Founded in 2023, Deepseek provides two language models with automatic caching. Developed in China, this technology is influenced by a specific cultural and regulatory framework, shaping its priorities and development choices. While its scope of application is still evolving, Deepseek offers an option for Delphi developers looking to experiment with AI tools.
This unofficial wrapper aims to simplify the integration of Deepseek APIs into Delphi projects. It provides a practical way for developers to explore and test these models, whether for natural language processing, conversational assistants, or other targeted use cases. The library enables quick experimentation while leveraging Delphi’s familiar environment.
This wrapper is primarily intended for exploratory purposes. It provides users with a tool to assess whether Deepseek meets their specific needs and to integrate it into their projects if deemed suitable.
Important
This is an unofficial library. Deepseek does not provide any official library for Delphi.
This repository contains Delphi implementation over Deepseek public API.
This section offers concise notifications and explanations about the tools designed to streamline the presentation and clarify the wrapper's functions throughout the tutorial.
To streamline the code examples provided in this tutorial and facilitate quick implementation, two units have been included in the source code: Deepseek.Tutorial.VCL and Deepseek.Tutorial.FMX. Depending on the platform you choose to test the provided source code, you will need to instantiate either the TVCLTutorialHub or TFMXTutorialHub class in the application's OnCreate event, as demonstrated below:
Tip
//uses Deepseek.Tutorial.VCL;
TutorialHub := TVCLTutorialHub.Create(Memo1, Button1);or
Tip
//uses Deepseek.Tutorial.FMX;
TutorialHub := TFMXTutorialHub.Create(Memo1, Button1);Make sure to add a TMemo and a TButton component to your form beforehand.
The TButton will allow the interruption of any streamed reception.
In the context of asynchronous methods, for a method that does not involve streaming, callbacks use the following generic record: TAsynCallBack<T> = record defined in the Deepseek.Async.Support.pas unit. This record exposes the following properties:
TAsynCallBack<T> = record
...
Sender: TObject;
OnStart: TProc<TObject>;
OnSuccess: TProc<TObject, T>;
OnError: TProc<TObject, string>; For methods requiring streaming, callbacks use the generic record TAsynStreamCallBack<T> = record, also defined in the Deepseek.Async.Support.pas unit. This record exposes the following properties:
TAsynCallBack<T> = record
...
Sender: TObject;
OnStart: TProc<TObject>;
OnProgress: TProc<TObject, T>;
OnSuccess: TProc<TObject, T>;
OnError: TProc<TObject, string>;
OnCancellation: TProc<TObject>;
OnDoCancel: TFunc<Boolean>;The name of each property is self-explanatory; if needed, refer to the internal documentation for more details.
Note
All methods managed by the wrapper are designed to support both synchronous and asynchronous execution modes. This dual-mode functionality ensures greater flexibility for users, allowing them to choose the approach that best suits their application's requirements and workflow.
To streamline the use of the API wrapper, the process for declaring units has been simplified. Regardless of the methods being utilized, you only need to reference the following two core units:
uses
Deepseek, Deepseek.Types;If required, you may also include the Deepseek.Schema unit or any plugin units developed for specific function calls (e.g., Deepseek.Functions.Example). This simplification ensures a more intuitive and efficient integration process for developers.
To initialize the API instance, you need to obtain an API key from Deepseek.
Once you have a token, you can initialize IDeepseek interface, which is an entry point to the API.
Note
uses Deepseek;
var Deepseek := TDeepseek.CreateInstance(API_KEY);
var DeepseekBeta := TDeepseekFactory.CreateBetaInstance(API_KEY); The DeepseekBeta client must be used to access APIs that are currently provided in beta version.
Warning
To effectively use the examples in this tutorial, particularly when working with asynchronous methods, it is recommended to define the Deepseek and DeepseekBeta interfaces with the broadest possible scope. For optimal implementation, these clients should be declared in the application's OnCreate method.
