# Settings

Atomic uses JSON settings files with project settings overriding global settings.

| Location | Scope |
|----------|-------|
| `~/.atomic/agent/settings.json` | Global (all projects) |
| `.atomic/settings.json` | Project (current directory) |

Edit directly or use `/settings` for common options. Atomic also reads legacy `~/.pi/agent/settings.json` and `.pi/settings.json` as compatibility fallbacks, with `.atomic` paths taking precedence.

## Project Trust

On interactive startup, Atomic asks before trusting a project folder that contains trust-gated project inputs and has no saved decision for the folder or a parent folder in `~/.atomic/agent/trust.json`. Trusting a project allows Atomic to load project-local `.atomic/settings.json` and `.atomic` resources, legacy `.pi/settings.json` and `.pi` resources, project-local context files, install missing project packages, and execute project extensions.

Non-interactive modes (`-p`, `--mode json`, and `--mode rpc`) do not show a trust prompt. Without an applicable saved trust decision, they use `defaultProjectTrust` from global settings: `ask` (default) and `never` ignore trust-gated project inputs, while `always` trusts them. Pass `--approve`/`-a` or `--no-approve`/`-na` to override project trust for one run.

If no extension or saved decision applies, `defaultProjectTrust` controls the fallback behavior. Set it to `"ask"`, `"always"`, or `"never"` in `~/.atomic/agent/settings.json`, or change it with `/settings`.

`atomic config` and package commands use the same project trust flow. Pass `--approve` to trust project-local settings for one command or `--no-approve` to ignore them.

Use `/trust` in interactive mode to save a project trust decision for future sessions, including trust for the immediate parent folder. It writes `~/.atomic/agent/trust.json` only; the current session is not reloaded, so restart Atomic for changes to take effect.

## All Settings

### Model & Thinking

| Setting | Type | Default | Description |
|---------|------|---------|-------------|
| `defaultProvider` | string | - | Default provider (e.g., `"anthropic"`, `"openai"`) |
| `defaultModel` | string | - | Default model ID |
| `defaultThinkingLevel` | string | - | `"off"`, `"minimal"`, `"low"`, `"medium"`, `"high"`, `"xhigh"` |
| `hideThinkingBlock` | boolean | `false` | Hide thinking blocks in output |
| `thinkingBudgets` | object | - | Custom token budgets per thinking level |

#### thinkingBudgets

```json
{
  "thinkingBudgets": {
    "minimal": 1024,
    "low": 4096,
    "medium": 10240,
    "high": 32768
  }
}
```

### Codex Fast Mode

Use `/fast` in interactive mode to edit these settings. Atomic applies fast mode only to supported `openai/*` and `openai-codex/*` providers, not `github-copilot/*` or other OpenAI-compatible providers. Chat and workflow-stage scopes are independent. When fast mode is active for the current supported model, Atomic shows `fast` after the model name in the chat footer and workflow stage model labels. Enable the workflow scope deliberately for broad fan-outs because each eligible stage can consume priority-tier requests.

| Setting | Type | Default | Description |
|---------|------|---------|-------------|
| `codexFastMode.chat` | boolean | `false` | Use OpenAI priority service tier for supported normal chat requests |
| `codexFastMode.workflow` | boolean | `false` | Use OpenAI priority service tier for supported workflow-stage requests |

```json
{
  "codexFastMode": {
    "chat": true,
    "workflow": false
  }
}
```

### UI & Display

| Setting | Type | Default | Description |
|---------|------|---------|-------------|
| `theme` | string | `"dark"` | Theme name (`"dark"`, `"light"`, a Catppuccin built-in, or custom) |
| `quietStartup` | boolean | `false` | Hide startup header |
| `defaultProjectTrust` | string | `"ask"` | Fallback project trust behavior: `"ask"`, `"always"`, or `"never"`. Global setting only |
| `collapseChangelog` | boolean | `false` | Show condensed changelog after updates |
| `enableInstallTelemetry` | boolean | `true` | Send an anonymous install/update version ping after first install or changelog-detected updates. This does not control update checks |
| `doubleEscapeAction` | string | `"tree"` | Action for double-escape: `"tree"`, `"fork"`, or `"none"` |
| `treeFilterMode` | string | `"default"` | Default filter for `/tree`: `"default"`, `"no-tools"`, `"user-only"`, `"labeled-only"`, `"all"` |
| `editorPaddingX` | number | `0` | Horizontal padding for input editor (0-3) |
| `autocompleteMaxVisible` | number | `5` | Max visible items in autocomplete dropdown (3-20) |
| `showHardwareCursor` | boolean | `false` | Show the terminal cursor while TUI positions it for IME support |

### Telemetry and update checks

`enableInstallTelemetry` only controls the anonymous install/update ping to `https://pi.dev/api/report-install`. Opting out of telemetry does not disable update checks; Atomic can still fetch the npm registry latest package metadata at `https://registry.npmjs.org/@bastani/atomic/latest` to look for the latest version.

