docs: add example config.toml (#5175)

I was missing an example config.toml, and following docs/config.md alone
was slower. I had GPT-5 scan the codebase for every accepted config key,
check the defaults, and generate a single example config.toml with
annotations. It lists all keys Codex reads from TOML, sets each to its
effective default where it exists, leaves optional ones commented, and
adds short comments on purpose and valid values. This should make
onboarding faster and reduce configuration errors. I can rename it to
config.example.toml or move it under docs/ if you prefer.

Author: sangoi-exe

README.md

@@ -81,6 +81,7 @@ Codex CLI supports a rich set of configuration options, with preferences stored
   - [Custom prompts](./docs/prompts.md)
   - [Memory with AGENTS.md](./docs/getting-started.md#memory-with-agentsmd)
 - [**Configuration**](./docs/config.md)
+  - [Example config](./docs/example-config.md)
 - [**Sandbox & approvals**](./docs/sandbox.md)
 - [**Authentication**](./docs/authentication.md)
   - [Auth methods](./docs/authentication.md#forcing-a-specific-auth-method-advanced)

docs/example-config.md

@@ -0,0 +1,374 @@
+# Example config.toml
+
+Use this example configuration as a starting point. For an explanation of each field and additional context, see [Configuration](./config.md). Copy the snippet below to `~/.codex/config.toml` and adjust values as needed.
+
+```toml
+# Codex example configuration (config.toml)
+#
+# This file lists all keys Codex reads from config.toml, their default values,
+# and concise explanations. Values here mirror the effective defaults compiled
+# into the CLI. Adjust as needed.
+#
+# Notes
+# - Root keys must appear before tables in TOML.
+# - Optional keys that default to "unset" are shown commented out with notes.
+# - MCP servers, profiles, and model providers are examples; remove or edit.
+
+################################################################################
+# Core Model Selection
+################################################################################
+
+# Primary model used by Codex. Default differs by OS; non-Windows defaults here.
+# Linux/macOS default: "gpt-5-codex"; Windows default: "gpt-5".
+model = "gpt-5-codex"
+
+# Model used by the /review feature (code reviews). Default: "gpt-5-codex".
+review_model = "gpt-5-codex"
+
+# Provider id selected from [model_providers]. Default: "openai".
+model_provider = "openai"
+
+# Optional manual model metadata. When unset, Codex auto-detects from model.
+# Uncomment to force values.
+# model_context_window = 128000       # tokens; default: auto for model
+# model_max_output_tokens = 8192      # tokens; default: auto for model
+# model_auto_compact_token_limit = 0  # disable/override auto; default: model family specific
+
+################################################################################
+# Reasoning & Verbosity (Responses API capable models)
+################################################################################
+
+# Reasoning effort: minimal | low | medium | high (default: medium)
+model_reasoning_effort = "medium"
+
+# Reasoning summary: auto | concise | detailed | none (default: auto)
+model_reasoning_summary = "auto"
+
+# Text verbosity for GPT-5 family (Responses API): low | medium | high (default: medium)
+model_verbosity = "medium"
+
+# Force-enable reasoning summaries for current model (default: false)
+model_supports_reasoning_summaries = false
+
+# Force reasoning summary format: none | experimental (default: none)
+model_reasoning_summary_format = "none"
+
+################################################################################
+# Instruction Overrides
+################################################################################
+
+# Additional user instructions appended after AGENTS.md. Default: unset.
+# developer_instructions = ""
+
+# Optional legacy base instructions override (prefer AGENTS.md). Default: unset.
+# instructions = ""
+
+# Inline override for the history compaction prompt. Default: unset.
+# compact_prompt = ""
+
+# Override built-in base instructions with a file path. Default: unset.
+# experimental_instructions_file = "/absolute/or/relative/path/to/instructions.txt"
+
+# Load the compact prompt override from a file. Default: unset.
+# experimental_compact_prompt_file = "/absolute/or/relative/path/to/compact_prompt.txt"
+
+################################################################################
+# Approval & Sandbox
+################################################################################
+
+# When to ask for command approval:
+# - untrusted: only known-safe read-only commands auto-run; others prompt
+# - on-failure: auto-run in sandbox; prompt only on failure for escalation
+# - on-request: model decides when to ask (default)
+# - never: never prompt (risky)
+approval_policy = "on-request"
+
+# Filesystem/network sandbox policy for tool calls:
+# - read-only (default)
+# - workspace-write
+# - danger-full-access (no sandbox; extremely risky)
+sandbox_mode = "read-only"
+
+# Extra settings used only when sandbox_mode = "workspace-write".
+[sandbox_workspace_write]
+# Additional writable roots beyond the workspace (cwd). Default: []
+writable_roots = []
+# Allow outbound network access inside the sandbox. Default: false
+network_access = false
+# Exclude $TMPDIR from writable roots. Default: false
+exclude_tmpdir_env_var = false
+# Exclude /tmp from writable roots. Default: false
+exclude_slash_tmp = false
+
+################################################################################
