Function convertMCPToolResponse

coderd/x/chatd/chattool/mcpworkspace.go:117–169

convertMCPToolResponse translates a workspace agent MCP tool response into a fantasy.ToolResponse. Text content blocks are collected and joined; binary content (image/media) is returned only when no text is available, matching the mcpclient conversion strategy.

(
	resp workspacesdk.CallMCPToolResponse,
)

// only when no text is available, matching the mcpclient
// conversion strategy.
func convertMCPToolResponse(
	resp workspacesdk.CallMCPToolResponse,
) fantasy.ToolResponse {
	var (
		textParts    []string
		binaryResult *fantasy.ToolResponse
	)

	for _, c := range resp.Content {
		switch c.Type {
		case "text":
			textParts = append(textParts, strings.ToValidUTF8(c.Text, "\uFFFD"))
		case "image", "audio":
			if c.Data == "" {
				continue
			}
			data, err := base64.StdEncoding.DecodeString(c.Data)
			if err != nil {
				textParts = append(textParts,
					"[binary decode error: "+err.Error()+"]",
				)
				continue
			}
			if binaryResult == nil {
				r := fantasy.ToolResponse{
					Type:      c.Type,
					Data:      data,
					MediaType: c.MediaType,
					IsError:   resp.IsError,
				}
				binaryResult = &r
			}
		default:
			textParts = append(textParts, strings.ToValidUTF8(c.Text, "\uFFFD"))
		}
	}

	// Prefer text content. Only fall back to binary when no
	// text was collected.
	if len(textParts) > 0 {
		r := fantasy.NewTextResponse(
			strings.Join(textParts, "\n"),
		)
		r.IsError = resp.IsError
		return r
	}
	if binaryResult != nil {
		return *binaryResult
	}
	r := fantasy.NewTextResponse("")
	r.IsError = resp.IsError
	return r
}