diff --git a/common/json-schema-to-grammar.cpp b/common/json-schema-to-grammar.cpp
index c3b4e5d9dc..2f67c74d79 100644
--- a/common/json-schema-to-grammar.cpp
+++ b/common/json-schema-to-grammar.cpp
@@ -305,8 +305,9 @@ static std::string format_literal(const std::string & literal) {
 
 std::string gbnf_format_literal(const std::string & literal) { return format_literal(literal); }
 
-class SchemaConverter {
+class common_schema_converter {
 private:
+    friend class common_schema_info;
     friend std::string build_grammar(const std::function<void(const common_grammar_builder &)> & cb, const common_grammar_options & options);
     std::function<json(const std::string &)> _fetch_json;
     bool _dotall;
@@ -729,7 +730,7 @@ private:
     }
 
 public:
-    SchemaConverter(
+    common_schema_converter(
         const std::function<json(const std::string &)> & fetch_json,
         bool dotall)
           : _fetch_json(fetch_json), _dotall(dotall)
@@ -990,6 +991,134 @@ public:
     }
 };
 
+// common_schema_info implementation (pimpl)
+
+common_schema_info::common_schema_info()
+    : impl_(std::make_unique<common_schema_converter>(
+        [](const std::string &) { return json(); },
+        false)) {}
+
+common_schema_info::~common_schema_info() = default;
+
+common_schema_info::common_schema_info(common_schema_info &&) noexcept = default;
+common_schema_info & common_schema_info::operator=(common_schema_info &&) noexcept = default;
+
+void common_schema_info::resolve_refs(nlohmann::ordered_json & schema) {
+    impl_->resolve_refs(schema, "");
+}
+
+// Determines if a JSON schema can resolve to a string type through any path.
+// Some models emit raw string values rather than JSON-encoded strings for string parameters.
+// If any branch of the schema (via oneOf, anyOf, $ref, etc.) permits a string, this returns
+// true, allowing callers to handle the value as a raw string for simplicity.
+bool common_schema_info::resolves_to_string(const nlohmann::ordered_json & schema) {
+    std::unordered_set<std::string> visited_refs;
+
+    std::function<bool(const json &)> check = [&](const json & s) -> bool {
+        if (!s.is_object()) {
+            return false;
+        }
+
+        // Handle $ref
+        if (s.contains("$ref")) {
+            const std::string & ref = s["$ref"];
+            if (visited_refs.find(ref) != visited_refs.end()) {
+                // Circular reference, assume not a string to be safe
+                return false;
+            }
+            visited_refs.insert(ref);
+            auto it = impl_->_refs.find(ref);
+            if (it != impl_->_refs.end()) {
+                return check(it->second);
+            }
+            return false;
+        }
+
+        // Check type field
+        if (s.contains("type")) {
+            const json & schema_type = s["type"];
+            if (schema_type.is_string()) {
+                if (schema_type == "string") {
+                    return true;
+                }
+            } else if (schema_type.is_array()) {
+                // Type can be an array like ["string", "null"]
+                for (const auto & t : schema_type) {
+                    if (t == "string") {
+                        return true;
+                    }
+                }
+            }
+        }
+
+        // Check oneOf/anyOf - if any alternative can be a string
+        if (s.contains("oneOf")) {
+            for (const auto & alt : s["oneOf"]) {
+                if (check(alt)) {
+                    return true;
+                }
+            }
+        }
+        if (s.contains("anyOf")) {
+            for (const auto & alt : s["anyOf"]) {
+                if (check(alt)) {
+                    return true;
+                }
+            }
+        }
+
+        // Check allOf - all components must be compatible with string type
+        if (s.contains("allOf")) {
+            bool all_string = true;
+            for (const auto & component : s["allOf"]) {
+                if (!check(component)) {
+                    all_string = false;
+                    break;
+                }
+            }
+            if (all_string) {
+                return true;
+            }
+        }
+
+        // Check const - if the constant value is a string
+        if (s.contains("const")) {
+            if (s["const"].is_string()) {
+                return true;
+            }
+        }
+
+        // Check enum - if any enum value is a string
+        if (s.contains("enum")) {
+            for (const auto & val : s["enum"]) {
+                if (val.is_string()) {
+                    return true;
+                }
+            }
+        }
+
+        // String-specific keywords imply string type
+        if (s.contains("pattern") || s.contains("minLength") || s.contains("maxLength")) {
+            return true;
+        }
+
+        // Check format - many formats imply string
+        if (s.contains("format")) {
+            const std::string & fmt = s["format"];
+            if (fmt == "date" || fmt == "time" || fmt == "date-time" ||
+                fmt == "uri" || fmt == "email" || fmt == "hostname" ||
+                fmt == "ipv4" || fmt == "ipv6" || fmt == "uuid" ||
+                fmt.find("uuid") == 0) {
+                return true;
+            }
+        }
+
+        return false;
+    };
+
+    return check(schema);
+}
+
 std::string json_schema_to_grammar(const json & schema, bool force_gbnf) {
 #ifdef LLAMA_USE_LLGUIDANCE
     if (!force_gbnf) {
@@ -1006,7 +1135,7 @@ std::string json_schema_to_grammar(const json & schema, bool force_gbnf) {
 }
 
