diff --git a/CHANGELOG.md b/CHANGELOG.md
index 58699af..5c3e6ce 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -9,6 +9,13 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Added
 
+- **Antigravity CLI (`agy`) as the gemini replacement orchestrator (#61)** — the packaged
+  example roster documents an `antigravity` sub entry (`agy -p {prompt}`, `parse: plain`;
+  verified live on agy 1.0.10: bare response on stdout, ~5s, rides the old CLI's `~/.gemini`
+  OAuth), restoring the third orchestrator slot the 2026-06-18 gemini sunset emptied. No
+  delegate injection yet — agy exposes no per-invocation MCP flags; #81 tracks wiring the
+  local-delegate tool when it does. The live suite exercises the entry when `agy` is installed.
+
 - **Serve-origin marker + parent-task attribution (#74)** — usage records now carry an
   `origin` field (`cli` | `gui` | `serve`) so serve-mode traffic is distinguishable from CLI and
   panel runs, and `tanglebrain --stats` shows the per-origin split (records predating the field
diff --git a/README.md b/README.md
index ce015d8..c54cd6a 100644
--- a/README.md
+++ b/README.md
@@ -80,7 +80,7 @@ posture.
 | Tier | Example | Default |
 |---|---|---|
 | **Free local** | a local model via Ollama / any OpenAI-compatible server you run | **active** |
-| **Subscription / authenticated CLI** | command-line tools you've installed and logged in (e.g. `claude -p`, `codex exec`, `gemini -p`) | opt-in (commented) |
+| **Subscription / authenticated CLI** | command-line tools you've installed and logged in (e.g. `claude -p`, `codex exec`, `agy -p`) | opt-in (commented) |
 | **Paid API** | bring-your-own-key overflow (any OpenAI-compatible endpoint you hold a key for) | opt-in, off by default |
 
 > **Opt-in adapters & your responsibility.** The subscription / authenticated-CLI tier and the
@@ -322,9 +322,9 @@ Register it with an orchestrator CLI (exact flags vary by CLI version — check
 ```sh
 # Claude Code:
 claude mcp add tanglebrain-delegate -- tanglebrain-delegate
-# Gemini CLI:
-gemini mcp add tanglebrain-delegate tanglebrain-delegate
 # Codex: add a stdio MCP server entry pointing at `tanglebrain-delegate` in its MCP config.
+# Antigravity CLI (`agy`, the gemini CLI's successor): no per-invocation MCP flags as of
+# 1.0.10 — antigravity orchestrates without the delegate for now (TangleBrain #81).
 ```
 
 Claude Code users can instead install it as a **plugin** — this repo is its own plugin marketplace
diff --git a/tanglebrain/cli.py b/tanglebrain/cli.py
index b3dd0f1..23e2a1f 100644
--- a/tanglebrain/cli.py
+++ b/tanglebrain/cli.py
@@ -10,7 +10,7 @@
     tanglebrain "Refactor this module and add tests."        # default: frontier-first router
     tanglebrain --task code "..."                            # task-fit hint for the router
     tanglebrain --local "Write a haiku about local inference."   # force the free local tier
-    tanglebrain --model gemini "Summarize this long document."   # pin a specific roster entry
+    tanglebrain --model antigravity "Summarize this long document."   # pin a specific roster entry
 """
 from __future__ import annotations
 
diff --git a/tanglebrain/config/roster.yaml b/tanglebrain/config/roster.yaml
index 2a02c41..74f4141 100644
--- a/tanglebrain/config/roster.yaml
+++ b/tanglebrain/config/roster.yaml
@@ -60,7 +60,7 @@
 
 # --- OPT-IN subscription / authenticated-CLI tier — COMMENTED OUT so it stays inert. ---
 # These entries drive authenticated CLIs you already have installed and logged in (Claude Code /
-# Codex / Gemini). They are OPT-IN: uncomment only the ones you use. Driving these CLIs is YOUR
+# Codex / Antigravity). They are OPT-IN: uncomment only the ones you use. Driving these CLIs is YOUR
 # responsibility under each provider's terms of service — see DISCLAIMER.md. Once uncommented, an
 # entry flagged `can_orchestrate: true` joins the orchestrator rotation (rotation + failover for
 # resilience). Adapt the `cmd`/`parse`/`delegate_args` to your installed CLI's flags.
@@ -94,17 +94,20 @@
 #   good_at: [code, agentic-code]
 #   can_orchestrate: true
 #
-# - id: gemini
+# - id: antigravity
 #   tier: sub
 #   invoke:
 #     kind: cli
-#     # -p requires the prompt as its value, so {prompt} marks the injection point.
-#     cmd: ["gemini", "-p", "{prompt}", "--output-format", "json"]
-#     parse: gemini-json
-#     # gemini has no per-invocation MCP-server config — it needs a one-time
-#     #   gemini mcp add tanglebrain-delegate -- <python> -m tanglebrain.mcp_server
-#     # (see README); these per-invocation flags then allow + auto-approve the tool.
-#     delegate_args: ["--allowed-mcp-server-names", "tanglebrain-delegate", "--approval-mode", "yolo"]
+#     # Antigravity CLI (`agy`) — Google's successor to the sunset `gemini` CLI (individuals,
+#     # 2026-06-18). `-p/--print` runs one prompt non-interactively and prints the bare response
+#     # to stdout, so parse is `plain`. Rides the same ~/.gemini OAuth as the old CLI.
+#     cmd: ["agy", "-p", "{prompt}"]
+#     parse: plain
+#     # No delegate_args: agy (verified 1.0.10 and 1.0.16) exposes no per-invocation MCP-server
+#     # flags, so this orchestrator answers directly instead of offloading to the local delegate
+#     # (#81 tracks wiring delegation when agy grows per-call MCP config). No scrub_env either —
+#     # unlike the old gemini CLI, agy reads no GEMINI_API_KEY/GOOGLE_API_KEY (verified against
+#     # the binary), so there is no API-key path to divert billing through; OAuth is the only auth.
 #   cost: subscription
 #   good_at: [long-context, structured-json]
 #   can_orchestrate: true
diff --git a/tanglebrain/delegate.py b/tanglebrain/delegate.py
index df78d8f..7581a19 100644
--- a/tanglebrain/delegate.py
+++ b/tanglebrain/delegate.py
@@ -1,6 +1,6 @@
 """Delegation logic — the sub-task offload behind the MCP tools.
 
