|
| 1 | +package mcp |
| 2 | + |
| 3 | +import ( |
| 4 | + "context" |
| 5 | + "fmt" |
| 6 | + "os" |
| 7 | + "path/filepath" |
| 8 | + "strings" |
| 9 | + |
| 10 | + aderule "github.com/phi42/ad-enforcement-tool/dslref" |
| 11 | + decisiondomain "github.com/adr/ad-guidance-tool/internal/domain/decision" |
| 12 | + mcplib "github.com/mark3labs/mcp-go/mcp" |
| 13 | + mcpserver "github.com/mark3labs/mcp-go/server" |
| 14 | +) |
| 15 | + |
| 16 | +// Serve starts the ADG MCP server over stdio. |
| 17 | +func Serve(modelPath string, decisionSvc decisiondomain.DecisionService) error { |
| 18 | + s := buildServer(modelPath, decisionSvc) |
| 19 | + return mcpserver.ServeStdio(s) |
| 20 | +} |
| 21 | + |
| 22 | +func buildServer(modelPath string, decisionSvc decisiondomain.DecisionService) *mcpserver.MCPServer { |
| 23 | + s := mcpserver.NewMCPServer( |
| 24 | + "adg", |
| 25 | + "1.0.0", |
| 26 | + mcpserver.WithInstructions(`ADG (Architectural Decision Guidance) MCP server. |
| 27 | +Use these tools to read architectural decision records (ADRs) and generate .rule files that enforce them. |
| 28 | +Always call get_dsl_reference before writing any .rule file content to ensure correct syntax.`), |
| 29 | + ) |
| 30 | + |
| 31 | + s.AddTool( |
| 32 | + mcplib.NewTool("list_adrs", |
| 33 | + mcplib.WithDescription("List all architectural decision records (ADRs) in the decision model. Returns each ADR's ID, title, and status."), |
| 34 | + mcplib.WithReadOnlyHintAnnotation(true), |
| 35 | + ), |
| 36 | + listADRsHandler(modelPath, decisionSvc), |
| 37 | + ) |
| 38 | + |
| 39 | + s.AddTool( |
| 40 | + mcplib.NewTool("get_adr", |
| 41 | + mcplib.WithDescription("Get the full content of an ADR by its ID. Returns the markdown content and the path where the corresponding .rule file should be placed."), |
| 42 | + mcplib.WithString("id", |
| 43 | + mcplib.Required(), |
| 44 | + mcplib.Description(`The ADR ID, e.g. "0001"`), |
| 45 | + ), |
| 46 | + mcplib.WithReadOnlyHintAnnotation(true), |
| 47 | + ), |
| 48 | + getADRHandler(modelPath, decisionSvc), |
| 49 | + ) |
| 50 | + |
| 51 | + s.AddTool( |
| 52 | + mcplib.NewTool("get_dsl_reference", |
| 53 | + mcplib.WithDescription("Get the full ADE rule DSL language reference. Always read this before writing .rule file content."), |
| 54 | + mcplib.WithReadOnlyHintAnnotation(true), |
| 55 | + ), |
| 56 | + getDSLReferenceHandler(), |
| 57 | + ) |
| 58 | + |
| 59 | + s.AddTool( |
| 60 | + mcplib.NewTool("list_rule_files", |
| 61 | + mcplib.WithDescription("List all existing .rule files in the decision model directory with their full content. Use these as examples when generating new rule files."), |
| 62 | + mcplib.WithReadOnlyHintAnnotation(true), |
| 63 | + ), |
| 64 | + listRuleFilesHandler(modelPath), |
| 65 | + ) |
| 66 | + |
| 67 | + s.AddTool( |
| 68 | + mcplib.NewTool("validate_rule", |
| 69 | + mcplib.WithDescription("Validate the syntax and semantics of rule file content. Call this after generating a .rule file to confirm it is correct before presenting it to the user."), |
| 70 | + mcplib.WithString("content", |
| 71 | + mcplib.Required(), |
| 72 | + mcplib.Description("The full .rule file content to validate."), |
| 73 | + ), |
| 74 | + ), |
| 75 | + validateRuleHandler(), |
| 76 | + ) |
| 77 | + |
| 78 | + return s |
| 79 | +} |
| 80 | + |
| 81 | +func listADRsHandler(modelPath string, decisionSvc decisiondomain.DecisionService) mcpserver.ToolHandlerFunc { |
| 82 | + return func(ctx context.Context, req mcplib.CallToolRequest) (*mcplib.CallToolResult, error) { |
| 83 | + decisions, err := decisionSvc.GetAllDecisions(modelPath) |
| 84 | + if err != nil { |
| 85 | + return mcplib.NewToolResultError(fmt.Sprintf("failed to list ADRs: %v", err)), nil |
| 86 | + } |
| 87 | + |
| 88 | + if len(decisions) == 0 { |
| 89 | + return mcplib.NewToolResultText("No ADRs found in the decision model."), nil |
| 90 | + } |
| 91 | + |
| 92 | + var sb strings.Builder |
| 93 | + for _, d := range decisions { |
| 94 | + fmt.Fprintf(&sb, "- ID: %s | Title: %s | Status: %s\n", d.ID, d.Title, d.Status) |
| 95 | + } |
| 96 | + return mcplib.NewToolResultText(sb.String()), nil |
