feat(jsontypes): add RawPaths and jsonrawpaths CLI

RawPaths walks JSON depth-first and emits flat paths with monotonically
numbered type names (Root0, People2, etc.). Each type intro immediately
precedes its fields, making the output streamable and order-stable.

Also improves map detection heuristics:
- All-numeric keys are always maps (even with 1-2 keys)
- Keys containing digits detected as IDs (e.g., emp_101)
- New isKnownFieldName with broad list of common field names
  (timestamps, flags, relations, etc.) as strong struct signal

tools/jsontypes/analyzer_test.go

@@ -517,9 +517,11 @@ func TestDecideMapOrStructDefault(t *testing.T) {
 		},
 	})
 
+	// Use 2 keys that aren't known field names — ambiguous enough to
+	// trigger the resolver (not confident either way).
 	obj := map[string]any{
-		"errors": []any{},
-		"rooms":  []any{map[string]any{"name": "foo"}},
+		"foo": []any{},
+		"bar": []any{map[string]any{"x": "y"}},
 	}
 	a.Analyze(".", obj)
 

tools/jsontypes/cmd/jsonrawpaths/main.go

@@ -0,0 +1,36 @@
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"os"
+
+	"github.com/therootcompany/golib/tools/jsontypes"
+)
+
+func main() {
+	var input *os.File
+	if len(os.Args) > 1 && os.Args[1] != "-" {
+		f, err := os.Open(os.Args[1])
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "error: %v\n", err)
+			os.Exit(1)
+		}
+		defer f.Close()
+		input = f
+	} else {
+		input = os.Stdin
+	}
+
+	var data any
+	dec := json.NewDecoder(input)
+	dec.UseNumber()
+	if err := dec.Decode(&data); err != nil {
+		fmt.Fprintf(os.Stderr, "error parsing JSON: %v\n", err)
+		os.Exit(1)
+	}
+
+	for _, path := range jsontypes.RawPaths(data) {
+		fmt.Println(path)
+	}
+}

tools/jsontypes/heuristics.go

@@ -14,12 +14,8 @@ import (
 func looksLikeMap(obj map[string]any) (isMap bool, confident bool) {
 	keys := sortedKeys(obj)
 	n := len(keys)
-	if n < 3 {
-		// Too few keys to be confident about anything
-		return false, false
-	}
 
-	// All keys are integers?
+	// All keys are integers → always a map, even with 1 key.
 	allInts := true
 	for _, k := range keys {
 		if _, err := strconv.ParseInt(k, 10, 64); err != nil {
@@ -27,28 +23,39 @@ func looksLikeMap(obj map[string]any) (isMap bool, confident bool) {
 			break
 		}
 	}
-	if allInts {
+	if allInts && n > 0 {
 		return true, true
 	}
 
-	// All keys same length and contain mixed letters+digits → likely IDs
-	if allSameLength(keys) && allAlphanumericWithDigits(keys) {
+	// If any key is a well-known struct field name, it's definitely a struct.
+	// This catches 1-2 key objects like {"name": ..., "age": ...}.
+	if hasKnownFieldName(keys) {
+		return false, true
+	}
+
+	// All keys contain mixed letters+digits → likely IDs (e.g., "emp_101").
+	if allContainDigits(keys) {
 		return true, true
 	}
 
-	// All keys same length and look like base64/hex IDs
+	// All keys same length and look like base64/hex IDs.
 	if allSameLength(keys) && allLookLikeIDs(keys) {
 		return true, true
 	}
 
-	// Keys look like typical struct field names (camelCase, snake_case, short words)
+	if n < 3 {
+		// Too few keys and no strong signal either way.
+		return false, false
+	}
+
+	// Keys look like typical struct field names (camelCase, snake_case, short words).
 	// This must be checked before value-shape heuristics: a struct with many
 	// fields whose values happen to share a shape is still a struct.
 	if allLookLikeFieldNames(keys) {
 		return false, true
 	}
 
