| 1 | // Package tools owns the MCP tool surface for last30days. |
| 2 | package tools |
| 3 | |
| 4 | import ( |
| 5 | "context" |
| 6 | "errors" |
| 7 | "fmt" |
| 8 | "os" |
| 9 | "strings" |
| 10 | |
| 11 | mcplib "github.com/mark3labs/mcp-go/mcp" |
| 12 | "github.com/mark3labs/mcp-go/server" |
| 13 | |
| 14 | "github.com/mvanhorn/last30days-skill/mcp/internal/engine" |
| 15 | ) |
| 16 | |
| 17 | // Config carries the version string used to namespace the per-user cache. |
| 18 | // main passes its ldflags-stamped Version here. |
| 19 | type Config struct { |
| 20 | Version string |
| 21 | } |
| 22 | |
| 23 | // BrowserCookiesEnvOverride is an explicit MCP-layer opt-in. It only removes |
| 24 | // the default-deny CLI flag; the engine still enforces its own recorded |
| 25 | // browser-cookie consent and configuration. |
| 26 | const BrowserCookiesEnvOverride = "LAST30DAYS_MCP_ALLOW_BROWSER_COOKIES" |
| 27 | |
| 28 | // Register adds every tool this server exposes to s. The caller supplies a |
| 29 | // Config so test harnesses can pin a version without touching globals. |
| 30 | func Register(s *server.MCPServer, cfg Config) { |
| 31 | registerPreflightTool(s, cfg) |
| 32 | s.AddTool( |
| 33 | mcplib.NewTool("research", |
| 34 | mcplib.WithDescription( |
| 35 | "Research what people are actually saying about any topic in the last 30 days. "+ |
| 36 | "Aggregates Reddit, X, YouTube, Hacker News, Polymarket, GitHub, and the web, "+ |
| 37 | "scored by upvotes, likes, transcripts, and real-money prediction-market odds. "+ |
| 38 | "Returns the engine's compact output for the model to synthesize.", |
| 39 | ), |
| 40 | mcplib.WithString("topic", mcplib.Required(), mcplib.Description("The subject to research (a person, company, product, event, or general topic).")), |
| 41 | mcplib.WithString("emit", mcplib.Description("Output shape: 'compact' (default) for inline synthesis or 'html' to save a shareable brief alongside the response.")), |
| 42 | mcplib.WithBoolean("save", mcplib.Description("Persist the synthesis as a markdown report under ~/Documents/Last30Days/ (or LAST30DAYS_MEMORY_DIR if set).")), |
| 43 | mcplib.WithReadOnlyHintAnnotation(false), |
| 44 | mcplib.WithDestructiveHintAnnotation(false), |
| 45 | mcplib.WithOpenWorldHintAnnotation(true), |
| 46 | ), |
| 47 | makeResearchHandler(cfg), |
| 48 | ) |
| 49 | } |
| 50 | |
| 51 | func makeResearchHandler(cfg Config) server.ToolHandlerFunc { |
| 52 | return func(ctx context.Context, req mcplib.CallToolRequest) (*mcplib.CallToolResult, error) { |
| 53 | args := req.GetArguments() |
| 54 | topic, err := requireString(args, "topic") |
| 55 | if err != nil { |
| 56 | return mcplib.NewToolResultError(err.Error()), nil |
| 57 | } |
| 58 | |
| 59 | emit, err := emitArgument(args) |
| 60 | if err != nil { |
| 61 | return mcplib.NewToolResultError(err.Error()), nil |
| 62 | } |
| 63 | |
| 64 | save, err := boolArgument(args, "save") |
| 65 | if err != nil { |
| 66 | return mcplib.NewToolResultError(err.Error()), nil |
| 67 | } |
| 68 | |
| 69 | src, err := engine.EngineFS() |
| 70 | if err != nil { |
| 71 | return mcplib.NewToolResultError(fmt.Sprintf("engine source unavailable: %v", err)), nil |
| 72 | } |
| 73 | cacheDir, err := engine.EnsureUserCache(src, cfg.Version) |
| 74 | if err != nil { |
| 75 | return mcplib.NewToolResultError(fmt.Sprintf( |