 std::string build_grammar(const std::function<void(const common_grammar_builder &)> & cb, const common_grammar_options & options) {
-    SchemaConverter converter([&](const std::string &) { return json(); }, options.dotall);
+    common_schema_converter converter([&](const std::string &) { return json(); }, options.dotall);
     common_grammar_builder builder {
         /* .add_rule = */ [&](const std::string & name, const std::string & rule) {
             return converter._add_rule(name, rule);
diff --git a/common/json-schema-to-grammar.h b/common/json-schema-to-grammar.h
index c89ab7f997..240d642311 100644
--- a/common/json-schema-to-grammar.h
+++ b/common/json-schema-to-grammar.h
@@ -3,11 +3,31 @@
 #include <nlohmann/json_fwd.hpp>
 
 #include <functional>
+#include <memory>
 #include <string>
 
 std::string json_schema_to_grammar(const nlohmann::ordered_json & schema,
                                    bool force_gbnf = false);
 
+class common_schema_converter;
+
+// Probes a JSON schema to extract information about its structure and type constraints.
+class common_schema_info {
+    std::unique_ptr<common_schema_converter> impl_;
+
+  public:
+    common_schema_info();
+    ~common_schema_info();
+
+    common_schema_info(const common_schema_info &) = delete;
+    common_schema_info & operator=(const common_schema_info &) = delete;
+    common_schema_info(common_schema_info &&) noexcept;
+    common_schema_info & operator=(common_schema_info &&) noexcept;
+
+    void resolve_refs(nlohmann::ordered_json & schema);
+    bool resolves_to_string(const nlohmann::ordered_json & schema);
+};
+
 struct common_grammar_builder {
     std::function<std::string(const std::string &, const std::string &)> add_rule;
     std::function<std::string(const std::string &, const nlohmann::ordered_json &)> add_schema;
diff --git a/tests/test-json-schema-to-grammar.cpp b/tests/test-json-schema-to-grammar.cpp
index 6a4bd8fb4d..a8e9ff33a4 100755
--- a/tests/test-json-schema-to-grammar.cpp
+++ b/tests/test-json-schema-to-grammar.cpp
@@ -1367,10 +1367,85 @@ static void test_all(const std::string & lang, std::function<void(const TestCase
     });
 }
 
