feat(ai-step): refresh github credential without a session

.github/actions/ai-step/README.md

@@ -294,3 +294,12 @@ make test-ai-step
 ```
 
 Runs the bats suite in `test/` against `src/resolve-config.sh`.
+
+### Refresh a GitHub MCP credential without a session
+
+Use `loft-sh/github-actions/.github/actions/ai-step/refresh@ai-step/v1` with
+`vault-id`, `github-app-id`, `github-app-installation-id`,
+`github-app-private-key`, and `github-app-repository`. The caller must supply
+Anthropic workload identity federation environment variables and an identity
+token. This renews the vault bearer once and starts no agent session. Failure
+fails the step without printing API error details.

.github/actions/ai-step/refresh/action.yml

@@ -0,0 +1,33 @@
+name: Refresh GitHub MCP credential
+description: Renew a repository-scoped GitHub App token in a managed-agent vault without starting a session.
+inputs:
+  vault-id:
+    description: Managed-agent vault ID.
+    required: true
+  github-app-id:
+    description: GitHub App ID.
+    required: true
+  github-app-installation-id:
+    description: GitHub App installation ID.
+    required: true
+  github-app-private-key:
+    description: GitHub App private key.
+    required: true
+  github-app-repository:
+    description: Single repository to scope the token to.
+    required: true
+runs:
+  using: composite
+  steps:
+    - name: Install Anthropic SDK
+      shell: bash
+      run: python3 -m pip install --quiet --disable-pip-version-check anthropic
+    - name: Refresh credential
+      shell: bash
+      env:
+        INPUT_VAULT_ID: ${{ inputs.vault-id }}
+        INPUT_GITHUB_APP_ID: ${{ inputs.github-app-id }}
+        INPUT_GITHUB_APP_INSTALLATION_ID: ${{ inputs.github-app-installation-id }}
+        INPUT_GITHUB_APP_PRIVATE_KEY: ${{ inputs.github-app-private-key }}
+        INPUT_GITHUB_APP_REPOSITORY: ${{ inputs.github-app-repository }}
+      run: python3 "$GITHUB_ACTION_PATH/../src/refresh_github.py"

.github/actions/ai-step/src/refresh_github.py

@@ -0,0 +1,30 @@
+# SPDX-License-Identifier: Apache-2.0
+"""Refresh the GitHub MCP bearer without creating an agent session."""
+import os
+import sys
+
+
+def main():
+    try:
+        from anthropic import Anthropic
+        from github_app import GitHubCredential
+
+        client = Anthropic(default_headers={"anthropic-beta": "managed-agents-2026-04-01"})
+        credential = GitHubCredential(
+            client, os.environ.get("INPUT_VAULT_ID", ""),
+            os.environ.get("INPUT_GITHUB_APP_ID", ""),
+            os.environ.get("INPUT_GITHUB_APP_INSTALLATION_ID", ""),
+            os.environ.get("INPUT_GITHUB_APP_PRIVATE_KEY", ""),
+            os.environ.get("INPUT_GITHUB_APP_REPOSITORY", ""),
+        )
+        credential.renew(force=True)
+    except Exception:
+        # SDK and API errors can contain credentials. Never print their details.
+        print("::error::GitHub MCP credential refresh failed", file=sys.stderr)
+        return 1
+    print("GitHub MCP credential refreshed")
+    return 0
+
+
+if __name__ == "__main__":
+    sys.exit(main())

.github/actions/ai-step/test/test_refresh_github.py

@@ -0,0 +1,30 @@
+import importlib.util
+import sys
+from pathlib import Path
+from types import SimpleNamespace
+from unittest.mock import Mock
+
+spec = importlib.util.spec_from_file_location("refresh_github", Path(__file__).parents[1] / "src/refresh_github.py")
+refresh = importlib.util.module_from_spec(spec)
+spec.loader.exec_module(refresh)
+
+
+def test_renews_once_without_creating_session(monkeypatch):
+    client = Mock()
+    credential = Mock()
+    factory = Mock(return_value=credential)
+    monkeypatch.setitem(sys.modules, "anthropic", SimpleNamespace(Anthropic=Mock(return_value=client)))
+    monkeypatch.setitem(sys.modules, "github_app", SimpleNamespace(GitHubCredential=factory))
+    for name, value in {"INPUT_VAULT_ID": "vault", "INPUT_GITHUB_APP_ID": "123", "INPUT_GITHUB_APP_INSTALLATION_ID": "456", "INPUT_GITHUB_APP_PRIVATE_KEY": "key", "INPUT_GITHUB_APP_REPOSITORY": "owner/repo"}.items():
+        monkeypatch.setenv(name, value)
+    assert refresh.main() == 0
+    factory.assert_called_once_with(client, "vault", "123", "456", "key", "owner/repo")
+    credential.renew.assert_called_once_with(force=True)
+    client.beta.sessions.create.assert_not_called()
+
+
+def test_failure_does_not_print_exception(monkeypatch, capsys):
+    monkeypatch.setitem(sys.modules, "anthropic", SimpleNamespace(Anthropic=Mock(side_effect=ValueError("secret"))))
+    monkeypatch.setitem(sys.modules, "github_app", SimpleNamespace(GitHubCredential=Mock()))
+    assert refresh.main() == 1
+    assert "secret" not in capsys.readouterr().err