diff --git a/src/agents/agents.test.ts b/src/agents/agents.test.ts
index 3c1bcbe4b..1f8dbd62f 100644
--- a/src/agents/agents.test.ts
+++ b/src/agents/agents.test.ts
@@ -10,6 +10,8 @@ describe("pi agent helpers", () => {
       bodyIndex: 1,
       isNewSession: true,
       sessionId: "sess",
+      provider: "anthropic",
+      model: "claude-opus-4-5",
       sendSystemOnce: false,
       systemSent: false,
       identityPrefix: "IDENT",
@@ -18,6 +20,10 @@ describe("pi agent helpers", () => {
     expect(built).toContain("-p");
     expect(built).toContain("--mode");
     expect(built).toContain("json");
+    expect(built).toContain("--provider");
+    expect(built).toContain("anthropic");
+    expect(built).toContain("--model");
+    expect(built).toContain("claude-opus-4-5");
     expect(built.at(-1)).toContain("IDENT");
 
     const builtNoIdentity = piSpec.buildArgs({
@@ -25,6 +31,8 @@ describe("pi agent helpers", () => {
       bodyIndex: 1,
       isNewSession: false,
       sessionId: "sess",
+      provider: "anthropic",
+      model: "claude-opus-4-5",
       sendSystemOnce: true,
       systemSent: true,
       identityPrefix: "IDENT",
@@ -33,6 +41,50 @@ describe("pi agent helpers", () => {
     expect(builtNoIdentity.at(-1)).toBe("hi");
   });
 
+  it("injects provider/model for pi invocations only and avoids duplicates", () => {
+    const base = piSpec.buildArgs({
+      argv: ["pi", "hello"],
+      bodyIndex: 1,
+      isNewSession: true,
+      sendSystemOnce: false,
+      systemSent: false,
+      format: "json",
+    });
+    expect(base.filter((a) => a === "--provider").length).toBe(1);
+    expect(base).toContain("anthropic");
+    expect(base.filter((a) => a === "--model").length).toBe(1);
+    expect(base).toContain("claude-opus-4-5");
+
+    const already = piSpec.buildArgs({
+      argv: [
+        "pi",
+        "--provider",
+        "anthropic",
+        "--model",
+        "claude-opus-4-5",
+        "hi",
+      ],
+      bodyIndex: 5,
+      isNewSession: true,
+      sendSystemOnce: false,
+      systemSent: false,
+      format: "json",
+    });
+    expect(already.filter((a) => a === "--provider").length).toBe(1);
+    expect(already.filter((a) => a === "--model").length).toBe(1);
+
+    const nonPi = piSpec.buildArgs({
+      argv: ["echo", "hi"],
+      bodyIndex: 1,
+      isNewSession: true,
+      sendSystemOnce: false,
+      systemSent: false,
+      format: "json",
+    });
+    expect(nonPi).not.toContain("--provider");
+    expect(nonPi).not.toContain("--model");
+  });
+
   it("parses final assistant message and preserves usage meta", () => {
     const stdout = [
       '{"type":"message_start","message":{"role":"assistant"}}',
diff --git a/src/config/config.test.ts b/src/config/config.test.ts
new file mode 100644
index 000000000..ea3ff425f
--- /dev/null
+++ b/src/config/config.test.ts
@@ -0,0 +1,140 @@
+import fs from "node:fs/promises";
+import os from "node:os";
+import path from "node:path";
+
+import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
+
+async function withTempHome<T>(fn: (home: string) => Promise<T>): Promise<T> {
+  const base = await fs.mkdtemp(path.join(os.tmpdir(), "clawdis-config-"));
+  const previousHome = process.env.HOME;
+  process.env.HOME = base;
+  try {
+    return await fn(base);
+  } finally {
+    process.env.HOME = previousHome;
+    await fs.rm(base, { recursive: true, force: true });
+  }
+}
+
+describe("config identity defaults", () => {
+  let previousHome: string | undefined;
+
+  beforeEach(() => {
