fix(cli): warn that fleet release does not tear down Cloud sandboxes

.agentworkforce/trajectories/issue-1922/compacted/compact_ridr6adoo0go_2026-10-15.json

@@ -0,0 +1,37 @@
+{
+  "id": "compact_ridr6adoo0go",
+  "version": 1,
+  "type": "compacted",
+  "compactedAt": "2026-10-15T19:57:17.694Z",
+  "sourceTrajectories": [
+    "traj_fesap23qytsg"
+  ],
+  "dateRange": {
+    "start": "2026-10-15T19:49:55.679Z",
+    "end": "2026-10-15T19:56:51.350Z"
+  },
+  "summary": {
+    "totalDecisions": 1,
+    "totalEvents": 2,
+    "uniqueAgents": [
+      "default"
+    ]
+  },
+  "decisionGroups": [
+    {
+      "category": "api",
+      "decisions": [
+        {
+          "question": "Warn once after a dispatched release acknowledgement, before optional identity cleanup",
+          "chosen": "Warn once after a dispatched release acknowledgement, before optional identity cleanup",
+          "reasoning": "The release endpoint acknowledges worker dispatch only. Emitting through the existing stderr warning sink preserves the single JSON stdout document and covers delete-agent variants without invoking Cloud/provider deletion.",
+          "fromTrajectory": "traj_fesap23qytsg"
+        }
+      ]
+    }
+  ],
+  "keyLearnings": [],
+  "keyFindings": [],
+  "filesAffected": [],
+  "commits": []
+}

.agentworkforce/trajectories/issue-1922/compacted/compact_ridr6adoo0go_2026-10-15.md

@@ -0,0 +1,18 @@
+# Trajectory Compaction: Oct 16, 2026 - Oct 16, 2026
+
+## Summary
+- Sessions: 1
+- Decisions: 1
+- Events: 2
+- Agents: default
+- Files: 0
+- Commits: 0
+
+## Api
+- Warn once after a dispatched release acknowledgement, before optional identity cleanup -> Warn once after a dispatched release acknowledgement, before optional identity cleanup (traj_fesap23qytsg)
+
+## Key Learnings
+- None
+
+## Key Findings
+- None

.agentworkforce/trajectories/issue-1922/completed/2026-10/traj_fesap23qytsg/compaction.json

@@ -0,0 +1,5 @@
+{
+  "trajectoryId": "traj_fesap23qytsg",
+  "compactedInto": "compact_ridr6adoo0go",
+  "compactedAt": "2026-10-15T19:57:17.709Z"
+}

.agentworkforce/trajectories/issue-1922/completed/2026-10/traj_fesap23qytsg/summary.md

@@ -0,0 +1,33 @@
+# Trajectory: Warn when fleet release leaves Cloud sandboxes running
+
+> **Status:** ✅ Completed
+> **Task:** 1922
+> **Confidence:** 90%
+> **Started:** October 16, 2026 at 01:19 AM
+> **Completed:** October 16, 2026 at 01:26 AM
+
+---
+
+## Summary
+
+Added the dispatched-release sandbox cost warning without changing JSON stdout or requesting provider teardown. Added seven regressions, one RelayFlow bugfix proof, and a patch changelog entry. Independent review found no actionable issues. Full Windows suite limitations are documented for maintainer validation.
+
+**Approach:** Standard approach
+
+---
+
+## Key Decisions
+
+### Warn once after a dispatched release acknowledgement, before optional identity cleanup
+- **Chose:** Warn once after a dispatched release acknowledgement, before optional identity cleanup
+- **Reasoning:** The release endpoint acknowledges worker dispatch only. Emitting through the existing stderr warning sink preserves the single JSON stdout document and covers delete-agent variants without invoking Cloud/provider deletion.
+
+---
+
+## Chapters
+
+### 1. Work
+*Agent: default*
+
+- Warn once after a dispatched release acknowledgement, before optional identity cleanup: Warn once after a dispatched release acknowledgement, before optional identity cleanup
+- The seven new regressions and all 18 release tests pass. Both proof observations match the expected bug/fixed behavior. Typecheck and formatting pass; full Windows validation has 342 failures and a worker OOM, and the fleet Unix-path mismatch is confirmed on unchanged main.

