diff --git a/.gitmodules b/.gitmodules
index 0f46dd90..82388e15 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -17,9 +17,9 @@
 [submodule "gpt4all-chat/deps/QXlsx"]
 	path = gpt4all-chat/deps/QXlsx
 	url = https://github.com/nomic-ai/QXlsx.git
-[submodule "gpt4all-chat/deps/Jinja2Cpp"]
-	path = gpt4all-chat/deps/Jinja2Cpp
-	url = https://github.com/nomic-ai/jinja2cpp.git
-[submodule "gpt4all-chat/deps/rapidjson"]
-	path = gpt4all-chat/deps/rapidjson
-	url = https://github.com/nomic-ai/rapidjson.git
+[submodule "gpt4all-chat/deps/minja"]
+	path = gpt4all-chat/deps/minja
+	url = https://github.com/nomic-ai/minja.git
+[submodule "gpt4all-chat/deps/json"]
+	path = gpt4all-chat/deps/json
+	url = https://github.com/nlohmann/json.git
diff --git a/gpt4all-chat/CHANGELOG.md b/gpt4all-chat/CHANGELOG.md
index 2eeea4d5..31fc996a 100644
--- a/gpt4all-chat/CHANGELOG.md
+++ b/gpt4all-chat/CHANGELOG.md
@@ -9,6 +9,9 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/).
 ### Added
 - Support DeepSeek-R1 Qwen models ([#3431](https://github.com/nomic-ai/gpt4all/pull/3431))
 
+### Changed
+- Use minja instead of Jinja2Cpp for significantly improved template compatibility ([#3433](https://github.com/nomic-ai/gpt4all/pull/3433))
+
 ### Fixed
 - Fix regression while using localdocs with server API ([#3410](https://github.com/nomic-ai/gpt4all/pull/3410))
 - Don't show system messages in server chat view ([#3411](https://github.com/nomic-ai/gpt4all/pull/3411))
diff --git a/gpt4all-chat/CMakeLists.txt b/gpt4all-chat/CMakeLists.txt
index ebd6a544..4a32abc0 100644
--- a/gpt4all-chat/CMakeLists.txt
+++ b/gpt4all-chat/CMakeLists.txt
@@ -51,7 +51,7 @@ set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
 set(CMAKE_CXX_STANDARD 23)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
 if (MSVC)
-    # Enable accurate __cplusplus macro to fix errors in Jinja2Cpp
+    # Enable accurate __cplusplus macro
     add_compile_options($<$<COMPILE_LANGUAGE:CXX>:/Zc:__cplusplus>)
 endif()
 
@@ -437,7 +437,10 @@ else()
     target_link_libraries(chat PRIVATE pdfium)
 endif()
 target_link_libraries(chat
-    PRIVATE llmodel SingleApplication fmt::fmt duckx::duckx QXlsx jinja2cpp)
+    PRIVATE llmodel SingleApplication fmt::fmt duckx::duckx QXlsx)
+target_include_directories(chat PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/deps/json/include)
+target_include_directories(chat PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/deps/json/include/nlohmann)
+target_include_directories(chat PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/deps/minja/include)
 
 if (APPLE)
     target_link_libraries(chat PRIVATE ${COCOA_LIBRARY})
diff --git a/gpt4all-chat/deps/CMakeLists.txt b/gpt4all-chat/deps/CMakeLists.txt
index e41dc1c2..898cd889 100644
--- a/gpt4all-chat/deps/CMakeLists.txt
+++ b/gpt4all-chat/deps/CMakeLists.txt
@@ -15,15 +15,6 @@ add_subdirectory(DuckX)
 set(QT_VERSION_MAJOR 6)
 add_subdirectory(QXlsx/QXlsx)
 
