Feat: add agent entity

agent/agent.go

@@ -0,0 +1,60 @@
+package agent
+
+// Agent defines an interface for processing tool outputs.
+// An Agent can clean, summarize, or otherwise transform raw tool outputs
+// before they are presented to the main LLM.
+type Agent interface {
+	// Process takes the original tool arguments and the raw output from the tool,
+	// and returns a cleaned/summarized version suitable for the main LLM context.
+	Process(args map[string]string, rawOutput []byte) []byte
+}
+
+// registry holds mapping from tool names to agents.
+var registry = make(map[string]Agent)
+
+// Register adds an agent for a specific tool name.
+// If an agent already exists for the tool, it will be replaced.
+func Register(toolName string, a Agent) {
+	registry[toolName] = a
+}
+
+// Get returns the agent for a tool name, or nil if none is registered.
+func Get(toolName string) Agent {
+	return registry[toolName]
+}
+
+// FormatterAgent is a simple agent that applies formatting functions.
+type FormatterAgent struct {
+	formatFunc func([]byte) (string, error)
+}
+
+// NewFormatterAgent creates a FormatterAgent that uses the given formatting function.
+func NewFormatterAgent(formatFunc func([]byte) (string, error)) *FormatterAgent {
+	return &FormatterAgent{formatFunc: formatFunc}
+}
+
+// Process applies the formatting function to raw output.
+func (a *FormatterAgent) Process(args map[string]string, rawOutput []byte) []byte {
+	if a.formatFunc == nil {
+		return rawOutput
+	}
+	formatted, err := a.formatFunc(rawOutput)
+	if err != nil {
+		// On error, return raw output with a warning prefix
+		return []byte("[formatting failed, showing raw output]\n" + string(rawOutput))
+	}
+	return []byte(formatted)
+}
+
+// DefaultFormatter returns a FormatterAgent that uses the appropriate formatting
+// based on tool name.
+func DefaultFormatter(toolName string) Agent {
+	switch toolName {
+	case "websearch":
+		return NewFormatterAgent(FormatSearchResults)
+	case "read_url":
+		return NewFormatterAgent(FormatWebPageContent)
+	default:
+		return nil
+	}
+}

agent/format.go

@@ -0,0 +1,120 @@
+package agent
+
+import (
+	"encoding/json"
+	"fmt"
+	"strings"
+)
+
+// FormatSearchResults takes raw JSON from websearch and returns a concise summary.
+func FormatSearchResults(rawJSON []byte) (string, error) {
+	// Try to unmarshal as generic slice of maps
+	var results []map[string]interface{}
+	if err := json.Unmarshal(rawJSON, &results); err != nil {
+		// If that fails, try as a single map (maybe wrapper object)
+		var wrapper map[string]interface{}
+		if err2 := json.Unmarshal(rawJSON, &wrapper); err2 == nil {
+			// Look for a "results" or "data" field
+			if data, ok := wrapper["results"].([]interface{}); ok {
+				// Convert to slice of maps
+				for _, item := range data {
+					if m, ok := item.(map[string]interface{}); ok {
+						results = append(results, m)
+					}
+				}
+			} else if data, ok := wrapper["data"].([]interface{}); ok {
+				for _, item := range data {
+					if m, ok := item.(map[string]interface{}); ok {
+						results = append(results, m)
+					}
+				}
+			} else {
+				// No slice found, treat wrapper as single result
+				results = []map[string]interface{}{wrapper}
+			}
+		} else {
+			return "", fmt.Errorf("failed to unmarshal search results: %v (also %v)", err, err2)
+		}
+	}
+
+	if len(results) == 0 {
+		return "No search results found.", nil
+	}
+
+	var sb strings.Builder
+	sb.WriteString(fmt.Sprintf("Found %d results:\n", len(results)))
+	for i, r := range results {
+		// Extract common fields
+		title := getString(r, "title", "Title", "name", "heading")
+		snippet := getString(r, "snippet", "description", "content", "body", "text", "summary")
+		url := getString(r, "url", "link", "uri", "source")
+
+		sb.WriteString(fmt.Sprintf("%d. ", i+1))
+		if title != "" {
+			sb.WriteString(fmt.Sprintf("**%s**", title))
+		} else {
+			sb.WriteString("(No title)")
+		}
+		if snippet != "" {
+			// Truncate snippet to reasonable length
+			if len(snippet) > 200 {
+				snippet = snippet[:200] + "..."
+			}
+			sb.WriteString(fmt.Sprintf(" — %s", snippet))
+		}
+		if url != "" {
+			sb.WriteString(fmt.Sprintf(" (%s)", url))
+		}
+		sb.WriteString("\n")
+	}
+	return sb.String(), nil
+}
+
+// FormatWebPageContent takes raw JSON from read_url and returns a concise summary.
+func FormatWebPageContent(rawJSON []byte) (string, error) {
+	// Try to unmarshal as generic map
+	var data map[string]interface{}
+	if err := json.Unmarshal(rawJSON, &data); err != nil {
+		// If that fails, try as string directly
+		var content string
+		if err2 := json.Unmarshal(rawJSON, &content); err2 == nil {
+			return truncateText(content, 500), nil
+		}
+		// Both failed, return first error
+		return "", fmt.Errorf("failed to unmarshal web page content: %v", err)
+	}
+
+	// Look for common content fields
+	content := getString(data, "content", "text", "body", "article", "html", "markdown", "data")
+	if content == "" {
+		// If no content field, marshal the whole thing as a short string
+		summary := fmt.Sprintf("%v", data)
+		return truncateText(summary, 300), nil
+	}
+	return truncateText(content, 500), nil
+}
+
+// Helper to get a string value from a map, trying multiple keys.
+func getString(m map[string]interface{}, keys ...string) string {
+	for _, k := range keys {
+		if val, ok := m[k]; ok {
+			switch v := val.(type) {
+			case string:
+				return v
+			case fmt.Stringer:
+				return v.String()
+			default:
+				return fmt.Sprintf("%v", v)
+			}
+		}
+	}
+	return ""
+}
+
+// Helper to truncate text and add ellipsis.
+func truncateText(s string, maxLen int) string {
+	if len(s) <= maxLen {
+		return s
+	}
+	return s[:maxLen] + "..."
+}