diff --git a/gpt4all-backend-test/src/main.cpp b/gpt4all-backend-test/src/main.cpp
index a5098dc9..130d3b4a 100644
--- a/gpt4all-backend-test/src/main.cpp
+++ b/gpt4all-backend-test/src/main.cpp
@@ -1,6 +1,9 @@
 #include "config.h"
 
+#include "pretty.h"
+
 #include <QCoro/QCoroTask> // IWYU pragma: keep
+#include <boost/json.hpp>
 #include <fmt/base.h>
 #include <gpt4all-backend/formatters.h> // IWYU pragma: keep
 #include <gpt4all-backend/ollama-client.h>
@@ -14,35 +17,43 @@
 #include <expected>
 #include <variant>
 
+namespace json = boost::json;
+using namespace Qt::Literals::StringLiterals;
 using gpt4all::backend::OllamaClient;
 
 
+template <typename T>
+static std::string to_json(const T &value)
+{ return pretty_print(json::value_from(value)); }
+
 static void run()
 {
     fmt::print("Connecting to server at {}\n", OLLAMA_URL);
     OllamaClient provider(OLLAMA_URL);
 
-    auto versionResp = QCoro::waitFor(provider.getVersion());
+    auto versionResp = QCoro::waitFor(provider.version());
     if (versionResp) {
-        fmt::print("Server version: {}\n", versionResp->version);
+        fmt::print("Version response: {}\n", to_json(*versionResp));
     } else {
         fmt::print("Error retrieving version: {}\n", versionResp.error().errorString);
         return QCoreApplication::exit(1);
     }
 
-    auto modelsResponse = QCoro::waitFor(provider.listModels());
+    auto modelsResponse = QCoro::waitFor(provider.list());
     if (modelsResponse) {
         fmt::print("Available models:\n");
         for (const auto & model : modelsResponse->models)
             fmt::print("{}\n", model.model);
+        if (!modelsResponse->models.empty())
+            fmt::print("First model: {}\n", to_json(modelsResponse->models.front()));
     } else {
         fmt::print("Error retrieving available models: {}\n", modelsResponse.error().errorString);
         return QCoreApplication::exit(1);
     }
 
-    auto showResponse = QCoro::waitFor(provider.showModelInfo({ .model = "DeepSeek-R1-Distill-Llama-70B-Q4_K_S" }));
+    auto showResponse = QCoro::waitFor(provider.show({ .model = "DeepSeek-R1-Distill-Llama-70B-Q4_K_S" }));
     if (showResponse) {
-        fmt::print("Model family: {}\n", showResponse->details.family);
+        fmt::print("Show response: {}\n", to_json(*showResponse));
     } else {
         fmt::print("Error retrieving model info: {}\n", showResponse.error().errorString);
         return QCoreApplication::exit(1);
@@ -51,7 +62,6 @@ static void run()
     QCoreApplication::exit(0);
 }
 