-# forked dependency of Jinja2Cpp
-set(RAPIDJSON_BUILD_DOC                  OFF)
-set(RAPIDJSON_BUILD_EXAMPLES             OFF)
-set(RAPIDJSON_BUILD_TESTS                OFF)
-set(RAPIDJSON_ENABLE_INSTRUMENTATION_OPT OFF)
-add_subdirectory(rapidjson)
-
-add_subdirectory(Jinja2Cpp)
-
 if (NOT GPT4ALL_USING_QTPDF)
     # If we do not use QtPDF, we need to get PDFium.
     set(GPT4ALL_PDFIUM_TAG "chromium/6954")
diff --git a/gpt4all-chat/deps/Jinja2Cpp b/gpt4all-chat/deps/Jinja2Cpp
deleted file mode 160000
index ce10f783..00000000
--- a/gpt4all-chat/deps/Jinja2Cpp
+++ /dev/null
@@ -1 +0,0 @@
-Subproject commit ce10f783bae46ede6afa4b09a8a169ebe88a14d4
diff --git a/gpt4all-chat/deps/json b/gpt4all-chat/deps/json
new file mode 160000
index 00000000..606b6347
--- /dev/null
+++ b/gpt4all-chat/deps/json
@@ -0,0 +1 @@
+Subproject commit 606b6347edf0758c531abb6c36743e09a4c48a84
diff --git a/gpt4all-chat/deps/minja b/gpt4all-chat/deps/minja
new file mode 160000
index 00000000..491f5cb2
--- /dev/null
+++ b/gpt4all-chat/deps/minja
@@ -0,0 +1 @@
+Subproject commit 491f5cb2e9925644bca2dddf09200042fa54bef4
diff --git a/gpt4all-chat/deps/rapidjson b/gpt4all-chat/deps/rapidjson
deleted file mode 160000
index 9b547ef4..00000000
--- a/gpt4all-chat/deps/rapidjson
+++ /dev/null
@@ -1 +0,0 @@
-Subproject commit 9b547ef4bd86210ef084abc2790bd1ddfe66b592
diff --git a/gpt4all-chat/src/chatllm.cpp b/gpt4all-chat/src/chatllm.cpp
index 17bdec77..faded163 100644
--- a/gpt4all-chat/src/chatllm.cpp
+++ b/gpt4all-chat/src/chatllm.cpp
@@ -12,12 +12,8 @@
 #include "toolcallparser.h"
 
 #include <fmt/format.h>
-
-#include <jinja2cpp/error_info.h>
-#include <jinja2cpp/template.h>
-#include <jinja2cpp/template_env.h>
-#include <jinja2cpp/user_callable.h>
-#include <jinja2cpp/value.h>
+#include <minja/minja.hpp>
+#include <nlohmann/json.hpp>
 
 #include <QDataStream>
 #include <QDebug>
@@ -60,59 +56,40 @@
 using namespace Qt::Literals::StringLiterals;
 using namespace ToolEnums;
 namespace ranges = std::ranges;
+using json = nlohmann::ordered_json;
 
