feat(antigravity-cli): emit root rules as AGENTS.md instead of GEMINI.md

README.md

@@ -118,7 +118,7 @@ The tables below show whether each tool supports a given feature (✅ = supporte
 ### Deprecation notes
 
 - **Gemini CLI (`geminicli`)** — Google is retiring Gemini CLI on **June 18, 2026**, when it stops serving requests for Google AI Pro/Ultra and free Gemini Code Assist for individuals (Enterprise plans are unaffected). The successor is the **Antigravity CLI (`antigravity-cli`)**. `geminicli` is **not** removed from rulesync — Enterprise access continues and existing `GEMINI.md`/`.gemini/` repositories still rely on it — but new projects should prefer `antigravity-cli`. See the [Gemini CLI → Antigravity CLI migration guide](https://dyoshikawa.github.io/rulesync/guide/geminicli-to-antigravity-cli).
-- **Google Antigravity (`antigravity`)** — Antigravity 2.0 splits into two products with separate global config trees: the desktop **`antigravity-ide`** and the **`antigravity-cli`** (`agy`). The legacy `antigravity` target is now a **deprecated alias for `antigravity-ide`** that keeps its original `.agent/` (singular) paths for backward compatibility. Migrate to `antigravity-ide` (desktop IDE) or `antigravity-cli` (CLI). For project-scope rules, `antigravity-ide` emits the root rule as a plain cross-tool **`AGENTS.md`** at the project root (read by the IDE since v1.20.3, with `GEMINI.md` taking precedence on conflict) and non-root rules under `.agents/rules/`.
+- **Google Antigravity (`antigravity`)** — Antigravity 2.0 splits into two products with separate global config trees: the desktop **`antigravity-ide`** and the **`antigravity-cli`** (`agy`). The legacy `antigravity` target is now a **deprecated alias for `antigravity-ide`** that keeps its original `.agent/` (singular) paths for backward compatibility. Migrate to `antigravity-ide` (desktop IDE) or `antigravity-cli` (CLI). For project-scope rules, **both `antigravity-ide` and `antigravity-cli`** emit the root rule as a plain cross-tool **`AGENTS.md`** at the project root (the Gemini-lineage discovery order is `AGENTS.md`, `CONTEXT.md`, `GEMINI.md`; the IDE has read `AGENTS.md` since v1.20.3) and non-root rules under `.agents/rules/`.
 
 Some features accept per-feature options (e.g., Claude Code's `ignore` feature supports `fileMode: "local"` to write to `settings.local.json` instead of `settings.json`). See [Configuration > Per-feature options](https://dyoshikawa.github.io/rulesync/guide/configuration#per-feature-options) for details.
 

docs/guide/geminicli-to-antigravity-cli.md

@@ -31,7 +31,7 @@ transition.
 
 | Feature     | `geminicli`                            | `antigravity-cli`                                                                           |
 | ----------- | -------------------------------------- | ------------------------------------------------------------------------------------------- |
-| rules       | root `GEMINI.md` + `.gemini/memories/` | root `GEMINI.md` + `.agents/rules/`; global `~/.gemini/GEMINI.md`                           |
+| rules       | root `GEMINI.md` + `.gemini/memories/` | root `AGENTS.md` + `.agents/rules/`; global `~/.gemini/GEMINI.md`                           |
 | skills      | `.gemini/skills/`                      | `.agents/skills/`; global `~/.gemini/antigravity-cli/skills/`                               |
 | mcp         | `.gemini/settings.json` (`mcpServers`) | `.agents/mcp_config.json`; global `~/.gemini/config/mcp_config.json` (shared config dir)    |
 | hooks       | `.gemini/` (Gemini hook shape)         | `.agents/hooks.json`; global `~/.gemini/config/hooks.json` (Claude-Code-like matcher shape) |
@@ -41,6 +41,13 @@ transition.
 
 ### Notable differences
 
+- **Root rules file**: `antigravity-cli` emits the project root rule as the
+  cross-tool **`AGENTS.md`** (matching `antigravity-ide`), not `GEMINI.md`. The
+  CLI reads both, with the Gemini-lineage discovery order `AGENTS.md`,
+  `CONTEXT.md`, `GEMINI.md`. If you previously generated `antigravity-cli` output
+  and have a generated root `GEMINI.md`, rulesync no longer manages it — delete
+  the stale `GEMINI.md` manually after regenerating. Global scope is unchanged
+  (`~/.gemini/GEMINI.md`).
 - **MCP**: Antigravity uses `serverUrl` (not `url`) for HTTP servers and honors
   a `disabledTools` array. Rulesync emits the Antigravity-compatible shape
   automatically.

