Built-In Harnesses
Built-in harnesses are ready-made tool groups for common agent capabilities.
| Harness | Use it for | Status |
|---|---|---|
| Coding | Workspace-aware read, search, edit, and command workflows | Use with permissions and sandboxing |
| FileSystem | Explicit filesystem operations over a configured root | Use with an explicit FileSystemContext |
| Coding TUI | TUI renderers and controls for coding harness events | Compose into the TUI registry |
| WebSearch | Public web search through Tavily | Use with an explicit Tavily key or Tavily:ApiKey configuration |
Use built-in harnesses the same way you use your own harnesses: register them on AgentBuilder, then configure the runtime context they require.
Safety Defaults
Filesystem and coding tools can mutate files or run processes. Start with:
- an explicit workspace root
WithPermissions()WithLocalSandbox()when command execution is available- shell disabled unless the workflow truly needs it
csharp
var agent = await new AgentBuilder()
.WithInstructions("Stay inside the configured workspace.")
.WithPermissions()
.WithLocalSandbox()
.WithToolHarness<CodingToolHarness>()
.BuildAsync();