 //#define DEBUG
 //#define DEBUG_MODEL_LOADING
 
-static std::string jinjaGetStringArg(const jinja2::ValuesMap &args, const std::string &name)
-{
-    auto arg = args.find(name);
-    if (arg == args.end() || !arg->second.isString())
-        throw std::runtime_error(fmt::format("'{}' argument to raise_exception() must be a string", name));
-    return arg->second.asString();
-}
-
 // NOTE: not threadsafe
-static jinja2::TemplateEnv *jinjaEnv()
+static const std::shared_ptr<minja::Context> &jinjaEnv()
 {
-    static std::optional<jinja2::TemplateEnv> environment;
+    static std::shared_ptr<minja::Context> environment;
     if (!environment) {
-        auto &env = environment.emplace();
-        auto &settings = env.GetSettings();
-        settings.trimBlocks = true;
-        settings.lstripBlocks = true;
-        env.AddGlobal("raise_exception", jinja2::UserCallable(
-            /*callable*/ [](auto &params) -> jinja2::Value {
-                auto message = jinjaGetStringArg(params.args, "message");
-                throw std::runtime_error(fmt::format("Jinja template error: {}", message));
-            },
-            /*argsInfo*/ { jinja2::ArgInfo("message", /*isMandatory*/ true) }
-        ));
-        env.AddGlobal("strftime_now", jinja2::UserCallable(
-            /*callable*/ [](auto &params) -> jinja2::Value {
+        environment = minja::Context::builtins();
+        environment->set("strftime_now", minja::simple_function(
+            "strftime_now", { "format" },
+            [](const std::shared_ptr<minja::Context> &, minja::Value &args) -> minja::Value {
+                auto format = args.at("format").get<std::string>();
                 using Clock = std::chrono::system_clock;
-                auto format = jinjaGetStringArg(params.args, "format");
                 time_t nowUnix = Clock::to_time_t(Clock::now());
                 auto localDate = *std::localtime(&nowUnix);
                 std::ostringstream ss;
                 ss << std::put_time(&localDate, format.c_str());
                 return ss.str();
-            },
-            /*argsInfo*/ { jinja2::ArgInfo("format", /*isMandatory*/ true) }
+            }
         ));
-        env.AddGlobal("regex_replace", jinja2::UserCallable(
-            /*callable*/ [](auto &params) -> jinja2::Value {
-                auto str     = jinjaGetStringArg(params.args, "str"    );
-                auto pattern = jinjaGetStringArg(params.args, "pattern");
-                auto repl    = jinjaGetStringArg(params.args, "repl"   );
+        environment->set("regex_replace", minja::simple_function(
+            "regex_replace", { "str", "pattern", "repl" },
+            [](const std::shared_ptr<minja::Context> &, minja::Value &args) -> minja::Value {
+                auto str     = args.at("str"    ).get<std::string>();
+                auto pattern = args.at("pattern").get<std::string>();
+                auto repl    = args.at("repl"   ).get<std::string>();
                 return std::regex_replace(str, std::regex(pattern), repl);
-            },
-            /*argsInfo*/ { jinja2::ArgInfo("str",     /*isMandatory*/ true),
-                           jinja2::ArgInfo("pattern", /*isMandatory*/ true),
-                           jinja2::ArgInfo("repl",    /*isMandatory*/ true) }
+            }
         ));
     }
-    return &*environment;
+    return environment;
 }
 
 class LLModelStore {
@@ -772,19 +749,18 @@ static uint parseJinjaTemplateVersion(QStringView tmpl)
     return 0;
 }
 
-static auto loadJinjaTemplate(
-    std::optional<jinja2::Template> &tmpl /*out*/, const std::string &source
-) -> jinja2::Result<void>
+static std::shared_ptr<minja::TemplateNode> loadJinjaTemplate(const std::string &source)
 {
-    tmpl.emplace(jinjaEnv());
-    return tmpl->Load(source);
+    return minja::Parser::parse(source, { .trim_blocks = true, .lstrip_blocks = true, .keep_trailing_newline = false });
 }
 
 std::optional<std::string> ChatLLM::checkJinjaTemplateError(const std::string &source)
 {
-    std::optional<jinja2::Template> tmpl;
-    if (auto res = loadJinjaTemplate(tmpl, source); !res)
-        return res.error().ToString();
+    try {
+        loadJinjaTemplate(source);
+    } catch (const std::runtime_error &e) {
+        return e.what();
+    }
     return std::nullopt;
 }
 
@@ -816,13 +792,13 @@ std::string ChatLLM::applyJinjaTemplate(std::span<const MessageItem> items) cons
     uint version = parseJinjaTemplateVersion(chatTemplate);
 
     auto makeMap = [version](const MessageItem &item) {
-        return jinja2::GenericMap([msg = std::make_shared<JinjaMessage>(version, item)] { return msg.get(); });
+        return JinjaMessage(version, item).AsJson();
     };
 
     std::unique_ptr<MessageItem> systemItem;
     bool useSystem = !isAllSpace(systemMessage);
 