-
 int main(int argc, char *argv[])
 {
     QCoreApplication app(argc, argv);
diff --git a/gpt4all-backend-test/src/pretty.h b/gpt4all-backend-test/src/pretty.h
new file mode 100644
index 00000000..cd817caf
--- /dev/null
+++ b/gpt4all-backend-test/src/pretty.h
@@ -0,0 +1,95 @@
+#pragma once
+
+#include <boost/json.hpp>
+
+#include <sstream>
+#include <string>
+
+
+inline void pretty_print( std::ostream& os, boost::json::value const& jv, std::string* indent = nullptr )
+{
+    std::string indent_;
+    if(! indent)
+        indent = &indent_;
+    switch(jv.kind())
+    {
+    case boost::json::kind::object:
+    {
+        os << "{\n";
+        indent->append(4, ' ');
+        auto const& obj = jv.get_object();
+        if(! obj.empty())
+        {
+            auto it = obj.begin();
+            for(;;)
+            {
+                os << *indent << boost::json::serialize(it->key()) << ": ";
+                pretty_print(os, it->value(), indent);
+                if(++it == obj.end())
+                    break;
+                os << ",\n";
+            }
+        }
+        os << "\n";
+        indent->resize(indent->size() - 4);
+        os << *indent << "}";
+        break;
+    }
+
+    case boost::json::kind::array:
+    {
+        os << "[\n";
+        indent->append(4, ' ');
+        auto const& arr = jv.get_array();
+        if(! arr.empty())
+        {
+            auto it = arr.begin();
+            for(;;)
+            {
+                os << *indent;
+                pretty_print( os, *it, indent);
+                if(++it == arr.end())
+                    break;
+                os << ",\n";
+            }
+        }
+        os << "\n";
+        indent->resize(indent->size() - 4);
+        os << *indent << "]";
+        break;
+    }
+
+    case boost::json::kind::string:
+    {
+        os << boost::json::serialize(jv.get_string());
+        break;
+    }
+
+    case boost::json::kind::uint64:
+    case boost::json::kind::int64:
+    case boost::json::kind::double_:
+        os << jv;
+        break;
+
+    case boost::json::kind::bool_:
+        if(jv.get_bool())
+            os << "true";
+        else
+            os << "false";
+        break;
+
+    case boost::json::kind::null:
+        os << "null";
+        break;
+    }
+
+    if(indent->empty())
+        os << "\n";
+}
+
+inline std::string pretty_print( boost::json::value const& jv, std::string* indent = nullptr )
+{
+    std::ostringstream ss;
+    pretty_print(ss, jv, indent);
+    return ss.str();
+}
diff --git a/gpt4all-backend/CMakeLists.txt b/gpt4all-backend/CMakeLists.txt
index d59d3116..eba241b4 100644
--- a/gpt4all-backend/CMakeLists.txt
+++ b/gpt4all-backend/CMakeLists.txt
@@ -13,6 +13,7 @@ add_subdirectory(src)
 target_sources(gpt4all-backend PUBLIC
     FILE_SET public_headers TYPE HEADERS BASE_DIRS include FILES
         include/gpt4all-backend/formatters.h
+        include/gpt4all-backend/json-helpers.h
         include/gpt4all-backend/ollama-client.h
         include/gpt4all-backend/ollama-types.h
 )
diff --git a/gpt4all-backend/src/json-helpers.h b/gpt4all-backend/include/gpt4all-backend/json-helpers.h
similarity index 100%
rename from gpt4all-backend/src/json-helpers.h
rename to gpt4all-backend/include/gpt4all-backend/json-helpers.h
diff --git a/gpt4all-backend/include/gpt4all-backend/ollama-client.h b/gpt4all-backend/include/gpt4all-backend/ollama-client.h
index f288d35e..da5e448c 100644
--- a/gpt4all-backend/include/gpt4all-backend/ollama-client.h
+++ b/gpt4all-backend/include/gpt4all-backend/ollama-client.h
@@ -3,6 +3,8 @@
 #include "ollama-types.h"
 
 #include <QCoro/QCoroTask> // IWYU pragma: keep
+#include <boost/json.hpp> // IWYU pragma: keep
+#include <boost/system.hpp>
 
 #include <QNetworkAccessManager>
 #include <QNetworkReply>
@@ -15,14 +17,20 @@
 #include <variant>
 
 class QNetworkRequest;
-namespace boost::json { class value; }
 
 
 namespace gpt4all::backend {
 
 struct ResponseError {
-    QNetworkReply::NetworkError error;
-    QString                     errorString;
+private:
+    using ErrorCode = std::variant<
+        QNetworkReply::NetworkError,
+        boost::system::error_code
+    >;
+
+public:
+    ErrorCode error;
+    QString   errorString;
 
     ResponseError(const QNetworkReply *reply)
         : error(reply->error())
@@ -30,6 +38,13 @@ struct ResponseError {
     {
         assert(reply->error());
     }
+
+    ResponseError(const boost::system::system_error &e)
+        : error(e.code())
+        , errorString(QString::fromUtf8(e.what()))
+    {
+        assert(e.code());
+    }
 };
 
 template <typename T>
@@ -45,40 +60,44 @@ public:
     const QUrl &baseUrl() const { return m_baseUrl; }
     void getBaseUrl(QUrl value) { m_baseUrl = std::move(value); }
 
