copilot_chat.rs

  1use std::path::PathBuf;
  2use std::sync::Arc;
  3use std::sync::OnceLock;
  4
  5use anyhow::{Result, anyhow};
  6use chrono::DateTime;
  7use collections::HashSet;
  8use fs::Fs;
  9use futures::{AsyncBufReadExt, AsyncReadExt, StreamExt, io::BufReader, stream::BoxStream};
 10use gpui::{App, AsyncApp, Global, prelude::*};
 11use http_client::{AsyncBody, HttpClient, Method, Request as HttpRequest};
 12use itertools::Itertools;
 13use paths::home_dir;
 14use serde::{Deserialize, Serialize};
 15use settings::watch_config_dir;
 16
 17pub const COPILOT_CHAT_COMPLETION_URL: &str = "https://api.githubcopilot.com/chat/completions";
 18pub const COPILOT_CHAT_AUTH_URL: &str = "https://api.github.com/copilot_internal/v2/token";
 19pub const COPILOT_CHAT_MODELS_URL: &str = "https://api.githubcopilot.com/models";
 20
 21// Copilot's base model; defined by Microsoft in premium requests table
 22// This will be moved to the front of the Copilot model list, and will be used for
 23// 'fast' requests (e.g. title generation)
 24// https://docs.github.com/en/copilot/managing-copilot/monitoring-usage-and-entitlements/about-premium-requests
 25const DEFAULT_MODEL_ID: &str = "gpt-4.1";
 26
 27#[derive(Clone, Copy, Serialize, Deserialize, Debug, Eq, PartialEq)]
 28#[serde(rename_all = "lowercase")]
 29pub enum Role {
 30    User,
 31    Assistant,
 32    System,
 33}
 34
 35#[derive(Deserialize)]
 36struct ModelSchema {
 37    #[serde(deserialize_with = "deserialize_models_skip_errors")]
 38    data: Vec<Model>,
 39}
 40
 41fn deserialize_models_skip_errors<'de, D>(deserializer: D) -> Result<Vec<Model>, D::Error>
 42where
 43    D: serde::Deserializer<'de>,
 44{
 45    let raw_values = Vec::<serde_json::Value>::deserialize(deserializer)?;
 46    let models = raw_values
 47        .into_iter()
 48        .filter_map(|value| match serde_json::from_value::<Model>(value) {
 49            Ok(model) => Some(model),
 50            Err(err) => {
 51                log::warn!("GitHub Copilot Chat model failed to deserialize: {:?}", err);
 52                None
 53            }
 54        })
 55        .collect();
 56
 57    Ok(models)
 58}
 59
 60#[derive(Clone, Serialize, Deserialize, Debug, Eq, PartialEq)]
 61pub struct Model {
 62    capabilities: ModelCapabilities,
 63    id: String,
 64    name: String,
 65    policy: Option<ModelPolicy>,
 66    vendor: ModelVendor,
 67    model_picker_enabled: bool,
 68}
 69
 70#[derive(Clone, Serialize, Deserialize, Debug, Eq, PartialEq)]
 71struct ModelCapabilities {
 72    family: String,
 73    #[serde(default)]
 74    limits: ModelLimits,
 75    supports: ModelSupportedFeatures,
 76}
 77
 78#[derive(Default, Clone, Serialize, Deserialize, Debug, Eq, PartialEq)]
 79struct ModelLimits {
 80    #[serde(default)]
 81    max_context_window_tokens: usize,
 82    #[serde(default)]
 83    max_output_tokens: usize,
 84    #[serde(default)]
 85    max_prompt_tokens: usize,
 86}
 87
 88#[derive(Clone, Serialize, Deserialize, Debug, Eq, PartialEq)]
 89struct ModelPolicy {
 90    state: String,
 91}
 92
 93#[derive(Clone, Serialize, Deserialize, Debug, Eq, PartialEq)]
 94struct ModelSupportedFeatures {
 95    #[serde(default)]
 96    streaming: bool,
 97    #[serde(default)]
 98    tool_calls: bool,
 99    #[serde(default)]
100    parallel_tool_calls: bool,
101    #[serde(default)]
102    vision: bool,
103}
104
105#[derive(Clone, Copy, Serialize, Deserialize, Debug, Eq, PartialEq)]
106pub enum ModelVendor {
107    // Azure OpenAI should have no functional difference from OpenAI in Copilot Chat
108    #[serde(alias = "Azure OpenAI")]
109    OpenAI,
110    Google,
111    Anthropic,
112}
113