-    jinja2::ValuesList messages;
+    json::array_t messages;
     messages.reserve(useSystem + items.size());
     if (useSystem) {
         systemItem = std::make_unique<MessageItem>(MessageItem::Type::System, systemMessage.toUtf8());
@@ -831,14 +807,14 @@ std::string ChatLLM::applyJinjaTemplate(std::span<const MessageItem> items) cons
     for (auto &item : items)
         messages.emplace_back(makeMap(item));
 
-    jinja2::ValuesList toolList;
+    json::array_t toolList;
     const int toolCount = ToolModel::globalInstance()->count();
     for (int i = 0; i < toolCount; ++i) {
         Tool *t = ToolModel::globalInstance()->get(i);
         toolList.push_back(t->jinjaValue());
     }
 
-    jinja2::ValuesMap params {
+    json::object_t params {
         { "messages",              std::move(messages) },
         { "add_generation_prompt", true                },
         { "toolList",              toolList            },
@@ -846,12 +822,14 @@ std::string ChatLLM::applyJinjaTemplate(std::span<const MessageItem> items) cons
     for (auto &[name, token] : model->specialTokens())
         params.emplace(std::move(name), std::move(token));
 
-    std::optional<jinja2::Template> tmpl;
-    auto maybeRendered = loadJinjaTemplate(tmpl, chatTemplate.toStdString())
-        .and_then([&] { return tmpl->RenderAsString(params); });
-    if (!maybeRendered)
-        throw std::runtime_error(fmt::format("Failed to parse chat template: {}", maybeRendered.error().ToString()));
-    return *maybeRendered;
+    try {
+        auto tmpl = loadJinjaTemplate(chatTemplate.toStdString());
+        auto context = minja::Context::make(minja::Value(std::move(params)), jinjaEnv());
+        return tmpl->render(context);
+    } catch (const std::runtime_error &e) {
+        throw std::runtime_error(fmt::format("Failed to parse chat template: {}", e.what()));
+    }
+    Q_UNREACHABLE();
 }
 
 auto ChatLLM::promptInternalChat(const QStringList &enabledCollections, const LLModel::PromptContext &ctx,
diff --git a/gpt4all-chat/src/jinja_helpers.cpp b/gpt4all-chat/src/jinja_helpers.cpp
index 133e58bc..9ae11f7d 100644
--- a/gpt4all-chat/src/jinja_helpers.cpp
+++ b/gpt4all-chat/src/jinja_helpers.cpp
@@ -7,111 +7,75 @@
 #include <QString>
 #include <QUrl>
 
-#include <memory>
+#include <iterator>
+#include <map>
+#include <ranges>
 #include <vector>
 
-using namespace std::literals::string_view_literals;
+namespace views  = std::views;
+using json = nlohmann::ordered_json;
 
 
-JinjaResultInfo::~JinjaResultInfo() = default;
-
-const JinjaFieldMap<ResultInfo> JinjaResultInfo::s_fields = {
-    { "collection", [](auto &s) { return s.collection.toStdString(); } },
-    { "path",       [](auto &s) { return s.path      .toStdString(); } },
-    { "file",       [](auto &s) { return s.file      .toStdString(); } },
-    { "title",      [](auto &s) { return s.title     .toStdString(); } },
-    { "author",     [](auto &s) { return s.author    .toStdString(); } },
-    { "date",       [](auto &s) { return s.date      .toStdString(); } },
-    { "text",       [](auto &s) { return s.text      .toStdString(); } },
-    { "page",       [](auto &s) { return s.page;                     } },
-    { "file_uri",   [](auto &s) { return s.fileUri() .toStdString(); } },
-};
-
-JinjaPromptAttachment::~JinjaPromptAttachment() = default;
-
-const JinjaFieldMap<PromptAttachment> JinjaPromptAttachment::s_fields = {
-    { "url",               [](auto &s) { return s.url.toString()    .toStdString(); } },
-    { "file",              [](auto &s) { return s.file()            .toStdString(); } },
-    { "processed_content", [](auto &s) { return s.processedContent().toStdString(); } },
-};
-
-std::vector<std::string> JinjaMessage::GetKeys() const
+json::object_t JinjaResultInfo::AsJson() const
 {
-    std::vector<std::string> result;
-    auto &keys = this->keys();
-    result.reserve(keys.size());
-    result.assign(keys.begin(), keys.end());
-    return result;
+    return {
+        { "collection", m_source->collection.toStdString() },
+        { "path",       m_source->path      .toStdString() },
+        { "file",       m_source->file      .toStdString() },
+        { "title",      m_source->title     .toStdString() },
+        { "author",     m_source->author    .toStdString() },
+        { "date",       m_source->date      .toStdString() },
+        { "text",       m_source->text      .toStdString() },
+        { "page",       m_source->page                     },
+        { "file_uri",   m_source->fileUri() .toStdString() },
+    };
 }
 