-    /// Returns the version of the Ollama server.
-    auto getVersion() -> QCoro::Task<DataOrRespErr<ollama::VersionResponse>>
+    /// Returns the Ollama server version as a string.
+    auto version() -> QCoro::Task<DataOrRespErr<ollama::VersionResponse>>
     { return get<ollama::VersionResponse>(QStringLiteral("version")); }
 
-    /// List models that are available locally.
-    auto listModels() -> QCoro::Task<DataOrRespErr<ollama::ModelsResponse>>
-    { return get<ollama::ModelsResponse>(QStringLiteral("tags")); }
+    /// Lists models that are available locally.
+    auto list() -> QCoro::Task<DataOrRespErr<ollama::ListResponse>>
+    { return get<ollama::ListResponse>(QStringLiteral("tags")); }
 
-    /// Show details about a model including modelfile, template, parameters, license, and system prompt.
-    auto showModelInfo(const ollama::ModelInfoRequest &req) -> QCoro::Task<DataOrRespErr<ollama::ModelInfo>>
-    { return post<ollama::ModelInfo>(QStringLiteral("show"), req); }
+    /// Obtains model information, including details, modelfile, license etc.
+    auto show(const ollama::ShowRequest &req) -> QCoro::Task<DataOrRespErr<ollama::ShowResponse>>
+    { return post<ollama::ShowResponse>(QStringLiteral("show"), req); }
 
 private:
     QNetworkRequest makeRequest(const QString &path) const;
 
+    auto processResponse(QNetworkReply &reply) -> QCoro::Task<DataOrRespErr<boost::json::value>>;
+
     template <typename Resp>
     auto get(const QString &path) -> QCoro::Task<DataOrRespErr<Resp>>;
     template <typename Resp, typename Req>
-    auto post(const QString &path, Req const &req) -> QCoro::Task<DataOrRespErr<Resp>>;
+    auto post(const QString &path, Req const &body) -> QCoro::Task<DataOrRespErr<Resp>>;
 
     auto getJson(const QString &path) -> QCoro::Task<DataOrRespErr<boost::json::value>>;
-    auto postJson(const QString &path, const boost::json::value &req)
+    auto postJson(const QString &path, const boost::json::value &body)
         -> QCoro::Task<DataOrRespErr<boost::json::value>>;
 
 private:
-    QUrl                  m_baseUrl;
-    QString               m_userAgent;
-    QNetworkAccessManager m_nam;
+    QUrl                       m_baseUrl;
+    QString                    m_userAgent;
+    QNetworkAccessManager      m_nam;
+    boost::json::stream_parser m_parser;
 };
 
 extern template auto OllamaClient::get(const QString &) -> QCoro::Task<DataOrRespErr<ollama::VersionResponse>>;
-extern template auto OllamaClient::get(const QString &) -> QCoro::Task<DataOrRespErr<ollama::ModelsResponse>>;
+extern template auto OllamaClient::get(const QString &) -> QCoro::Task<DataOrRespErr<ollama::ListResponse>>;
+
+extern template auto OllamaClient::post(const QString &, const ollama::ShowRequest &)
+    -> QCoro::Task<DataOrRespErr<ollama::ShowResponse>>;
 
-extern template auto OllamaClient::post(const QString &, const ollama::ModelInfoRequest &)
-    -> QCoro::Task<DataOrRespErr<ollama::ModelInfo>>;
 
 } // namespace gpt4all::backend
diff --git a/gpt4all-backend/include/gpt4all-backend/ollama-types.h b/gpt4all-backend/include/gpt4all-backend/ollama-types.h
index 622a3307..4cc3c2e9 100644
--- a/gpt4all-backend/include/gpt4all-backend/ollama-types.h
+++ b/gpt4all-backend/include/gpt4all-backend/ollama-types.h
@@ -1,131 +1,128 @@
 #pragma once
 
