diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 22948ee..820ca6d 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -93,6 +93,8 @@ jobs:
           pwsh -NoProfile -Command '$null = [scriptblock]::Create((Get-Content -Raw scripts/install.ps1))'
       - name: Verify release contracts
         run: |
+          python -m pip install --only-binary :all: PyYAML==6.0.2
+          python scripts/ci/test-release-cache-policy.py
           python scripts/ci/test-native-prerequisites.py
           node --test scripts/ci/test-release-workflow-metadata.js
           node --test scripts/ci/test-standalone-runtime.js
diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index 7ccbc57..963d375 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -466,12 +466,13 @@ jobs:
     steps:
       - uses: actions/checkout@d23441a48e516b6c34aea4fa41551a30e30af803  # v6
         with:
-          ref: ${{ needs.resolve-release.outputs.commit }}
+          ref: ${{ github.sha }}
+          persist-credentials: false
 
       - name: Checkout qualified phpmicro toolchain policy
         uses: actions/checkout@d23441a48e516b6c34aea4fa41551a30e30af803  # v6
         with:
-          ref: ${{ needs.resolve-release.outputs.control_commit }}
+          ref: ${{ github.sha }}
           path: release-toolchain-control
           persist-credentials: false
           sparse-checkout: |
@@ -552,7 +553,7 @@ jobs:
            (needs.resolve-release.outputs.cache_warm != 'true' &&
             ((github.event_name == 'push' && startsWith(github.ref, 'refs/tags/')) ||
              (github.event_name == 'workflow_dispatch' && github.ref == 'refs/heads/main'))))
-        uses: actions/cache@caa296126883cff596d87d8935842f9db880ef25  # v5
+        uses: actions/cache/restore@caa296126883cff596d87d8935842f9db880ef25  # v5
         with:
           path: build/.tools/native-prerequisite-cache/musl-${{ env.MUSL_VERSION }}.tar.gz
           key: native-prerequisite-${{ env.NATIVE_PREREQUISITE_CACHE_SCHEMA }}-musl-${{ env.MUSL_VERSION }}-${{ env.MUSL_SHA256 }}
@@ -622,6 +623,23 @@ jobs:
           )"
           echo "toolchain_id=$native_toolchain_id" >> "$GITHUB_OUTPUT"
 
+      - name: Save verified native prerequisites for trusted cache warm
+        if: >-
+          runner.os == 'Linux' &&
+          github.repository == 'durable-workflow/cli' &&
+          needs.resolve-release.outputs.cache_warm == 'true' &&
+          github.ref == 'refs/heads/main' &&
+          needs.resolve-release.outputs.commit == github.sha &&
+          needs.resolve-release.outputs.control_commit == github.sha &&
+          (github.event_name == 'push' ||
+           github.event_name == 'schedule' ||
+           github.event_name == 'workflow_dispatch') &&
+          steps.native-prerequisite-cache.outputs.cache-hit != 'true'
+        uses: actions/cache/save@caa296126883cff596d87d8935842f9db880ef25  # v5
+        with:
+          path: build/.tools/native-prerequisite-cache/musl-${{ env.MUSL_VERSION }}.tar.gz
+          key: native-prerequisite-${{ env.NATIVE_PREREQUISITE_CACHE_SCHEMA }}-musl-${{ env.MUSL_VERSION }}-${{ env.MUSL_SHA256 }}
+
       - name: Resolve exact phpmicro cache identity
         id: phpmicro-toolchain
         shell: bash
@@ -694,7 +712,7 @@ jobs:
            (needs.resolve-release.outputs.cache_warm != 'true' &&
             ((github.event_name == 'push' && startsWith(github.ref, 'refs/tags/')) ||
              (github.event_name == 'workflow_dispatch' && github.ref == 'refs/heads/main'))))
-        uses: actions/cache@caa296126883cff596d87d8935842f9db880ef25  # v5
+        uses: actions/cache/restore@caa296126883cff596d87d8935842f9db880ef25  # v5
         with:
           path: |
             build/.tools/buildroot/bin/micro.sfx
@@ -836,6 +854,24 @@ jobs:
           cat standalone-runtime-verification.json
           rm standalone-runtime-probe
 
+      - name: Save verified phpmicro for trusted cache warm
+        if: >-
+          github.repository == 'durable-workflow/cli' &&
+          needs.resolve-release.outputs.cache_warm == 'true' &&