114#[derive(Serialize, Deserialize, Debug, Eq, PartialEq, Clone)]
115#[serde(tag = "type")]
116pub enum ChatMessagePart {
117    #[serde(rename = "text")]
118    Text { text: String },
119    #[serde(rename = "image_url")]
120    Image { image_url: ImageUrl },
121}
122
123#[derive(Serialize, Deserialize, Debug, Eq, PartialEq, Clone)]
124pub struct ImageUrl {
125    pub url: String,
126}
127
128impl Model {
129    pub fn uses_streaming(&self) -> bool {
130        self.capabilities.supports.streaming
131    }
132
133    pub fn id(&self) -> &str {
134        self.id.as_str()
135    }
136
137    pub fn display_name(&self) -> &str {
138        self.name.as_str()
139    }
140
141    pub fn max_token_count(&self) -> usize {
142        self.capabilities.limits.max_prompt_tokens
143    }
144
145    pub fn supports_tools(&self) -> bool {
146        self.capabilities.supports.tool_calls
147    }
148
149    pub fn vendor(&self) -> ModelVendor {
150        self.vendor
151    }
152
153    pub fn supports_vision(&self) -> bool {
154        self.capabilities.supports.vision
155    }
156
157    pub fn supports_parallel_tool_calls(&self) -> bool {
158        self.capabilities.supports.parallel_tool_calls
159    }
160}
161
162#[derive(Serialize, Deserialize)]
163pub struct Request {
164    pub intent: bool,
165    pub n: usize,
166    pub stream: bool,
167    pub temperature: f32,
168    pub model: String,
169    pub messages: Vec<ChatMessage>,
170    #[serde(default, skip_serializing_if = "Vec::is_empty")]
171    pub tools: Vec<Tool>,
172    #[serde(default, skip_serializing_if = "Option::is_none")]
173    pub tool_choice: Option<ToolChoice>,
174}
175
176#[derive(Serialize, Deserialize)]
177pub struct Function {
178    pub name: String,
179    pub description: String,
180    pub parameters: serde_json::Value,
181}
182
183#[derive(Serialize, Deserialize)]
184#[serde(tag = "type", rename_all = "snake_case")]
185pub enum Tool {
186    Function { function: Function },
187}
188
189#[derive(Serialize, Deserialize)]
190#[serde(rename_all = "lowercase")]
191pub enum ToolChoice {
192    Auto,
193    Any,
194    None,
195}
196
197#[derive(Serialize, Deserialize, Debug)]
198#[serde(tag = "role", rename_all = "lowercase")]
199pub enum ChatMessage {
200    Assistant {
201        content: ChatMessageContent,
202        #[serde(default, skip_serializing_if = "Vec::is_empty")]
203        tool_calls: Vec<ToolCall>,
204    },
205    User {
206        content: ChatMessageContent,
207    },
208    System {
209        content: String,
210    },
211    Tool {
212        content: ChatMessageContent,
213        tool_call_id: String,
214    },
215}
216
217#[derive(Debug, Serialize, Deserialize)]
218#[serde(untagged)]
219pub enum ChatMessageContent {
220    Plain(String),
221    Multipart(Vec<ChatMessagePart>),
222}
223
224impl ChatMessageContent {
225    pub fn empty() -> Self {
226        ChatMessageContent::Multipart(vec![])
227    }
228}
229
230impl From<Vec<ChatMessagePart>> for ChatMessageContent {
231    fn from(mut parts: Vec<ChatMessagePart>) -> Self {
232        if let [ChatMessagePart::Text { text }] = parts.as_mut_slice() {
233            ChatMessageContent::Plain(std::mem::take(text))
234        } else {
235            ChatMessageContent::Multipart(parts)
236        }
237    }
238}
239
240impl From<String> for ChatMessageContent {
241    fn from(text: String) -> Self {
242        ChatMessageContent::Plain(text)
243    }
244}
245
246#[derive(Serialize, Deserialize, Debug, Eq, PartialEq)]
247pub struct ToolCall {
248    pub id: String,
249    #[serde(flatten)]
250    pub content: ToolCallContent,
251}
252
253#[derive(Serialize, Deserialize, Debug, Eq, PartialEq)]