-A frontier orchestrator (e.g. claude / codex / gemini) decomposes a task and hands sub-tasks to a
+A frontier orchestrator (e.g. claude / codex / antigravity) decomposes a task and hands sub-tasks to a
 **configured** backend, then reviews the result. The default target is TangleBrain's **free local
 tier** at $0 marginal cost (:func:`run_local_delegate` / ``target=None``); the orchestrator may also
 target any roster entry flagged ``can_delegate`` (:func:`run_delegate`) — a cheaper sub or a
diff --git a/tanglebrain/mcp_server.py b/tanglebrain/mcp_server.py
index 47f8c55..8c5d74a 100644
--- a/tanglebrain/mcp_server.py
+++ b/tanglebrain/mcp_server.py
@@ -1,6 +1,6 @@
 """MCP server exposing TangleBrain's delegate tools to an orchestrator.
 
-A stdio MCP server an orchestrator (e.g. claude / codex / gemini) registers so it can offload
+A stdio MCP server an orchestrator (e.g. claude / codex / antigravity) registers so it can offload
 sub-tasks to a configured backend mid-task — the mechanism that makes frontier-first decompose
 actually offload work rather than running everything on the orchestrator itself. It exposes four
 tools: ``delegate_local`` (free local default), ``delegate`` (route to a configured ``can_delegate``
diff --git a/tests/test_live.py b/tests/test_live.py
index 4c3ea25..9969659 100644
--- a/tests/test_live.py
+++ b/tests/test_live.py
@@ -208,11 +208,15 @@ def test_claude_returns_text(self):
     def test_codex_returns_text(self):
         self._route("codex")
 
-    def test_gemini_returns_text(self):
-        # The `gemini` CLI sunset for individuals on 2026-06-18 (migrated to Antigravity); it now exits
-        # non-zero with an IneligibleTierError, so this can no longer pass. The roster entry is disabled
-        # (can_orchestrate: false) and a replacement is tracked in #61 — skip until then.
-        self.skipTest("gemini CLI sunset 2026-06-18 (migrated to Antigravity); see issue #61")
+    def test_antigravity_returns_text(self):
+        # Antigravity (`agy`) replaced the sunset `gemini` CLI as the third orchestrator (#61).
+        # The roster id ("antigravity") differs from the binary ("agy"), so this can't use
+        # _route()'s which(model) guard directly.
+        if shutil.which("agy") is None:
+            self.skipTest("agy (Antigravity CLI) not installed/logged in")
+        text = run_once("Reply with exactly: PONG", model="antigravity")
+        self.assertIsInstance(text, str)
+        self.assertTrue(text.strip(), "expected non-empty text from antigravity")
 
 
 @unittest.skipUnless(LIVE, "set TANGLEBRAIN_LIVE=1 to run the live router test")
diff --git a/tests/test_roster.py b/tests/test_roster.py
index 723f96b..d0e3a78 100644
--- a/tests/test_roster.py
+++ b/tests/test_roster.py
@@ -30,7 +30,7 @@ class PackagedRosterTest(unittest.TestCase):
     """The GENERIC example roster shipped with the package parses correctly.
 
     R2a (public-OSS rollout): the bundled default ships exactly ONE active entry — the free local
-    tier — and no orchestrators. The opt-in subscription/authenticated-CLI tier (claude/codex/gemini)
+    tier — and no orchestrators. The opt-in subscription/authenticated-CLI tier (claude/codex/antigravity)
     and the paid-API tier ship as COMMENTED examples, so a fresh clone routes to local out of the box
     and an operator opts in by uncommenting. Pinned to ``packaged_roster_path()`` so it tests the
     bundled example regardless of any operator roster the dev machine may have at
@@ -70,7 +70,8 @@ def test_opt_in_tiers_present_as_commented_examples(self):
         # The subscription-CLI and paid-API tiers ship as commented opt-in examples, not active
         # entries — uncommenting one (and its tier-specific gate) is how an operator enables it.
         raw = packaged_roster_path().read_text()
-        for marker in ("# - id: claude", "# - id: codex", "# - id: gemini", "# - id: paid-overflow"):
+        # antigravity replaced gemini as the third CLI example when the gemini CLI sunset (#61).
+        for marker in ("# - id: claude", "# - id: codex", "# - id: antigravity", "# - id: paid-overflow"):
             self.assertIn(marker, raw, f"{marker!r} should ship as a commented opt-in example")