-	// Large number of keys where most values have the same shape — likely a map
+	// Large number of keys where most values have the same shape → likely a map.
 	if n > 20 && valuesHaveSimilarShape(obj) {
 		return true, true
 	}
@@ -56,6 +63,122 @@ func looksLikeMap(obj map[string]any) (isMap bool, confident bool) {
 	return false, false
 }
 
+// hasKnownFieldName returns true if any key matches a well-known struct field
+// name. A single match is a strong signal — real maps don't have keys named
+// "created_at" or "email".
+func hasKnownFieldName(keys []string) bool {
+	for _, k := range keys {
+		if isKnownFieldName(k) {
+			return true
+		}
+	}
+	return false
+}
+
+// isKnownFieldName checks whether a key is a common struct/object field name.
+// This is deliberately broad — false positives (calling a map key a field)
+// are less harmful than false negatives (treating a struct as a map).
+func isKnownFieldName(k string) bool {
+	lower := strings.ToLower(k)
+
+	// Suffix patterns: timestamps, flags, relations
+	suffixes := []string{
+		"_at", "_on", "_by", "_id", "_ids", "_url", "_uri",
+		"_name", "_type", "_kind", "_key", "_code", "_date",
+		"_count", "_size", "_path", "_hash", "_token",
+		"_enabled", "_disabled", "_active", "_status",
+	}
+	for _, s := range suffixes {
+		if strings.HasSuffix(lower, s) {
+			return true
+		}
+	}
+	// camelCase suffixes
+	camelSuffixes := []string{
+		"At", "On", "By", "Id", "Ids", "Url", "Uri",
+		"Name", "Type", "Kind", "Key", "Code", "Date",
+		"Count", "Size", "Path", "Hash", "Token",
+	}
+	for _, s := range camelSuffixes {
+		if strings.HasSuffix(k, s) && len(k) > len(s) {
+			return true
+		}
+	}
+
+	// Exact matches: common field names across APIs
+	switch lower {
+	case
+		// identity
+		"id", "uid", "uuid", "guid", "slug",
+		// naming
+		"name", "title", "label", "description", "summary",
+		// typing/classification
+		"type", "kind", "category", "class", "role", "status", "state",
+		// content
+		"value", "data", "content", "body", "text", "message", "comment",
+		"url", "uri", "href", "link", "path",
+		"email", "phone", "address",
+		// flags
+		"active", "enabled", "disabled", "visible", "hidden",
+		"required", "optional", "readonly", "deleted", "archived",
+		"public", "private", "verified", "approved", "published",
+		// numbers
+		"count", "total", "size", "length", "width", "height",
+		"amount", "price", "cost", "quantity", "weight",
+		"score", "rating", "level", "priority", "order", "index", "position",
+		"version", "revision",
+		"min", "max", "limit", "offset", "page",
+		"latitude", "longitude", "lat", "lng", "lon",
+		// structure
+		"parent", "children", "items", "entries", "results", "records",
+		"tags", "labels", "groups", "members", "users", "roles",
+		"permissions", "scopes", "features", "options", "settings",
+		"config", "configuration", "preferences", "metadata", "meta",
+		"errors", "warnings",
+		// media
+		"format", "encoding", "charset", "locale", "language", "currency",
+		"color", "icon", "image", "avatar", "thumbnail", "logo",
+		"filename", "extension", "mimetype",
+		// auth
+		"username", "password", "token", "secret", "credential",
+		// time
+		"date", "time", "timestamp", "duration", "interval",
+		"start", "end", "expires":
+		return true
+	}
+
+	// Prefix patterns: is_*, has_*, can_*, should_*, allow_*
+	prefixes := []string{"is_", "has_", "can_", "should_", "allow_", "num_"}
+	for _, p := range prefixes {
+		if strings.HasPrefix(lower, p) {
+			return true
+		}
+	}
+
+	return false
+}
+
+// allContainDigits checks if every key contains at least one digit,
+// suggesting they are IDs rather than field names (e.g., "emp_101", "abc123").
+func allContainDigits(keys []string) bool {
+	if len(keys) == 0 {
+		return false
+	}
+	for _, k := range keys {
+		hasDigit := false
+		for _, r := range k {
+			if unicode.IsDigit(r) {
+				hasDigit = true
+				break
+			}
+		}
+		if !hasDigit {
+			return false
+		}
+	}
+	return true
+}
+
 func allSameLength(keys []string) bool {
 	if len(keys) == 0 {
 		return true
@@ -99,25 +222,7 @@ func isAlphanumeric(s string) bool {
 	return true
 }
 