-#ifdef G4A_BACKEND_IMPL
-#   include <boost/describe/class.hpp>
-#   include <boost/describe/enum.hpp>
-#endif
+#include "json-helpers.h" // IWYU pragma: keep
+
+#include <boost/describe/class.hpp>
 #include <boost/json.hpp> // IWYU pragma: keep
 
+#include <QByteArray>
 #include <QString>
 #include <QtTypes>
 
+#include <chrono>
 #include <optional>
 #include <vector>
 
 
 namespace gpt4all::backend::ollama {
 
+
 //
 // basic types
 //
 
-/// Details about a model.
+struct Time : std::chrono::sys_time<std::chrono::nanoseconds> {};
+
+void tag_invoke(const boost::json::value_from_tag &, boost::json::value &value, Time time);
+Time tag_invoke(const boost::json::value_to_tag<Time> &, const boost::json::value &value);
+
+/// ImageData represents the raw binary data of an image file.
+struct ImageData : QByteArray {};
+
+void tag_invoke(const boost::json::value_from_tag &, boost::json::value &value, const ImageData &image);
+ImageData tag_invoke(const boost::json::value_to_tag<ImageData> &, const boost::json::value &value);
+
 struct ModelDetails {
-    QString              parent_model;       /// The parent of the model.
-    QString              format;             /// The format of the model.
-    QString              family;             /// The family of the model.
-    std::vector<QString> families;           /// The families of the model.
-    QString              parameter_size;     /// The size of the model's parameters.
-    QString              quantization_level; /// The quantization level of the model.
+    QString              parent_model;
+    QString              format;
+    QString              family;
+    std::vector<QString> families;
+    QString              parameter_size;
+    QString              quantization_level;
 };
-#ifdef G4A_BACKEND_IMPL
 BOOST_DESCRIBE_STRUCT(ModelDetails, (), (parent_model, format, family, families, parameter_size, quantization_level))
-#endif
 
-/// A model available locally.
-struct Model {
-    QString      model;       /// The model name.
-    QString      modified_at; /// Model modification date.
-    quint64      size;        /// Size of the model on disk.
-    QString      digest;      /// The model's digest.
-    ModelDetails details;     /// The model's details.
+/// ListModelResponse is a single model description in ListResponse.
+struct ListModelResponse {
+    QString                     name;
+    QString                     model;
+    Time                        modified_at;
+    qint64                      size;        /// Size of the model on disk.
+    QString                     digest;
+    std::optional<ModelDetails> details;
 };
-#ifdef G4A_BACKEND_IMPL
-BOOST_DESCRIBE_STRUCT(Model, (), (model, modified_at, size, digest, details))
-#endif
+BOOST_DESCRIBE_STRUCT(ListModelResponse, (), (model, modified_at, size, digest, details))
 
-enum MessageRole {
-    system,
-    user,
-    assistant,
-    tool,
-};
-#ifdef G4A_BACKEND_IMPL
-BOOST_DESCRIBE_ENUM(MessageRole, system, user, assistant, tool)
-#endif
+using ToolCallFunctionArguments = boost::json::object;
 
 struct ToolCallFunction {
-    QString             name;      /// The name of the function to be called.
-    boost::json::object arguments; /// The arguments to pass to the function.
+    std::optional<int>        index;
+    QString                   name;
+    ToolCallFunctionArguments arguments;
 };
-#ifdef G4A_BACKEND_IMPL
-BOOST_DESCRIBE_STRUCT(ToolCallFunction, (), (name, arguments))
-#endif
+BOOST_DESCRIBE_STRUCT(ToolCallFunction, (), (index, name, arguments))
 
 struct ToolCall {
-    ToolCallFunction function; /// The function the model wants to call.
+    ToolCallFunction function;
 };
-#ifdef G4A_BACKEND_IMPL
 BOOST_DESCRIBE_STRUCT(ToolCall, (), (function))
-#endif
 
