gpt-5.6-sol consistently fails with: "timed out negotiating with code-mode host"

What version of Codex CLI is running?

0.147.0

What subscription do you have?

$20

Which model were you using?

gpt-5.6-sol

What platform is your computer?

macOS

What terminal emulator and version are you using (if applicable)?

VS Code remote

Codex doctor report

"schemaVersion": 1,
  "generatedAt": "1786839882s since unix epoch",
  "overallStatus": "warning",
  "codexVersion": "0.147.0",
  "checks": {
    "app_server.status": {
      "id": "app_server.status",
      "category": "app-server",
      "status": "ok",
      "summary": "background server is not running",
      "details": {
        "control socket": "/Volumes/ExternalSSD/home/.codex/app-server-control/app-server-control.sock",
        "daemon state dir": "/Volumes/ExternalSSD/home/.codex/app-server-daemon",
        "mode": "ephemeral",
        "pid file": "/Volumes/ExternalSSD/home/.codex/app-server-daemon/app-server.pid (missing)",
        "settings": "/Volumes/ExternalSSD/home/.codex/app-server-daemon/settings.json (missing)",
        "status": "not running",
        "update-loop pid file": "/Volumes/ExternalSSD/home/.codex/app-server-daemon/app-server-updater.pid (missing)"
      },
      "remediation": null,
      "durationMs": 0
    },
    "auth.credentials": {
      "id": "auth.credentials",
      "category": "auth",
      "status": "ok",
      "summary": "auth is configured",
      "details": {
        "auth file": "/Volumes/ExternalSSD/home/.codex/auth.json",
        "auth storage mode": "File",
        "stored API key": "false",
        "stored ChatGPT tokens": "true",
        "stored agent identity": "false",
        "stored auth mode": "chatgpt"
      },
      "remediation": null,
      "durationMs": 0
    },
    "config.load": {
      "id": "config.load",
      "category": "config",
      "status": "ok",
      "summary": "config loaded",
      "details": {
        "CODEX_HOME": "/Volumes/ExternalSSD/home/.codex",
        "config.toml": "/Volumes/ExternalSSD/home/.codex/config.toml",
        "config.toml parse": "ok",
        "cwd": "/Volumes/ExternalSSD/Developer/juke-app",
        "enabled feature flags": "shell_tool, view_image, unified_exec, shell_snapshot, code_mode, code_mode_host, terminal_resize_reflow, sqlite, hooks, enable_request_compression, multi_agent, apps, tool_search_always_defer_mcp_tools, tool_suggest, plugins, in_app_browser, in_app_updates, browser_use, browser_use_full_cdp_access, browser_use_external, computer_use, remote_plugin, plugin_sharing, image_generation, resize_all_images, item_ids, skill_mcp_dependency_install, skill_search, mentions_v2, steer, guardian_approval, goals, collaboration_modes, tool_call_mcp_elicitation, auth_elicitation, personality, fast_mode, tui_app_server, remote_compaction_v2, workspace_dependencies",
        "feature flag overrides": "code_mode=true",
        "feature flags enabled": "40",
        "log dir": "/Volumes/ExternalSSD/home/.codex/log",
        "mcp servers": "0",
        "model": "gpt-5.4-mini",
        "model provider": "openai",
        "sqlite home": "/Volumes/ExternalSSD/home/.codex"
      },
      "remediation": null,
      "durationMs": 0
    },
    "git.environment": {
      "id": "git.environment",
      "category": "git",
      "status": "ok",
      "summary": "git version 2.50.1 (Apple Git-155)",
      "details": {
        ".git entry": "directory",
        "PATH git #1": "/usr/bin/git",
        "PATH git entries": "1",
        "git branch": "codex/phase-28-reviewer-verification-foundation",
        "git build options": "git version 2.50.1 (Apple Git-155); cpu: arm64; no commit associated with this build; sizeof-long: 8; sizeof-size_t: 8; shell-path: /bin/sh; feature: fsmonitor--daemon; libcurl: 8.7.1; zlib: 1.2.12; SHA-1: SHA1_DC; SHA-256: SHA256_BLK",
        "git exec path": "/Library/Developer/CommandLineTools/usr/libexec/git-core",
        "git version": "git version 2.50.1 (Apple Git-155)",
        "repo detected": "true",
        "repo root": "/Volumes/ExternalSSD/Developer/juke-app",
        "selected git": "/usr/bin/git"
      },
      "remediation": null,
      "durationMs": 103
    },
    "installation": {
      "id": "installation",
      "category": "install",
      "status": "ok",
      "summary": "installation looks consistent",
      "details": {
        "PATH codex #1": "/opt/homebrew/bin/codex",
