---
title: "Configuration"
description: "Preferences, model selection, MCP servers, hooks, and all settings."
---

SF preferences live in `~/.sf/PREFERENCES.md` (global) or `.sf/PREFERENCES.md` (project-local). Manage interactively with `/sf prefs`.

## Preferences commands

| Command | Description |
|---------|-------------|
| `/sf prefs` | Open the global preferences wizard |
| `/sf prefs global` | Global preferences wizard |
| `/sf prefs project` | Project preferences wizard |
| `/sf prefs status` | Show current files, merged values, and skill status |

## Preferences file format

Preferences use YAML frontmatter in a markdown file:

```yaml
---
version: 1
models:
  research: claude-sonnet-4-6
  planning: claude-opus-4-6
  execution: claude-sonnet-4-6
  completion: claude-sonnet-4-6
skill_discovery: suggest
auto_supervisor:
  soft_timeout_minutes: 20
  idle_timeout_minutes: 10
  hard_timeout_minutes: 30
budget_ceiling: 50.00
token_profile: balanced
---
```

## Global vs project preferences

| Scope | Path | Applies to |
|-------|------|-----------|
| Global | `~/.sf/PREFERENCES.md` | All projects |
| Project | `.sf/PREFERENCES.md` | Current project only |

**Merge behavior:**
- **Scalar fields** — project wins if defined
- **Array fields** — concatenated (global first, then project)
- **Object fields** — shallow-merged, project overrides per-key

## Global API keys

Tool API keys are stored globally in `~/.sf/agent/auth.json`. Set them once with `/sf config`.

| Tool | Environment variable | Purpose |
|------|---------------------|---------|
| Tavily Search | `TAVILY_API_KEY` | Web search for non-Anthropic models |
| Brave Search | `BRAVE_API_KEY` | Web search for non-Anthropic models |
| Context7 Docs | `CONTEXT7_API_KEY` | Library documentation lookup |

Anthropic models have built-in web search — no extra keys needed.

## MCP servers

SF connects to external MCP servers configured in project files:

- `.mcp.json` — repo-shared config
- `.sf/mcp.json` — local-only config

<Tabs>
  <Tab title="stdio server">
    ```json
    {
      "mcpServers": {
        "my-server": {
          "type": "stdio",
          "command": "/absolute/path/to/python3",
          "args": ["/absolute/path/to/server.py"],
          "env": {
            "API_URL": "http://localhost:8000"
          }
        }
      }
    }
    ```
  </Tab>
  <Tab title="HTTP server">
    ```json
    {
      "mcpServers": {
        "my-http-server": {
          "url": "http://localhost:8080/mcp"
        }
      }
    }
    ```
  </Tab>
</Tabs>

Verify from a SF session: `mcp_servers` → `mcp_discover` → `mcp_call`.

## Models

Per-phase model selection:

```yaml
models:
  research: claude-sonnet-4-6
  planning:
    model: claude-opus-4-6
    fallbacks:
      - openrouter/z-ai/glm-5
  execution: claude-sonnet-4-6
  execution_simple: claude-haiku-4-5-20250414
  completion: claude-sonnet-4-6
  subagent: claude-sonnet-4-6
```

**Phases:** `research`, `planning`, `execution`, `execution_simple`, `completion`, `subagent`

When a model fails to switch, SF automatically tries the next model in the `fallbacks` list.

For custom providers (Ollama, vLLM, LM Studio), see [custom models](/guides/custom-models).

## All settings

### `token_profile`

Coordinates model selection, phase skipping, and context compression. Values: `budget`, `balanced` (default), `quality`. See [token optimization](/guides/token-optimization).

### `budget_ceiling`

Maximum USD spend during auto mode:

```yaml
budget_ceiling: 50.00
budget_enforcement: pause    # warn, pause (default), or halt
```

### `auto_supervisor`

Timeout thresholds:

```yaml
auto_supervisor:
  soft_timeout_minutes: 20
  idle_timeout_minutes: 10
  hard_timeout_minutes: 30
```

### `skill_discovery`

| Value | Behavior |
|-------|----------|
| `auto` | Skills found and applied automatically |
| `suggest` | Skills identified but not auto-installed (default) |
| `off` | Disabled |

### Verification

```yaml
verification_commands:
  - npm run lint
  - npm run test
verification_auto_fix: true
verification_max_retries: 2
```

### Git

See [git strategy](/guides/git-strategy) for full git configuration.

### Notifications

```yaml
notifications:
  enabled: true
  on_complete: true
  on_error: true
  on_budget: true
  on_milestone: true
  on_attention: true
```

### Post-unit hooks

```yaml
post_unit_hooks:
  - name: code-review
    after: [execute-task]
    prompt: "Review the code changes for quality and security."
    model: claude-opus-4-6
    max_cycles: 1
    artifact: REVIEW.md
```

### Pre-dispatch hooks

```yaml
pre_dispatch_hooks:
  - name: add-standards
    before: [execute-task]
    action: modify          # modify, skip, or replace
    prepend: "Follow our coding standards."
```

### Skill routing

```yaml
always_use_skills:
  - debug-like-expert
prefer_skills:
  - frontend-design
skill_rules:
  - when: task involves authentication
    use: [clerk]
```

### Custom instructions

```yaml
custom_instructions:
  - "Always use TypeScript strict mode"
  - "Prefer functional patterns over classes"
```

### Dynamic routing

See [dynamic model routing](/guides/dynamic-model-routing).

### Parallel execution

See [parallel orchestration](/guides/parallel-orchestration).

## Environment variables

| Variable | Default | Description |
|----------|---------|-------------|
| `SF_HOME` | `~/.sf` | Global SF directory |
| `SF_PROJECT_ID` | (auto-hash) | Override project identity hash |
| `SF_STATE_DIR` | `$SF_HOME` | Per-project state root |
| `SF_CODING_AGENT_DIR` | `$SF_HOME/agent` | Agent directory |

## Full example

<Accordion title="Complete preferences file">
```yaml
---
version: 1

models:
  research: openrouter/deepseek/deepseek-r1
  planning:
    model: claude-opus-4-6
    fallbacks:
      - openrouter/z-ai/glm-5
  execution: claude-sonnet-4-6
  execution_simple: claude-haiku-4-5-20250414
  completion: claude-sonnet-4-6

token_profile: balanced

dynamic_routing:
  enabled: true
  escalate_on_failure: true
  budget_pressure: true

budget_ceiling: 25.00
budget_enforcement: pause
context_pause_threshold: 80

auto_supervisor:
  soft_timeout_minutes: 15
  hard_timeout_minutes: 25

git:
  auto_push: true
  merge_strategy: squash
  isolation: none
  commit_docs: true

skill_discovery: suggest
always_use_skills:
  - debug-like-expert
skill_rules:
  - when: task involves authentication
    use: [clerk]

notifications:
  on_complete: false
  on_milestone: true
  on_attention: true

auto_visualize: true
service_tier: priority
forensics_dedup: true
show_token_cost: true

post_unit_hooks:
  - name: code-review
    after: [execute-task]
    prompt: "Review {sliceId}/{taskId} for quality and security."
    artifact: REVIEW.md
---
```
</Accordion>