-// allAlphanumericWithDigits checks if all keys are alphanumeric and each
-// contains at least one digit (distinguishing IDs like "abc123" from field
-// names like "name").
-func allAlphanumericWithDigits(keys []string) bool {
-	for _, k := range keys {
-		hasDigit := false
-		for _, r := range k {
-			if unicode.IsDigit(r) {
-				hasDigit = true
-			} else if !unicode.IsLetter(r) {
-				return false
-			}
-		}
-		if !hasDigit {
-			return false
-		}
-	}
-	return true
-}
+
 
 func isBase64(s string) bool {
 	// Try standard and URL-safe base64

tools/jsontypes/rawpaths.go

@@ -0,0 +1,218 @@
+package jsontypes
+
+import (
+	"encoding/json"
+	"fmt"
+)
+
+// RawPaths walks a decoded JSON value depth-first and emits flat paths with
+// monotonically numbered type names. Every struct shape gets a unique name
+// derived from its parent path segment and a global counter (e.g., Root0,
+// People2, People3). Type intros appear immediately before their fields,
+// making the output streamable and order-stable.
+//
+// The value must have been decoded with json.Decoder.UseNumber() so that
+// integers and floats are distinguishable.
+func RawPaths(v any) []string {
+	w := &rawWalker{}
+	w.walk(".", v)
+	return w.paths
+}
+
+type rawWalker struct {
+	counter int
+	paths   []string
+}
+
+func (w *rawWalker) emit(path string) {
+	w.paths = append(w.paths, path)
+}
+
+func (w *rawWalker) nextName(path string) string {
+	name := inferTypeName(path)
+	id := w.counter
+	w.counter++
+	return fmt.Sprintf("%s%d", name, id)
+}
+
+func (w *rawWalker) walk(prefix string, v any) {
+	switch val := v.(type) {
+	case nil:
+		w.emit(prefix + "{null}")
+	case bool:
+		w.emit(prefix + "{bool}")
+	case json.Number:
+		if _, err := val.Int64(); err == nil {
+			w.emit(prefix + "{int}")
+		} else {
+			w.emit(prefix + "{float}")
+		}
+	case string:
+		w.emit(prefix + "{string}")
+	case map[string]any:
+		w.walkObject(prefix, val)
+	case []any:
+		w.walkArray(prefix, val)
+	}
+}
+
+func (w *rawWalker) walkObject(prefix string, obj map[string]any) {
+	if len(obj) == 0 {
+		w.emit(prefix + "{any}")
+		return
+	}
+
+	isMap, _ := looksLikeMap(obj)
+	if isMap {
+		w.walkMap(prefix, obj)
+		return
+	}
+
+	w.walkStruct(prefix, []map[string]any{obj})
+}
+
+func (w *rawWalker) walkMap(prefix string, obj map[string]any) {
+	keyName := inferKeyName(obj)
+	mapPrefix := prefix + "[" + keyName + "]"
+
+	// Collect all values and walk as a collection.
+	values := make([]any, 0, len(obj))
+	for _, v := range obj {
+		values = append(values, v)
+	}
+	w.walkCollection(mapPrefix, values)
+}
+
+func (w *rawWalker) walkStruct(prefix string, instances []map[string]any) {
+	merged := mergeObjects(instances)
+	typeName := w.nextName(prefix)
+	typePrefix := prefix + "{" + typeName + "}"
+
+	// Emit type intro.
+	w.emit(typePrefix)
+
+	keys := sortedKeys(merged)
+	for _, k := range keys {
+		// Collect all values for this field across instances.
