1use anyhow::{Context as _, Result, anyhow};
2use futures::{AsyncBufReadExt, AsyncReadExt, StreamExt, io::BufReader, stream::BoxStream};
3use http_client::{AsyncBody, HttpClient, Method, Request as HttpRequest};
4use serde::{Deserialize, Serialize};
5use serde_json::Value;
6use std::{convert::TryFrom, future::Future};
7use strum::EnumIter;
8
9pub const VERCEL_API_URL: &str = "https://api.v0.dev/v1";
10
11fn is_none_or_empty<T: AsRef<[U]>, U>(opt: &Option<T>) -> bool {
12 opt.as_ref().map_or(true, |v| v.as_ref().is_empty())
13}
14
15#[derive(Clone, Copy, Serialize, Deserialize, Debug, Eq, PartialEq)]
16#[serde(rename_all = "lowercase")]
17pub enum Role {
18 User,
19 Assistant,
20 System,
21 Tool,
22}
23
24impl TryFrom<String> for Role {
25 type Error = anyhow::Error;
26
27 fn try_from(value: String) -> Result<Self> {
28 match value.as_str() {
29 "user" => Ok(Self::User),
30 "assistant" => Ok(Self::Assistant),
31 "system" => Ok(Self::System),
32 "tool" => Ok(Self::Tool),
33 _ => anyhow::bail!("invalid role '{value}'"),
34 }
35 }
36}
37
38impl From<Role> for String {
39 fn from(val: Role) -> Self {
40 match val {
41 Role::User => "user".to_owned(),
42 Role::Assistant => "assistant".to_owned(),
43 Role::System => "system".to_owned(),
44 Role::Tool => "tool".to_owned(),
45 }
46 }
47}
48
49#[cfg_attr(feature = "schemars", derive(schemars::JsonSchema))]
50#[derive(Clone, Debug, Default, Serialize, Deserialize, PartialEq, EnumIter)]
51pub enum Model {
52 #[serde(rename = "v-0")]
53 #[default]
54 VZero,
55
56 #[serde(rename = "custom")]
57 Custom {
58 name: String,
59 /// The name displayed in the UI, such as in the assistant panel model dropdown menu.
60 display_name: Option<String>,
61 max_tokens: u64,
62 max_output_tokens: Option<u64>,
63 max_completion_tokens: Option<u64>,
64 },
65}
66
67impl Model {
68 pub fn default_fast() -> Self {
69 Self::VZero
70 }
71
72 pub fn from_id(id: &str) -> Result<Self> {
73 match id {
74 "v-0" => Ok(Self::VZero),
75 invalid_id => anyhow::bail!("invalid model id '{invalid_id}'"),
76 }
77 }
78
79 pub fn id(&self) -> &str {
80 match self {
81 Self::VZero => "v-0",
82 Self::Custom { name, .. } => name,
83 }
84 }
85
86 pub fn display_name(&self) -> &str {
87 match self {
88 Self::VZero => "Vercel v0",
89 Self::Custom {
90 name, display_name, ..
91 } => display_name.as_ref().unwrap_or(name),
92 }
93 }
94
95 pub fn max_token_count(&self) -> u64 {
96 match self {
97 Self::VZero => 128_000,
98 Self::Custom { max_tokens, .. } => *max_tokens,
99 }
100 }
101
102 pub fn max_output_tokens(&self) -> Option<u64> {
103 match self {
104 Self::Custom {
105 max_output_tokens, ..
106 } => *max_output_tokens,
107 Self::VZero => Some(32_768),
108 }
109 }
110
111 /// Returns whether the given model supports the `parallel_tool_calls` parameter.
112 ///
113 /// If the model does not support the parameter, do not pass it up, or the API will return an error.
114 pub fn supports_parallel_tool_calls(&self) -> bool {
115 match self {
116 Self::VZero => true,
117 Model::Custom { .. } => false,
118 }
119 }
120}
121
122#[derive(Debug, Serialize, Deserialize)]
123pub struct Request {
124 pub model: String,
125 pub messages: Vec<RequestMessage>,
126 pub stream: bool,
127 #[serde(default, skip_serializing_if = "Option::is_none")]
128 pub max_completion_tokens: Option<u64>,
129 #[serde(default, skip_serializing_if = "Vec::is_empty")]
130 pub stop: Vec<String>,
131 pub temperature: f32,
132 #[serde(default, skip_serializing_if = "Option::is_none")]
133 pub tool_choice: Option<ToolChoice>,
134 /// Whether to enable parallel function calling during tool use.