-/// A message in the chat endpoint
+/// Message is a single message in a chat sequence. The message contains the
+/// role ("system", "user", or "assistant"), the content and an optional list
+/// of images.
 struct Message {
-    MessageRole           role;       /// The role of the message
-    QString               content;    /// The content of the message
-    std::vector<QString>  images;     /// (optional) a list of Base64-encoded images to include in the message
-    std::vector<ToolCall> tool_calls; /// A list of tool calls the model wants to call.
+    QString                               role;
+    QString                               content;
+    std::optional<std::vector<ImageData>> images;
+    std::optional<std::vector<ToolCall>>  tool_calls;
 };
-#ifdef G4A_BACKEND_IMPL
 BOOST_DESCRIBE_STRUCT(Message, (), (role, content, images, tool_calls))
-#endif
 
 //
 // request types
 //
 
-/// Request class for the show model info endpoint.
-struct ModelInfoRequest {
-    QString model; /// The model name.
+/// ShowRequest is the request passed to OllamaClient::show().
+struct ShowRequest {
+    QString                            model;
+    std::optional<QString>             system  {};
+    std::optional<bool>                verbose {};
+    std::optional<boost::json::object> options {};
 };
-#ifdef G4A_BACKEND_IMPL
-BOOST_DESCRIBE_STRUCT(ModelInfoRequest, (), (model))
-#endif
+BOOST_DESCRIBE_STRUCT(ShowRequest, (), (model, system, verbose, options))
 
 //
 // response types
 //
 
-/// The response class for the version endpoint.
+/// VersionRepsonse is the response from OllamaClient::version().
 struct VersionResponse {
     QString version; /// The version of the Ollama server.
 };
-#ifdef G4A_BACKEND_IMPL
 BOOST_DESCRIBE_STRUCT(VersionResponse, (), (version))
-#endif
 
-/// Response class for the list models endpoint.
-struct ModelsResponse {
-    std::vector<Model> models; /// List of models available locally.
-};
-#ifdef G4A_BACKEND_IMPL
-BOOST_DESCRIBE_STRUCT(ModelsResponse, (), (models))
-#endif
-
-/// Details about a model including modelfile, template, parameters, license, and system prompt.
-struct ModelInfo {
-    std::optional<QString>              license;    /// The model's license.
+/// ShowResponse is the response from OllamaClient::show().
+struct ShowResponse {
+    std::optional<QString>              license;
     std::optional<QString>              modelfile;  /// The modelfile associated with the model.
-    std::optional<QString>              parameters; /// The model parameters.
+    std::optional<QString>              parameters;
     std::optional<QString>              template_;  /// The prompt template for the model.
     std::optional<QString>              system;     /// The system prompt for the model.
-    ModelDetails                        details;
-    boost::json::object                 model_info;
+    std::optional<ModelDetails>         details;
     std::optional<std::vector<Message>> messages;   /// The default messages for the model.
+    std::optional<boost::json::object>  model_info;
+    std::optional<boost::json::object>  projector_info;
+    std::optional<Time>                 modified_at;
 };
 
-#ifdef G4A_BACKEND_IMPL
-ModelInfo tag_invoke(const boost::json::value_to_tag<ModelInfo> &, const boost::json::value &value);
-#endif
+void tag_invoke(const boost::json::value_from_tag &, boost::json::value &value, const ShowResponse &resp);
+ShowResponse tag_invoke(const boost::json::value_to_tag<ShowResponse> &, const boost::json::value &value);
+
+/// ListResponse is the response from OllamaClient::list().
+struct ListResponse {
+    std::vector<ListModelResponse> models; /// List of available models.
+};
+BOOST_DESCRIBE_STRUCT(ListResponse, (), (models))
+
 
