Tools & Surface

client, err := sdk.NewClient(&sdk.ClientConfig{
    Model: sdk.ModelIdentifier{
        Provider: sdk.APIProviderAnthropic,
        Model:    "claude-sonnet-4-20250514",
    },
    APIKey:         os.Getenv("ANTHROPIC_API_KEY"),
    PermissionMode: sdk.PermissionModeOnRequest,
})
if err != nil {
    log.Fatal(err)
}
defer client.Close()

fmt.Println(client.ToolNames())

surface, err := client.BuildToolSurface(ctx)
if err != nil {
    log.Fatal(err)
}
for _, tool := range surface.Tools {
    fmt.Println(tool.Name)
}

session, err := client.CreateSession(ctx)
if err != nil {
    log.Fatal(err)
}
defer session.Close()

session.SetPermissionMode(sdk.PermissionModeOnRequest)

for _, blocked := range []string{"bash", "write_file", "edit_file", "apply_patch"} {
    _ = session.UnregisterTool(blocked)
}

fmt.Println(session.GetToolNames())

resp, err := session.SubmitMessage(ctx, "Audit the repository and report findings only.")
if err != nil {
    log.Fatal(err)
}

fmt.Println(resp.StopReason)

type WorkerProfile struct {
    Name           string
    PermissionMode sdk.PermissionMode
    RemoveTools    []string
}

func NewWorkerSession(ctx context.Context, client *sdk.Client, profile WorkerProfile) (*sdk.Session, error) {
    session, err := client.CreateSession(ctx)
    if err != nil {
        return nil, err
    }

    session.SetPermissionMode(profile.PermissionMode)
    for _, toolName := range profile.RemoveTools {
        _ = session.UnregisterTool(toolName)
    }

    return session, nil
}

reviewSession, err := NewWorkerSession(ctx, client, WorkerProfile{
    Name:           "review",
    PermissionMode: sdk.PermissionModeOnRequest,
    RemoveTools:    []string{"bash", "write_file", "edit_file", "apply_patch"},
})

client, err := sdk.NewClient(&sdk.ClientConfig{
    Model: sdk.ModelIdentifier{
        Provider: sdk.APIProviderAnthropic,
        Model:    "claude-sonnet-4-20250514",
    },
    APIKey:         os.Getenv("ANTHROPIC_API_KEY"),
    PermissionMode: sdk.PermissionModeOnRequest,
    PreToolHooks: []sdk.PreToolHookConfig{
        {
            Matcher: "bash|write_file|edit_file|apply_patch",
            Command: "./scripts/pre_tool_guard.sh",
            Timeout: 5,
        },
    },
})

servers := []sdk.MCPServerConfig{
    {
        Name:      "github",
        Transport: sdk.MCPTransportStdio,
        Command:   "npx",
        Args:      []string{"-y", "@modelcontextprotocol/server-github"},
    },
}

client, err := sdk.NewClient(&sdk.ClientConfig{
    Model: sdk.ModelIdentifier{
        Provider: sdk.APIProviderAnthropic,
        Model:    "claude-sonnet-4-20250514",
    },
    APIKey:     os.Getenv("ANTHROPIC_API_KEY"),
    MCPServers: servers,
})
if err != nil {
    log.Fatal(err)
}
defer client.Close()

if err := client.ReloadMCPServers(ctx, servers); err != nil {
    log.Fatal(err)
}

// Public SDK surface today:
// - client.ToolNames()
// - client.BuildToolSurface(ctx)
// - client.RegisterTool(...)
// - session.RegisterTool(...)
// - session.UnregisterTool(...)
// - client.ReloadMCPServers(...)
// - ClientConfig.PreToolHooks
//
// Practical guidance:
// Start with built-in tools + MCP + session shaping first.
// Custom tools are possible, but their implementation still follows the
// underlying runtime tool contract rather than a simplified SDK-only builder.