-auto JinjaMessage::keys() const -> const std::unordered_set<std::string_view> &
+json::object_t JinjaPromptAttachment::AsJson() const
 {
-    static const std::unordered_set<std::string_view> baseKeys
-        { "role", "content" };
-    static const std::unordered_set<std::string_view> userKeys
-        { "role", "content", "sources", "prompt_attachments" };
-    switch (m_item->type()) {
-        using enum MessageItem::Type;
-    case System:
-    case Response:
-    case ToolResponse:
-        return baseKeys;
-    case Prompt:
-        return userKeys;
-        break;
-    }
-    Q_UNREACHABLE();
+    return {
+        { "url",               m_attachment->url.toString()    .toStdString() },
+        { "file",              m_attachment->file()            .toStdString() },
+        { "processed_content", m_attachment->processedContent().toStdString() },
+    };
 }
 
-bool operator==(const JinjaMessage &a, const JinjaMessage &b)
+json::object_t JinjaMessage::AsJson() const
 {
-    if (a.m_item == b.m_item)
-        return true;
-    const auto &[ia, ib] = std::tie(*a.m_item, *b.m_item);
-    auto type = ia.type();
-    if (type != ib.type() || ia.content() != ib.content())
-        return false;
-
-    switch (type) {
-        using enum MessageItem::Type;
-    case System:
-    case Response:
-    case ToolResponse:
-        return true;
-    case Prompt:
-        return ia.sources() == ib.sources() && ia.promptAttachments() == ib.promptAttachments();
-        break;
-    }
-    Q_UNREACHABLE();
-}
-
-const JinjaFieldMap<JinjaMessage> JinjaMessage::s_fields = {
-    { "role", [](auto &m) {
-        switch (m.item().type()) {
+    json::object_t obj;
+    {
+        json::string_t role;
+        switch (m_item->type()) {
             using enum MessageItem::Type;
-            case System:   return "system"sv;
-            case Prompt:   return "user"sv;
-            case Response: return "assistant"sv;
-            case ToolResponse: return "tool"sv;
-                break;
+            case System:       role = "system";    break;
+            case Prompt:       role = "user";      break;
+            case Response:     role = "assistant"; break;
+            case ToolResponse: role = "tool";      break;
         }
-        Q_UNREACHABLE();
-    } },
-    { "content", [](auto &m) {
-        if (m.version() == 0 && m.item().type() == MessageItem::Type::Prompt)
-            return m.item().bakedPrompt().toStdString();
-        return m.item().content().toStdString();
-    } },
-    { "sources", [](auto &m) {
-        auto sources = m.item().sources() | views::transform([](auto &r) {
-            return jinja2::GenericMap([map = std::make_shared<JinjaResultInfo>(r)] { return map.get(); });
-        });
-        return jinja2::ValuesList(sources.begin(), sources.end());
-    } },
-    { "prompt_attachments", [](auto &m) {
-        auto attachments = m.item().promptAttachments() | views::transform([](auto &pa) {
-            return jinja2::GenericMap([map = std::make_shared<JinjaPromptAttachment>(pa)] { return map.get(); });
-        });
-        return jinja2::ValuesList(attachments.begin(), attachments.end());
-    } },
-};
+        obj.emplace_back("role", std::move(role));
+    }
+    {
+        QString content;
+        if (m_version == 0 && m_item->type() == MessageItem::Type::Prompt) {
+            content = m_item->bakedPrompt();
+        } else {
+            content = m_item->content();
+        }
+        obj.emplace_back("content", content.toStdString());
+    }
+    if (m_item->type() == MessageItem::Type::Prompt) {
+        {
+            auto sources = m_item->sources() | views::transform([](auto &r) {
+                return JinjaResultInfo(r).AsJson();
+            });
+            obj.emplace("sources", json::array_t(sources.begin(), sources.end()));
+        }
+        {
+            auto attachments = m_item->promptAttachments() | views::transform([](auto &pa) {
+                return JinjaPromptAttachment(pa).AsJson();
+            });
+            obj.emplace("prompt_attachments", json::array_t(attachments.begin(), attachments.end()));
+        }
+    }
+    return obj;
+}
diff --git a/gpt4all-chat/src/jinja_helpers.h b/gpt4all-chat/src/jinja_helpers.h
index f7f4ff9b..75dc1776 100644
--- a/gpt4all-chat/src/jinja_helpers.h
+++ b/gpt4all-chat/src/jinja_helpers.h
@@ -3,47 +3,17 @@
 #include "chatmodel.h"
 #include "database.h"
 