 } // namespace gpt4all::backend::ollama
diff --git a/gpt4all-backend/src/CMakeLists.txt b/gpt4all-backend/src/CMakeLists.txt
index 37c30390..c6e618db 100644
--- a/gpt4all-backend/src/CMakeLists.txt
+++ b/gpt4all-backend/src/CMakeLists.txt
@@ -7,7 +7,6 @@ add_library(${TARGET} STATIC
     qt-json-stream.cpp
 )
 target_compile_features(${TARGET} PUBLIC cxx_std_23)
-target_compile_definitions(${TARGET} PRIVATE G4A_BACKEND_IMPL)
 gpt4all_add_warning_options(${TARGET})
 target_include_directories(${TARGET} PRIVATE
     .
diff --git a/gpt4all-backend/src/ollama-client.cpp b/gpt4all-backend/src/ollama-client.cpp
index c621f3f9..5a1f1ddf 100644
--- a/gpt4all-backend/src/ollama-client.cpp
+++ b/gpt4all-backend/src/ollama-client.cpp
@@ -5,7 +5,6 @@
 
 #include <QCoro/QCoroIODevice> // IWYU pragma: keep
 #include <QCoro/QCoroNetworkReply> // IWYU pragma: keep
-#include <boost/json.hpp> // IWYU pragma: keep
 
 #include <QByteArray>
 #include <QNetworkRequest>
@@ -22,24 +21,6 @@ namespace json = boost::json;
 namespace gpt4all::backend {
 
 
-static auto processResponse(QNetworkReply &reply) -> QCoro::Task<DataOrRespErr<json::value>>
-{
-    if (reply.error())
-        co_return std::unexpected(&reply);
-
-    json::parser p;
-    auto coroReply = qCoro(reply);
-    do {
-        auto chunk = co_await coroReply.readAll();
-        if (reply.error())
-            co_return std::unexpected(&reply);
-        p.write(chunk.data(), chunk.size());
-    } while (!reply.atEnd());
-
-    co_return p.release();
-}
-
-
 QNetworkRequest OllamaClient::makeRequest(const QString &path) const
 {
     QNetworkRequest req(m_baseUrl.resolved(QUrl(path)));
@@ -47,29 +28,56 @@ QNetworkRequest OllamaClient::makeRequest(const QString &path) const
     return req;
 }
 
+auto OllamaClient::processResponse(QNetworkReply &reply) -> QCoro::Task<DataOrRespErr<json::value>>
+{
+    if (reply.error())
+        co_return std::unexpected(&reply);
+
+    auto coroReply = qCoro(reply);
+    do {
+        auto chunk = co_await coroReply.readAll();
+        if (reply.error())
+            co_return std::unexpected(&reply);
+        m_parser.write(chunk.data(), chunk.size());
+    } while (!reply.atEnd());
+
+    m_parser.finish();
+    co_return m_parser.release();
+}
+
 template <typename Resp>
 auto OllamaClient::get(const QString &path) -> QCoro::Task<DataOrRespErr<Resp>>
 {
-    auto value = co_await getJson(path);
-    if (value)
-        co_return json::value_to<Resp>(*value);
-    co_return std::unexpected(value.error());
+    // get() should not throw exceptions
+    try {
+        auto value = co_await getJson(path);
+        if (value)
+            co_return json::value_to<Resp>(*value);
+        co_return std::unexpected(value.error());
+    } catch (const boost::system::system_error &e) {
+        co_return std::unexpected(e);
+    }
 }
 
 template auto OllamaClient::get(const QString &) -> QCoro::Task<DataOrRespErr<VersionResponse>>;
-template auto OllamaClient::get(const QString &) -> QCoro::Task<DataOrRespErr<ModelsResponse>>;
+template auto OllamaClient::get(const QString &) -> QCoro::Task<DataOrRespErr<ListResponse>>;
 
 template <typename Resp, typename Req>
-auto OllamaClient::post(const QString &path, const Req &req) -> QCoro::Task<DataOrRespErr<Resp>>
+auto OllamaClient::post(const QString &path, const Req &body) -> QCoro::Task<DataOrRespErr<Resp>>
 {
-    auto reqJson = json::value_from(req);
-    auto value = co_await postJson(path, reqJson);
-    if (value)
-        co_return json::value_to<Resp>(*value);
-    co_return std::unexpected(value.error());
+    // post() should not throw exceptions
+    try {
+        auto reqJson = json::value_from(body);
+        auto value = co_await postJson(path, reqJson);
+        if (value)
+            co_return json::value_to<Resp>(*value);
+        co_return std::unexpected(value.error());
+    } catch (const boost::system::system_error &e) {
+        co_return std::unexpected(e);
+    }
 }
 