Two models are currently available:
- deepseek-chat
- deepseek-coder. et sur HuggingFace
Regarding the APIs, only version 3 appears to be available, although the documentation lacks clarity on this point.
To retrieve the list of available models, you can use the following code example:
// uses Deepseek, Deepseek.Types, Deepseek.Tutorial.VCL;
//Asynchronous example
DeepSeek.Models.AsynList(
function : TAsynModels
begin
Result.Sender := TutorialHub;
Result.OnStart := Start;
Result.OnSuccess := Display;
Result.OnError := Display;
end);
//Synchronous example
// var Value := DeepSeek.Models.List;
// try
// Display(TutorialHub, Value);
// finally
// Value.Free;
// end;To find a model, although this is not relevant and not specified in the official documentation:
// uses Deepseek, Deepseek.Types, Deepseek.Tutorial.VCL;
TutorialHub.ModelId := 'deepseek-chat';
//Asynchronous example
DeepSeek.Models.AsynRetrieve(TutorialHub.ModelId,
function : TAsynModel
begin
Result.Sender := TutorialHub;
Result.OnStart := Start;
Result.OnSuccess := Display;
Result.OnError := Display;
end);
//Synchronous example
// var Value := DeepSeek.Models.Retrieve(TutorialHub.ModelId);
// try
// Display(TutorialHub, Value);
// finally
// Value.Free;
// end;You can send a structured list of input messages containing only text content, and the model will generate the next message in the conversation.
The Messages API can be used for both single-turn requests and multi-turn, stateless conversations.
// uses Deepseek, Deepseek.Types, Deepseek.Tutorial.VCL;
//Asynchronous example
DeepSeek.Chat.AsynCreate(
procedure (Params: TChatParams)
begin
Params.Model('deepseek-chat');
Params.Messages([
FromUser('What is the capital of France, and then the capital of champagne?')
]);
end,
function : TAsynChat
begin
Result.Sender := TutorialHub;
Result.OnStart := Start;
Result.OnSuccess := Display;
Result.OnError := Display;
end);
//Synchronous example
// var Value := DeepSeek.Chat.Create(
// procedure (Params: TChatParams)
// begin
// Params.Model('deepseek-chat');
// Params.Messages([
// FromUser('What is the capital of France, and then the capital of champagne?')
// ]);
// end);
// try
// Display(TutorialHub, Value);
// finally
// Value.Free;
// end;When generating a Message, you can enable "stream": true to progressively receive the response through server-sent events (SSE).
// uses Deepseek, Deepseek.Types, Deepseek.Tutorial.VCL;
//Asynchronous example
DeepSeek.Chat.ASynCreateStream(
procedure (Params: TChatParams)
begin
Params.Model('deepseek-chat');
Params.Messages([
FromUser('Are there accumulation points in a discrete topology?')
]);
Params.MaxTokens(1024);
Params.Stream;
end,
function : TAsynChatStream
begin
Result.Sender := TutorialHub;
Result.OnStart := Start;
Result.OnProgress := DisplayStream;
Result.OnError := Display;
Result.OnDoCancel := DoCancellation;
Result.OnCancellation := Cancellation;
end);
//Synchronous example
// DeepSeek.Chat.CreateStream(
// procedure (Params: TChatParams)
// begin
// Params.Model('deepseek-chat');
// Params.Messages([
// FromUser('Are there accumulation points in a discrete topology?')
// ]);
// Params.MaxTokens(1024);
// Params.Stream;
// end,
// procedure (var Chat: TChat; IsDone: Boolean; var Cancel: Boolean)
// begin
// if Assigned(Chat) and not IsDone then
// DisplayStream(TutorialHub, Chat);
// end);The Deepseek API enables the creation of interactive chat experiences tailored to your users' needs. Its chat functionality supports multiple rounds of questions and answers, allowing users to gradually work toward solutions or receive help with complex, multi-step issues. This capability is especially useful for applications requiring ongoing interaction, such as:
- Chatbots
- Educational tools
- Customer support assistants.
