1package agent
2
3import (
4 "context"
5 "encoding/json"
6 "fmt"
7 "log/slog"
8 "sync"
9
10 "github.com/charmbracelet/crush/internal/config"
11 "github.com/charmbracelet/crush/internal/llm/tools"
12
13 "github.com/charmbracelet/crush/internal/permission"
14 "github.com/charmbracelet/crush/internal/version"
15
16 "github.com/mark3labs/mcp-go/client"
17 "github.com/mark3labs/mcp-go/client/transport"
18 "github.com/mark3labs/mcp-go/mcp"
19)
20
21type mcpTool struct {
22 mcpName string
23 tool mcp.Tool
24 mcpConfig config.MCPConfig
25 permissions permission.Service
26 workingDir string
27}
28
29type MCPClient interface {
30 Initialize(
31 ctx context.Context,
32 request mcp.InitializeRequest,
33 ) (*mcp.InitializeResult, error)
34 ListTools(ctx context.Context, request mcp.ListToolsRequest) (*mcp.ListToolsResult, error)
35 CallTool(ctx context.Context, request mcp.CallToolRequest) (*mcp.CallToolResult, error)
36 Close() error
37}
38
39func (b *mcpTool) Name() string {
40 return fmt.Sprintf("mcp_%s_%s", b.mcpName, b.tool.Name)
41}
42
43func (b *mcpTool) Info() tools.ToolInfo {
44 required := b.tool.InputSchema.Required
45 if required == nil {
46 required = make([]string, 0)
47 }
48 return tools.ToolInfo{
49 Name: fmt.Sprintf("mcp_%s_%s", b.mcpName, b.tool.Name),
50 Description: b.tool.Description,
51 Parameters: b.tool.InputSchema.Properties,
52 Required: required,
53 }
54}
55
56func runTool(ctx context.Context, c MCPClient, toolName string, input string) (tools.ToolResponse, error) {
57 defer c.Close()
58 initRequest := mcp.InitializeRequest{}
59 initRequest.Params.ProtocolVersion = mcp.LATEST_PROTOCOL_VERSION
60 initRequest.Params.ClientInfo = mcp.Implementation{
61 Name: "Crush",
62 Version: version.Version,
63 }
64
65 _, err := c.Initialize(ctx, initRequest)
66 if err != nil {
67 return tools.NewTextErrorResponse(err.Error()), nil
68 }
69
70 toolRequest := mcp.CallToolRequest{}
71 toolRequest.Params.Name = toolName
72 var args map[string]any
73 if err = json.Unmarshal([]byte(input), &args); err != nil {
74 return tools.NewTextErrorResponse(fmt.Sprintf("error parsing parameters: %s", err)), nil
75 }
76 toolRequest.Params.Arguments = args
77 result, err := c.CallTool(ctx, toolRequest)
78 if err != nil {
79 return tools.NewTextErrorResponse(err.Error()), nil
80 }
81
82 output := ""
83 for _, v := range result.Content {
84 if v, ok := v.(mcp.TextContent); ok {
85 output = v.Text
86 } else {
87 output = fmt.Sprintf("%v", v)
88 }
89 }
90
91 return tools.NewTextResponse(output), nil
92}
93
94func (b *mcpTool) Run(ctx context.Context, params tools.ToolCall) (tools.ToolResponse, error) {
95 sessionID, messageID := tools.GetContextValues(ctx)
96 if sessionID == "" || messageID == "" {
97 return tools.ToolResponse{}, fmt.Errorf("session ID and message ID are required for creating a new file")
98 }
99 permissionDescription := fmt.Sprintf("execute %s with the following parameters: %s", b.Info().Name, params.Input)
100 p := b.permissions.Request(
101 permission.CreatePermissionRequest{
102 SessionID: sessionID,
103 Path: b.workingDir,
104 ToolName: b.Info().Name,
105 Action: "execute",
106 Description: permissionDescription,
107 Params: params.Input,
108 },
109 )
110 if !p {
111 return tools.ToolResponse{}, permission.ErrorPermissionDenied
112 }
113
114 switch b.mcpConfig.Type {
115 case config.MCPStdio:
116 c, err := client.NewStdioMCPClient(
117 b.mcpConfig.Command,
118 b.mcpConfig.ResolvedEnv(),
119 b.mcpConfig.Args...,
120 )
121 if err != nil {
122 return tools.NewTextErrorResponse(err.Error()), nil
123 }
124 return runTool(ctx, c, b.tool.Name, params.Input)
125 case config.MCPHttp:
126 c, err := client.NewStreamableHttpClient(