-template auto OllamaClient::post(const QString &, const ModelInfoRequest &) -> QCoro::Task<DataOrRespErr<ModelInfo>>;
+template auto OllamaClient::post(const QString &, const ShowRequest &) -> QCoro::Task<DataOrRespErr<ShowResponse>>;
 
 auto OllamaClient::getJson(const QString &path) -> QCoro::Task<DataOrRespErr<json::value>>
 {
@@ -77,12 +85,12 @@ auto OllamaClient::getJson(const QString &path) -> QCoro::Task<DataOrRespErr<jso
     co_return co_await processResponse(*reply);
 }
 
-auto OllamaClient::postJson(const QString &path, const json::value &req) -> QCoro::Task<DataOrRespErr<json::value>>
+auto OllamaClient::postJson(const QString &path, const json::value &body) -> QCoro::Task<DataOrRespErr<json::value>>
 {
-    JsonStreamDevice reqStream(&req);
-    std::unique_ptr<QNetworkReply> reply(
-        m_nam.post(makeRequest(path), &reqStream)
-    );
+    JsonStreamDevice stream(&body);
+    auto req = makeRequest(path);
+    req.setHeader(QNetworkRequest::ContentTypeHeader, "application/json"_ba);
+    std::unique_ptr<QNetworkReply> reply(m_nam.post(req, &stream));
     co_return co_await processResponse(*reply);
 }
 
diff --git a/gpt4all-backend/src/ollama-types.cpp b/gpt4all-backend/src/ollama-types.cpp
index 600a67ed..d4f9addb 100644
--- a/gpt4all-backend/src/ollama-types.cpp
+++ b/gpt4all-backend/src/ollama-types.cpp
@@ -2,30 +2,97 @@
 
 #include "json-helpers.h"
 
+#include <fmt/chrono.h> // IWYU pragma: keep
+#include <fmt/format.h>
+
+#include <sstream>
+#include <string>
+#include <system_error>
 #include <type_traits>
 #include <utility>
 
 namespace json = boost::json;
 
 
+template <typename T>
+static T get_optional(const json::object &o, json::string_view key)
+{
+    if (auto *p = o.if_contains(key))
+        return value_to<typename T::value_type>(*p);
+    return std::nullopt;
+}
+
+
 namespace gpt4all::backend::ollama {
 