+          github.ref == 'refs/heads/main' &&
+          needs.resolve-release.outputs.commit == github.sha &&
+          needs.resolve-release.outputs.control_commit == github.sha &&
+          (github.event_name == 'push' ||
+           github.event_name == 'schedule' ||
+           github.event_name == 'workflow_dispatch') &&
+          steps.phpmicro-cache.outputs.cache-hit != 'true'
+        uses: actions/cache/save@caa296126883cff596d87d8935842f9db880ef25  # v5
+        with:
+          path: |
+            build/.tools/buildroot/bin/micro.sfx
+            build/.tools/phpmicro-cache.manifest
+          key: phpmicro-${{ env.PHPMICRO_CACHE_SCHEMA }}-${{ steps.phpmicro-toolchain.outputs.toolchain_id }}
+
       - name: Record phpmicro toolchain timing
         if: always()
         working-directory: build/.tools
@@ -1048,12 +1084,13 @@ jobs:
     steps:
       - uses: actions/checkout@d23441a48e516b6c34aea4fa41551a30e30af803  # v6
         with:
-          ref: ${{ needs.resolve-release.outputs.commit }}
+          ref: ${{ github.sha }}
+          persist-credentials: false
 
       - name: Checkout qualified phpmicro toolchain policy
         uses: actions/checkout@d23441a48e516b6c34aea4fa41551a30e30af803  # v6
         with:
-          ref: ${{ needs.resolve-release.outputs.control_commit }}
+          ref: ${{ github.sha }}
           path: release-toolchain-control
           persist-credentials: false
           sparse-checkout: |
@@ -1239,7 +1276,7 @@ jobs:
            (needs.resolve-release.outputs.cache_warm != 'true' &&
             ((github.event_name == 'push' && startsWith(github.ref, 'refs/tags/')) ||
              (github.event_name == 'workflow_dispatch' && github.ref == 'refs/heads/main'))))
-        uses: actions/cache@caa296126883cff596d87d8935842f9db880ef25  # v5
+        uses: actions/cache/restore@caa296126883cff596d87d8935842f9db880ef25  # v5
         with:
           path: |
             build/.tools/buildroot/bin/micro.sfx
@@ -1423,6 +1460,24 @@ jobs:
           Get-Content -Raw standalone-runtime-verification.json
           Remove-Item -Force $runtimeProbe
 
+      - name: Save verified phpmicro for trusted cache warm
+        if: >-
+          github.repository == 'durable-workflow/cli' &&
+          needs.resolve-release.outputs.cache_warm == 'true' &&
+          github.ref == 'refs/heads/main' &&
+          needs.resolve-release.outputs.commit == github.sha &&
+          needs.resolve-release.outputs.control_commit == github.sha &&
+          (github.event_name == 'push' ||
+           github.event_name == 'schedule' ||
+           github.event_name == 'workflow_dispatch') &&
+          steps.phpmicro-cache.outputs.cache-hit != 'true'
+        uses: actions/cache/save@caa296126883cff596d87d8935842f9db880ef25  # v5
+        with:
+          path: |
+            build/.tools/buildroot/bin/micro.sfx
+            build/.tools/phpmicro-cache.manifest
+          key: phpmicro-${{ env.PHPMICRO_CACHE_SCHEMA }}-${{ steps.phpmicro-toolchain.outputs.toolchain_id }}
+
       - name: Record phpmicro toolchain timing
         if: always()
         shell: pwsh
diff --git a/scripts/ci/test-release-cache-policy.py b/scripts/ci/test-release-cache-policy.py
new file mode 100644
index 0000000..7235d1b
--- /dev/null
+++ b/scripts/ci/test-release-cache-policy.py
@@ -0,0 +1,188 @@
+#!/usr/bin/env python3
+
+import os
+from pathlib import Path
+import subprocess
+import tempfile
+import unittest
+
+import yaml
+
+
+ROOT = Path(__file__).resolve().parents[2]
+WORKFLOW = ROOT / ".github/workflows/release.yml"
+CACHE_REVISION = "caa296126883cff596d87d8935842f9db880ef25"
+MAIN = "a" * 40
+RELEASE = "b" * 40
+
+
+def compact(expression: str) -> str:
+    return " ".join(expression.split())
+
+
+class ReleaseCachePolicyTest(unittest.TestCase):
+    def setUp(self) -> None:
+        self.workflow = yaml.safe_load(WORKFLOW.read_text(encoding="utf-8"))
+
+    def native_jobs(self):
+        for name in ("build-binary", "build-binary-windows"):
+            yield self.workflow["jobs"][name]
