What causes "input is required" in wavetermdev/waveterm?

Always pass a JSON object as tool input, at minimum {"contents": "..."}

input is required

Error message

input is required

What it means

parseBuilderWriteAppFileInput validates raw input for the builder write-app-file tool. A nil input cannot be unmarshaled into builderWriteAppFileParams, so nil is rejected immediately with this sentinel error before ReUnmarshal is attempted.

Source

Thrown at pkg/aiusechat/tools_builder.go:63

		return map[string]any{
			"build_success": false,
			"build_error":   err.Error(),
			"build_output":  "",
		}
	}

	return map[string]any{
		"build_success": result.Success,
		"build_error":   result.ErrorMessage,
		"build_output":  result.BuildOutput,
	}
}

func parseBuilderWriteAppFileInput(input any) (*builderWriteAppFileParams, error) {
	result := &builderWriteAppFileParams{}

	if input == nil {
		return nil, fmt.Errorf("input is required")
	}

	if err := utilfn.ReUnmarshal(result, input); err != nil {
		return nil, fmt.Errorf("invalid input format: %w", err)
	}

	if result.Contents == "" {
		return nil, fmt.Errorf("missing contents parameter")
	}

	return result, nil
}

func GetBuilderWriteAppFileToolDefinition(appId string, builderId string) uctypes.ToolDefinition {
	return uctypes.ToolDefinition{
		Name:        "builder_write_app_file",
		DisplayName: "Write App File",
		Description: fmt.Sprintf("Write the app.go file for app %s", appId),

View on GitHub (pinned to a4447c1563)

Solutions

Always pass a JSON object as tool input, at minimum {"contents": "..."}
Fix any upstream argument-decoding layer so it produces an empty map {} rather than nil on parse failure
If calling parseBuilderWriteAppFileInput directly (tests), pass map[string]any{"contents": ...} not nil

Example fix

// before
parseBuilderWriteAppFileInput(nil)
// after
parseBuilderWriteAppFileInput(map[string]any{"contents": "file body"})

Defensive patterns

Strategy: validation

Validate before calling

if input == nil { input = map[string]any{} }; if _, ok := input.(map[string]any); !ok { return errors.New("tool input must be an object") }

Type guard

func nonNilObject(input any) (map[string]any, bool) { if input == nil { return nil, false }; m, ok := input.(map[string]any); return m, ok }

Try / catch

params, err := parseBuilderWriteAppFileInput(input); if err != nil { if err.Error() == "input is required" { input = map[string]any{} } else { return err } }

Prevention

Never forward nil tool arguments; default to an empty object
Fix dispatch layers to surface JSON decode errors instead of passing nil
Ensure tool calls always serialize an arguments object, even when minimal

When it happens

Trigger: The builder tool is invoked with input == nil: no arguments object supplied at all, or an upstream layer passes nil through when arguments parsing failed silently.

Common situations: LLM tool call with empty arguments; a dispatch layer that swallows JSON parse errors and forwards nil; calling the parse function directly in tests with a nil argument.

Understand the failure class

Background: "missing required argument" and "the following required arguments were not provided": what required-argument errors mean and how to fix them — this error's family across 20 libraries.

Related errors

AI-assisted analysis of wavetermdev/waveterm@a4447c1563 (2026-09-01). Data as JSON: /api/errors/f07a44136790b7eb. Report an issue: GitHub.