
 
-      // Add successful examples if available
-      if (successfulExamples.length > 0) {
-        const examplesText = successfulExamples
-          .map((ex, i) => `Example ${i + 1}:\n${ex}`)
-          .join('\n\n');
-
-        prompt = `Here are some examples of messages that got positive responses:\n\n${examplesText}\n\n---\n\nNow generate a new message in a similar style:\n\n${prompt}`;
-
-        this.logger.debug(`Including ${successfulExamples.length} successful examples in prompt`);
-      }
+      prompt = this.addLearningContext(prompt, successfulExamples, recentMessages);
 
       const message = await this.generateTextWithFallback('generateMessage', prompt, {
         max_tokens: 300,
@@ -414,6 +406,7 @@ Just write the message, nothing else.`;
     strategyPrompt?: string,
     postFlair?: string | null,
     toneGuidance?: string,
+    recentMessages: readonly string[] = [],
   ): Promise<string> {
     try {
       this.logger.debug('Generating chat opener...');
@@ -433,12 +426,7 @@ Just write the message, nothing else.`;
         prompt += `\n\n${toneGuidance}`;
       }
 
-      if (successfulExamples.length > 0) {
-        const examplesText = successfulExamples
-          .map((ex, i) => `Example ${i + 1}:\n${ex}`)
-          .join('\n\n');
-        prompt = `Here are openers that got responses:\n\n${examplesText}\n\n---\n\nNow generate a new opener in a similar style:\n\n${prompt}`;
-      }
+      prompt = this.addLearningContext(prompt, successfulExamples, recentMessages);
 
       const message = await this.generateTextWithFallback('generateChatOpener', prompt, {
         max_tokens: 200,
@@ -476,6 +464,30 @@ Just write the message, nothing else.`;
     };
   }
 
+  private addLearningContext(
+    prompt: string,
+    successfulExamples: readonly string[],
+    recentMessages: readonly string[],
+  ): string {
+    const sections: string[] = [];
+    if (successfulExamples.length > 0) {
+      sections.push(
+        'PERFORMANCE EXAMPLES (use only as evidence about themes that earned replies; do not copy their opening words, sentence structure, or closing hook):\n' +
+        successfulExamples.map((example, index) => `${index + 1}. ${example}`).join('\n'),
+      );
+      this.logger.debug(`Including ${successfulExamples.length} successful message examples as performance context`);
+    }
+    if (recentMessages.length > 0) {
+      sections.push(
+        'RECENT MESSAGES TO AVOID IMITATING:\n' +
+        recentMessages.slice(0, 12).map((message, index) => `${index + 1}. ${message}`).join('\n') +
+        '\nYour output must use different opening words, a different sentence pattern, and a different closing device from these messages.',
+      );
+      this.logger.debug(`Including ${Math.min(recentMessages.length, 12)} recent messages for repetition avoidance`);
+    }
+    return sections.length > 0 ? `${sections.join('\n\n')}\n\n---\n\n${prompt}` : prompt;
+  }
+
   private async generateTextWithFallback(
     label: string,
     prompt: string | ProtectedTextPrompt,
@@ -611,9 +623,20 @@ Just write the message, nothing else.`;
     strategyPrompt?: string,
     postFlair?: string | null,
     toneGuidance?: string,
+    recentMessages: readonly string[] = [],
   ): Promise<{ analysis: ImageAnalysisResult; message: string }> {
     const analysis = await this.analyzeImage(imageBase64, mimeType);
-    const message = await this.generateMessage(analysis.description, postTitle, authorName, successfulExamples, strategyPrompt, analysis.attractivenessScore, postFlair, toneGuidance);
+    const message = await this.generateMessage(
+      analysis.description,
+      postTitle,
+      authorName,
+      successfulExamples,
+      strategyPrompt,
+      analysis.attractivenessScore,
+      postFlair,
+      toneGuidance,
+      recentMessages,
+    );
     return { analysis, message };
   }
 }

src/bootstrap.ts

@@ -177,7 +177,17 @@ export async function bootstrap(
     redditApi, postsRepo, recipientDeduplicator, config, logger, 1000,
     createConfigBackedSubredditPollingControl(config, new ConfigStore(db), logger),
   );
-  const processorService = new ProcessorService(redditApi, aiClient, config, logger);
+  const processorService = new ProcessorService(
+    redditApi,
+    aiClient,
+    config,
+    logger,
+    undefined,
+    (sourceType) => messagesRepo
+      .getRecent(20)
+      .filter((message) => message.sourceType === sourceType || (sourceType === 'image' && !message.sourceType))
+      .map((message) => message.message),
+  );
   const strategySelector = new StrategySelector(config, messagesRepo, logger);
   processorService.setStrategySelector(strategySelector);
   const chatStrategySelector = new StrategySelector(config, messagesRepo, logger, 'chatStrategies');