+    previousHome = process.env.HOME;
+  });
+
+  afterEach(() => {
+    process.env.HOME = previousHome;
+  });
+
+  it("derives responsePrefix, mentionPatterns, and sessionIntro when identity is set", async () => {
+    await withTempHome(async (home) => {
+      const configDir = path.join(home, ".clawdis");
+      await fs.mkdir(configDir, { recursive: true });
+      await fs.writeFile(
+        path.join(configDir, "clawdis.json"),
+        JSON.stringify(
+          {
+            identity: { name: "Samantha", theme: "helpful sloth", emoji: "🦥" },
+            inbound: {
+              reply: {
+                mode: "command",
+                command: ["pi", "--mode", "rpc", "x"],
+                session: {},
+              },
+            },
+          },
+          null,
+          2,
+        ),
+        "utf-8",
+      );
+
+      vi.resetModules();
+      const { loadConfig } = await import("./config.js");
+      const cfg = loadConfig();
+
+      expect(cfg.inbound?.responsePrefix).toBe("🦥");
+      expect(cfg.inbound?.groupChat?.mentionPatterns).toEqual([
+        "\\b@?Samantha\\b",
+      ]);
+      expect(cfg.inbound?.reply?.session?.sessionIntro).toContain(
+        "You are Samantha.",
+      );
+      expect(cfg.inbound?.reply?.session?.sessionIntro).toContain(
+        "Theme: helpful sloth.",
+      );
+      expect(cfg.inbound?.reply?.session?.sessionIntro).toContain(
+        "Your emoji is 🦥.",
+      );
+    });
+  });
+
+  it("does not override explicit values", async () => {
+    await withTempHome(async (home) => {
+      const configDir = path.join(home, ".clawdis");
+      await fs.mkdir(configDir, { recursive: true });
+      await fs.writeFile(
+        path.join(configDir, "clawdis.json"),
+        JSON.stringify(
+          {
+            identity: {
+              name: "Samantha Sloth",
+              theme: "space lobster",
+              emoji: "🦞",
+            },
+            inbound: {
+              responsePrefix: "✅",
+              groupChat: { mentionPatterns: ["@clawd"] },
+              reply: {
+                mode: "command",
+                command: ["pi", "--mode", "rpc", "x"],
+                session: { sessionIntro: "Explicit intro" },
+              },
+            },
+          },
+          null,
+          2,
+        ),
+        "utf-8",
+      );
+
+      vi.resetModules();
+      const { loadConfig } = await import("./config.js");
+      const cfg = loadConfig();
+
+      expect(cfg.inbound?.responsePrefix).toBe("✅");
+      expect(cfg.inbound?.groupChat?.mentionPatterns).toEqual(["@clawd"]);
+      expect(cfg.inbound?.reply?.session?.sessionIntro).toBe("Explicit intro");
+    });
+  });
+
+  it("does not synthesize inbound.reply when it is absent", async () => {
+    await withTempHome(async (home) => {
+      const configDir = path.join(home, ".clawdis");
+      await fs.mkdir(configDir, { recursive: true });
+      await fs.writeFile(
+        path.join(configDir, "clawdis.json"),
+        JSON.stringify(
+          {
+            identity: { name: "Samantha", theme: "helpful sloth", emoji: "🦥" },
+            inbound: {},
+          },
+          null,
+          2,
+        ),
+        "utf-8",
+      );
+
+      vi.resetModules();
+      const { loadConfig } = await import("./config.js");
+      const cfg = loadConfig();
+
+      expect(cfg.inbound?.responsePrefix).toBe("🦥");
+      expect(cfg.inbound?.groupChat?.mentionPatterns).toEqual([
+        "\\b@?Samantha\\b",
+      ]);
+      expect(cfg.inbound?.reply).toBeUndefined();
+    });
+  });
+});