+		var fieldVals []any
+		for _, inst := range instances {
+			if v, ok := inst[k]; ok {
+				fieldVals = append(fieldVals, v)
+			} else {
+				fieldVals = append(fieldVals, nil)
+			}
+		}
+		w.walkCollection(typePrefix+"."+k, fieldVals)
+	}
+}
+
+func (w *rawWalker) walkArray(prefix string, arr []any) {
+	if len(arr) == 0 {
+		w.emit(prefix + "[]{any}")
+		return
+	}
+
+	if isTupleCandidate(arr) {
+		w.walkTuple(prefix, arr)
+		return
+	}
+
+	w.walkCollection(prefix+"[]", arr)
+}
+
+func (w *rawWalker) walkTuple(prefix string, arr []any) {
+	for i, v := range arr {
+		w.walk(fmt.Sprintf("%s[%d]", prefix, i), v)
+	}
+}
+
+// walkCollection handles multiple values at the same path position (array
+// elements, map values, or field values across struct instances). It groups
+// objects by shape and walks each shape separately.
+func (w *rawWalker) walkCollection(prefix string, values []any) {
+	// Separate by kind: objects, primitives/arrays, nulls.
+	type shapeInstances struct {
+		sig       string
+		instances []map[string]any
+	}
+	var shapes []shapeInstances
+	shapeIndex := make(map[string]int)
+	hasNull := false
+	var nonObjects []any
+
+	for _, v := range values {
+		switch val := v.(type) {
+		case nil:
+			hasNull = true
+		case map[string]any:
+			sig := shapeSignature(val)
+			if idx, ok := shapeIndex[sig]; ok {
+				shapes[idx].instances = append(shapes[idx].instances, val)
+			} else {
+				shapeIndex[sig] = len(shapes)
+				shapes = append(shapes, shapeInstances{sig, []map[string]any{val}})
+			}
+		default:
+			nonObjects = append(nonObjects, val)
+		}
+	}
+
+	// Emit null if seen.
+	if hasNull {
+		w.emit(prefix + "{null}")
+	}
+
+	// Emit each object shape. If a shape has exactly one instance and it
+	// looks like a map, walk it as a map instead of a struct.
+	for _, shape := range shapes {
+		if len(shape.instances) == 1 {
+			obj := shape.instances[0]
+			isMap, _ := looksLikeMap(obj)
+			if isMap {
+				w.walkMap(prefix, obj)
+				continue
+			}
+		}
+		w.walkStruct(prefix, shape.instances)
+	}
+
+	// Emit primitive/array types (deduplicated).
+	seen := make(map[string]bool)
+	for _, v := range nonObjects {
+		switch val := v.(type) {
+		case json.Number:
+			var typ string
+			if _, err := val.Int64(); err == nil {
+				typ = "int"
+			} else {
+				typ = "float"
+			}
+			if !seen[typ] {
+				seen[typ] = true
+				w.emit(prefix + "{" + typ + "}")
+			}
+		case string:
+			if !seen["string"] {
+				seen["string"] = true
+				w.emit(prefix + "{string}")
+			}
+		case bool:
+			if !seen["bool"] {
+				seen["bool"] = true
+				w.emit(prefix + "{bool}")
+			}
+		case []any:
+			// Nested arrays — walk once.
+			if !seen["array"] {
+				seen["array"] = true
+				w.walkArray(prefix, val)
+			}
+		}
+	}
+
+	// If nothing was emitted (all nils, empty), emit any.
+	if !hasNull && len(shapes) == 0 && len(nonObjects) == 0 {
+		w.emit(prefix + "{any}")
+	}
+}
+