-#include <jinja2cpp/value.h>
-
-#include <functional>
-#include <ranges>
-#include <string>
-#include <string_view>
-#include <unordered_map>
-#include <unordered_set>
+#include <nlohmann/json.hpp>
 
 #include <QtGlobal>
 
-namespace views = std::views;
+using json = nlohmann::ordered_json;
 
 
-template <typename T>
-using JinjaFieldMap = std::unordered_map<std::string_view, std::function<jinja2::Value (const T &)>>;
-
 template <typename Derived>
-class JinjaComparable : public jinja2::IMapItemAccessor {
+class JinjaHelper {
 public:
-    JinjaComparable() = default;
-
-    bool IsEqual(const jinja2::IComparable &other) const override;
-
-private:
-    Q_DISABLE_COPY_MOVE(JinjaComparable)
-};
-
-template <typename Derived>
-class JinjaHelper : public JinjaComparable<Derived> {
-public:
-    size_t GetSize() const override
-    { return Derived::s_fields.size(); }
-
-    bool HasValue(const std::string &name) const override
-    { return Derived::s_fields.contains(name); }
-
-    jinja2::Value GetValueByName(const std::string &name) const override;
-
-    std::vector<std::string> GetKeys() const override
-    { auto keys = views::elements<0>(Derived::s_fields); return { keys.begin(), keys.end() }; }
+    json::object_t AsJson() const { return static_cast<const Derived *>(this)->AsJson(); }
 };
 
 class JinjaResultInfo : public JinjaHelper<JinjaResultInfo> {
@@ -51,18 +21,10 @@ public:
     explicit JinjaResultInfo(const ResultInfo &source) noexcept
         : m_source(&source) {}
 
-    ~JinjaResultInfo() override;
-
-    const ResultInfo &value() const { return *m_source; }
-
-    friend bool operator==(const JinjaResultInfo &a, const JinjaResultInfo &b)
-    { return a.m_source == b.m_source || *a.m_source == *b.m_source; }
+    json::object_t AsJson() const;
 
 private:
-    static const JinjaFieldMap<ResultInfo> s_fields;
     const ResultInfo *m_source;
-
-    friend class JinjaHelper<JinjaResultInfo>;
 };
 
 class JinjaPromptAttachment : public JinjaHelper<JinjaPromptAttachment> {
@@ -70,18 +32,10 @@ public:
     explicit JinjaPromptAttachment(const PromptAttachment &attachment) noexcept
         : m_attachment(&attachment) {}
 
