ds_api/agent/agent_core.rs
1use std::collections::HashMap;
2
3use crate::api::ApiClient;
4use crate::conversation::{Conversation, LlmSummarizer, Summarizer};
5use crate::raw::request::message::{Message, Role};
6use crate::tool_trait::Tool;
7use serde_json::Value;
8use tokio::sync::mpsc;
9
10/// Information about a tool call requested by the model.
11///
12/// Yielded as `AgentEvent::ToolCall` when the model requests a tool invocation.
13/// At this point the tool has not yet been executed.
14#[derive(Debug, Clone)]
15pub struct ToolCallInfo {
16 pub id: String,
17 pub name: String,
18 pub args: Value,
19}
20
21/// The result of a completed tool invocation.
22///
23/// Yielded as `AgentEvent::ToolResult` after the tool has finished executing.
24#[derive(Debug, Clone)]
25pub struct ToolCallResult {
26 pub id: String,
27 pub name: String,
28 pub args: Value,
29 pub result: Value,
30}
31
32/// Events emitted by [`AgentStream`][crate::agent::AgentStream].
33///
34/// Each variant represents a distinct, self-contained event in the agent lifecycle:
35///
36/// - `Token(String)` — a text fragment from the assistant. In streaming mode each
37/// `Token` is a single SSE delta; in non-streaming mode the full response text
38/// arrives as one `Token`.
39/// - `ToolCall(ToolCallInfo)` — the model has requested a tool invocation. One event
40/// is emitted per call, before execution begins.
41/// - `ToolResult(ToolCallResult)` — a tool has finished executing. One event is
42/// emitted per call, in the same order as the corresponding `ToolCall` events.
43#[derive(Debug, Clone)]
44pub enum AgentEvent {
45 Token(String),
46 ToolCall(ToolCallInfo),
47 ToolResult(ToolCallResult),
48}
49
50/// An agent that combines a [`Conversation`] with a set of callable tools.
51///
52/// Build one with the fluent builder methods, then call [`chat`][DeepseekAgent::chat]
53/// to start a turn:
54///
55/// ```no_run
56/// use ds_api::{DeepseekAgent, tool};
57/// use serde_json::{Value, json};
58///
59/// struct MyTool;
60///
61/// #[tool]
62/// impl ds_api::Tool for MyTool {
63/// async fn greet(&self, name: String) -> Value {
64/// json!({ "greeting": format!("Hello, {name}!") })
65/// }
66/// }
67///
68/// # #[tokio::main] async fn main() {
69/// let agent = DeepseekAgent::new("sk-...")
70/// .add_tool(MyTool);
71/// # }
72/// ```
73pub struct DeepseekAgent {
74 /// The conversation manages history, the API client, and context-window compression.
75 pub(crate) conversation: Conversation,
76 pub(crate) tools: Vec<Box<dyn Tool>>,
77 pub(crate) tool_index: HashMap<String, usize>,
78 /// When `true` the agent uses SSE streaming for each API turn so `Token` events
79 /// arrive incrementally. When `false` (default) the full response is awaited.
80 pub(crate) streaming: bool,
81 /// The model to use for every API turn. Defaults to `"deepseek-chat"`.
82 pub(crate) model: String,
83 /// Optional channel for injecting user messages mid-loop.
84 /// Messages received here are drained after each tool-execution round and
85 /// appended to the conversation history as `Role::User` messages before the
86 /// next API turn begins.
87 pub(crate) interrupt_rx: Option<mpsc::UnboundedReceiver<String>>,
88}
89
90impl DeepseekAgent {
91 fn from_parts(client: ApiClient, model: impl Into<String>) -> Self {
92 let model = model.into();
93 let summarizer = LlmSummarizer::new(client.clone()).with_model(model.clone());
94 Self {
95 conversation: Conversation::new(client).with_summarizer(summarizer),
96 tools: vec![],
97 tool_index: HashMap::new(),
98 streaming: false,
99 model,
100 interrupt_rx: None,
101 }
102 }
103
104 /// Create a new agent targeting the DeepSeek API with `deepseek-chat`.
105 pub fn new(token: impl Into<String>) -> Self {
106 Self::from_parts(ApiClient::new(token), "deepseek-chat")
107 }
108
109 /// Create an agent targeting an OpenAI-compatible provider.
110 ///
111 /// All three parameters are set at construction time and never change:
112 ///
113 /// ```no_run
114 /// use ds_api::DeepseekAgent;
115 ///
116 /// let agent = DeepseekAgent::custom(
117 /// "sk-or-...",
118 /// "https://openrouter.ai/api/v1",
119 /// "meta-llama/llama-3.3-70b-instruct:free",
120 /// );
121 /// ```
122 pub fn custom(
123 token: impl Into<String>,
124 base_url: impl Into<String>,
125 model: impl Into<String>,
126 ) -> Self {
127 let client = ApiClient::new(token).with_base_url(base_url);
128 Self::from_parts(client, model)
129 }
130
131 /// Register a tool (builder-style, supports chaining).
132 ///
133 /// The tool's protocol-level function names are indexed so incoming tool-call
134 /// requests from the model can be dispatched to the correct implementation.
135 pub fn add_tool<TT: Tool + 'static>(mut self, tool: TT) -> Self {
136 let idx = self.tools.len();
137 for raw in tool.raw_tools() {
138 self.tool_index.insert(raw.function.name.clone(), idx);
139 }
140 self.tools.push(Box::new(tool));
141 self
142 }
143
144 /// Push a user message and return an [`AgentStream`][crate::agent::AgentStream]
145 /// that drives the full agent loop (API calls + tool execution).