+static void test_resolves_to_string() {
+    fprintf(stderr, "#\n# Testing resolves_to_string\n#\n");
+
+    auto test = [](const std::string & name, const std::string & schema_str, bool expected) {
+        fprintf(stderr, "- %s\n", name.c_str());
+        common_schema_info info;
+        auto schema = nlohmann::ordered_json::parse(schema_str);
+        info.resolve_refs(schema);
+        bool result = info.resolves_to_string(schema);
+        if (result != expected) {
+            fprintf(stderr, "#\n# Test '%s' failed.\n#\n", name.c_str());
+            fprintf(stderr, "Schema: %s\n", schema_str.c_str());
+            fprintf(stderr, "Expected: %s, Got: %s\n", expected ? "true" : "false", result ? "true" : "false");
+            assert(false);
+        }
+    };
+
+    // Basic type checks
+    test("type string", R"({"type": "string"})", true);
+    test("type integer", R"({"type": "integer"})", false);
+    test("type number", R"({"type": "number"})", false);
+    test("type boolean", R"({"type": "boolean"})", false);
+    test("type object", R"({"type": "object"})", false);
+    test("type array", R"({"type": "array"})", false);
+
+    // Type array (nullable string)
+    test("type array with string", R"({"type": ["string", "null"]})", true);
+    test("type array without string", R"({"type": ["integer", "null"]})", false);
+
+    // String-specific keywords
+    test("minLength implies string", R"({"minLength": 1})", true);
+    test("maxLength implies string", R"({"maxLength": 10})", true);
+    test("pattern implies string", R"({"pattern": "^[a-z]+$"})", true);
+
+    // Format
+    test("format date", R"({"format": "date"})", true);
+    test("format uuid", R"({"format": "uuid"})", true);
+    test("format email", R"({"format": "email"})", true);
+
+    // Const
+    test("const string", R"({"const": "hello"})", true);
+    test("const number", R"({"const": 123})", false);
+
+    // Enum
+    test("enum with strings", R"({"enum": ["a", "b", "c"]})", true);
+    test("enum with numbers", R"({"enum": [1, 2, 3]})", false);
+    test("enum mixed with string", R"({"enum": [1, "a", null]})", true);
+
+    // anyOf
+    test("anyOf with string", R"({"anyOf": [{"type": "string"}, {"type": "integer"}]})", true);
+    test("anyOf without string", R"({"anyOf": [{"type": "integer"}, {"type": "boolean"}]})", false);
+
+    // oneOf
+    test("oneOf with string", R"({"oneOf": [{"type": "string"}, {"type": "number"}]})", true);
+    test("oneOf without string", R"({"oneOf": [{"type": "object"}, {"type": "array"}]})", false);
+
+    // allOf - all must be strings
+    test("allOf all strings", R"({"allOf": [{"type": "string"}, {"minLength": 1}]})", true);
+    test("allOf mixed types", R"({"allOf": [{"type": "string"}, {"type": "integer"}]})", false);
+
+    // $ref
+    test("$ref to string",
+        R"({"$ref": "#/$defs/str", "$defs": {"str": {"type": "string"}}})", true);
+    test("$ref to integer",
+        R"({"$ref": "#/$defs/num", "$defs": {"num": {"type": "integer"}}})", false);
+
+    // Nested
+    test("nested anyOf with string",
+        R"({"anyOf": [{"anyOf": [{"type": "integer"}, {"type": "string"}]}, {"type": "boolean"}]})", true);
+
+    fprintf(stderr, "All resolves_to_string tests passed!\n");
+}
+
 int main() {
     fprintf(stderr, "LLAMA_NODE_AVAILABLE = %s\n", getenv("LLAMA_NODE_AVAILABLE") ? "true" : "false");
     fprintf(stderr, "LLAMA_PYTHON_AVAILABLE = %s\n", getenv("LLAMA_PYTHON_AVAILABLE") ? "true" : "false");
 
+    test_resolves_to_string();
+
     test_all("C++", [](const TestCase & tc) {
         try {
             tc.verify(json_schema_to_grammar(nlohmann::ordered_json::parse(tc.schema), true));