docs/reference/supported-tools.md

@@ -45,4 +45,4 @@ Rulesync supports both **generation** and **import** for All of the major AI cod
 ## Deprecation notes
 
 - **Gemini CLI (`geminicli`)** — Google is retiring Gemini CLI on **June 18, 2026**, when it stops serving requests for Google AI Pro/Ultra and free Gemini Code Assist for individuals (Enterprise plans are unaffected). The successor is the **Antigravity CLI (`antigravity-cli`)**. `geminicli` is **not** removed from rulesync — Enterprise access continues and existing `GEMINI.md`/`.gemini/` repositories still rely on it — but new projects should prefer `antigravity-cli`. See the [Gemini CLI → Antigravity CLI migration guide](../guide/geminicli-to-antigravity-cli.md).
-- **Google Antigravity (`antigravity`)** — Antigravity 2.0 splits into two products: the desktop **`antigravity-ide`** and the **`antigravity-cli`** (`agy`). The legacy `antigravity` target is now a **deprecated alias for `antigravity-ide`** that keeps its original `.agent/` (singular) paths for backward compatibility. Migrate to `antigravity-ide` (desktop IDE) or `antigravity-cli` (CLI). As of Antigravity 2.0 the IDE reads its global MCP config and skills from the shared `~/.gemini/config/` tree — `~/.gemini/config/mcp_config.json` and `~/.gemini/config/skills/`, matching the current [MCP](https://antigravity.google/docs/mcp) and [Skills](https://antigravity.google/docs/skills) docs. The `antigravity-cli` global MCP config also lives in the shared `~/.gemini/config/mcp_config.json`, while the CLI keeps its own global skills tree at `~/.gemini/antigravity-cli/skills/`. Both targets also intentionally **share** the global rule file `~/.gemini/GEMINI.md` and the global hooks file `~/.gemini/config/hooks.json` — enabling both targets in `--global` mode writes those shared files once. For project-scope rules, `antigravity-ide` emits the root rule as a plain cross-tool **`AGENTS.md`** at the project root (read by the Antigravity IDE since v1.20.3 in addition to `GEMINI.md`, which takes precedence on conflict) and non-root rules under `.agents/rules/` with trigger frontmatter.
+- **Google Antigravity (`antigravity`)** — Antigravity 2.0 splits into two products: the desktop **`antigravity-ide`** and the **`antigravity-cli`** (`agy`). The legacy `antigravity` target is now a **deprecated alias for `antigravity-ide`** that keeps its original `.agent/` (singular) paths for backward compatibility. Migrate to `antigravity-ide` (desktop IDE) or `antigravity-cli` (CLI). As of Antigravity 2.0 the IDE reads its global MCP config and skills from the shared `~/.gemini/config/` tree — `~/.gemini/config/mcp_config.json` and `~/.gemini/config/skills/`, matching the current [MCP](https://antigravity.google/docs/mcp) and [Skills](https://antigravity.google/docs/skills) docs. The `antigravity-cli` global MCP config also lives in the shared `~/.gemini/config/mcp_config.json`, while the CLI keeps its own global skills tree at `~/.gemini/antigravity-cli/skills/`. Both targets also intentionally **share** the global rule file `~/.gemini/GEMINI.md` and the global hooks file `~/.gemini/config/hooks.json` — enabling both targets in `--global` mode writes those shared files once. For project-scope rules, **both `antigravity-ide` and `antigravity-cli`** emit the root rule as a plain cross-tool **`AGENTS.md`** at the project root (the Gemini-lineage discovery order is `AGENTS.md`, `CONTEXT.md`, `GEMINI.md`; the IDE has read `AGENTS.md` since v1.20.3) and non-root rules under `.agents/rules/` (the IDE adds trigger frontmatter to non-root rules; the CLI keeps them as plain markdown).

skills/rulesync/geminicli-to-antigravity-cli.md

@@ -31,7 +31,7 @@ transition.
 
 | Feature     | `geminicli`                            | `antigravity-cli`                                                                           |
 | ----------- | -------------------------------------- | ------------------------------------------------------------------------------------------- |
-| rules       | root `GEMINI.md` + `.gemini/memories/` | root `GEMINI.md` + `.agents/rules/`; global `~/.gemini/GEMINI.md`                           |
+| rules       | root `GEMINI.md` + `.gemini/memories/` | root `AGENTS.md` + `.agents/rules/`; global `~/.gemini/GEMINI.md`                           |
 | skills      | `.gemini/skills/`                      | `.agents/skills/`; global `~/.gemini/antigravity-cli/skills/`                               |
 | mcp         | `.gemini/settings.json` (`mcpServers`) | `.agents/mcp_config.json`; global `~/.gemini/config/mcp_config.json` (shared config dir)    |
 | hooks       | `.gemini/` (Gemini hook shape)         | `.agents/hooks.json`; global `~/.gemini/config/hooks.json` (Claude-Code-like matcher shape) |
@@ -41,6 +41,13 @@ transition.
 
