github/github-mcp-server · error

field %q is NUMBER; value must be a number

Error message

field %q is NUMBER; value must be a number

What it means

Raised by convertProjectFieldValue (pkg/github/projects_batch.go:588) when the resolved field has DataType "NUMBER" but the supplied value cannot be treated as a number by toFloat64: strings ("42"), bools, null, arrays, objects, or NaN/Infinity. Note toFloat64 accepts float64, int, and int64 — so any valid JSON number passes. The mismatch fails conversion before the write; values must be sent as JSON numbers.

Source

Thrown at pkg/github/projects_batch.go:588

	return candidates
}

func convertProjectFieldValue(field *ResolvedField, raw any) (githubv4.ProjectV2FieldValue, error) {
	var zero githubv4.ProjectV2FieldValue

	switch field.DataType {
	case "TEXT":
		s, ok := raw.(string)
		if !ok {
			return zero, fmt.Errorf("field %q is TEXT; value must be a string", field.Name)
		}
		v := githubv4.String(s)
		return githubv4.ProjectV2FieldValue{Text: &v}, nil

	case "NUMBER":
		f, ok := toFloat64(raw)
		if !ok {
			return zero, fmt.Errorf("field %q is NUMBER; value must be a number", field.Name)
		}
		v := githubv4.Float(f)
		return githubv4.ProjectV2FieldValue{Number: &v}, nil

	case "DATE":
		s, ok := raw.(string)
		if !ok {
			return zero, fmt.Errorf("field %q is DATE; value must be a YYYY-MM-DD string", field.Name)
		}
		t, err := time.Parse("2006-01-02", s)
		if err != nil {
			return zero, fmt.Errorf("field %q is DATE; value %q is not in YYYY-MM-DD format: %w", field.Name, s, err)
		}
		return githubv4.ProjectV2FieldValue{Date: &githubv4.Date{Time: t}}, nil

	case "SINGLE_SELECT":
		s, ok := raw.(string)
		if !ok || s == "" {

View on GitHub (pinned to 0ea1f775a7)

Solutions

1. Send the value unquoted: "value": 8 instead of "8"
2. Parse numeric source strings to int/float before building the payload
3. To clear a number field, use the dedicated clear operation rather than null or 0-by-accident
4. Check the field's data_type via list_project_fields when types are uncertain

Example fix

// before (field "Story Points" is NUMBER)
{"updated_field": {"name": "Story Points", "value": "8"}}
// after
{"updated_field": {"name": "Story Points", "value": 8}}

if field.DataType == "NUMBER" {
	switch value.(type) {
	case float64, int, int64: // ok
	default:
		return fmt.Errorf("field %s is NUMBER: send an unquoted JSON number", field.Name)
	}
}

func isJSONNumber(v any) bool {
	switch v.(type) {
	case float64, int, int64: return true
	}
	return false
}

When it happens

Trigger: A number field (e.g. "Story Points", "Velocity") updated with "value": "8" (quoted), true, or null. The field type comes from the GitHub project; the caller sent the wrong JSON type.

Common situations: Numbers quoted by CSV/JSON exports or string-typed config; a null intended to blank out a number field (unsupported here — use the clear flow); booleans for 0/1 flags; clients that forward all values as strings for safety.

Related errors

• field %q is TEXT; value must be a string
• node_id must be a non-empty string
• item_id: %w
• %s must be a non-empty string
• %s must be a positive integer: %w

AI-assisted analysis of github/github-mcp-server@0ea1f775a7 (2026-08-15). Data as JSON: /api/errors/0bb917e75c5f6467. Report an issue: GitHub.