135 #[serde(default, skip_serializing_if = "Option::is_none")]
136 pub parallel_tool_calls: Option<bool>,
137 #[serde(default, skip_serializing_if = "Vec::is_empty")]
138 pub tools: Vec<ToolDefinition>,
139}
140
141#[derive(Debug, Serialize, Deserialize)]
142#[serde(untagged)]
143pub enum ToolChoice {
144 Auto,
145 Required,
146 None,
147 Other(ToolDefinition),
148}
149
150#[derive(Clone, Deserialize, Serialize, Debug)]
151#[serde(tag = "type", rename_all = "snake_case")]
152pub enum ToolDefinition {
153 #[allow(dead_code)]
154 Function { function: FunctionDefinition },
155}
156
157#[derive(Clone, Debug, Serialize, Deserialize)]
158pub struct FunctionDefinition {
159 pub name: String,
160 pub description: Option<String>,
161 pub parameters: Option<Value>,
162}
163
164#[derive(Serialize, Deserialize, Debug, Eq, PartialEq)]
165#[serde(tag = "role", rename_all = "lowercase")]
166pub enum RequestMessage {
167 Assistant {
168 content: Option<MessageContent>,
169 #[serde(default, skip_serializing_if = "Vec::is_empty")]
170 tool_calls: Vec<ToolCall>,
171 },
172 User {
173 content: MessageContent,
174 },
175 System {
176 content: MessageContent,
177 },
178 Tool {
179 content: MessageContent,
180 tool_call_id: String,
181 },
182}
183
184#[derive(Serialize, Deserialize, Clone, Debug, Eq, PartialEq)]
185#[serde(untagged)]
186pub enum MessageContent {
187 Plain(String),
188 Multipart(Vec<MessagePart>),
189}
190
191impl MessageContent {
192 pub fn empty() -> Self {
193 MessageContent::Multipart(vec![])
194 }
195
196 pub fn push_part(&mut self, part: MessagePart) {
197 match self {
198 MessageContent::Plain(text) => {
199 *self =
200 MessageContent::Multipart(vec![MessagePart::Text { text: text.clone() }, part]);
201 }
202 MessageContent::Multipart(parts) if parts.is_empty() => match part {
203 MessagePart::Text { text } => *self = MessageContent::Plain(text),
204 MessagePart::Image { .. } => *self = MessageContent::Multipart(vec![part]),
205 },
206 MessageContent::Multipart(parts) => parts.push(part),
207 }
208 }
209}
210
211impl From<Vec<MessagePart>> for MessageContent {
212 fn from(mut parts: Vec<MessagePart>) -> Self {
213 if let [MessagePart::Text { text }] = parts.as_mut_slice() {
214 MessageContent::Plain(std::mem::take(text))
215 } else {
216 MessageContent::Multipart(parts)
217 }
218 }
219}
220
221#[derive(Serialize, Deserialize, Clone, Debug, Eq, PartialEq)]
222#[serde(tag = "type")]
223pub enum MessagePart {
224 #[serde(rename = "text")]
225 Text { text: String },
226 #[serde(rename = "image_url")]
227 Image { image_url: ImageUrl },
228}
229
230#[derive(Serialize, Deserialize, Clone, Debug, Eq, PartialEq)]
231pub struct ImageUrl {
232 pub url: String,
233 #[serde(skip_serializing_if = "Option::is_none")]
234 pub detail: Option<String>,
235}
236
237#[derive(Serialize, Deserialize, Debug, Eq, PartialEq)]
238pub struct ToolCall {
239 pub id: String,
240 #[serde(flatten)]
241 pub content: ToolCallContent,
242}
243
244#[derive(Serialize, Deserialize, Debug, Eq, PartialEq)]
245#[serde(tag = "type", rename_all = "lowercase")]
246pub enum ToolCallContent {
247 Function { function: FunctionContent },
248}
249
250#[derive(Serialize, Deserialize, Debug, Eq, PartialEq)]
251pub struct FunctionContent {
252 pub name: String,
253 pub arguments: String,
254}
255
256#[derive(Serialize, Deserialize, Debug, Eq, PartialEq)]
257pub struct ResponseMessageDelta {
258 pub role: Option<Role>,
259 pub content: Option<String>,
260 #[serde(default, skip_serializing_if = "is_none_or_empty")]
261 pub tool_calls: Option<Vec<ToolCallChunk>>,
262}
263
264#[derive(Serialize, Deserialize, Debug, Eq, PartialEq)]
265pub struct ToolCallChunk {
266 pub index: usize,
267 pub id: Option<String>,
268
269 // There is also an optional `type` field that would determine if a
270 // function is there. Sometimes this streams in with the `function` before
271 // it streams in the `type`
272 pub function: Option<FunctionChunk>,
273}
274
275#[derive(Serialize, Deserialize, Debug, Eq, PartialEq)]
276pub struct FunctionChunk {
277 pub name: Option<String>,
278 pub arguments: Option<String>,
279}
280
281#[derive(Serialize, Deserialize, Debug)]
282pub struct Usage {
