diff --git a/app/agents/__tests__/sentiment.test.ts b/app/agents/__tests__/sentiment.test.ts
new file mode 100644
index 0000000..5fa5c0c
--- /dev/null
+++ b/app/agents/__tests__/sentiment.test.ts
@@ -0,0 +1,38 @@
+import { describe, it, expect } from "vitest";
+import { SentimentAnalyst } from "../sentiment";
+import type { OpenRouterClient } from "../../lib/openrouter";
+
+describe("SentimentAnalyst", () => {
+  it("should analyze sentiment from headlines", async () => {
+    const mockClient = {
+      createChatCompletion: async () => ({
+        choices: [
+          {
+            message: {
+              content:
+                '{"signal":"bullish","confidence":0.85,"reasoning":"Positive sentiment from news"}',
+            },
+          },
+        ],
+      }),
+    } as unknown as OpenRouterClient;
+
+    const analyst = new SentimentAnalyst(mockClient);
+    const result = await analyst.analyze("AAPL", {
+      headlines: ["Apple beats earnings", "New iPhone launch"],
+      source: "news",
+    });
+
+    expect(result.analyst).toBe("sentiment");
+    expect(result.signal.signal).toBe("bullish");
+  });
+
+  it("should use specified model", () => {
+    const mockClient = {} as unknown as OpenRouterClient;
+    const analyst = new SentimentAnalyst(mockClient, {
+      model: "custom/model",
+    });
+
+    expect(analyst.getModel()).toBe("custom/model");
+  });
+});
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diff --git a/app/agents/sentiment.ts b/app/agents/sentiment.ts
new file mode 100644
index 0000000..c4264cf
--- /dev/null
+++ b/app/agents/sentiment.ts
@@ -0,0 +1,84 @@
+import { OpenRouterClient } from "../lib/openrouter";
+import type { AnalystReport, AgentSignal, SignalType } from "../types/agents";
+
+export interface SentimentConfig {
+  model?: string;
+}
+
+export interface SentimentData {
+  headlines: string[];
+  source?: "news" | "social" | "stocktwits";
+}
+
+export class SentimentAnalyst {
+  private client: OpenRouterClient;
+  private model: string;
+
+  constructor(client: OpenRouterClient, config?: SentimentConfig) {
+    this.client = client;
+    this.model = config?.model ?? "google/gemini-2.0-flash-exp:free";
+  }
+
+  getModel(): string {
+    return this.model;
+  }
+
+  async analyze(ticker: string, data: SentimentData): Promise<AnalystReport> {
+    const messages = [
+      {
+        role: "system" as const,
+        content:
+          "You are a sentiment analyst. Analyze the headlines for the given ticker and provide a bullish, bearish, or neutral signal with reasoning. Respond in JSON format with 'signal', 'confidence', and 'reasoning' fields.",
+      },
+      {
+        role: "user" as const,
+        content: `Analyze ${ticker} sentiment from ${data.source ?? "news"}:\n${data.headlines.join("\n")}`,
+      },
+    ];
+
+    const response = await this.client.createChatCompletion(
+      messages,
+      this.model
+    );
+
+    const parsedResponse = response as {
+      choices?: Array<{ message?: { content?: string } }>;
+    };
+    const content = parsedResponse.choices?.[0]?.message?.content ?? "";
+
+    let signal: SignalType = "neutral";
+    let confidence = 0.5;
+    let reasoning = content;
+
+    try {
+      const parsed = JSON.parse(content);
+      if (
+        parsed.signal === "bullish" ||
+        parsed.signal === "bearish" ||
+        parsed.signal === "neutral"
+      ) {
+        signal = parsed.signal;
+        confidence = parsed.confidence ?? 0.5;
+        reasoning = parsed.reasoning ?? content;
+      }
+    } catch {
+      const lowerContent = content.toLowerCase();
+      if (lowerContent.includes("bullish")) signal = "bullish";
+      else if (lowerContent.includes("bearish")) signal = "bearish";
+    }
+
+    const agentSignal: AgentSignal = {
+      agent: "sentiment",
+      signal,
+      confidence,
+      reasoning,
+      timestamp: new Date().toISOString(),
+    };
+
+    return {
+      analyst: "sentiment",
+      report: content,
+      signal: agentSignal,
+    };
+  }
+}
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