-ModelInfo tag_invoke(const boost::json::value_to_tag<ModelInfo> &, const boost::json::value &value)
+
+void tag_invoke(const json::value_from_tag &, json::value &value, Time time)
+{
+    value = json::value_from(fmt::format(
+        "{:%FT%T}Z",
+        static_cast<const std::chrono::sys_time<std::chrono::nanoseconds> &>(time)
+    ));
+}
+
+Time tag_invoke(const json::value_to_tag<Time> &, const json::value &value)
+{
+    namespace sys = boost::system;
+
+    Time time;
+    std::istringstream iss(json::string_view(value.as_string()));
+    iss >> std::chrono::parse("%FT%T%Ez", time);
+    if (!iss && !iss.eof())
+        throw sys::system_error(std::make_error_code(std::errc::invalid_argument), __func__);
+    return time;
+}
+
+void tag_invoke(const json::value_from_tag &, json::value &value, const ImageData &image)
+{
+    auto base64 = image.toBase64();
+    value = json::value_from(json::string_view(base64.data(), base64.size()));
+}
+
+ImageData tag_invoke(const json::value_to_tag<ImageData> &, const json::value &value)
+{
+    auto &str = value.as_string();
+    return ImageData(QByteArray::fromBase64(QByteArray::fromRawData(str.data(), str.size())));
+}
+
+void tag_invoke(const json::value_from_tag &, json::value &value, const ShowResponse &resp)
+{
+    auto &o = value.emplace_object();
+
+    auto maybe_add = [&o](json::string_view key, auto &v) { if (v) o[key] = json::value_from(*v); };
+    maybe_add("license",        resp.license       );
+    maybe_add("modelfile",      resp.modelfile     );
+    maybe_add("parameters",     resp.parameters    );
+    maybe_add("template",       resp.template_     );
+    maybe_add("system",         resp.system        );
+    maybe_add("details",        resp.details       );
+    maybe_add("messages",       resp.messages      );
+    maybe_add("model_info",     resp.model_info    );
+    maybe_add("projector_info", resp.projector_info);
+    maybe_add("modified_at",    resp.modified_at   );
+}
+
+ShowResponse tag_invoke(const json::value_to_tag<ShowResponse> &, const json::value &value)
 {
-    using namespace json;
     auto &o = value.as_object();
     return {
-#define T(name) std::remove_reference_t<decltype(std::declval<ModelInfo>().name)>
-        .license    = value_to<T(license   )>(o.at("license"   )),
-        .modelfile  = value_to<T(modelfile )>(o.at("modelfile" )),
-        .parameters = value_to<T(parameters)>(o.at("parameters")),
-        .template_  = value_to<T(template_ )>(o.at("template"  )), // :(
-        .system     = value_to<T(system    )>(o.at("system"    )),
-        .details    = value_to<T(details   )>(o.at("details"   )),
-        .model_info = value_to<T(model_info)>(o.at("model_info")),
-        .messages   = value_to<T(messages  )>(o.at("messages"  )),
+#define T(name) std::remove_reference_t<decltype(std::declval<ShowResponse>().name)>
+        .license        = get_optional<T(license       )>(o, "license"       ),
+        .modelfile      = get_optional<T(modelfile     )>(o, "modelfile"     ),
+        .parameters     = get_optional<T(parameters    )>(o, "parameters"    ),
+        .template_      = get_optional<T(template_     )>(o, "template"      ), // :(
+        .system         = get_optional<T(system        )>(o, "system"        ),
+        .details        = get_optional<T(details       )>(o, "details"       ),
+        .messages       = get_optional<T(messages      )>(o, "messages"      ),
+        .model_info     = get_optional<T(model_info    )>(o, "model_info"    ),
+        .projector_info = get_optional<T(projector_info)>(o, "projector_info"),
+        .modified_at    = get_optional<T(modified_at   )>(o, "modified_at"   ),
 #undef T
     };
 }
 
+
 } // namespace gpt4all::backend::ollama
diff --git a/gpt4all-backend/src/qt-json-stream.cpp b/gpt4all-backend/src/qt-json-stream.cpp
index c4b7269d..216e491d 100644
--- a/gpt4all-backend/src/qt-json-stream.cpp
+++ b/gpt4all-backend/src/qt-json-stream.cpp
@@ -10,6 +10,7 @@ namespace json = boost::json;
 
 namespace gpt4all::backend {
 
+
 JsonStreamDevice::JsonStreamDevice(const json::value *jv, QObject *parent)
     : QIODevice(parent)
 {
@@ -31,4 +32,5 @@ qint64 JsonStreamDevice::writeData(const char *data, qint64 maxSize)
     return -1;
 }
 
+
 } // namespace gpt4all::backend
diff --git a/gpt4all-backend/src/qt-json-stream.h b/gpt4all-backend/src/qt-json-stream.h
index 00e34788..15fc0c7d 100644
--- a/gpt4all-backend/src/qt-json-stream.h
+++ b/gpt4all-backend/src/qt-json-stream.h
@@ -10,6 +10,7 @@ class QObject;
 
 namespace gpt4all::backend {
 
+
 class JsonStreamDevice : public QIODevice
 {
 public:
@@ -25,4 +26,5 @@ private:
     boost::json::serializer m_sr;
 };
 
+
 } // namespace gpt4all::backend