-    ~JinjaPromptAttachment() override;
-
-    const PromptAttachment &value() const { return *m_attachment; }
-
-    friend bool operator==(const JinjaPromptAttachment &a, const JinjaPromptAttachment &b)
-    { return a.m_attachment == b.m_attachment || *a.m_attachment == *b.m_attachment; }
+    json::object_t AsJson() const;
 
 private:
-    static const JinjaFieldMap<PromptAttachment> s_fields;
     const PromptAttachment *m_attachment;
-
-    friend class JinjaHelper<JinjaPromptAttachment>;
 };
 
 class JinjaMessage : public JinjaHelper<JinjaMessage> {
@@ -89,28 +43,9 @@ public:
     explicit JinjaMessage(uint version, const MessageItem &item) noexcept
         : m_version(version), m_item(&item) {}
 
-    const JinjaMessage &value  () const { return *this;     }
-    uint                version() const { return m_version; }
-    const MessageItem      &item  () const { return *m_item;   }
-
-    size_t GetSize() const override { return keys().size(); }
-    bool HasValue(const std::string &name) const override { return keys().contains(name); }
-
-    jinja2::Value GetValueByName(const std::string &name) const override
-    { return HasValue(name) ? JinjaHelper::GetValueByName(name) : jinja2::EmptyValue(); }
-
-    std::vector<std::string> GetKeys() const override;
+    json::object_t AsJson() const;
 
 private:
-    auto keys() const -> const std::unordered_set<std::string_view> &;
-
-private:
-    static const JinjaFieldMap<JinjaMessage> s_fields;
-    uint            m_version;
+    uint               m_version;
     const MessageItem *m_item;
-
-    friend class JinjaHelper<JinjaMessage>;
-    friend bool operator==(const JinjaMessage &a, const JinjaMessage &b);
 };
-
-#include "jinja_helpers.inl"
diff --git a/gpt4all-chat/src/jinja_helpers.inl b/gpt4all-chat/src/jinja_helpers.inl
deleted file mode 100644
index a8ae938b..00000000
--- a/gpt4all-chat/src/jinja_helpers.inl
+++ /dev/null
@@ -1,17 +0,0 @@
-template <typename D>
-bool JinjaComparable<D>::IsEqual(const jinja2::IComparable &other) const
-{
-    if (auto *omsg = dynamic_cast<const D *>(&other))
-        return *static_cast<const D *>(this) == *omsg;
-    return false;
-}
-
-template <typename D>
-jinja2::Value JinjaHelper<D>::GetValueByName(const std::string &name) const
-{
-    if (auto it = D::s_fields.find(name); it != D::s_fields.end()) {
-        auto [_, func] = *it;
-        return func(static_cast<const D *>(this)->value());
-    }
-    return jinja2::EmptyValue();
-}
diff --git a/gpt4all-chat/src/jinja_replacements.cpp b/gpt4all-chat/src/jinja_replacements.cpp
index f86d28a9..d5e18074 100644
--- a/gpt4all-chat/src/jinja_replacements.cpp
+++ b/gpt4all-chat/src/jinja_replacements.cpp
@@ -5,26 +5,9 @@
 // This is a list of prompt templates known to GPT4All and their associated replacements which are automatically used
 // instead when loading the chat template from GGUF. These exist for two primary reasons:
 // - HuggingFace model authors make ugly chat templates because they do not expect the end user to see them;
-// - and our Jinja2Cpp-based template parsing is not fully compatible with HuggingFace transformers and jinja2.
-
-// Below is a list of known incompatibilities with the official HF jinja2 implementation. These are not all necessarily
-// reflected in the below substitution list, and this cannot be an exhaustive list because there are a plethora of edge
-// cases in template parsing in which jinja2 and Jinja2Cpp differ. These are differences that could be reasonably
-// expected to affect chat templates that could be seen in the wild, or that cause a crash:
-// - Jinja2Cpp crashes (in debug builds) if given the template `a[""(`
-// - Jinja2Cpp does not support these jinja2 constructs:
-//   - `is not none`
-//   - list slicing, e.g. `messages[1:]`
-//   - the jinja2.ext.loopcontrols extension, which HF enables by default
-//   - a missing space after a quote in substitution (e.g. `{{ 'foo'}}`), which *has* been seen in the wild
-// - GPT4All does not currently support these HuggingFace template features:
-//   - customized "tojson" filter (we provide the built-in Jinja2Cpp one)
-//   - the AssistantTracker extension
-
+// - and chat templates occasionally use features we do not support. This is less true now that we use minja.
 