        "current executable": "/opt/homebrew/bin/codex",
        "install context": "brew (package /opt/homebrew/Caskroom/codex/0.147.0, bin /opt/homebrew/Caskroom/codex/0.147.0/bin, resources /opt/homebrew/Caskroom/codex/0.147.0/codex-resources, path /opt/homebrew/Caskroom/codex/0.147.0/codex-path)",
        "managed by bun": "false",
        "managed by npm": "false",
        "managed by pnpm": "false",
        "managed package root": "not set"
      },
      "remediation": null,
      "durationMs": 2
    },
    "mcp.config": {
      "id": "mcp.config",
      "category": "mcp",
      "status": "ok",
      "summary": "no MCP servers configured",
      "details": {},
      "remediation": null,
      "durationMs": 0
    },
    "network.env": {
      "id": "network.env",
      "category": "network",
      "status": "ok",
      "summary": "network-related environment looks readable",
      "details": {
        "proxy env vars": "none"
      },
      "remediation": null,
      "durationMs": 0
    },
    "network.provider_reachability": {
      "id": "network.provider_reachability",
      "category": "reachability",
      "status": "ok",
      "summary": "active provider endpoints are reachable over HTTP",
      "details": {
        "ChatGPT base URL": "https://chatgpt.com/backend-api/ reachable (HTTP 404)",
        "reachability mode": "ChatGPT auth"
      },
      "remediation": null,
      "durationMs": 272
    },
    "network.websocket_reachability": {
      "id": "network.websocket_reachability",
      "category": "websocket",
      "status": "ok",
      "summary": "Responses WebSocket handshake succeeded",
      "details": {
        "DNS": "2 IPv4, 2 IPv6, first IPv4",
        "auth mode": "chatgpt",
        "connect timeout": "15000 ms",
        "endpoint": "wss://chatgpt.com/backend-api/<redacted>",
        "handshake result": "HTTP 101 Switching Protocols",
        "model provider": "openai",
        "models etag present": "true",
        "provider name": "OpenAI",
        "proxy env vars": "none",
        "reasoning header": "false",
        "server model present": "false",
        "supports websockets": "true",
        "wire API": "responses"
      },
      "remediation": null,
      "durationMs": 1193
    },
    "runtime.provenance": {
      "id": "runtime.provenance",
      "category": "runtime",
      "status": "ok",
      "summary": "running brew on macos-aarch64",
      "details": {
        "commit": "unknown",
        "current executable": "/opt/homebrew/bin/codex",
        "install method": "brew (package /opt/homebrew/Caskroom/codex/0.147.0, bin /opt/homebrew/Caskroom/codex/0.147.0/bin, resources /opt/homebrew/Caskroom/codex/0.147.0/codex-resources, path /opt/homebrew/Caskroom/codex/0.147.0/codex-path)",
        "platform": "macos-aarch64",
        "version": "0.147.0"
      },
      "remediation": null,
      "durationMs": 0
    },
    "runtime.search": {
      "id": "runtime.search",
      "category": "search",
      "status": "ok",
      "summary": "search is OK (bundled)",
      "details": {
        "search command": "/opt/homebrew/Caskroom/codex/0.147.0/codex-path/rg",
        "search command readiness": "file exists",
        "search provider": "bundled"
      },
      "remediation": null,
      "durationMs": 0
    },
    "sandbox.helpers": {
      "id": "sandbox.helpers",
      "category": "sandbox",
      "status": "ok",
      "summary": "sandbox configuration is readable",
      "details": {
        "approval policy": "OnRequest",
        "codex-linux-sandbox helper": "none",
        "execve wrapper helper": "/Volumes/ExternalSSD/home/.codex/tmp/arg0/codex-arg0sdnzfV/codex-execve-wrapper",
        "filesystem sandbox": "restricted",
        "network sandbox": "restricted"
      },
      "remediation": null,
      "durationMs": 0
    },
    "state.paths": {
      "id": "state.paths",
      "category": "state",
      "status": "ok",
      "summary": "state paths and databases are inspectable",
      "details": {
        "CODEX_HOME": "/Volumes/ExternalSSD/home/.codex (dir)",
        "active rollout files": "7 files, 1051258 total bytes, 150179 average bytes",
        "archived rollout files": "0 files, 0 total bytes, 0 average bytes",
        "goals DB": "/Volumes/ExternalSSD/home/.codex/goals_1.sqlite (file)",
        "goals DB integrity": "ok",
        "log DB": "/Volumes/ExternalSSD/home/.codex/logs_2.sqlite (file)",
