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deepseek/agent/
builder.rs

1//! Back-compatible `AgentBuilder` / `DeepSeekAgent` over the new streaming
2//! loop. Existing callers (e.g. `crates/research`, `crates/genesis`) keep
3//! working unchanged.
4
5use std::sync::Arc;
6
7use futures::StreamExt;
8
9use crate::client::HttpClient;
10use crate::error::{DeepSeekError, Result};
11
12use super::loop_runner::run;
13use super::messages::{ResultSubtype, SdkMessage};
14use super::options::RunOptions;
15use super::tool::Tool;
16
17/// Fluent constructor for [`DeepSeekAgent`]. Mirrors the pre-port API.
18pub struct AgentBuilder<H: HttpClient> {
19    http: H,
20    api_key: String,
21    model: String,
22    preamble: String,
23    tools: Vec<Box<dyn Tool>>,
24    base_url: String,
25    worker_id: String,
26    options: RunOptions,
27}
28
29impl<H: HttpClient> AgentBuilder<H> {
30    pub fn new(http: H, api_key: impl Into<String>, model: impl Into<String>) -> Self {
31        let model = model.into();
32        let mut options = RunOptions::new(model.clone());
33        options.base_url = "https://api.deepseek.com/v1".into();
34        Self {
35            http,
36            api_key: api_key.into(),
37            model,
38            preamble: String::new(),
39            tools: Vec::new(),
40            base_url: "https://api.deepseek.com".into(),
41            worker_id: String::new(),
42            options,
43        }
44    }
45
46    pub fn preamble(mut self, p: &str) -> Self {
47        self.preamble = p.into();
48        self
49    }
50
51    pub fn tool(mut self, t: impl Tool + 'static) -> Self {
52        self.tools.push(Box::new(t));
53        self
54    }
55
56    /// Back-compat: callers historically passed the `https://api.deepseek.com`
57    /// host (no `/v1`). The loop appends `/v1/chat/completions` itself, so we
58    /// store both shapes.
59    pub fn base_url(mut self, url: &str) -> Self {
60        let trimmed = url.trim_end_matches('/').to_string();
61        self.base_url = trimmed.clone();
62        // Preserve legacy behaviour: append `/v1` for the new loop's base URL.
63        self.options.base_url = if trimmed.ends_with("/v1") {
64            trimmed
65        } else {
66            format!("{trimmed}/v1")
67        };
68        self
69    }
70
71    pub fn worker_id(mut self, id: impl Into<String>) -> Self {
72        self.worker_id = id.into();
73        self
74    }
75
76    /// Override the full [`RunOptions`] for advanced control (max_turns,
77    /// permission mode, hooks, etc.). Settings that overlap with the legacy
78    /// builder methods (`base_url`, `model`) are kept in sync.
79    pub fn options(mut self, opts: RunOptions) -> Self {
80        self.options = opts;
81        self
82    }
83
84    pub fn build(self) -> DeepSeekAgent<H> {
85        let mut options = self.options;
86        options.model = self.model.clone();
87        options.system_prompt = self.preamble;
88        DeepSeekAgent {
89            http: self.http,
90            api_key: self.api_key,
91            tools: Arc::new(self.tools),
92            options,
93            worker_id: self.worker_id,
94        }
95    }
96}
97
98/// Bound DeepSeek agent. Call [`prompt`](Self::prompt) for the legacy
99/// `Result<String>` API or [`run`](Self::run) for the streaming `SdkMessage`
100/// API.
101pub struct DeepSeekAgent<H: HttpClient> {
102    http: H,
103    api_key: String,
104    tools: Arc<Vec<Box<dyn Tool>>>,
105    options: RunOptions,
106    #[allow(dead_code)]
107    worker_id: String,
108}
109
110impl<H: HttpClient + Clone + Send + Sync + 'static> DeepSeekAgent<H> {
111    /// Stream the loop's [`SdkMessage`] sequence.
112    pub fn run(
113        &self,
114        user_prompt: String,
115    ) -> impl futures::Stream<Item = SdkMessage> + use<H> {
116        run(
117            self.http.clone(),
118            self.api_key.clone(),
119            Arc::clone(&self.tools),
120            user_prompt,
121            self.options.clone_for_run(),
122        )
123    }
124
125    /// Legacy entry point — runs the loop to completion and returns the final
126    /// assistant text.
127    pub async fn prompt(&self, user_prompt: String) -> Result<String> {
128        let mut stream = Box::pin(self.run(user_prompt));
129        let mut last_text: Option<String> = None;
130        while let Some(msg) = stream.next().await {
131            match msg {
132                SdkMessage::Result {
133                    subtype: ResultSubtype::Success,
134                    result: Some(text),
135                    ..
136                } => return Ok(text),
137                SdkMessage::Result { subtype, .. } => {
138                    return Err(DeepSeekError::Other(format!(
139                        "agent stopped with subtype {subtype:?}"
140                    )));
141                }
142                SdkMessage::Assistant { content, .. } => {
143                    if let Some(t) = content.iter().find_map(|b| match b {
144                        super::messages::ContentBlock::Text { text } => Some(text.clone()),
145                        _ => None,
146                    }) {
147                        last_text = Some(t);
148                    }
149                }
150                _ => {}
151            }
152        }
153        last_text.ok_or_else(|| {
154            DeepSeekError::Other("agent stream ended without a Result message".into())
155        })
156    }
157}
158
159impl RunOptions {
160    /// Cheap clone for spawning a single `run()` — `Arc<dyn PreToolHook>` is
161    /// shared, all other fields are owned.
162    fn clone_for_run(&self) -> RunOptions {
163        RunOptions {
164            model: self.model.clone(),
165            system_prompt: self.system_prompt.clone(),
166            allowed_tools: self.allowed_tools.clone(),
167            disallowed_tools: self.disallowed_tools.clone(),
168            max_turns: self.max_turns,
169            max_budget_usd: self.max_budget_usd,
170            effort: self.effort.clone(),
171            permission_mode: self.permission_mode,
172            pre_tool_hook: self.pre_tool_hook.clone(),
173            session_id: self.session_id.clone(),
174            base_url: self.base_url.clone(),
175        }
176    }
177}