127 b.mcpConfig.URL,
128 transport.WithHTTPHeaders(b.mcpConfig.ResolvedHeaders()),
129 )
130 if err != nil {
131 return tools.NewTextErrorResponse(err.Error()), nil
132 }
133 return runTool(ctx, c, b.tool.Name, params.Input)
134 case config.MCPSse:
135 c, err := client.NewSSEMCPClient(
136 b.mcpConfig.URL,
137 client.WithHeaders(b.mcpConfig.ResolvedHeaders()),
138 )
139 if err != nil {
140 return tools.NewTextErrorResponse(err.Error()), nil
141 }
142 return runTool(ctx, c, b.tool.Name, params.Input)
143 }
144
145 return tools.NewTextErrorResponse("invalid mcp type"), nil
146}
147
148func NewMcpTool(name string, tool mcp.Tool, permissions permission.Service, mcpConfig config.MCPConfig, workingDir string) tools.BaseTool {
149 return &mcpTool{
150 mcpName: name,
151 tool: tool,
152 mcpConfig: mcpConfig,
153 permissions: permissions,
154 workingDir: workingDir,
155 }
156}
157
158func getTools(ctx context.Context, name string, m config.MCPConfig, permissions permission.Service, c MCPClient, workingDir string) []tools.BaseTool {
159 var stdioTools []tools.BaseTool
160 initRequest := mcp.InitializeRequest{}
161 initRequest.Params.ProtocolVersion = mcp.LATEST_PROTOCOL_VERSION
162 initRequest.Params.ClientInfo = mcp.Implementation{
163 Name: "Crush",
164 Version: version.Version,
165 }
166
167 _, err := c.Initialize(ctx, initRequest)
168 if err != nil {
169 slog.Error("error initializing mcp client", "error", err)
170 return stdioTools
171 }
172 toolsRequest := mcp.ListToolsRequest{}
173 tools, err := c.ListTools(ctx, toolsRequest)
174 if err != nil {
175 slog.Error("error listing tools", "error", err)
176 return stdioTools
177 }
178 for _, t := range tools.Tools {
179 stdioTools = append(stdioTools, NewMcpTool(name, t, permissions, m, workingDir))
180 }
181 defer c.Close()
182 return stdioTools
183}
184
185var (
186 mcpToolsOnce sync.Once
187 mcpTools []tools.BaseTool
188)
189
190func GetMCPTools(ctx context.Context, permissions permission.Service, cfg *config.Config) []tools.BaseTool {
191 mcpToolsOnce.Do(func() {
192 mcpTools = doGetMCPTools(ctx, permissions, cfg)
193 })
194 return mcpTools
195}
196
197func doGetMCPTools(ctx context.Context, permissions permission.Service, cfg *config.Config) []tools.BaseTool {
198 var mu sync.Mutex
199 var wg sync.WaitGroup
200 var result []tools.BaseTool
201 for name, m := range cfg.MCP {
202 if m.Disabled {
203 slog.Debug("skipping disabled mcp", "name", name)
204 continue
205 }
206 wg.Add(1)
207 go func(name string, m config.MCPConfig) {
208 defer wg.Done()
209 switch m.Type {
210 case config.MCPStdio:
211 c, err := client.NewStdioMCPClient(
212 m.Command,
213 m.ResolvedEnv(),
214 m.Args...,
215 )
216 if err != nil {
217 slog.Error("error creating mcp client", "error", err)
218 return
219 }
220
221 mu.Lock()
222 result = append(result, getTools(ctx, name, m, permissions, c, cfg.WorkingDir())...)
223 mu.Unlock()
224 case config.MCPHttp:
225 c, err := client.NewStreamableHttpClient(
226 m.URL,
227 transport.WithHTTPHeaders(m.ResolvedHeaders()),
228 )
229 if err != nil {
230 slog.Error("error creating mcp client", "error", err)
231 return
232 }
233 mu.Lock()
234 result = append(result, getTools(ctx, name, m, permissions, c, cfg.WorkingDir())...)
235 mu.Unlock()
236 case config.MCPSse:
237 c, err := client.NewSSEMCPClient(
238 m.URL,
239 client.WithHeaders(m.ResolvedHeaders()),
240 )
241 if err != nil {
242 slog.Error("error creating mcp client", "error", err)
243 return
244 }
245 mu.Lock()
246 result = append(result, getTools(ctx, name, m, permissions, c, cfg.WorkingDir())...)
247 mu.Unlock()
248 }
249 }(name, m)
250 }
251 wg.Wait()
252 return result
253}