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