src/config/index.ts

@@ -130,24 +130,24 @@ export const ConfigSchema = z.object({
   }).default({ syncIntervalMs: 1800000, syncEnabled: true }),
   strategies: z.object({
     explorationRate: z.number().min(0).max(1).default(0.2),
-    minSamples: z.number().int().positive().transform((value) => Math.max(30, value)).default(30),
+    minSamples: z.number().int().positive().transform((value) => Math.max(20, value)).default(20),
     responseWindowHours: z.number().positive().default(12),
     variants: z.array(z.object({
       id: z.string(),
       weight: z.number().default(1),
       promptOverride: z.string(),
     })).default([]),
-  }).default({ explorationRate: 0.2, minSamples: 30, responseWindowHours: 12, variants: [] }),
+  }).default({ explorationRate: 0.2, minSamples: 20, responseWindowHours: 12, variants: [] }),
   chatStrategies: z.object({
     explorationRate: z.number().min(0).max(1).default(0.2),
-    minSamples: z.number().int().positive().transform((value) => Math.max(30, value)).default(30),
+    minSamples: z.number().int().positive().transform((value) => Math.max(20, value)).default(20),
     responseWindowHours: z.number().positive().default(12),
     variants: z.array(z.object({
       id: z.string(),
       weight: z.number().default(1),
       promptOverride: z.string(),
     })).default([]),
-  }).default({ explorationRate: 0.2, minSamples: 30, responseWindowHours: 12, variants: [] }),
+  }).default({ explorationRate: 0.2, minSamples: 20, responseWindowHours: 12, variants: [] }),
   web: z.object({
     enabled: z.boolean().default(true),
     port: z.number().default(3000),

src/services/processor.ts

@@ -33,6 +33,7 @@ export function isSkip(result: ProcessResult): result is SkipResult {
 }
 
 export type ImageFetcher = (url: string, userAgent: string) => Promise<DownloadedImage>;
+export type RecentMessageProvider = (sourceType: 'image' | 'chat') => readonly string[];
 
 export class ProcessorService {
   private successfulExamples: string[] = [];
@@ -46,6 +47,7 @@ export class ProcessorService {
     private config: Config,
     private logger: Logger,
     fetchImage?: ImageFetcher,
+    private readonly recentMessageProvider: RecentMessageProvider = () => [],
   ) {
     this.fetchImage = fetchImage ?? downloadImage;
   }
@@ -183,7 +185,8 @@ export class ProcessorService {
           this.successfulExamples,
           scriptedPrompt,
           post.link_flair_text ?? undefined,
-          undefined
+          undefined,
+          this.recentMessageProvider('image'),
         ));
       } else {
         ({ analysis, message } = await this.aiClient.analyzeAndGenerateMessage(
@@ -195,6 +198,7 @@ export class ProcessorService {
           selectedStrategy?.promptOverride,
           post.link_flair_text ?? undefined,
           tone.profile.promptGuidance || undefined,
+          this.recentMessageProvider('image'),
         ));
       }
     } catch (error) {
@@ -268,7 +272,8 @@ export class ProcessorService {
           this.successfulExamples,
           scriptedPrompt,
           post.link_flair_text ?? undefined,
-          undefined
+          undefined,
+          this.recentMessageProvider('chat'),
         );
       } else {
         message = await this.aiClient.generateChatOpener(
@@ -280,6 +285,7 @@ export class ProcessorService {
           selectedStrategy?.promptOverride,
           post.link_flair_text ?? undefined,
           tone.profile.promptGuidance || undefined,
+          this.recentMessageProvider('chat'),
         );
       }
     } catch (error) {

src/services/reddit-account-runtime-builder.ts

@@ -127,7 +127,17 @@ async function buildRuntime(
       redditApi, postsRepo, recipientDeduplicator, accountConfig, logger,
       1000, createConfigBackedSubredditPollingControl(config, new ConfigStore(db), logger),
     );
-    const processorService = new ProcessorService(redditApi, aiClient, accountConfig, logger);
+    const processorService = new ProcessorService(
+      redditApi,
+      aiClient,
+      accountConfig,
+      logger,
+      undefined,
+      (sourceType) => messagesRepo
+        .getRecent(20)
+        .filter((message) => message.sourceType === sourceType || (sourceType === 'image' && !message.sourceType))
+        .map((message) => message.message),
+    );
     processorService.setStrategySelector(new StrategySelector(accountConfig, messagesRepo, logger));
     processorService.setChatStrategySelector(new StrategySelector(accountConfig, messagesRepo, logger, 'chatStrategies'));
 

src/services/strategy-selector.ts

@@ -1,3 +1,4 @@
+import { createHash } from 'node:crypto';
 import type { Config } from '../config/index.js';
 import type { MessagesRepository, StrategyStats } from '../database/repositories.js';
 import type { Logger } from '../utils/logger.js';
@@ -54,7 +55,13 @@ export class StrategySelector {
     });
 
     if (unexplored.length > 0) {
-      const variant = this.weightedChoice(unexplored);
+      const observedCount = (variant: Config['strategies']['variants'][number]): number => {
+        const stats = statsMap.get(variant.id);
+        return (stats?.totalSent ?? 0) + (stats?.pendingSent ?? 0);
+      };
+      const smallestSample = Math.min(...unexplored.map(observedCount));
+      const leastSampled = unexplored.filter((variant) => observedCount(variant) === smallestSample);
+      const variant = this.weightedChoice(leastSampled);
       this.logger.debug(`Strategy selected (under-sampled): ${variant.id}`);
       return this.selected(variant, 'explore');
     }
@@ -137,4 +144,3 @@ export class StrategySelector {
     return variants[variants.length - 1];
   }
 }
-import { createHash } from 'node:crypto';