 // The substitution list.
-// For templates that apply to models listed in models3.json, these should be copied there as well for best
-// compatibility with older versions of GPT4All.
 
 const std::unordered_map<std::string_view, std::string_view> CHAT_TEMPLATE_SUBSTITUTIONS {
     // calme-2.1-phi3.5-4b.Q6_K.gguf (reported by ThilotE on Discord), Phi-3.5-mini-instruct-Q4_0.gguf (nomic-ai/gpt4all#3345)
diff --git a/gpt4all-chat/src/tool.cpp b/gpt4all-chat/src/tool.cpp
index 74975d28..4aa877f2 100644
--- a/gpt4all-chat/src/tool.cpp
+++ b/gpt4all-chat/src/tool.cpp
@@ -1,12 +1,13 @@
 #include "tool.h"
 
-#include <jinja2cpp/value.h>
-
 #include <string>
 
-jinja2::Value Tool::jinjaValue() const
+using json = nlohmann::ordered_json;
+
+
+json::object_t Tool::jinjaValue() const
 {
-    jinja2::ValuesList paramList;
+    json::array_t paramList;
     const QList<ToolParamInfo> p = parameters();
     for (auto &info : p) {
         std::string typeStr;
@@ -20,26 +21,24 @@ jinja2::Value Tool::jinjaValue() const
         case Boolean:  typeStr = "boolean"; break;
         case Null:     typeStr = "null"; break;
         }
-        jinja2::ValuesMap infoMap {
-            { "name", info.name.toStdString() },
-            { "type", typeStr},
+        paramList.emplace_back(json::initializer_list_t {
+            { "name",        info.name.toStdString()        },
+            { "type",        typeStr                        },
             { "description", info.description.toStdString() },
-            { "required", info.required }
-        };
-        paramList.push_back(infoMap);
+            { "required",    info.required                  },
+        });
     }
 
-    jinja2::ValuesMap params {
-        { "name", name().toStdString() },
-        { "description", description().toStdString() },
-        { "function", function().toStdString() },
-        { "parameters", paramList },
+    return {
+        { "name",           name().toStdString()           },
+        { "description",    description().toStdString()    },
+        { "function",       function().toStdString()       },
+        { "parameters",     paramList                      },
         { "symbolicFormat", symbolicFormat().toStdString() },
-        { "examplePrompt", examplePrompt().toStdString() },
-        { "exampleCall", exampleCall().toStdString() },
-        { "exampleReply", exampleReply().toStdString() }
+        { "examplePrompt",  examplePrompt().toStdString()  },
+        { "exampleCall",    exampleCall().toStdString()    },
+        { "exampleReply",   exampleReply().toStdString()   },
     };
-    return params;
 }
 
 void ToolCallInfo::serialize(QDataStream &stream, int version)
diff --git a/gpt4all-chat/src/tool.h b/gpt4all-chat/src/tool.h
index a8861e13..209cf470 100644
--- a/gpt4all-chat/src/tool.h
+++ b/gpt4all-chat/src/tool.h
@@ -1,13 +1,16 @@
 #ifndef TOOL_H
 #define TOOL_H
 
+#include <nlohmann/json.hpp>
+
 #include <QList>
 #include <QObject>
 #include <QString>
 #include <QVariant>
 #include <QtGlobal>
 
-#include <jinja2cpp/value.h>
+using json = nlohmann::ordered_json;
+
 
 namespace ToolEnums
 {
@@ -122,7 +125,7 @@ public:
 
     bool operator==(const Tool &other) const { return function() == other.function(); }
 
-    jinja2::Value jinjaValue() const;
+    json::object_t jinjaValue() const;
 
 Q_SIGNALS:
     void runComplete(const ToolCallInfo &info);