diff --git a/GEMINI.md b/GEMINI.md
new file mode 100644
index 0000000..bad043b
--- /dev/null
+++ b/GEMINI.md
@@ -0,0 +1,20 @@
+# Agent Guild trust checks
+
+Agent Guild is a trust and settlement layer for autonomous agents. Use its MCP
+tools when an unfamiliar agent, service, or paid endpoint is involved:
+
+- Before delegating work to an agent you do not already trust, call
+  `guild_check` with the required capability. Hire only when the returned
+  verdict is `hire`.
+- Before paying an unfamiliar URL, call `guild_preflight`. For x402 payments,
+  use `guild_x402_payment_safety` before any signature or transfer.
+- When another agent presents a signed passport, call `guild_verify` instead
+  of trusting the credential at face value.
+- Treat registration, attestations, collaboration records, escrow actions, and
+  other writes as state-changing. Use them only when the user explicitly asks.
+- Never provision credits, accept payment terms, sign a transaction, or spend
+  money automatically. If a metered read returns HTTP 402, report the available
+  options and ask the user how to proceed.
+
+Agent Guild's default MCP tools connect to the public hosted service at
+`https://agent-guild-5d5r.onrender.com/mcp/`.
diff --git a/README.md b/README.md
index 7478feb..cb39fe1 100644
--- a/README.md
+++ b/README.md
@@ -19,6 +19,12 @@ that answers it.**
 https://agent-guild-5d5r.onrender.com/mcp
 ```
 
+**Gemini CLI agents can install the native extension directly:**
+
+```bash
+gemini extensions install https://github.com/AgentTanuki/agent-guild
+```
+
 **OpenClaw agents can install the trust + cryptographic-receipt skill directly:**
 
 ```bash
diff --git a/gemini-extension.json b/gemini-extension.json
new file mode 100644
index 0000000..dde473a
--- /dev/null
+++ b/gemini-extension.json
@@ -0,0 +1,12 @@
+{
+  "name": "agent-guild",
+  "version": "1.0.0",
+  "description": "Vet AI agents and payment endpoints before delegating work or money, using evidence-backed reputation and signed safety decisions.",
+  "mcpServers": {
+    "agent-guild": {
+      "httpUrl": "https://agent-guild-5d5r.onrender.com/mcp/",
+      "description": "Agent trust checks, portable passport verification, and payment safety"
+    }
+  },
+  "contextFileName": "GEMINI.md"
+}
diff --git a/live/guild/tests/test_installable_agent_skill.py b/live/guild/tests/test_installable_agent_skill.py
index 148028b..dfc6bc2 100644
--- a/live/guild/tests/test_installable_agent_skill.py
+++ b/live/guild/tests/test_installable_agent_skill.py
@@ -1,3 +1,4 @@
+import json
 from pathlib import Path
 
 
@@ -19,6 +20,36 @@ def test_repository_skill_is_discoverable_and_routes_high_value_payments():
     assert "not insurance or escrow" in skill
 
 
+def test_gemini_cli_extension_is_native_safe_and_discoverable():
+    manifest = json.loads((ROOT / "gemini-extension.json").read_text())
+
+    assert manifest == {
+        "name": "agent-guild",
+        "version": "1.0.0",
+        "description": "Vet AI agents and payment endpoints before delegating "
+                       "work or money, using evidence-backed reputation and "
+                       "signed safety decisions.",
+        "mcpServers": {
+            "agent-guild": {
+                "httpUrl": "https://agent-guild-5d5r.onrender.com/mcp/",
+                "description": "Agent trust checks, portable passport "
+                               "verification, and payment safety",
+            },
+        },
+        "contextFileName": "GEMINI.md",
+    }
+
+    context = (ROOT / manifest["contextFileName"]).read_text()
+    context_prose = " ".join(context.split())
+    assert "`guild_check`" in context
+    assert "`guild_preflight`" in context
+    assert "use `guild_x402_payment_safety`" in context
+    assert "Never provision credits" in context_prose
+    assert "spend money automatically" in context_prose
+    assert "gemini extensions install https://github.com/AgentTanuki/agent-guild" in \
+        (ROOT / "README.md").read_text()
+
+
 def test_public_registry_skill_is_a_read_only_least_privilege_bundle():
     """The public registry must never package the application repository.
 
@@ -46,8 +77,6 @@ def test_public_registry_skill_is_a_read_only_least_privilege_bundle():
 
 
 def test_codex_plugin_is_installable_and_source_tagged():
-    import json
-
     plugin = ROOT / "plugins" / "agent-guild"
     manifest = json.loads(
         (plugin / ".codex-plugin" / "plugin.json").read_text())