Set `ATOMIC_SKIP_VERSION_CHECK=1` to disable the Atomic version update check. Use `--offline` or `ATOMIC_OFFLINE=1` to disable all startup network operations described here, including update checks, package update checks, and install/update telemetry. Legacy `PI_*` aliases are also supported for app-specific environment variables.

### Warnings

| Setting | Type | Default | Description |
|---------|------|---------|-------------|
| `warnings.anthropicExtraUsage` | boolean | `true` | Show a warning when Anthropic subscription auth may use paid extra usage |

```json
{
  "warnings": {
    "anthropicExtraUsage": false
  }
}
```

### Compaction

| Setting | Type | Default | Description |
|---------|------|---------|-------------|
| `compaction.enabled` | boolean | `true` | Enable automatic Verbatim Compaction |
| `compaction.reserveTokens` | number | `16384` | Tokens reserved for LLM response |

```json
{
  "compaction": {
    "enabled": true,
    "reserveTokens": 16384
  }
}
```

### Branch Summary

| Setting | Type | Default | Description |
|---------|------|---------|-------------|
| `branchSummary.reserveTokens` | number | `16384` | Tokens reserved for branch summarization |
| `branchSummary.skipPrompt` | boolean | `false` | Skip "Summarize branch?" prompt on `/tree` navigation (defaults to no summary) |

### Retry

| Setting | Type | Default | Description |
|---------|------|---------|-------------|
| `retry.enabled` | boolean | `true` | Enable automatic agent-level retry on transient errors |
| `retry.maxRetries` | number | `3` | Maximum agent-level retry attempts |
| `retry.baseDelayMs` | number | `2000` | Base delay for agent-level exponential backoff (2s, 4s, 8s) |
| `retry.provider.timeoutMs` | number | SDK default | Provider/SDK request timeout in milliseconds |
| `retry.provider.maxRetries` | number | `0` | Provider/SDK retry attempts |
| `retry.provider.maxRetryDelayMs` | number | `60000` | Max server-requested delay before failing (60s) |

When a provider requests a retry delay longer than `retry.provider.maxRetryDelayMs` (e.g., Google's "quota will reset after 5h"), the request fails immediately with an informative error instead of waiting silently. Set to `0` to disable the cap.

Keep `retry.provider.maxRetries` at `0` unless provider-level retries are explicitly needed. Setting it above `0` can make SDK/provider retries handle out-of-usage-limit errors before Atomic sees them, which may block the agent until the provider quota resets in some circumstances.

```json
{
  "retry": {
    "enabled": true,
    "maxRetries": 3,
    "baseDelayMs": 2000,
    "provider": {
      "timeoutMs": 3600000,
      "maxRetries": 0,
      "maxRetryDelayMs": 60000
    }
  }
}
```

### HTTP

| Setting | Type | Default | Description |
|---------|------|---------|-------------|
| `httpIdleTimeoutMs` | number | `300000` | HTTP header/body idle timeout in milliseconds. Must be a non-negative finite number; decimals are rounded down. Set to `0` to disable the idle timeout. |

Atomic applies this timeout to the global HTTP dispatcher used by `fetch` and provider SDK HTTP clients. The default is 300,000 ms (5 minutes), which keeps long-running requests working while reclaiming stale idle connections.

The `/settings` picker offers these presets:

| Label | Value |
|-------|-------|
| `30 sec` | `30000` |
| `1 min` | `60000` |
| `5 min` | `300000` |
| `10 min` | `600000` |
| `30 min` | `1800000` |
| `Disabled` | `0` |

```json
{
  "httpIdleTimeoutMs": 300000
}
```

### Message Delivery

| Setting | Type | Default | Description |
|---------|------|---------|-------------|
| `steeringMode` | string | `"one-at-a-time"` | How steering messages are sent: `"all"` or `"one-at-a-time"` |
| `followUpMode` | string | `"one-at-a-time"` | How follow-up messages are sent: `"all"` or `"one-at-a-time"` |
| `transport` | string | `"auto"` | Preferred transport for providers that support multiple transports: `"sse"`, `"websocket"`, `"websocket-cached"`, or `"auto"` |
| `httpIdleTimeoutMs` | number | `300000` | HTTP header/body idle timeout in milliseconds, also used by providers with explicit stream idle timeouts. Set to `0` to disable. |
| `websocketConnectTimeoutMs` | number | `15000` | WebSocket connect/open handshake timeout in milliseconds for providers that support WebSocket transports. Set to `0` to disable. |