Refer to the official documentation
// uses Deepseek, Deepseek.Types, Deepseek.Tutorial.VCL;
//Asynchronous example
DeepSeek.Chat.ASynCreateStream(
procedure (Params: TChatParams)
begin
Params.Model('deepseek-chat');
Params.Messages([
FromSystem('You are a funny domestic assistant.'),
FromUser('Hello'),
FromAssistant('Great to meet you. What would you like to know?'),
FromUser('I have two dogs in my house. How many paws are in my house?')
]);
Params.MaxTokens(1024);
Params.Stream;
end,
function : TAsynChatStream
begin
Result.Sender := TutorialHub;
Result.OnStart := Start;
Result.OnProgress := DisplayStream;
Result.OnError := Display;
Result.OnDoCancel := DoCancellation;
Result.OnCancellation := Cancellation;
end);
//Synchronous example
// DeepSeek.Chat.CreateStream(
// procedure (Params: TChatParams)
// begin
// Params.Model('deepseek-chat');
// Params.Messages([
// FromSystem('You are a funny domestic assistant.'),
// FromUser('Hello'),
// FromAssistant('Great to meet you. What would you like to know?'),
// FromUser('I have two dogs in my house. How many paws are in my house?')
// ]);
// Params.MaxTokens(1024);
// Params.Stream;
// end,
// procedure (var Chat: TChat; IsDone: Boolean; var Cancel: Boolean)
// begin
// if Assigned(Chat) and not IsDone then
// DisplayStream(TutorialHub, Chat);
// end);Caution
Note from DeepSeek in their official documentation "The current version of the deepseek-chat model's Function Calling capabilitity is unstable, which may result in looped calls or empty responses. We are actively working on a fix, and it is expected to be resolved in the next version."
Furthermore, function calls cannot be made in the context of a streaming request. Regarding the APIs, Delta does not support the tool_calls object.
What’s the weather in Paris?
In the Deepseek.Functions.Example unit, there is a class that defines a function which Deepseek can choose to use or not, depending on the options provided. This class inherits from a parent class defined in the Deepseek.Functions.Core unit. To create new functions, you can derive from the TFunctionCore class and define a new plugin.
In this unit, this schema will be used for function calls.
{
"type": "object",
"properties": {
"location": {
"type": "string",
"description": "The city and department, e.g. Marseille, 13"
},
"unit": {
"type": "string",
"enum": ["celsius", "fahrenheit"]
}
},
"required": ["location"]
}- We will use the TWeatherReportFunction plugin defined in the
Deepseek.Functions.Exampleunit.
var Weather := TWeatherReportFunction.CreateInstance;
//See step 3- We then define a method to display the result of the query using the Weather tool.
procedure TMy_Form.DisplayWeather(const Value: string);
begin
//Asynchronous example
DeepSeek.Chat.ASynCreateStream(
procedure (Params: TChatParams)
begin
Params.Model('deepseek-chat');
Params.Messages([
FromSystem('You are a star weather presenter on a national TV channel.'),
FromUser(Value)
]);
Params.MaxTokens(1024);
Params.Stream;
end,
function : TAsynChatStream
begin
Result.Sender := TutorialHub;
Result.OnProgress := DisplayStream;
Result.OnError := Display;
Result.OnDoCancel := DoCancellation;
Result.OnCancellation := Cancellation;
end);
end;- Building the query using the Weather tool
// uses Deepseek, Deepseek.Types, Deepseek.Functions.Example, Deepseek.Tutorial.VCL;
var Weather := TWeatherReportFunction.CreateInstance;
TutorialHub.Tool := Weather;
TutorialHub.ToolCall := DisplayWeather;
//Asynchronous example
DeepSeek.Chat.AsynCreate(
procedure (Params: TChatParams)
begin
Params.Model('deepseek-chat');
Params.Messages([
TContentParams.User('What is the weather in Paris?')