 ### Notable differences
 
+- **Root rules file**: `antigravity-cli` emits the project root rule as the
+  cross-tool **`AGENTS.md`** (matching `antigravity-ide`), not `GEMINI.md`. The
+  CLI reads both, with the Gemini-lineage discovery order `AGENTS.md`,
+  `CONTEXT.md`, `GEMINI.md`. If you previously generated `antigravity-cli` output
+  and have a generated root `GEMINI.md`, rulesync no longer manages it — delete
+  the stale `GEMINI.md` manually after regenerating. Global scope is unchanged
+  (`~/.gemini/GEMINI.md`).
 - **MCP**: Antigravity uses `serverUrl` (not `url`) for HTTP servers and honors
   a `disabledTools` array. Rulesync emits the Antigravity-compatible shape
   automatically.

skills/rulesync/supported-tools.md

@@ -45,4 +45,4 @@ Rulesync supports both **generation** and **import** for All of the major AI cod
 ## Deprecation notes
 
 - **Gemini CLI (`geminicli`)** — Google is retiring Gemini CLI on **June 18, 2026**, when it stops serving requests for Google AI Pro/Ultra and free Gemini Code Assist for individuals (Enterprise plans are unaffected). The successor is the **Antigravity CLI (`antigravity-cli`)**. `geminicli` is **not** removed from rulesync — Enterprise access continues and existing `GEMINI.md`/`.gemini/` repositories still rely on it — but new projects should prefer `antigravity-cli`. See the [Gemini CLI → Antigravity CLI migration guide](../guide/geminicli-to-antigravity-cli.md).
-- **Google Antigravity (`antigravity`)** — Antigravity 2.0 splits into two products: the desktop **`antigravity-ide`** and the **`antigravity-cli`** (`agy`). The legacy `antigravity` target is now a **deprecated alias for `antigravity-ide`** that keeps its original `.agent/` (singular) paths for backward compatibility. Migrate to `antigravity-ide` (desktop IDE) or `antigravity-cli` (CLI). As of Antigravity 2.0 the IDE reads its global MCP config and skills from the shared `~/.gemini/config/` tree — `~/.gemini/config/mcp_config.json` and `~/.gemini/config/skills/`, matching the current [MCP](https://antigravity.google/docs/mcp) and [Skills](https://antigravity.google/docs/skills) docs. The `antigravity-cli` global MCP config also lives in the shared `~/.gemini/config/mcp_config.json`, while the CLI keeps its own global skills tree at `~/.gemini/antigravity-cli/skills/`. Both targets also intentionally **share** the global rule file `~/.gemini/GEMINI.md` and the global hooks file `~/.gemini/config/hooks.json` — enabling both targets in `--global` mode writes those shared files once. For project-scope rules, `antigravity-ide` emits the root rule as a plain cross-tool **`AGENTS.md`** at the project root (read by the Antigravity IDE since v1.20.3 in addition to `GEMINI.md`, which takes precedence on conflict) and non-root rules under `.agents/rules/` with trigger frontmatter.
+- **Google Antigravity (`antigravity`)** — Antigravity 2.0 splits into two products: the desktop **`antigravity-ide`** and the **`antigravity-cli`** (`agy`). The legacy `antigravity` target is now a **deprecated alias for `antigravity-ide`** that keeps its original `.agent/` (singular) paths for backward compatibility. Migrate to `antigravity-ide` (desktop IDE) or `antigravity-cli` (CLI). As of Antigravity 2.0 the IDE reads its global MCP config and skills from the shared `~/.gemini/config/` tree — `~/.gemini/config/mcp_config.json` and `~/.gemini/config/skills/`, matching the current [MCP](https://antigravity.google/docs/mcp) and [Skills](https://antigravity.google/docs/skills) docs. The `antigravity-cli` global MCP config also lives in the shared `~/.gemini/config/mcp_config.json`, while the CLI keeps its own global skills tree at `~/.gemini/antigravity-cli/skills/`. Both targets also intentionally **share** the global rule file `~/.gemini/GEMINI.md` and the global hooks file `~/.gemini/config/hooks.json` — enabling both targets in `--global` mode writes those shared files once. For project-scope rules, **both `antigravity-ide` and `antigravity-cli`** emit the root rule as a plain cross-tool **`AGENTS.md`** at the project root (the Gemini-lineage discovery order is `AGENTS.md`, `CONTEXT.md`, `GEMINI.md`; the IDE has read `AGENTS.md` since v1.20.3) and non-root rules under `.agents/rules/` (the IDE adds trigger frontmatter to non-root rules; the CLI keeps them as plain markdown).

