From f68d2f5ee5e5dd4ddef60e5624e8d3a459fe891b Mon Sep 17 00:00:00 2001 From: Matt Van Horn <455140+mvanhorn@users.noreply.github.com> Date: Wed, 2 Sep 2026 20:14:33 +0700 Subject: [PATCH] fix(antigravity): preserve client identity on model catalog requests Restrict the legacy IDE-version override to generation endpoints so catalog and other passthrough requests keep their original User-Agent and metadata.ideVersion, letting newer Antigravity releases see current models like Gemini 3.7 Flash in the MITM selector. Fixes #3414 --- src/mitm/antigravityIdeVersion.js | 12 +-- src/mitm/server.js | 2 +- tests/unit/antigravity-ide-version.test.js | 89 ++++++++++++++++++++++ 3 files changed, 97 insertions(+), 6 deletions(-) create mode 100644 tests/unit/antigravity-ide-version.test.js diff --git a/src/mitm/antigravityIdeVersion.js b/src/mitm/antigravityIdeVersion.js index 1b9458d8..e5fe3113 100644 --- a/src/mitm/antigravityIdeVersion.js +++ b/src/mitm/antigravityIdeVersion.js @@ -1,8 +1,8 @@ "use strict"; -// Rewrite Antigravity IDE markers so upstream AG 2.x backend accepts the request. -// User-Agent header (antigravity/) and body.metadata.ideVersion are forced -// to a known-good IDE version. Hardcoded MVP — toggle/version configurable later. +// Rewrite Antigravity IDE markers on generation requests so upstream AG 2.x +// backend accepts them. Catalog and other passthrough requests retain the +// client's current identity. Hardcoded MVP — toggle/version configurable later. const ANTIGRAVITY_IDE_VERSION = "1.23.2"; const ANTIGRAVITY_IDE_VERSION_OVERRIDE_ENABLED = true; @@ -19,8 +19,10 @@ function rewriteAntigravityUserAgent(userAgent, version) { return userAgent.replace(/antigravity\/[^\s]+/, `antigravity/${version}`); } -function applyAntigravityIdeVersionOverride(bodyBuffer, headers) { - if (!ANTIGRAVITY_IDE_VERSION_OVERRIDE_ENABLED) { +function applyAntigravityIdeVersionOverride(bodyBuffer, headers, requestUrl) { + const isGenerationEndpoint = requestUrl?.includes(":generateContent") || + requestUrl?.includes(":streamGenerateContent"); + if (!ANTIGRAVITY_IDE_VERSION_OVERRIDE_ENABLED || !isGenerationEndpoint) { return { bodyBuffer, headers, applied: false, version: ANTIGRAVITY_IDE_VERSION }; } diff --git a/src/mitm/server.js b/src/mitm/server.js index 550d1ba0..e9be1a47 100644 --- a/src/mitm/server.js +++ b/src/mitm/server.js @@ -132,7 +132,7 @@ async function passthrough(req, res, bodyBuffer, onResponse) { const tool = getToolForHost(req.headers.host); const versionOverride = tool === "antigravity" - ? applyAntigravityIdeVersionOverride(bodyBuffer, req.headers) + ? applyAntigravityIdeVersionOverride(bodyBuffer, req.headers, req.url) : { bodyBuffer, headers: req.headers }; const bodyForForwarding = versionOverride.bodyBuffer; const headersForForwarding = { ...versionOverride.headers, host: targetHost }; diff --git a/tests/unit/antigravity-ide-version.test.js b/tests/unit/antigravity-ide-version.test.js new file mode 100644 index 00000000..7a71869f --- /dev/null +++ b/tests/unit/antigravity-ide-version.test.js @@ -0,0 +1,89 @@ +import { createRequire } from "module"; +import { describe, expect, it } from "vitest"; + +const require = createRequire(import.meta.url); +const { + ANTIGRAVITY_IDE_VERSION, + applyAntigravityIdeVersionOverride, +} = require("../../src/mitm/antigravityIdeVersion.js"); + +const CURRENT_VERSION = "2.11.0"; + +function makeRequest(metadata = { ideName: "antigravity", ideVersion: CURRENT_VERSION }) { + const bodyBuffer = Buffer.from(JSON.stringify({ metadata, request: { contents: [] } })); + const headers = { + "content-type": "application/json", + "content-length": String(bodyBuffer.length), + "user-agent": `antigravity/${CURRENT_VERSION}`, + }; + return { bodyBuffer, headers }; +} + +describe("Antigravity IDE version override", () => { + it("preserves catalog request identity and bytes", () => { + const { bodyBuffer, headers } = makeRequest(); + + const result = applyAntigravityIdeVersionOverride( + bodyBuffer, + headers, + "/v1internal:fetchAvailableModels" + ); + + expect(result.applied).toBe(false); + expect(result.bodyBuffer).toBe(bodyBuffer); + expect(result.headers).toBe(headers); + expect(result.headers["user-agent"]).toBe(`antigravity/${CURRENT_VERSION}`); + expect(JSON.parse(result.bodyBuffer.toString()).metadata.ideVersion).toBe(CURRENT_VERSION); + expect(result.headers["content-length"]).toBe(String(bodyBuffer.length)); + }); + + it.each([":generateContent", ":streamGenerateContent"])( + "rewrites identity for %s requests", + (endpoint) => { + const { bodyBuffer, headers } = makeRequest(); + + const result = applyAntigravityIdeVersionOverride( + bodyBuffer, + headers, + `/v1internal/models/gemini-3.7-flash-tiered${endpoint}` + ); + + expect(result.applied).toBe(true); + expect(result.bodyBuffer).not.toBe(bodyBuffer); + expect(result.headers["user-agent"]).toBe(`antigravity/${ANTIGRAVITY_IDE_VERSION}`); + expect(JSON.parse(result.bodyBuffer.toString()).metadata.ideVersion).toBe(ANTIGRAVITY_IDE_VERSION); + } + ); + + it("preserves malformed non-generation request content byte-for-byte", () => { + const bodyBuffer = Buffer.from([0xff, 0x00, 0x7b, 0x6e, 0x6f, 0x74, 0x2d, 0x6a, 0x73, 0x6f, 0x6e]); + const headers = { + "content-type": "application/octet-stream", + "content-length": String(bodyBuffer.length), + "user-agent": `antigravity/${CURRENT_VERSION}`, + }; + + const result = applyAntigravityIdeVersionOverride(bodyBuffer, headers, "/v1internal:loadCodeAssist"); + + expect(result.applied).toBe(false); + expect(result.bodyBuffer).toBe(bodyBuffer); + expect(result.headers).toBe(headers); + }); + + it("does not synthesize missing Antigravity identity", () => { + const bodyBuffer = Buffer.from(JSON.stringify({ metadata: {}, request: { contents: [] } })); + const headers = { "content-type": "application/json", "content-length": String(bodyBuffer.length) }; + + const result = applyAntigravityIdeVersionOverride( + bodyBuffer, + headers, + "/v1internal/models/gemini-3.7-flash-tiered:generateContent" + ); + + expect(result.applied).toBe(false); + expect(result.bodyBuffer).toBe(bodyBuffer); + expect(result.headers).toEqual(headers); + expect(result.headers).not.toHaveProperty("user-agent"); + expect(JSON.parse(result.bodyBuffer.toString()).metadata).not.toHaveProperty("ideVersion"); + }); +});