.agentworkforce/trajectories/issue-1922/completed/2026-10/traj_fesap23qytsg/trajectory.json

@@ -0,0 +1,69 @@
+{
+  "id": "traj_fesap23qytsg",
+  "version": 1,
+  "task": {
+    "title": "Warn when fleet release leaves Cloud sandboxes running",
+    "source": {
+      "system": "plain",
+      "id": "1922"
+    }
+  },
+  "status": "completed",
+  "startedAt": "2026-10-15T19:49:55.679Z",
+  "completedAt": "2026-10-15T19:56:51.350Z",
+  "agents": [
+    {
+      "name": "default",
+      "role": "lead",
+      "joinedAt": "2026-10-15T19:51:26.854Z"
+    }
+  ],
+  "chapters": [
+    {
+      "id": "chap_w5couri5corw",
+      "title": "Work",
+      "agentName": "default",
+      "startedAt": "2026-10-15T19:51:26.854Z",
+      "endedAt": "2026-10-15T19:56:51.350Z",
+      "events": [
+        {
+          "ts": 1792093886855,
+          "type": "decision",
+          "content": "Warn once after a dispatched release acknowledgement, before optional identity cleanup: Warn once after a dispatched release acknowledgement, before optional identity cleanup",
+          "raw": {
+            "question": "Warn once after a dispatched release acknowledgement, before optional identity cleanup",
+            "chosen": "Warn once after a dispatched release acknowledgement, before optional identity cleanup",
+            "alternatives": [],
+            "reasoning": "The release endpoint acknowledges worker dispatch only. Emitting through the existing stderr warning sink preserves the single JSON stdout document and covers delete-agent variants without invoking Cloud/provider deletion."
+          },
+          "significance": "high"
+        },
+        {
+          "ts": 1792094210071,
+          "type": "reflection",
+          "content": "The seven new regressions and all 18 release tests pass. Both proof observations match the expected bug/fixed behavior. Typecheck and formatting pass; full Windows validation has 342 failures and a worker OOM, and the fleet Unix-path mismatch is confirmed on unchanged main.",
+          "raw": {
+            "confidence": 0.9
+          },
+          "significance": "high",
+          "tags": [
+            "confidence:0.9"
+          ]
+        }
+      ]
+    }
+  ],
+  "retrospective": {
+    "summary": "Added the dispatched-release sandbox cost warning without changing JSON stdout or requesting provider teardown. Added seven regressions, one RelayFlow bugfix proof, and a patch changelog entry. Independent review found no actionable issues. Full Windows suite limitations are documented for maintainer validation.",
+    "approach": "Standard approach",
+    "confidence": 0.9
+  },
+  "commits": [],
+  "filesChanged": [],
+  "projectId": "AgentWorkforce/relay",
+  "tags": [],
+  "_trace": {
+    "startRef": "c1ffabbc4a933585ca2ddda729b22a34e3b2a3f2",
+    "endRef": "c1ffabbc4a933585ca2ddda729b22a34e3b2a3f2"
+  }
+}

CHANGELOG.md

@@ -5,7 +5,11 @@ All notable changes to Agent Relay will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
-## [Unreleased]
+## [Unreleased - Patch]
+
+### Fixed
+
+- `fleet release` warns that a dispatched worker release leaves Cloud/provider sandboxes running and may continue incurring cost, while preserving JSON output on stdout.
 