+
+    def test_restores_have_no_automatic_save_post_action(self) -> None:
+        actions = [
+            step
+            for job in self.native_jobs()
+            for step in job["steps"]
+            if step.get("uses", "").startswith("actions/cache")
+        ]
+        self.assertEqual(6, len(actions))
+        self.assertEqual(
+            {f"actions/cache/{mode}@{CACHE_REVISION}" for mode in ("restore", "save")},
+            {step["uses"] for step in actions},
+        )
+        for job in self.native_jobs():
+            restores = {
+                step["id"]: step
+                for step in job["steps"]
+                if step.get("uses", "").startswith("actions/cache/restore@")
+            }
+            saves = [
+                step for step in job["steps"]
+                if step.get("uses", "").startswith("actions/cache/save@")
+            ]
+            self.assertEqual(len(restores), len(saves))
+            for save in saves:
+                cache = (
+                    "native-prerequisite-cache"
+                    if save["with"]["key"].startswith("native-prerequisite-")
+                    else "phpmicro-cache"
+                )
+                self.assertEqual(restores[cache]["with"], save["with"])
+                self.assertNotIn("restore-keys", save["with"])
+
+    def test_only_verified_default_branch_cache_warming_can_save(self) -> None:
+        saves = [
+            (job, index, step)
+            for job in self.native_jobs()
+            for index, step in enumerate(job["steps"])
+            if step.get("uses", "").startswith("actions/cache/save@")
+        ]
+        self.assertEqual(3, len(saves))
+        for job, index, step in saves:
+            native = step["with"]["key"].startswith("native-prerequisite-")
+            cache = "native-prerequisite-cache" if native else "phpmicro-cache"
+            expected = (
+                ("runner.os == 'Linux' && " if native else "")
+                + "github.repository == 'durable-workflow/cli' && "
+                + "needs.resolve-release.outputs.cache_warm == 'true' && "
+                + "github.ref == 'refs/heads/main' && "
+                + "needs.resolve-release.outputs.commit == github.sha && "
+                + "needs.resolve-release.outputs.control_commit == github.sha && "
+                + "(github.event_name == 'push' || "
+                + "github.event_name == 'schedule' || "
+                + "github.event_name == 'workflow_dispatch') && "
+                + f"steps.{cache}.outputs.cache-hit != 'true'"
+            )
+            self.assertEqual(expected, compact(step["if"]))
+            guard = "native-prerequisites" if native else "runtime-policy"
+            guard_index = next(
+                i for i, candidate in enumerate(job["steps"])
+                if candidate.get("id") == guard
+            )
+            self.assertGreater(index, guard_index)
+            self.assertNotIn("continue-on-error", job["steps"][guard_index])
+            self.assertNotIn("if", job["steps"][guard_index])
+
+    def test_cache_writing_jobs_only_check_out_the_trusted_event_commit(self) -> None:
+        for job in self.native_jobs():
+            checkouts = [
+                step for step in job["steps"]
+                if step.get("uses", "").startswith("actions/checkout@")
+            ]
+            self.assertEqual(2, len(checkouts))
+            for checkout in checkouts:
+                self.assertEqual("${{ github.sha }}", checkout["with"]["ref"])
+                self.assertIs(False, checkout["with"]["persist-credentials"])
+
+    def resolve(self, event, ref, operation="", commit="", tag=""):
+        step = next(
+            step
+            for step in self.workflow["jobs"]["resolve-release"]["steps"]
+            if step.get("id") == "resolve"
+        )
+        sha = RELEASE if ref.startswith("refs/tags/") else MAIN
+        with tempfile.TemporaryDirectory(prefix="cli-release-cache-") as directory:
+            output = Path(directory) / "outputs"