254#[serde(tag = "type", rename_all = "lowercase")]
255pub enum ToolCallContent {
256    Function { function: FunctionContent },
257}
258
259#[derive(Serialize, Deserialize, Debug, Eq, PartialEq)]
260pub struct FunctionContent {
261    pub name: String,
262    pub arguments: String,
263}
264
265#[derive(Deserialize, Debug)]
266#[serde(tag = "type", rename_all = "snake_case")]
267pub struct ResponseEvent {
268    pub choices: Vec<ResponseChoice>,
269    pub id: String,
270}
271
272#[derive(Debug, Deserialize)]
273pub struct ResponseChoice {
274    pub index: usize,
275    pub finish_reason: Option<String>,
276    pub delta: Option<ResponseDelta>,
277    pub message: Option<ResponseDelta>,
278}
279
280#[derive(Debug, Deserialize)]
281pub struct ResponseDelta {
282    pub content: Option<String>,
283    pub role: Option<Role>,
284    #[serde(default)]
285    pub tool_calls: Vec<ToolCallChunk>,
286}
287
288#[derive(Deserialize, Debug, Eq, PartialEq)]
289pub struct ToolCallChunk {
290    pub index: usize,
291    pub id: Option<String>,
292    pub function: Option<FunctionChunk>,
293}
294
295#[derive(Deserialize, Debug, Eq, PartialEq)]
296pub struct FunctionChunk {
297    pub name: Option<String>,
298    pub arguments: Option<String>,
299}
300
301#[derive(Deserialize)]
302struct ApiTokenResponse {
303    token: String,
304    expires_at: i64,
305}
306
307#[derive(Clone)]
308struct ApiToken {
309    api_key: String,
310    expires_at: DateTime<chrono::Utc>,
311}
312
313impl ApiToken {
314    pub fn remaining_seconds(&self) -> i64 {
315        self.expires_at
316            .timestamp()
317            .saturating_sub(chrono::Utc::now().timestamp())
318    }
319}
320
321impl TryFrom<ApiTokenResponse> for ApiToken {
322    type Error = anyhow::Error;
323
324    fn try_from(response: ApiTokenResponse) -> Result<Self, Self::Error> {
325        let expires_at = DateTime::from_timestamp(response.expires_at, 0)
326            .ok_or_else(|| anyhow!("invalid expires_at"))?;
327
328        Ok(Self {
329            api_key: response.token,
330            expires_at,
331        })
332    }
333}
334
335struct GlobalCopilotChat(gpui::Entity<CopilotChat>);
336
337impl Global for GlobalCopilotChat {}
338
339pub struct CopilotChat {
340    oauth_token: Option<String>,
341    api_token: Option<ApiToken>,
342    models: Option<Vec<Model>>,
343    client: Arc<dyn HttpClient>,
344}
345
346pub fn init(fs: Arc<dyn Fs>, client: Arc<dyn HttpClient>, cx: &mut App) {
347    let copilot_chat = cx.new(|cx| CopilotChat::new(fs, client, cx));
348    cx.set_global(GlobalCopilotChat(copilot_chat));
349}
350
351pub fn copilot_chat_config_dir() -> &'static PathBuf {
352    static COPILOT_CHAT_CONFIG_DIR: OnceLock<PathBuf> = OnceLock::new();
353
354    COPILOT_CHAT_CONFIG_DIR.get_or_init(|| {
355        if cfg!(target_os = "windows") {
356            home_dir().join("AppData").join("Local")
357        } else {
358            home_dir().join(".config")
359        }
360        .join("github-copilot")
361    })
362}
363
364fn copilot_chat_config_paths() -> [PathBuf; 2] {
365    let base_dir = copilot_chat_config_dir();
366    [base_dir.join("hosts.json"), base_dir.join("apps.json")]
367}
368
369impl CopilotChat {
370    pub fn global(cx: &App) -> Option<gpui::Entity<Self>> {
371        cx.try_global::<GlobalCopilotChat>()
372            .map(|model| model.0.clone())
373    }
374
375    pub fn new(fs: Arc<dyn Fs>, client: Arc<dyn HttpClient>, cx: &App) -> Self {
376        let config_paths: HashSet<PathBuf> = copilot_chat_config_paths().into_iter().collect();
377        let dir_path = copilot_chat_config_dir();
378
379        cx.spawn({
380            let client = client.clone();