| 76 | "engine extract failed: %v\nhint: set %s to a writable directory if the default cache location is locked down", |
| 77 | err, engine.CacheEnvOverride, |
| 78 | )), nil |
| 79 | } |
| 80 | |
| 81 | runArgs := researchRunArgs(topic, emit, save) |
| 82 | |
| 83 | res, runErr := engine.Run(ctx, engine.RunOptions{ |
| 84 | CacheDir: cacheDir, |
| 85 | Args: runArgs, |
| 86 | }) |
| 87 | if runErr != nil { |
| 88 | return mcplib.NewToolResultError(formatRunError(runErr, res)), nil |
| 89 | } |
| 90 | return mcplib.NewToolResultText(string(res.Stdout)), nil |
| 91 | } |
| 92 | } |
| 93 | |
| 94 | func researchRunArgs(topic, emit string, save bool) []string { |
| 95 | runArgs := []string{topic, "--emit=" + emit} |
| 96 | if !browserCookiesAllowed() { |
| 97 | runArgs = append(runArgs, "--no-browser-cookies") |
| 98 | } |
| 99 | if save { |
| 100 | runArgs = append(runArgs, "--save-dir", mcpSaveDir()) |
| 101 | } |
| 102 | return runArgs |
| 103 | } |
| 104 | |
| 105 | func browserCookiesAllowed() bool { |
| 106 | raw := os.Getenv(BrowserCookiesEnvOverride) |
| 107 | return raw == "1" || |
| 108 | strings.EqualFold(raw, "true") || |
| 109 | strings.EqualFold(raw, "yes") || |
| 110 | strings.EqualFold(raw, "on") |
| 111 | } |
| 112 | |
| 113 | func mcpSaveDir() string { |
| 114 | saveDir := os.Getenv("LAST30DAYS_MEMORY_DIR") |
| 115 | if saveDir == "" { |
| 116 | return "~/Documents/Last30Days" |
| 117 | } |
| 118 | return saveDir |
| 119 | } |
| 120 | |
| 121 | func requireString(args map[string]any, name string) (string, error) { |
| 122 | raw, ok := args[name] |
| 123 | if !ok { |
| 124 | return "", fmt.Errorf("%s is required", name) |
| 125 | } |
| 126 | value, ok := raw.(string) |
| 127 | if !ok || strings.TrimSpace(value) == "" { |
| 128 | return "", fmt.Errorf("%s must be a non-empty string", name) |
| 129 | } |
| 130 | return value, nil |
| 131 | } |
| 132 | |
| 133 | func emitArgument(args map[string]any) (string, error) { |
| 134 | raw, ok := args["emit"] |
| 135 | if !ok { |
| 136 | return "compact", nil |
| 137 | } |
| 138 | value, ok := raw.(string) |
| 139 | if !ok { |
| 140 | return "", errors.New("emit must be a string") |
| 141 | } |
| 142 | switch value { |
| 143 | case "": |
| 144 | return "compact", nil |
| 145 | case "compact", "html": |
| 146 | return value, nil |
| 147 | default: |
| 148 | return "", fmt.Errorf("emit must be 'compact' or 'html', got %q", value) |
| 149 | } |
| 150 | } |
| 151 | |
| 152 | func boolArgument(args map[string]any, name string) (bool, error) { |
| 153 | raw, ok := args[name] |
| 154 | if !ok { |
| 155 | return false, nil |
| 156 | } |
| 157 | value, ok := raw.(bool) |
| 158 | if !ok { |
| 159 | return false, fmt.Errorf("%s must be a boolean", name) |
| 160 | } |
| 161 | return value, nil |
| 162 | } |
| 163 | |
| 164 | // formatRunError flattens engine.Run's distinct error shapes into a single |
| 165 | // user-facing message that includes the relevant stderr context. |
| 166 | func formatRunError(runErr error, res *engine.RunResult) string { |
| 167 | var msg strings.Builder |
| 168 | msg.WriteString(runErr.Error()) |
| 169 | if res != nil && len(res.Stderr) > 0 { |
| 170 | msg.WriteString("\nengine stderr:\n") |
| 171 | msg.Write(res.Stderr) |
| 172 | } |
| 173 | return msg.String() |
| 174 | } |
| 175 |