283 pub prompt_tokens: u32,
284 pub completion_tokens: u32,
285 pub total_tokens: u32,
286}
287
288#[derive(Serialize, Deserialize, Debug)]
289pub struct ChoiceDelta {
290 pub index: u32,
291 pub delta: ResponseMessageDelta,
292 pub finish_reason: Option<String>,
293}
294
295#[derive(Serialize, Deserialize, Debug)]
296#[serde(untagged)]
297pub enum ResponseStreamResult {
298 Ok(ResponseStreamEvent),
299 Err { error: String },
300}
301
302#[derive(Serialize, Deserialize, Debug)]
303pub struct ResponseStreamEvent {
304 pub model: String,
305 pub choices: Vec<ChoiceDelta>,
306 pub usage: Option<Usage>,
307}
308
309pub async fn stream_completion(
310 client: &dyn HttpClient,
311 api_url: &str,
312 api_key: &str,
313 request: Request,
314) -> Result<BoxStream<'static, Result<ResponseStreamEvent>>> {
315 let uri = format!("{api_url}/chat/completions");
316 let request_builder = HttpRequest::builder()
317 .method(Method::POST)
318 .uri(uri)
319 .header("Content-Type", "application/json")
320 .header("Authorization", format!("Bearer {}", api_key));
321
322 let request = request_builder.body(AsyncBody::from(serde_json::to_string(&request)?))?;
323 let mut response = client.send(request).await?;
324 if response.status().is_success() {
325 let reader = BufReader::new(response.into_body());
326 Ok(reader
327 .lines()
328 .filter_map(|line| async move {
329 match line {
330 Ok(line) => {
331 let line = line.strip_prefix("data: ")?;
332 if line == "[DONE]" {
333 None
334 } else {
335 match serde_json::from_str(line) {
336 Ok(ResponseStreamResult::Ok(response)) => Some(Ok(response)),
337 Ok(ResponseStreamResult::Err { error }) => {
338 Some(Err(anyhow!(error)))
339 }
340 Err(error) => Some(Err(anyhow!(error))),
341 }
342 }
343 }
344 Err(error) => Some(Err(anyhow!(error))),
345 }
346 })
347 .boxed())
348 } else {
349 let mut body = String::new();
350 response.body_mut().read_to_string(&mut body).await?;
351
352 #[derive(Deserialize)]
353 struct VercelResponse {
354 error: VercelError,
355 }
356
357 #[derive(Deserialize)]
358 struct VercelError {
359 message: String,
360 }
361
362 match serde_json::from_str::<VercelResponse>(&body) {
363 Ok(response) if !response.error.message.is_empty() => Err(anyhow!(
364 "Failed to connect to Vercel API: {}",
365 response.error.message,
366 )),
367
368 _ => anyhow::bail!(
369 "Failed to connect to Vercel API: {} {}",
370 response.status(),
371 body,
372 ),
373 }
374 }
375}
376
377#[derive(Copy, Clone, Serialize, Deserialize)]
378pub enum VercelEmbeddingModel {
379 #[serde(rename = "text-embedding-3-small")]
380 TextEmbedding3Small,
381 #[serde(rename = "text-embedding-3-large")]
382 TextEmbedding3Large,
383}
384
385#[derive(Serialize)]
386struct VercelEmbeddingRequest<'a> {
387 model: VercelEmbeddingModel,
388 input: Vec<&'a str>,
389}
390
391#[derive(Deserialize)]
392pub struct VercelEmbeddingResponse {
393 pub data: Vec<VercelEmbedding>,
394}
395
396#[derive(Deserialize)]
397pub struct VercelEmbedding {
398 pub embedding: Vec<f32>,
399}
400
401pub fn embed<'a>(
402 client: &dyn HttpClient,
403 api_url: &str,
404 api_key: &str,
405 model: VercelEmbeddingModel,
406 texts: impl IntoIterator<Item = &'a str>,
407) -> impl 'static + Future<Output = Result<VercelEmbeddingResponse>> {
408 let uri = format!("{api_url}/embeddings");
409
410 let request = VercelEmbeddingRequest {
411 model,
412 input: texts.into_iter().collect(),
413 };
414 let body = AsyncBody::from(serde_json::to_string(&request).unwrap());
415 let request = HttpRequest::builder()
416 .method(Method::POST)
417 .uri(uri)
418 .header("Content-Type", "application/json")
419 .header("Authorization", format!("Bearer {}", api_key))
420 .body(body)
421 .map(|request| client.send(request));
422
423 async move {
424 let mut response = request?.await?;
425 let mut body = String::new();
426 response.body_mut().read_to_string(&mut body).await?;
427
428 anyhow::ensure!(
429 response.status().is_success(),
430 "error during embedding, status: {:?}, body: {:?}",
431 response.status(),
432 body
433 );
434 let response: VercelEmbeddingResponse =
435 serde_json::from_str(&body).context("failed to parse Vercel embedding response")?;
436 Ok(response)
437 }
438}