+# Shell Environment Policy for spawned processes
+################################################################################
+
+[shell_environment_policy]
+# inherit: all (default) | core | none
+inherit = "all"
+# Skip default excludes for names containing KEY/TOKEN (case-insensitive). Default: false
+ignore_default_excludes = false
+# Case-insensitive glob patterns to remove (e.g., "AWS_*", "AZURE_*"). Default: []
+exclude = []
+# Explicit key/value overrides (always win). Default: {}
+set = {}
+# Whitelist; if non-empty, keep only matching vars. Default: []
+include_only = []
+# Experimental: run via user shell profile. Default: false
+experimental_use_profile = false
+
+################################################################################
+# History & File Opener
+################################################################################
+
+[history]
+# save-all (default) | none
+persistence = "save-all"
+# Maximum bytes for history file (currently not enforced). Example: 5242880
+# max_bytes = 0
+
+# URI scheme for clickable citations: vscode (default) | vscode-insiders | windsurf | cursor | none
+file_opener = "vscode"
+
+################################################################################
+# UI, Notifications, and Misc
+################################################################################
+
+[tui]
+# Desktop notifications from the TUI: boolean or filtered list. Default: false
+# Examples: true | ["agent-turn-complete", "approval-requested"]
+notifications = false
+
+# Suppress internal reasoning events from output (default: false)
+hide_agent_reasoning = false
+
+# Show raw reasoning content when available (default: false)
+show_raw_agent_reasoning = false
+
+# Disable burst-paste detection in the TUI (default: false)
+disable_paste_burst = false
+
+# Track Windows onboarding acknowledgement (Windows only). Default: false
+windows_wsl_setup_acknowledged = false
+
+# External notifier program (argv array). When unset: disabled.
+# Example: notify = ["notify-send", "Codex"]
+# notify = [ ]
+
+# In-product notices (mostly set automatically by Codex).
+[notice]
+# hide_full_access_warning = true
+
+################################################################################
+# Authentication & Login
+################################################################################
+
+# Where to persist CLI login credentials: file (default) | keyring | auto
+cli_auth_credentials_store = "file"
+
+# Base URL for ChatGPT auth flow (not OpenAI API). Default:
+chatgpt_base_url = "https://chatgpt.com/backend-api/"
+
+# Restrict ChatGPT login to a specific workspace id. Default: unset.
+# forced_chatgpt_workspace_id = ""
+
+# Force login mechanism when Codex would normally auto-select. Default: unset.
+# Allowed values: chatgpt | api
+# forced_login_method = "chatgpt"
+
+################################################################################
+# Project Documentation Controls
+################################################################################
+
+# Max bytes from AGENTS.md to embed into first-turn instructions. Default: 32768
+project_doc_max_bytes = 32768
+
+# Ordered fallbacks when AGENTS.md is missing at a directory level. Default: []
+project_doc_fallback_filenames = []
+
+################################################################################
+# Tools (legacy toggles kept for compatibility)
+################################################################################
+
+[tools]
+# Enable web search tool (alias: web_search_request). Default: false
+web_search = false
+
+# Enable the view_image tool so the agent can attach local images. Default: true
+view_image = true
+
+# (Alias accepted) You can also write:
+# web_search_request = false
+
+################################################################################
+# Centralized Feature Flags (preferred)
+################################################################################
+
+[features]
+# Leave this table empty to accept defaults. Set explicit booleans to opt in/out.
+unified_exec = false
+streamable_shell = false
+rmcp_client = false
+apply_patch_freeform = false
+view_image_tool = true
+web_search_request = false
+experimental_sandbox_command_assessment = false
+ghost_commit = false
+enable_experimental_windows_sandbox = false
+
+################################################################################
+# Experimental toggles (legacy; prefer [features])
+################################################################################
+
+# Use experimental exec command tool (streamable shell). Default: false
+experimental_use_exec_command_tool = false
+
+# Use experimental unified exec tool. Default: false
+experimental_use_unified_exec_tool = false
+
+# Use experimental Rust MCP client (enables OAuth for HTTP MCP). Default: false
+experimental_use_rmcp_client = false
+
+# Include apply_patch via freeform editing path (affects default tool set). Default: false
+experimental_use_freeform_apply_patch = false
+
+# Enable model-based sandbox command assessment. Default: false
+experimental_sandbox_command_assessment = false
+
+################################################################################
+# MCP (Model Context Protocol) servers
+################################################################################
+
+# Preferred store for MCP OAuth credentials: auto (default) | file | keyring
+mcp_oauth_credentials_store = "auto"
+