146 pub fn chat(mut self, user_message: &str) -> crate::agent::stream::AgentStream {
147 self.conversation.push_user_input(user_message);
148 crate::agent::stream::AgentStream::new(self)
149 }
150
151 /// Start an agent turn from the current history **without** pushing a new
152 /// user message first.
153 ///
154 /// Use this when you have already appended the user message manually (e.g.
155 /// via [`push_user_message_with_name`][Self::push_user_message_with_name])
156 /// and want to drive the agent loop from that point.
157 pub fn chat_from_history(self) -> crate::agent::stream::AgentStream {
158 crate::agent::stream::AgentStream::new(self)
159 }
160
161 /// Enable SSE streaming for each API turn (builder-style).
162 pub fn with_streaming(mut self) -> Self {
163 self.streaming = true;
164 self
165 }
166
167 /// Prepend a permanent system prompt to the conversation history (builder-style).
168 ///
169 /// System messages added this way are never removed by the built-in summarizers.
170 pub fn with_system_prompt(mut self, prompt: impl Into<String>) -> Self {
171 self.conversation
172 .add_message(Message::new(Role::System, &prompt.into()));
173 self
174 }
175
176 /// Replace the summarizer used for context-window management (builder-style).
177 pub fn with_summarizer(mut self, summarizer: impl Summarizer + 'static) -> Self {
178 self.conversation = self.conversation.with_summarizer(summarizer);
179 self
180 }
181
182 /// Seed the agent with an existing message history (builder-style).
183 ///
184 /// Used to restore a conversation from persistent storage (e.g. SQLite)
185 /// after a process restart. The messages are set directly on the
186 /// underlying `Conversation` and will be included in the next API call.
187 ///
188 /// # Example
189 ///
190 /// ```no_run
191 /// use ds_api::DeepseekAgent;
192 /// use ds_api::raw::request::message::{Message, Role};
193 ///
194 /// # #[tokio::main] async fn main() {
195 /// let history = vec![
196 /// Message::new(Role::User, "Hello"),
197 /// Message::new(Role::Assistant, "Hi there!"),
198 /// ];
199 /// let agent = DeepseekAgent::new("sk-...").with_history(history);
200 /// # }
201 /// ```
202 pub fn with_history(mut self, history: Vec<crate::raw::request::message::Message>) -> Self {
203 self.conversation = self.conversation.with_history(history);
204 self
205 }
206
207 /// Append a user message with an optional display name to the conversation
208 /// history.
209 ///
210 /// The `name` field is passed through to the API as-is (OpenAI-compatible
211 /// providers use it to distinguish speakers in a shared channel).
212 ///
213 /// # Example
214 ///
215 /// ```no_run
216 /// use ds_api::DeepseekAgent;
217 ///
218 /// # #[tokio::main] async fn main() {
219 /// let mut agent = DeepseekAgent::new("sk-...");
220 /// agent.push_user_message_with_name("What time is it?", Some("alice"));
221 /// # }
222 /// ```
223 pub fn push_user_message_with_name(&mut self, text: &str, name: Option<&str>) {
224 use crate::raw::request::message::{Message, Role};
225 let mut msg = Message::new(Role::User, text);
226 msg.name = name.map(|n| n.to_string());
227 self.conversation.history_mut().push(msg);
228 }
229
230 /// Read-only view of the current conversation history.
231 ///
232 /// Returns all messages in order, including system prompts, user turns,
233 /// assistant replies, tool calls, and tool results. Auto-summary messages
234 /// inserted by the built-in summarizers are also included.
235 ///
236 /// # Example
237 ///
238 /// ```no_run
239 /// use ds_api::DeepseekAgent;
240 ///
241 /// # #[tokio::main] async fn main() {
242 /// let agent = DeepseekAgent::new("sk-...");
243 /// for msg in agent.history() {
244 /// println!("{:?}: {:?}", msg.role, msg.content);
245 /// }
246 /// # }
247 /// ```
248 pub fn history(&self) -> &[crate::raw::request::message::Message] {
249 self.conversation.history()
250 }
251
252 /// Attach an interrupt channel to the agent (builder-style).
253 ///
254 /// Returns the agent and the sender half of the channel. Send any `String`
255 /// through the `UnboundedSender` at any time; the message will be picked up
256 /// after the current tool-execution round finishes and inserted into the
257 /// conversation history as a `Role::User` message before the next API turn.
258 ///
259 /// # Example
260 ///
261 /// ```no_run
262 /// use ds_api::DeepseekAgent;
263 /// use tokio::sync::mpsc;
264 ///
265 /// # #[tokio::main] async fn main() {
266 /// let (agent, tx) = DeepseekAgent::new("sk-...")
267 /// .with_interrupt_channel();
268 ///
269 /// // In another task or callback:
270 /// tx.send("Actually, use Python instead.".into()).unwrap();
271 /// # }
272 /// ```
273 pub fn with_interrupt_channel(mut self) -> (Self, mpsc::UnboundedSender<String>) {
274 let (tx, rx) = mpsc::unbounded_channel();
275 self.interrupt_rx = Some(rx);
276 (self, tx)
277 }
278
279 /// Drain any pending messages from the interrupt channel and append them
280 /// to the conversation history as `Role::User` messages.
281 ///
282 /// Called by the state machine in [`AgentStream`] at the top of every
283 /// `Idle` transition so that injected messages are visible before each API
284 /// turn, not just after tool-execution rounds.
285 pub(crate) fn drain_interrupts(&mut self) {
286 if let Some(rx) = self.interrupt_rx.as_mut() {
287 while let Ok(msg) = rx.try_recv() {
288 self.conversation
289 .history_mut()
290 .push(Message::new(Role::User, &msg));
291 }
292 }
293 }
294}