        "log DB integrity": "ok",
        "log dir": "/Volumes/ExternalSSD/home/.codex/log (missing)",
        "memories DB": "/Volumes/ExternalSSD/home/.codex/memories_1.sqlite (file)",
        "memories DB integrity": "ok",
        "queue DB": "/Volumes/ExternalSSD/home/.codex/queue_1.sqlite (file)",
        "queue DB integrity": "ok",
        "sqlite home": "/Volumes/ExternalSSD/home/.codex (dir)",
        "state DB": "/Volumes/ExternalSSD/home/.codex/state_5.sqlite (file)",
        "state DB integrity": "ok",
        "thread history DB": "/Volumes/ExternalSSD/home/.codex/thread_history_1.sqlite (file)",
        "thread history DB integrity": "ok"
      },
      "remediation": null,
      "durationMs": 113
    },
    "state.rollout_db_parity": {
      "id": "state.rollout_db_parity",
      "category": "threads",
      "status": "ok",
      "summary": "rollout files and state DB thread inventory agree",
      "details": {
        "default model provider": "openai",
        "rollout DB active files": "7",
        "rollout DB active rows": "7",
        "rollout DB archive mismatches": "0",
        "rollout DB archived files": "0",
        "rollout DB archived rows": "0",
        "rollout DB duplicate DB paths": "0",
        "rollout DB duplicate rollout thread ids": "0",
        "rollout DB malformed file names": "0",
        "rollout DB missing active rows": "0",
        "rollout DB missing archived rows": "0",
        "rollout DB model providers": "openai=7",
        "rollout DB rows": "7",
        "rollout DB scan cap reached": "false",
        "rollout DB scan errors": "0",
        "rollout DB sources": "cli=7",
        "rollout DB stale rows": "0"
      },
      "remediation": null,
      "durationMs": 103
    },
    "system.environment": {
      "id": "system.environment",
      "category": "system",
      "status": "ok",
      "summary": "OS language en-US",
      "details": {
        "EDITOR": "not set",
        "LANG": "C.UTF-8",
        "VISUAL": "not set",
        "os": "Mac OS 15.6.0 [64-bit]",
        "os language": "en-US",
        "os type": "Mac OS",
        "os version": "15.6.0"
      },
      "remediation": null,
      "durationMs": 4
    },
    "terminal.env": {
      "id": "terminal.env",
      "category": "terminal",
      "status": "warning",
      "summary": "width 76 cols - output may wrap (recommended >=80)",
      "details": {
        "COLORTERM": "truecolor",
        "SSH_CLIENT": "present",
        "SSH_CONNECTION": "present",
        "TERM_PROGRAM": "vscode",
        "VSCODE_INJECTION": "present",
        "VSCODE_IPC_HOOK_CLI": "present",
        "color output": "enabled",
        "effective locale": "C.UTF-8",
        "stderr is terminal": "true",
        "stdin is terminal": "true",
        "stdout is terminal": "true",
        "terminal": "VS Code",
        "terminal size": "76x30",
        "terminal version": "1.132.0"
      },
      "issues": [
        {
          "severity": "warning",
          "cause": "width 76 cols - output may wrap (recommended >=80)",
          "measured": "76 x 30",
          "expected": ">= 80 columns",
          "remedy": "resize the window to at least 80 columns",
          "fields": [
            "terminal size"
          ]
        }
      ],
      "remediation": null,
      "durationMs": 0
    },
    "terminal.title": {
      "id": "terminal.title",
      "category": "title",
      "status": "ok",
      "summary": "terminal title default",
      "details": {
        "terminal title activity": "true",
        "terminal title items": "activity, project-name",
        "terminal title project source": "git repo root",
        "terminal title project value": "juke-app",
        "terminal title source": "default"
      },
      "remediation": null,
      "durationMs": 0
    },
    "updates.status": {
      "id": "updates.status",
      "category": "updates",
      "status": "ok",
      "summary": "update configuration is locally consistent",
      "details": {
        "cached latest version": "0.147.0",
        "check for update on startup": "true",
        "last checked at": "2026-08-15T23:44:09.489879Z",
        "latest version": "0.147.0",
        "latest version status": "current version is not older",
        "update action": "brew upgrade --cask codex",
        "version cache": "/Volumes/ExternalSSD/home/.codex/version.json"
      },
      "remediation": null,
      "durationMs": 79
    }
  }
}