+            env = dict(os.environ)
+            env.update({
+                "GITHUB_EVENT_NAME": event,
+                "GITHUB_REF_NAME": ref.removeprefix("refs/heads/").removeprefix("refs/tags/"),
+                "GITHUB_OUTPUT": str(output),
+                "DISPATCH_OPERATION": operation,
+                "DISPATCH_TAG": tag,
+                "DISPATCH_COMMIT": commit,
+                "PUSH_COMMIT": sha,
+                "CONTROL_REF": ref,
+                "CONTROL_COMMIT": sha,
+            })
+            result = subprocess.run(
+                ["bash", "-euo", "pipefail", "-c", step["run"]],
+                cwd=ROOT,
+                env=env,
+                capture_output=True,
+                text=True,
+                timeout=10,
+            )
+            values = {
+                key: value
+                for key, _, value in (
+                    line.partition("=") for line in output.read_text().splitlines()
+                )
+            } if output.exists() else {}
+            return result, values, sha
+
+    def test_warm_events_use_the_same_protected_source_and_control(self) -> None:
+        for event, operation in (
+            ("push", ""),
+            ("schedule", ""),
+            ("workflow_dispatch", "phpmicro-cache-warm"),
+        ):
+            with self.subTest(event=event):
+                result, values, sha = self.resolve(
+                    event, "refs/heads/main", operation, RELEASE, "2.3.3"
+                )
+                self.assertEqual(0, result.returncode, result.stderr)
+                self.assertEqual("true", values["cache_warm"])
+                self.assertEqual("", values["tag"])
+                self.assertEqual(sha, values["commit"])
+                self.assertEqual(sha, values["control_commit"])
+                self.assertEqual("refs/heads/main", values["control_ref"])
+
+    def test_tag_and_manual_releases_never_select_cache_warming(self) -> None:
+        for event, ref, operation, commit, tag in (
+            ("push", "refs/tags/2.3.3", "", "", ""),
+            ("workflow_dispatch", "refs/heads/main", "release", RELEASE, "2.3.3"),
+        ):
+            with self.subTest(event=event):
+                result, values, _ = self.resolve(event, ref, operation, commit, tag)
+                self.assertEqual(0, result.returncode, result.stderr)
+                self.assertEqual("false", values["cache_warm"])
+                self.assertEqual(RELEASE, values["commit"])
+                self.assertEqual("2.3.3", values["tag"])
+
+    def test_untrusted_refs_and_incomplete_releases_are_rejected(self) -> None:
+        for event, ref, operation, commit, tag in (
+            ("schedule", "refs/heads/topic", "", "", ""),
+            ("workflow_dispatch", "refs/heads/topic", "phpmicro-cache-warm", "", ""),
+            ("workflow_dispatch", "refs/heads/topic", "release", RELEASE, "2.3.3"),
+            ("workflow_dispatch", "refs/heads/main", "release", RELEASE, ""),
+            ("workflow_dispatch", "refs/heads/main", "release", "short", "2.3.3"),
+        ):
+            with self.subTest(event=event, ref=ref, operation=operation, commit=commit):
+                result, values, _ = self.resolve(event, ref, operation, commit, tag)
+                self.assertNotEqual(0, result.returncode)
+                self.assertEqual({}, values)
+
+
+if __name__ == "__main__":
+    unittest.main()
diff --git a/tests/ReleaseInstallerContractTest.php b/tests/ReleaseInstallerContractTest.php
index 54d48bd..0fe2086 100644
--- a/tests/ReleaseInstallerContractTest.php
+++ b/tests/ReleaseInstallerContractTest.php
@@ -285,13 +285,13 @@ public function test_release_phpmicro_toolchain_is_pinned_verified_and_trust_sco
         self::assertStringNotContainsString('/nightly/', $releaseWorkflow);
         self::assertStringNotContainsString('git clone', $releaseWorkflow);
 
-        self::assertSame(3, substr_count($releaseWorkflow, "github.repository == 'durable-workflow/cli'"));
+        self::assertSame(6, substr_count($releaseWorkflow, "github.repository == 'durable-workflow/cli'"));