+# Define MCP servers under this table. Leave empty to disable.
+[mcp_servers]
+
+# --- Example: STDIO transport ---
+# [mcp_servers.docs]
+# command = "docs-server"                 # required
+# args = ["--port", "4000"]               # optional
+# env = { "API_KEY" = "value" }           # optional key/value pairs copied as-is
+# env_vars = ["ANOTHER_SECRET"]            # optional: forward these from the parent env
+# cwd = "/path/to/server"                 # optional working directory override
+# startup_timeout_sec = 10.0               # optional; default 10.0 seconds
+# # startup_timeout_ms = 10000              # optional alias for startup timeout (milliseconds)
+# tool_timeout_sec = 60.0                  # optional; default 60.0 seconds
+# enabled_tools = ["search", "summarize"]  # optional allow-list
+# disabled_tools = ["slow-tool"]           # optional deny-list (applied after allow-list)
+
+# --- Example: Streamable HTTP transport ---
+# [mcp_servers.github]
+# url = "https://github-mcp.example.com/mcp"  # required
+# bearer_token_env_var = "GITHUB_TOKEN"        # optional; Authorization: Bearer <token>
+# http_headers = { "X-Example" = "value" }    # optional static headers
+# env_http_headers = { "X-Auth" = "AUTH_ENV" } # optional headers populated from env vars
+# startup_timeout_sec = 10.0                   # optional
+# tool_timeout_sec = 60.0                      # optional
+# enabled_tools = ["list_issues"]             # optional allow-list
+
+################################################################################
+# Model Providers (extend/override built-ins)
+################################################################################
+
+# Built-ins include:
+# - openai (Responses API; requires login or OPENAI_API_KEY via auth flow)
+# - oss (Chat Completions API; defaults to http://localhost:11434/v1)
+
+[model_providers]
+
+# --- Example: override OpenAI with explicit base URL or headers ---
+# [model_providers.openai]
+# name = "OpenAI"
+# base_url = "https://api.openai.com/v1"         # default if unset
+# wire_api = "responses"                         # "responses" | "chat" (default varies)
+# # requires_openai_auth = true                    # built-in OpenAI defaults to true
+# # request_max_retries = 4                        # default 4; max 100
+# # stream_max_retries = 5                         # default 5;  max 100
+# # stream_idle_timeout_ms = 300000                # default 300_000 (5m)
+# # experimental_bearer_token = "sk-example"      # optional dev-only direct bearer token
+# # http_headers = { "X-Example" = "value" }
+# # env_http_headers = { "OpenAI-Organization" = "OPENAI_ORGANIZATION", "OpenAI-Project" = "OPENAI_PROJECT" }
+
+# --- Example: Azure (Chat/Responses depending on endpoint) ---
+# [model_providers.azure]
+# name = "Azure"
+# base_url = "https://YOUR_PROJECT_NAME.openai.azure.com/openai"
+# wire_api = "responses"                          # or "chat" per endpoint
+# query_params = { api-version = "2025-04-01-preview" }
+# env_key = "AZURE_OPENAI_API_KEY"
+# # env_key_instructions = "Set AZURE_OPENAI_API_KEY in your environment"
+
+# --- Example: Local OSS (e.g., Ollama-compatible) ---
+# [model_providers.ollama]
+# name = "Ollama"
+# base_url = "http://localhost:11434/v1"
+# wire_api = "chat"
+
+################################################################################
+# Profiles (named presets)
+################################################################################
+
+# Active profile name. When unset, no profile is applied.
+# profile = "default"
+
+[profiles]
+
+# [profiles.default]
+# model = "gpt-5-codex"
+# model_provider = "openai"
+# approval_policy = "on-request"
+# sandbox_mode = "read-only"
+# model_reasoning_effort = "medium"
+# model_reasoning_summary = "auto"
+# model_verbosity = "medium"
+# chatgpt_base_url = "https://chatgpt.com/backend-api/"
+# experimental_compact_prompt_file = "compact_prompt.txt"
+# include_apply_patch_tool = false
+# experimental_use_unified_exec_tool = false
+# experimental_use_exec_command_tool = false
+# experimental_use_rmcp_client = false
+# experimental_use_freeform_apply_patch = false
+# experimental_sandbox_command_assessment = false
+# tools_web_search = false
+# tools_view_image = true
+# features = { unified_exec = false }
+
+################################################################################
+# Projects (trust levels)
+################################################################################
+
+# Mark specific worktrees as trusted. Only "trusted" is recognized.
+[projects]
+# [projects."/absolute/path/to/project"]
+# trust_level = "trusted"
+
+################################################################################
+# OpenTelemetry (OTEL) – disabled by default
+################################################################################
+
+[otel]
+# Include user prompt text in logs. Default: false
+log_user_prompt = false
+# Environment label applied to telemetry. Default: "dev"
+environment = "dev"
+# Exporter: none (default) | otlp-http | otlp-grpc
+exporter = "none"
+
+# Example OTLP/HTTP exporter configuration
+# [otel]
+# exporter = { otlp-http = {
+#   endpoint = "https://otel.example.com/v1/logs",
+#   protocol = "binary",                      # "binary" | "json"
+#   headers = { "x-otlp-api-key" = "${OTLP_TOKEN}" }
+# }}
+
+# Example OTLP/gRPC exporter configuration
+# [otel]
+# exporter = { otlp-grpc = {
+#   endpoint = "https://otel.example.com:4317",
+#   headers = { "x-otlp-meta" = "abc123" }
+# }}
+```