What issue are you seeing?

Title

gpt-5.6-sol tool calls time out negotiating with code-mode host; other
models work

Description

Shell/tool execution consistently fails when using gpt-5.6-sol in Codex
CLI. The same command succeeds immediately when using gpt-5.4-mini in an
otherwise identical session.

Environment

• Codex CLI: 0.147.0
• Installation: Homebrew cask
• Binary: native ARM64 Mach-O
• macOS: 15.6 (24G84)
• Hardware architecture: Apple Silicon (arm64)
• Terminal: Codex CLI inside a VS Code Remote SSH terminal
• Working directory: /Volumes/ExternalSSD/Developer/juke-app
• Node.js: 25.8.1
• npm: 11.11.0

Steps to reproduce

1. Launch a standard Codex CLI session.
2. Select gpt-5.4-mini.
3. Ask: Run pwd.
4. Observe that the command succeeds.
5. Switch the same session to gpt-5.6-sol.
6. Ask: Run pwd.
7. Observe that tool execution times out.

The failure also reproduces in fresh Sol sessions.

Actual behavior

Every Sol tool call fails before the shell command starts:

timed out negotiating with the code-mode host

The structured log records the failure under:

codex_core::tools::router
dispatch_tool_call_with_code_mode_result
dispatch_tool_call_with_terminal_outcome

Example thread ID:

01a007dc-4d28-7412-9f8-a137e55c6459

Expected behavior

gpt-5.6-sol should execute shell tools successfully, as gpt-5.4-mini does
in the same environment.

Troubleshooting performed

• Confirmed Codex 0.147.0 is the current Homebrew version.
• Confirmed the binary is native ARM64.
• Confirmed the filesystem is writable APFS.
• Confirmed the temporary directory has normal ownership and permissions.
• Confirmed there are no proxy-related environment variables.
• Confirmed code_mode_host is enabled.
• Explicitly enabled code_mode; Sol still failed.
• Launched Sol with --disable code_mode_host; it still failed.
• Reproduced across separate Codex processes and sessions.
• Confirmed another model can execute pwd successfully in the same
  environment.

Assessment

This appears to be a model-specific tool-routing or code-mode-host
compatibility issue involving gpt-5.6-sol, rather than a shell,
filesystem, installation, or machine configuration problem.

What steps can reproduce the bug?

Uploaded thread: 01a007dc-4d28-7412-9f8a-2d6eb0646604

What is the expected behavior?

No response

Additional information

No response

Start by reproducing the timeout with Codex CLI 0.147.0 on macOS using gpt-5.6-sol and the enabled code_mode and code_mode_host features. Compare the negotiation behavior with another model and use the reported doctor diagnostics to identify whether the failure is in the CLI or the model service; done means the model negotiates successfully or the failure has a confirmed, actionable cause.