src/cli/commands/gitignore-entries.test.ts

@@ -128,7 +128,18 @@ describe("filterGitignoreEntries", () => {
       // non-root rules under .agents/rules/.
       expect(result).toContain("**/AGENTS.md");
       expect(result).toContain("**/.agents/rules/");
-      // The CLI-only GEMINI.md must NOT be included for the IDE target.
+      // GEMINI.md (a geminicli-only entry) must NOT be included for this target.
+      expect(result).not.toContain("**/GEMINI.md");
+    });
+
+    it("should include the root AGENTS.md and .agents/rules entries for antigravity-cli", () => {
+      const result = filterGitignoreEntries({ logger, targets: ["antigravity-cli"] });
+
+      // antigravity-cli now emits the project root rule as AGENTS.md (matching
+      // antigravity-ide), not GEMINI.md, plus non-root rules under .agents/rules/.
+      expect(result).toContain("**/AGENTS.md");
+      expect(result).toContain("**/.agents/rules/");
+      // The project root is no longer GEMINI.md (that is a geminicli-only entry).
       expect(result).not.toContain("**/GEMINI.md");
     });
 

src/cli/commands/gitignore-entries.ts

@@ -52,7 +52,7 @@ export const GITIGNORE_ENTRY_REGISTRY: ReadonlyArray<GitignoreEntryTag> = [
 
   // AGENTS.md
   {
-    target: ["agentsmd", "amp", "antigravity-ide", "pi", "vibe", "warp"],
+    target: ["agentsmd", "amp", "antigravity-cli", "antigravity-ide", "pi", "vibe", "warp"],
     feature: "rules",
     entry: "**/AGENTS.md",
   },
@@ -68,16 +68,15 @@ export const GITIGNORE_ENTRY_REGISTRY: ReadonlyArray<GitignoreEntryTag> = [
   { target: "amp", feature: "skills", entry: "**/.agents/skills/" },
 
   // Antigravity (IDE + CLI, Antigravity 2.0)
-  // Both targets share the `.agents/` project tree; the IDE additionally writes
-  // a root `AGENTS.md` (handled by the shared AGENTS.md entry above) and the CLI
-  // a root `GEMINI.md`. Global-scope paths (under the home directory) are
+  // Both targets share the `.agents/` project tree and both write a root
+  // `AGENTS.md` (handled by the shared AGENTS.md entry above). Global-scope
+  // paths (under the home directory, e.g. `~/.gemini/GEMINI.md`) are
   // intentionally not gitignored.
   {
     target: ["antigravity-ide", "antigravity-cli"],
     feature: "rules",
     entry: "**/.agents/rules/",
   },
-  { target: "antigravity-cli", feature: "rules", entry: "**/GEMINI.md" },
   { target: "antigravity-cli", feature: "ignore", entry: "**/.geminiignore" },
   {
     target: "antigravity-ide",

src/constants/antigravity-cli-paths.ts

@@ -15,4 +15,12 @@ export {
 
 export const ANTIGRAVITY_AGENTS_DIR = ANTIGRAVITY_DIR;
 
-export const ANTIGRAVITY_RULE_FILE_NAME = "GEMINI.md";
+// Project-root rules file. The CLI reads the cross-tool `AGENTS.md` standard at
+// the workspace root (Gemini-lineage discovery order is `AGENTS.md`,
+// `CONTEXT.md`, `GEMINI.md`), so rulesync emits `AGENTS.md` to align with the
+// standard and the `antigravity-ide` target.
+export const ANTIGRAVITY_RULE_FILE_NAME = "AGENTS.md";
+
+// Global (user-scope) rules file lives in `~/.gemini/` and stays `GEMINI.md`,
+// matching the `antigravity-ide` global file and the shared Gemini home config.
+export const ANTIGRAVITY_GLOBAL_RULE_FILE_NAME = "GEMINI.md";

