diff --git a/src/drivers/antigravity/driver.ts b/src/drivers/antigravity/driver.ts
index 5febaa7..e33694f 100644
--- a/src/drivers/antigravity/driver.ts
+++ b/src/drivers/antigravity/driver.ts
@@ -10,7 +10,7 @@ import { parseAntigravityLine } from "./parser.js";
 
 // Pure so the flag spellings and effort clamping are testable without spawning agy.
 export function buildAntigravityArgs(options: StartOptions): string[] {
-  const args: string[] = ["-p", "--output-format", "stream-json", "--dangerously-skip-permissions"];
+  const args: string[] = ["--output-format", "stream-json", "--dangerously-skip-permissions"];
 
   if (options.resumeSessionId) {
     args.push("--conversation", options.resumeSessionId);
@@ -27,10 +27,62 @@ export function buildAntigravityArgs(options: StartOptions): string[] {
     args.push("--effort", clampedEffort);
   }
 
-  args.push(options.prompt);
+  // -p/--print takes the prompt as its value, so a bare -p up front swallows
+  // the next flag as the prompt ("-p took --output-format as its prompt").
+  // Attach with `=` so the prompt is unambiguous anywhere on the line, even
+  // when it starts with a dash.
+  args.push(`-p=${options.prompt}`);
   return args;
 }
 
+// Pure so the TAB-separated `agy models` table is testable without the binary.
+export function parseAntigravityModelsList(stdout: string): ProviderModels[] {
+  const lines = stdout.split("\n");
+  const providerMap = new Map<string, ModelInfo[]>();
+
+  for (const rawLine of lines) {
+    // Strip spinner prefix if present (e.g. ⠋ Fetching available models...)
+    const clean = rawLine.replace(/^[⠋⠙⠹⠸⠼⠴⠦⠧⠇⠏\s]+Fetching available models\.\.\./g, "").trim();
+    if (!clean) continue;
+    // Banner without spinner prefix is not a model row either.
+    if (/^fetching available models\.\.\./i.test(clean)) continue;
+
+    // `agy models` separates id and display name with a TAB; fall back to
+    // column spacing for anything else.
+    const tab = clean.indexOf("\t");
+    const parts = tab >= 0 ? [clean.slice(0, tab), clean.slice(tab + 1)] : clean.split(/\s{2,}/);
+    const id = parts[0]?.trim();
+    const name = parts[1]?.trim() || id;
+    if (!id || id.startsWith("#") || id.startsWith("Usage")) continue;
+
+    let provider = "google";
+    if (id.startsWith("claude-")) provider = "anthropic";
+    else if (id.startsWith("gpt-")) provider = "openai";
+
+    if (!providerMap.has(provider)) {
+      providerMap.set(provider, []);
+    }
+
+    providerMap.get(provider)!.push({
+      id,
+      name,
+      provider,
+      supportsThinking: id.includes("thinking") || id.includes("high") || id.includes("medium"),
+    });
+  }
+
+  const result: ProviderModels[] = [];
+  for (const [provider, models] of providerMap.entries()) {
+    result.push({
+      provider,
+      displayName: provider.charAt(0).toUpperCase() + provider.slice(1),
+      models,
+    });
+  }
+
+  return result;
+}
+
 export class AntigravityDriver extends SessionDriver {
   readonly id = "antigravity" as const;
 