### Terminal & Images

| Setting | Type | Default | Description |
|---------|------|---------|-------------|
| `terminal.showImages` | boolean | `true` | Show images in terminal (if supported) |
| `terminal.imageWidthCells` | number | `60` | Preferred inline image width in terminal cells |
| `terminal.clearOnShrink` | boolean | `false` | Clear empty rows when content shrinks (can cause flicker) |
| `images.autoResize` | boolean | `true` | Resize images to 2000x2000 max |
| `images.blockImages` | boolean | `false` | Block all images from being sent to LLM |

### Shell

| Setting | Type | Default | Description |
|---------|------|---------|-------------|
| `shellPath` | string | - | Custom shell path (e.g., for Cygwin on Windows) |
| `shellCommandPrefix` | string | - | Prefix for every bash command (e.g., `"shopt -s expand_aliases"`) |
| `npmCommand` | string[] | - | Command argv used for npm package lookup/install operations (e.g., `["mise", "exec", "node@20", "--", "npm"]`) |

```json
{
  "npmCommand": ["mise", "exec", "node@20", "--", "npm"]
}
```

`npmCommand` is used for all npm package-manager operations, including installs, uninstalls, and dependency installs inside git packages. Use argv-style entries exactly as the process should be launched. When `npmCommand` is configured, git package dependency installs use plain `install` to avoid npm-specific flags in wrappers or alternate package managers.

Normally the package manager's global modules location is queried using `root -g`. As a special case, if the first element of `npmCommand` is `"bun"`, the modules location will instead be queried with `pm bin -g`.

### Sessions

| Setting | Type | Default | Description |
|---------|------|---------|-------------|
| `sessionDir` | string | - | Directory where session files are stored. Accepts absolute or relative paths, plus `~`. |

```json
{ "sessionDir": ".atomic/sessions" }
```

When multiple sources specify a session directory, precedence is `--session-dir`, `ATOMIC_CODING_AGENT_SESSION_DIR`, then `sessionDir` in settings.json.

### Model Cycling

| Setting | Type | Default | Description |
|---------|------|---------|-------------|
| `enabledModels` | string[] | - | Model patterns for CTRL+P cycling (same format as `--models` CLI flag) |

```json
{
  "enabledModels": ["claude-*", "gpt-4o", "gemini-2*"]
}
```

### Markdown

| Setting | Type | Default | Description |
|---------|------|---------|-------------|
| `markdown.codeBlockIndent` | string | `"  "` | Indentation for code blocks |

### Resources

These settings define where to load extensions, skills, prompts, themes, and workflows from.

Paths in `~/.atomic/agent/settings.json` resolve relative to `~/.atomic/agent`. Paths in `.atomic/settings.json` resolve relative to `.atomic`. Absolute paths and `~` are supported.

| Setting | Type | Default | Description |
|---------|------|---------|-------------|
| `packages` | array | `[]` | npm/git packages to load resources from |
| `extensions` | string[] | `[]` | Local extension file paths or directories |
| `skills` | string[] | `[]` | Local skill file paths or directories |
| `prompts` | string[] | `[]` | Local prompt template paths or directories |
| `themes` | string[] | `[]` | Local theme file paths or directories |
| `workflows` | string[] | `[]` | Local workflow file paths or directories |
| `enableSkillCommands` | boolean | `true` | Register skills as `/skill:name` commands |

Arrays support glob patterns and exclusions. Use `!pattern` to exclude. Use `+path` to force-include an exact path and `-path` to force-exclude an exact path.

#### packages

String form loads all resources from a package:

```json
{
  "packages": ["pi-skills", "@org/my-extension"]
}
```

Object form filters which resources to load:

```json
{
  "packages": [
    {
      "source": "pi-skills",
      "skills": ["brave-search", "transcribe"],
      "extensions": [],
      "workflows": []
    }
  ]
}
```

See [Atomic packages](/packages) for package management details.

## Example

```json
{
  "defaultProvider": "anthropic",
  "defaultModel": "claude-sonnet-4-20250514",
  "defaultThinkingLevel": "medium",
  "theme": "dark",
  "compaction": {
    "enabled": true,
    "reserveTokens": 16384
  },
  "retry": {
    "enabled": true,
    "maxRetries": 3
  },
  "httpIdleTimeoutMs": 300000,
  "enabledModels": ["claude-*", "gpt-4o"],
  "warnings": {
    "anthropicExtraUsage": true
  },
  "packages": ["pi-skills"],
  "workflows": ["./workflows/*.ts"]
}
```

## Project Overrides

Project settings (`.atomic/settings.json`) override global settings. Nested objects are merged:

```json
// ~/.atomic/agent/settings.json (global)
{
  "theme": "dark",
  "compaction": { "enabled": true, "reserveTokens": 16384 }
}

// .atomic/settings.json (project)
{
  "compaction": { "reserveTokens": 8192 }
}

// Result
{
  "theme": "dark",
  "compaction": { "enabled": true, "reserveTokens": 8192 }
}
```