src/e2e/e2e-rules.spec.ts

@@ -27,7 +27,7 @@ describe("E2E: rules", () => {
     { target: "copilot", outputPath: join(".github", "copilot-instructions.md") },
     { target: "opencode", outputPath: "AGENTS.md" },
     { target: "geminicli", outputPath: "GEMINI.md" },
-    { target: "antigravity-cli", outputPath: "GEMINI.md" },
+    { target: "antigravity-cli", outputPath: "AGENTS.md" },
     { target: "antigravity-ide", outputPath: "AGENTS.md" },
     { target: "goose", outputPath: ".goosehints" },
     { target: "copilotcli", outputPath: join(".github", "copilot-instructions.md") },
@@ -285,7 +285,7 @@ describe("E2E: rules (import)", () => {
     },
     {
       target: "antigravity-cli",
-      sourcePath: "GEMINI.md",
+      sourcePath: "AGENTS.md",
       importedFileName: "overview.md",
     },
     {

src/features/rules/antigravity-cli-rule.test.ts

@@ -35,11 +35,11 @@ describe("AntigravityCliRule", () => {
   });
 
   describe("getSettablePaths", () => {
-    it("should return root GEMINI.md and nonRoot .agents/rules for project scope", () => {
+    it("should return root AGENTS.md and nonRoot .agents/rules for project scope", () => {
       const paths = AntigravityCliRule.getSettablePaths();
 
       expect(paths.root.relativeDirPath).toBe(".");
-      expect(paths.root.relativeFilePath).toBe("GEMINI.md");
+      expect(paths.root.relativeFilePath).toBe("AGENTS.md");
       const nonRoot = (paths as { nonRoot: { relativeDirPath: string } }).nonRoot;
       expect(nonRoot.relativeDirPath).toBe(join(".agents", "rules"));
     });
@@ -53,7 +53,7 @@ describe("AntigravityCliRule", () => {
   });
 
   describe("fromRulesyncRule", () => {
-    it("should place a root rule in root GEMINI.md", () => {
+    it("should place a root rule in root AGENTS.md", () => {
       const rulesyncRule = new RulesyncRule({
         relativeDirPath: RULESYNC_RELATIVE_DIR_PATH,
         relativeFilePath: "overview.md",
@@ -69,7 +69,7 @@ describe("AntigravityCliRule", () => {
 
       expect(cliRule).toBeInstanceOf(AntigravityCliRule);
       expect(cliRule.getRelativeDirPath()).toBe(".");
-      expect(cliRule.getRelativeFilePath()).toBe("GEMINI.md");
+      expect(cliRule.getRelativeFilePath()).toBe("AGENTS.md");
       expect(cliRule.isRoot()).toBe(true);
       expect(cliRule.getFileContent().trim()).toBe("# Root Memory\n\nPlain body.");
     });

src/features/rules/antigravity-cli-rule.ts

@@ -3,6 +3,7 @@ import { join } from "node:path";
 import {
   ANTIGRAVITY_AGENTS_DIR,
   ANTIGRAVITY_GEMINI_DIR,
+  ANTIGRAVITY_GLOBAL_RULE_FILE_NAME,
   ANTIGRAVITY_RULE_FILE_NAME,
 } from "../../constants/antigravity-cli-paths.js";
 import { readFileContent } from "../../utils/file.js";
@@ -34,10 +35,11 @@ export type AntigravityCliRuleSettablePathsGlobal = ToolRuleSettablePathsGlobal;
  * successor in Antigravity 2.0).
  *
  * The CLI reads the same plain-markdown context files as Gemini CLI — a root
- * `GEMINI.md` plus non-root memory files in `.agents/rules/` — so this class
+ * context file plus non-root memory files in `.agents/rules/` — so this class
  * mirrors {@link GeminiCliRule} but points at the new `.agents/` tree.
  *
- * - Project scope: root `GEMINI.md`; non-root `.agents/rules/*.md`.
+ * - Project scope: root `AGENTS.md` (the cross-tool standard, matching
+ *   `antigravity-ide`); non-root `.agents/rules/*.md`.
  * - Global scope: a single plain `~/.gemini/GEMINI.md` (shared with the IDE).
  */
 export class AntigravityCliRule extends ToolRule {
@@ -52,7 +54,7 @@ export class AntigravityCliRule extends ToolRule {
       return {
         root: {
           relativeDirPath: buildToolPath(ANTIGRAVITY_GEMINI_DIR, ".", excludeToolDir),
-          relativeFilePath: ANTIGRAVITY_RULE_FILE_NAME,
+          relativeFilePath: ANTIGRAVITY_GLOBAL_RULE_FILE_NAME,
         },
       };
     }