| 97 | + } |
| 98 | +} |
| 99 | + |
| 100 | +func getADRHandler(modelPath string, decisionSvc decisiondomain.DecisionService) mcpserver.ToolHandlerFunc { |
| 101 | + return func(ctx context.Context, req mcplib.CallToolRequest) (*mcplib.CallToolResult, error) { |
| 102 | + id, err := req.RequireString("id") |
| 103 | + if err != nil { |
| 104 | + return mcplib.NewToolResultError(`parameter "id" is required`), nil |
| 105 | + } |
| 106 | + |
| 107 | + decision, err := decisionSvc.GetDecisionByID(modelPath, id) |
| 108 | + if err != nil { |
| 109 | + return mcplib.NewToolResultError(fmt.Sprintf("ADR %q not found: %v", id, err)), nil |
| 110 | + } |
| 111 | + |
| 112 | + adrPath, err := decisionSvc.GetDecisionFilePath(modelPath, decision.ID) |
| 113 | + if err != nil { |
| 114 | + return mcplib.NewToolResultError(fmt.Sprintf("failed to resolve ADR file path: %v", err)), nil |
| 115 | + } |
| 116 | + |
| 117 | + content, err := os.ReadFile(adrPath) |
| 118 | + if err != nil { |
| 119 | + return mcplib.NewToolResultError(fmt.Sprintf("failed to read ADR file: %v", err)), nil |
| 120 | + } |
| 121 | + |
| 122 | + base := strings.TrimSuffix(filepath.Base(adrPath), filepath.Ext(adrPath)) |
| 123 | + ruleFilePath := filepath.Join(filepath.Dir(adrPath), base+".rule") |
| 124 | + |
| 125 | + ruleFileStatus := "does not exist yet (create it at: " + ruleFilePath + ")" |
| 126 | + if _, statErr := os.Stat(ruleFilePath); statErr == nil { |
| 127 | + ruleFileStatus = "already exists at: " + ruleFilePath |
| 128 | + } |
| 129 | + |
| 130 | + var sb strings.Builder |
| 131 | + fmt.Fprintf(&sb, "ADR ID: %s\n", decision.ID) |
| 132 | + fmt.Fprintf(&sb, "Title: %s\n", decision.Title) |
| 133 | + fmt.Fprintf(&sb, "Status: %s\n", decision.Status) |
| 134 | + fmt.Fprintf(&sb, "File: %s\n", adrPath) |
| 135 | + fmt.Fprintf(&sb, "Rule file: %s\n\n", ruleFileStatus) |
| 136 | + fmt.Fprintf(&sb, "=== Content ===\n%s", string(content)) |
| 137 | + |
| 138 | + return mcplib.NewToolResultText(sb.String()), nil |
| 139 | + } |
| 140 | +} |
| 141 | + |
| 142 | +func getDSLReferenceHandler() mcpserver.ToolHandlerFunc { |
| 143 | + return func(ctx context.Context, req mcplib.CallToolRequest) (*mcplib.CallToolResult, error) { |
| 144 | + return mcplib.NewToolResultText(aderule.Reference), nil |
| 145 | + } |
| 146 | +} |
| 147 | + |
| 148 | +func validateRuleHandler() mcpserver.ToolHandlerFunc { |
| 149 | + return func(ctx context.Context, req mcplib.CallToolRequest) (*mcplib.CallToolResult, error) { |
| 150 | + content, err := req.RequireString("content") |
| 151 | + if err != nil { |
| 152 | + return mcplib.NewToolResultError(`parameter "content" is required`), nil |
| 153 | + } |
| 154 | + |
| 155 | + if err := aderule.Validate(content); err != nil { |
| 156 | + return mcplib.NewToolResultError(fmt.Sprintf("Validation failed:\n%v", err)), nil |
| 157 | + } |
| 158 | + return mcplib.NewToolResultText("\u2713 Rule is valid."), nil |
| 159 | + } |
| 160 | +} |
| 161 | + |
| 162 | +func listRuleFilesHandler(modelPath string) mcpserver.ToolHandlerFunc { |
| 163 | + return func(ctx context.Context, req mcplib.CallToolRequest) (*mcplib.CallToolResult, error) { |
| 164 | + entries, err := os.ReadDir(modelPath) |
| 165 | + if err != nil { |
| 166 | + return mcplib.NewToolResultError(fmt.Sprintf("failed to read model directory: %v", err)), nil |
| 167 | + } |
| 168 | + |
| 169 | + var sb strings.Builder |
| 170 | + count := 0 |
| 171 | + for _, entry := range entries { |
| 172 | + if entry.IsDir() || filepath.Ext(entry.Name()) != ".rule" { |
| 173 | + continue |
| 174 | + } |
| 175 | + content, err := os.ReadFile(filepath.Join(modelPath, entry.Name())) |
| 176 | + if err != nil { |
| 177 | + continue |
| 178 | + } |
| 179 | + fmt.Fprintf(&sb, "=== %s ===\n%s\n", entry.Name(), string(content)) |
| 180 | + count++ |
| 181 | + } |
| 182 | + |
| 183 | + if count == 0 { |
| 184 | + return mcplib.NewToolResultText("No .rule files found in the model directory."), nil |
| 185 | + } |
| 186 | + return mcplib.NewToolResultText(sb.String()), nil |
| 187 | + } |
| 188 | +} |
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