 ## [14.0.0] - 2026-10-13
 

packages/cli/src/cli/commands/fleet.test.ts

@@ -5356,6 +5356,85 @@ describe('fleet command support', () => {
     expect(createAgentRelay).not.toHaveBeenCalled();
   });
 
+  describe('fleet release sandbox warning', () => {
+    function fixture(status = 'dispatched') {
+      const stdout: string[] = [];
+      const stderr: string[] = [];
+      const receipt = { invocationId: 'inv_release', actionName: 'agent.release', status };
+      const release = vi.fn(async () => receipt);
+      const deleteSandbox = vi.fn();
+      const program = new Command();
+      program.exitOverride();
+      registerFleetCommands(program, {
+        sdk: {
+          createAgentRelay: vi.fn() as never,
+          createWorkspaceRelay: (() => ({
+            agents: {
+              get: async () => {
+                throw { status: 404 };
+              },
+              list: vi.fn(),
+            },
+          })) as never,
+          createWorkspace: vi.fn() as never,
+          log: (message: unknown) => stdout.push(String(message)),
+          error: (message: unknown) => stderr.push(String(message)),
+          exit: ((code: number) => {
+            throw new Error(`CLI exit ${code}`);
+          }) as never,
+        },
+        createFleetWorkspaceClient: (() => ({ agents: { release } })) as never,
+        deleteCloudFleetSandbox: deleteSandbox as never,
+        retireOwnedBindings: vi.fn(async () => undefined),
+        warn: (message: unknown) => stderr.push(String(message)),
+      });
+      return { program, stdout, stderr, receipt, release, deleteSandbox };
+    }
+
+    it.each([{ options: [] }, { options: ['--delete-agent'] }, { options: ['--delete-agent', '--wait'] }])(
+      'warns once for a dispatched release with options $options and preserves JSON stdout',
+      async ({ options }) => {
+        const { program, stdout, stderr, receipt, deleteSandbox } = fixture();
+        await program.parseAsync(['fleet', 'release', 'worker', '--workspace-key', 'rk_test', ...options], {
+          from: 'user',
+        });
+
+        expect(stdout).toHaveLength(1);
+        expect(JSON.parse(stdout[0]!)).toMatchObject(receipt);
+        expect(stderr).toHaveLength(1);
+        expect(stderr[0]).toContain('Release was dispatched');
+        expect(stderr[0]).toContain('Cloud/provider sandbox may keep running and incurring cost');
+        expect(stderr[0]).toContain('`fleet release` does not tear it down');
+        expect(deleteSandbox).not.toHaveBeenCalled();
+      }
+    );
+
+    it.each(['pending', 'completed', 'failed'])(
+      'does not claim dispatch for a %s release acknowledgement',
+      async (status) => {
+        const { program, stdout, stderr, receipt } = fixture(status);
+        await program.parseAsync(['fleet', 'release', 'worker', '--workspace-key', 'rk_test'], {
+          from: 'user',
+        });
+        expect(stdout).toHaveLength(1);
+        expect(JSON.parse(stdout[0]!)).toEqual(receipt);
+        expect(stderr).toEqual([]);
+      }
+    );
+
+    it('does not claim dispatch when release fails', async () => {
+      const { program, stdout, stderr, release } = fixture();
+      release.mockRejectedValueOnce(new Error('release unavailable'));
+      await expect(
+        program.parseAsync(['fleet', 'release', 'worker', '--workspace-key', 'rk_test'], {
+          from: 'user',
+        })
+      ).rejects.toThrow('CLI exit 1');
+      expect(stdout).toEqual([]);
+      expect(stderr).toEqual(['release unavailable']);
+    });
+  });
+
   it('fleet release delegates to the workspace lifecycle API with a default reason and actor', async () => {
     const release = vi.fn(async () => ({
       name: 'api-worker',

packages/cli/src/cli/commands/fleet.ts

@@ -1477,6 +1477,11 @@ export function registerFleetCommands(
         reason,
         deleteAgent: false,
       });
+      if (released.status === 'dispatched') {
+        deps.warn(
+          'Release was dispatched. If this worker is sandbox-backed, its Cloud/provider sandbox may keep running and incurring cost; `fleet release` does not tear it down.'
+        );
+      }
       if (options.unsubscribeBindings === true || deleteAgent) {
         try {
           // Helper progress (`Retired ...`, `Unsubscribed ...`) must not land