]);
Params.Tools([Weather]);
Params.ToolChoice(auto);
Params.MaxTokens(1024);
end,
function : TAsynChat
begin
Result.Sender := TutorialHub;
Result.OnStart := Start;
Result.OnSuccess := Display;
Result.OnError
end;In many scenarios, users require the model to produce output in strictly JSON format to ensure structured data, facilitating seamless downstream processing.
DeepSeek provides a JSON Output feature to guarantee the generation of valid JSON strings.
Key Considerations:
-
Enabling JSON Output:
- Set the response_format parameter to
{'type': 'json_object'}. - Include the word "json" in the system or user prompt, and provide an example of the desired JSON format to guide the model in producing compliant outputs.
- Set the response_format parameter to
-
Adjusting Output Length:
- Configure the max_tokens parameter appropriately to prevent the JSON string from being truncated.
-
Handling Potential Issues:
- The API may occasionally return empty content. This issue is under active optimization. Adjusting the prompt can help mitigate such occurrences.
Refer to official documentation
// uses Deepseek, Deepseek.Types, Deepseek.Tutorial.VCL;
//Asynchronous example
DeepSeek.Chat.AsynCreate(
procedure (Params: TChatParams)
begin
Params.Model('deepseek-chat');
Params.Messages([
TContentParams.System('The user will provide some exam text. Please parse the "question" and "answer" and output them in JSON format. EXAMPLE INPUT: Which is the highest mountain in the world? Mount Everest. EXAMPLE JSON OUTPUT: { "question": "Which is the highest mountain in the world?", "answer": "Mount Everest" }'),
TContentParams.User('Which is the longest river in the world? The Nile River')
]);
Params.ResponseFormat(json_object);
end,
function : TAsynChat
begin
Result.Sender := TutorialHub;
Result.OnStart := Start;
Result.OnSuccess := Display;
Result.OnError := Display;
end);
//Synchronous example
// var Value := DeepSeek.Chat.Create(
// procedure (Params: TChatParams)
// begin
// Params.Model('deepseek-chat');
// Params.Messages([
// TContentParams.System('The user will provide some exam text. Please parse the "question" and "answer" and output them in JSON format. EXAMPLE INPUT: Which is the highest mountain in the world? Mount Everest. EXAMPLE JSON OUTPUT: { "question": "Which is the highest mountain in the world?", "answer": "Mount Everest" }'),
// TContentParams.User('Which is the longest river in the world? The Nile River')
// ]);
// end);
// try
// Display(TutorialHub, Value);
// finally
// Value.Free;
// end;The model will output:
{
"question": "Which is the longest river in the world?",
"answer": "The Nile River"
} Refer to the official documentation
The automatic enforcement of caching has the effect of limiting the diversity of generated responses. While adjusting the temperature parameter can provide some flexibility, it is not an optimal solution in all cases.
Additionally, users are unable to directly intervene to perform a manual "cache clearing." In this regard, I refer you to the official documentation, which states:
- "Cache construction takes seconds. Once the cache is no longer in use, it will be automatically cleared, usually within a few hours to a
few days.."
View account details, including available credit balance.
// uses Deepseek, Deepseek.Types, Deepseek.Tutorial.VCL;
//Asynchronous example
DeepSeek.User.AsynBalance(
function : TAsynBalance
begin
Result.Sender := TutorialHub;
Result.OnStart := Start;
Result.OnSuccess := Display;
Result.OnError := Display;
end);
//Synchronous example
// var Value := DeepSeek.User.Balance;
// try
// Display(TutorialHub, Value);
// finally
// Value.Free;
// end;In Fill-In-the-Middle (FIM) completion, users can specify a prefix and optionally a suffix, allowing the model to generate content that seamlessly fills the gap between them. This approach is particularly useful for tasks such as content and code completion.
Important Notes:
- Token Limit: FIM completion supports a maximum token limit of 4,000.
- Enabling the Beta Feature: Users must set base_url=https://api.deepseek.com/beta to activate this functionality.
Tip
In this case, we will use the DeepseekBeta client in our code examples.