         self::assertSame(3, substr_count($releaseWorkflow, "github.event_name != 'pull_request'"));
         self::assertSame(3, substr_count(
             $releaseWorkflow,
             "(github.event_name == 'workflow_dispatch' && github.ref == 'refs/heads/main')",
         ));
-        self::assertSame(2, substr_count(
+        self::assertSame(4, substr_count(
             $releaseWorkflow,
             'key: phpmicro-${{ env.PHPMICRO_CACHE_SCHEMA }}-${{ steps.phpmicro-toolchain.outputs.toolchain_id }}',
         ));
@@ -320,12 +320,12 @@ public function test_release_phpmicro_toolchain_is_pinned_verified_and_trust_sco
         ] as $cacheInput) {
             self::assertGreaterThanOrEqual(2, substr_count($releaseWorkflow, $cacheInput), $cacheInput);
         }
-        self::assertSame(2, substr_count($releaseWorkflow, 'build/.tools/buildroot/bin/micro.sfx'));
+        self::assertSame(4, substr_count($releaseWorkflow, 'build/.tools/buildroot/bin/micro.sfx'));
         self::assertSame(2, substr_count(
             $releaseWorkflow,
             'Checkout qualified phpmicro toolchain policy',
         ));
-        self::assertSame(5, substr_count(
+        self::assertSame(3, substr_count(
             $releaseWorkflow,
             'ref: ${{ needs.resolve-release.outputs.control_commit }}',
         ));
@@ -404,7 +404,7 @@ public function test_release_checks_the_produced_runtime_before_combining_the_ap
             self::assertIsInt($guard);
             self::assertIsInt($combine);
             self::assertLessThan($combine, $guard);
-            $stepEnd = strpos($platform, '- name: Record phpmicro toolchain timing', $guard);
+            $stepEnd = strpos($platform, "\n      - ", $guard);
             self::assertIsInt($stepEnd);
             $step = substr($platform, $guard, $stepEnd - $guard);
             self::assertStringNotContainsString('if:', $step);
@@ -451,7 +451,7 @@ public function test_release_phpmicro_cache_has_a_non_publishing_default_branch_
             "needs.resolve-release.outputs.cache_warm != 'true' &&\n".
             "            ((github.event_name == 'push' && startsWith(github.ref, 'refs/tags/'))",
         ));
-        self::assertSame(2, substr_count(
+        self::assertSame(4, substr_count(
             $releaseWorkflow,
             'key: phpmicro-${{ env.PHPMICRO_CACHE_SCHEMA }}-${{ steps.phpmicro-toolchain.outputs.toolchain_id }}',
         ));
@@ -526,7 +526,7 @@ public function test_release_binds_the_exact_source_at_publication(): void
         self::assertStringContainsString('release-control/scripts/verify-public-release-assets.sh', $releaseWorkflow);
         self::assertStringContainsString('durable-workflow.cli.release-control-authority/v1', $releaseWorkflow);
         self::assertStringContainsString('"control": {"ref": "%s", "commit": "%s"}', $releaseWorkflow);
-        self::assertSame(5, substr_count($releaseWorkflow, 'ref: ${{ needs.resolve-release.outputs.commit }}'));
+        self::assertSame(3, substr_count($releaseWorkflow, 'ref: ${{ needs.resolve-release.outputs.commit }}'));
         self::assertStringNotContainsString('|| github.ref }}', $releaseWorkflow);
         self::assertStringContainsString('EXPECTED_COMMIT: ${{ needs.resolve-release.outputs.commit }}', $releaseWorkflow);
         self::assertSame(2, substr_count($releaseWorkflow, 'RELEASE_COMMIT: ${{ needs.resolve-release.outputs.commit }}'));
@@ -563,7 +563,7 @@ public function test_release_rejects_tag_movement_before_publication(): void
         self::assertTrue(chmod($fakeGh, 0755));
 
         self::assertStringContainsString('PUSH_COMMIT: ${{ github.sha }}', $releaseWorkflow);
-        self::assertSame(5, substr_count($releaseWorkflow, 'ref: ${{ needs.resolve-release.outputs.commit }}'));
+        self::assertSame(3, substr_count($releaseWorkflow, 'ref: ${{ needs.resolve-release.outputs.commit }}'));
         self::assertSame(2, substr_count($releaseWorkflow, 'RELEASE_COMMIT: ${{ needs.resolve-release.outputs.commit }}'));
 
         $environment = [