tests/relayflows/cases/1922-fleet-release-sandbox-warning/case.json

@@ -0,0 +1,21 @@
+{
+  "version": 1,
+  "id": "1922-fleet-release-sandbox-warning",
+  "kind": "bugfix",
+  "title": "Warn that fleet release does not tear down Cloud sandboxes",
+  "runner": {
+    "command": ["node", "tests/relayflows/cases/1922-fleet-release-sandbox-warning/run.mjs"]
+  },
+  "requirements": [],
+  "timeoutSeconds": 900,
+  "expected": {
+    "base": {
+      "outcome": "bug",
+      "signature": "fleet_release_missing_sandbox_warning"
+    },
+    "head": {
+      "outcome": "fixed",
+      "signature": "fleet_release_warns_sandbox_may_keep_running"
+    }
+  }
+}

tests/relayflows/cases/1922-fleet-release-sandbox-warning/probe.test.mts

@@ -0,0 +1,62 @@
+import fs from 'node:fs';
+
+import { Command } from 'commander';
+import { expect, test, vi } from 'vitest';
+
+// The runner copies this probe into <target>/.relay-pr-proof/.
+import { registerFleetCommands } from '../packages/cli/src/cli/commands/fleet.js';
+
+test('a dispatched fleet release keeps JSON stdout and reports sandbox costs on stderr', async () => {
+  const observationPath = process.env.RELAY_PR1922_OBSERVATION_PATH;
+  if (!observationPath) throw new Error('Missing RELAY_PR1922_OBSERVATION_PATH.');
+
+  const stdout: string[] = [];
+  const stderr: string[] = [];
+  const errors: string[] = [];
+  const receipt = {
+    invocationId: 'inv_release_proof',
+    actionName: 'agent.release',
+    status: 'dispatched',
+  };
+  const release = vi.fn(async () => receipt);
+  const deleteSandbox = vi.fn();
+  const program = new Command();
+  program.exitOverride();
+  // Exercise the production default log/warn sinks; only the remote lifecycle API is stubbed.
+  const log = vi.spyOn(console, 'log').mockImplementation((message) => stdout.push(String(message)));
+  const warn = vi.spyOn(console, 'warn').mockImplementation((message) => stderr.push(String(message)));
+  const error = vi.spyOn(console, 'error').mockImplementation((message) => errors.push(String(message)));
+
+  try {
+    registerFleetCommands(program, {
+      createFleetWorkspaceClient: (() => ({ agents: { release } })) as never,
+      deleteCloudFleetSandbox: deleteSandbox as never,
+    });
+    await program.parseAsync(['fleet', 'release', 'proof-worker', '--workspace-key', 'rk_proof'], {
+      from: 'user',
+    });
+
+    expect(errors).toEqual([]);
+    expect(stdout).toHaveLength(1);
+    expect(JSON.parse(stdout[0]!)).toEqual(receipt);
+    expect(release).toHaveBeenCalledExactlyOnceWith({
+      name: 'proof-worker',
+      reason: expect.stringMatching(/^fleet agent released \(actor: .+\)$/),
+      deleteAgent: false,
+    });
+    expect(deleteSandbox).not.toHaveBeenCalled();
+
+    const missingWarning = stderr.length === 0;
+    const hasWarning =
+      stderr.length === 1 &&
+      stderr[0]!.includes('Release was dispatched') &&
+      stderr[0]!.includes('Cloud/provider sandbox may keep running and incurring cost') &&
+      stderr[0]!.includes('`fleet release` does not tear it down');
+    expect(missingWarning || hasWarning, JSON.stringify(stderr)).toBe(true);
+    fs.writeFileSync(observationPath, JSON.stringify({ missingWarning, hasWarning }));
+  } finally {
+    log.mockRestore();
+    warn.mockRestore();
+    error.mockRestore();
+  }
+});