// uses Deepseek, Deepseek.Types, Deepseek.Tutorial.VCL;
//Asynchronous example
DeepSeekBeta.FIM.AsynCreate(
procedure (Params: TFIMParams)
begin
Params.Model('deepseek-chat');
Params.Prompt('def fib(a):');
Params.Suffix(' return fib(a-1) + fib(a-2)');
Params.MaxTokens(1024);
end,
function : TAsynFIM
begin
Result.Sender := TutorialHub;
Result.OnStart := Start;
Result.OnSuccess := Display;
Result.OnError := Display;
end);
//Synchronous example
// var Value := DeepSeekBeta.FIM.Create(
// procedure (Params: TFIMParams)
// begin
// Params.Model('deepseek-chat');
// Params.Prompt('def fib(a):');
// Params.Suffix(' return fib(a-1) + fib(a-2)');
// Params.MaxTokens(1024);
// end);
// try
// Display(TutorialHub, Value);
// finally
// Value.Free;
// end;The model will output:
if a == 0:
return 0
elif a == 1:
return 1
else:
// uses Deepseek, Deepseek.Types, Deepseek.Tutorial.VCL;
//Asynchronous example
DeepSeekBeta.FIM.AsynCreateStream(
procedure (Params: TFIMParams)
begin
Params.Model('deepseek-chat');
Params.Prompt('def fib(a):');
Params.Suffix(' return fib(a-1) + fib(a-2)');
Params.MaxTokens(1024);
Params.Stream;
end,
function : TAsynFIMStream
begin
Result.Sender := TutorialHub;
Result.OnStart := Start;
Result.OnProgress := DisplayStream;
Result.OnError := Display;
Result.OnDoCancel := DoCancellation;
Result.OnCancellation := Cancellation;
end);
//Synchronous example
// DeepSeekBeta.FIM.CreateStream(
// procedure (Params: TFIMParams)
// begin
// Params.Model('deepseek-chat');
// Params.Prompt('def fib(a):');
// Params.Suffix(' return fib(a-1) + fib(a-2)');
// Params.MaxTokens(1024);
// Params.Stream;
// end,
// procedure (var FIM: TFIM; IsDone: Boolean; var Cancel: Boolean)
// begin
// if Assigned(FIM) and not IsDone then
// DisplayStream(TutorialHub, FIM);
// end);To utilize the chat prefix completion feature, users must provide a message prefix for the assistant, allowing the model to complete the rest of the message.
Important Note
When using prefix completion, it is essential to ensure that the role of the last message in the message list is set to "assistant" and that the prefix parameter for this message is enabled (set to True). Additionally, users must configure base_url="https://api.deepseek.com/beta" to activate the Beta feature.
Tip
In this case, we will use the DeepseekBeta client in our code examples.
// uses Deepseek, Deepseek.Types, Deepseek.Tutorial.VCL;
//Asynchronous example
DeepSeekBeta.Chat.AsynCreate(
procedure (Params: TChatParams)
begin
Params.Model('deepseek-chat');
Params.Messages([
FromUser('Please write quick sort code'),
FromAssistant('```python\n', True)
]);
Params.Stop('```');
end,
function : TAsynChat
begin
Result.Sender := TutorialHub;
Result.OnStart := Start;
Result.OnSuccess := Display;
Result.OnError := Display;
end);The model will output:
# Quick Sort implementation in Python
def quick_sort(arr):
if len(arr) <= 1:
return arr
pivot = arr[len(arr) // 2]
left = [x for x in arr if x < pivot]
middle = [x for x in arr if x == pivot]
right = [x for x in arr if x > pivot]
return quick_sort(left) + middle + quick_sort(right)
# Example usage:
arr = [3, 6, 8, 10, 1, 2, 1]
sorted_arr = quick_sort(arr)
print("Sorted array:", sorted_arr)Pull requests are welcome. If you're planning to make a major change, please open an issue first to discuss your proposed changes.
This project is licensed under the MIT License.