@@ -132,45 +184,7 @@ export class AntigravityDriver extends SessionDriver {
 
     try {
       const stdout = await runCommandWithTimeout(install.path, ["models"], { timeoutMs: 10000 });
-      const lines = stdout.split("\n");
-      const providerMap = new Map<string, ModelInfo[]>();
-
-      for (const rawLine of lines) {
-        // Strip spinner prefix if present (e.g. ⠋ Fetching available models...)
-        const clean = rawLine.replace(/^[⠋⠙⠹⠸⠼⠴⠦⠧⠇⠏\s]+Fetching available models\.\.\./g, "").trim();
-        if (!clean) continue;
-
-        const parts = clean.split(/\s{2,}/);
-        const id = parts[0]?.trim();
-        const name = parts[1]?.trim() || id;
-        if (!id || id.startsWith("#") || id.startsWith("Usage")) continue;
-
-        let provider = "google";
-        if (id.startsWith("claude-")) provider = "anthropic";
-        else if (id.startsWith("gpt-")) provider = "openai";
-
-        if (!providerMap.has(provider)) {
-          providerMap.set(provider, []);
-        }
-
-        providerMap.get(provider)!.push({
-          id,
-          name,
-          provider,
-          supportsThinking: id.includes("thinking") || id.includes("high") || id.includes("medium"),
-        });
-      }
-
-      const result: ProviderModels[] = [];
-      for (const [provider, models] of providerMap.entries()) {
-        result.push({
-          provider,
-          displayName: provider.charAt(0).toUpperCase() + provider.slice(1),
-          models,
-        });
-      }
-
-      return result;
+      return parseAntigravityModelsList(stdout);
     } catch {
       return [];
     }
diff --git a/tests/antigravity-driver.test.ts b/tests/antigravity-driver.test.ts
index a6c37ff..4642afc 100644
--- a/tests/antigravity-driver.test.ts
+++ b/tests/antigravity-driver.test.ts
@@ -1,5 +1,9 @@
 import { describe, it, expect } from "vitest";
-import { buildAntigravityArgs, AntigravityDriver } from "../src/drivers/antigravity/driver.js";
+import {
+  buildAntigravityArgs,
+  parseAntigravityModelsList,
+  AntigravityDriver,
+} from "../src/drivers/antigravity/driver.js";
 import { parseAntigravityLine } from "../src/drivers/antigravity/parser.js";
 import type { AgentEvent } from "../src/core/events.js";
 
@@ -10,14 +14,24 @@ describe("buildAntigravityArgs", () => {
   it("builds default headless flags with auto-permissions and prompt", () => {
     const args = buildAntigravityArgs(base);
     expect(args).toEqual([
-      "-p",
       "--output-format",
       "stream-json",
       "--dangerously-skip-permissions",
-      "do something",
+      "-p=do something",
     ]);
   });
 
+  it("attaches the prompt to -p so it cannot swallow the next flag", () => {
+    const args = buildAntigravityArgs(base);
+    expect(args).not.toContain("-p");
+    expect(args[args.length - 1]).toBe("-p=do something");
+  });
+
+  it("keeps a dash-leading prompt attached to -p", () => {
+    const args = buildAntigravityArgs({ ...base, prompt: "--help is a flag" });
+    expect(args).toContain("-p=--help is a flag");
+  });
+
   it("adds --conversation on resume", () => {
     const args = buildAntigravityArgs({ ...base, resumeSessionId: "conv-1234" });
     expect(args).toContain("--conversation");
@@ -220,6 +234,43 @@ describe("parseAntigravityLine", () => {
   });
 });
 
+describe("parseAntigravityModelsList", () => {
+  // Mirrors real `agy models` output: a banner line plus TAB-separated rows.
+  const stdout = [
+    "Fetching available models...",
+    "gemini-3.8-flash-high\tGemini 3.8 Flash (High)",
+    "claude-sonnet-4-6\tClaude Sonnet 4.6 (Thinking)",
+    "gpt-oss-120b-medium\tGPT-OSS 120B (Medium)",
+    "",
+  ].join("\n");
+
+  it("splits TAB-separated id and display name", () => {
+    const providers = parseAntigravityModelsList(stdout);
+    const ids = providers.flatMap((p) => p.models.map((m) => m.id));
+    expect(ids).toEqual(["gemini-3.8-flash-high", "claude-sonnet-4-6", "gpt-oss-120b-medium"]);
+    const names = providers.flatMap((p) => p.models.map((m) => m.name));
+    expect(names).toEqual([
+      "Gemini 3.8 Flash (High)",
+      "Claude Sonnet 4.6 (Thinking)",
+      "GPT-OSS 120B (Medium)",
+    ]);
+  });
+
+  it("drops the banner line instead of listing it as a model", () => {
+    const providers = parseAntigravityModelsList(stdout);
+    const ids = providers.flatMap((p) => p.models.map((m) => m.id));
+    expect(ids.every((id) => !/fetching/i.test(id))).toBe(true);
+  });
+
+  it("strips spinner-prefixed banner output", () => {
+    const providers = parseAntigravityModelsList(
+      "⠋ Fetching available models...\ngemini-3.8-flash-high\tGemini 3.8 Flash (High)\n",
+    );
+    const ids = providers.flatMap((p) => p.models.map((m) => m.id));
+    expect(ids).toEqual(["gemini-3.8-flash-high"]);
+  });
+});
+
 describe("AntigravityDriver", () => {
   it("declares expected capabilities", () => {
     const driver = new AntigravityDriver();