381            async move |cx| {
382                let mut parent_watch_rx = watch_config_dir(
383                    cx.background_executor(),
384                    fs.clone(),
385                    dir_path.clone(),
386                    config_paths,
387                );
388                while let Some(contents) = parent_watch_rx.next().await {
389                    let oauth_token = extract_oauth_token(contents);
390                    cx.update(|cx| {
391                        if let Some(this) = Self::global(cx).as_ref() {
392                            this.update(cx, |this, cx| {
393                                this.oauth_token = oauth_token.clone();
394                                cx.notify();
395                            });
396                        }
397                    })?;
398
399                    if let Some(ref oauth_token) = oauth_token {
400                        let api_token = request_api_token(oauth_token, client.clone()).await?;
401                        cx.update(|cx| {
402                            if let Some(this) = Self::global(cx).as_ref() {
403                                this.update(cx, |this, cx| {
404                                    this.api_token = Some(api_token.clone());
405                                    cx.notify();
406                                });
407                            }
408                        })?;
409                        let models = get_models(api_token.api_key, client.clone()).await?;
410                        cx.update(|cx| {
411                            if let Some(this) = Self::global(cx).as_ref() {
412                                this.update(cx, |this, cx| {
413                                    this.models = Some(models);
414                                    cx.notify();
415                                });
416                            }
417                        })?;
418                    }
419                }
420                anyhow::Ok(())
421            }
422        })
423        .detach_and_log_err(cx);
424
425        Self {
426            oauth_token: None,
427            api_token: None,
428            models: None,
429            client,
430        }
431    }
432
433    pub fn is_authenticated(&self) -> bool {
434        self.oauth_token.is_some()
435    }
436
437    pub fn models(&self) -> Option<&[Model]> {
438        self.models.as_deref()
439    }
440
441    pub async fn stream_completion(
442        request: Request,
443        mut cx: AsyncApp,
444    ) -> Result<BoxStream<'static, Result<ResponseEvent>>> {
445        let Some(this) = cx.update(|cx| Self::global(cx)).ok().flatten() else {
446            return Err(anyhow!("Copilot chat is not enabled"));
447        };
448
449        let (oauth_token, api_token, client) = this.read_with(&cx, |this, _| {
450            (
451                this.oauth_token.clone(),
452                this.api_token.clone(),
453                this.client.clone(),
454            )
455        })?;
456
457        let oauth_token = oauth_token.ok_or_else(|| anyhow!("No OAuth token available"))?;
458
459        let token = match api_token {
460            Some(api_token) if api_token.remaining_seconds() > 5 * 60 => api_token.clone(),
461            _ => {
462                let token = request_api_token(&oauth_token, client.clone()).await?;
463                this.update(&mut cx, |this, cx| {
464                    this.api_token = Some(token.clone());
465                    cx.notify();
466                })?;
467                token
468            }
469        };
470
471        stream_completion(client.clone(), token.api_key, request).await
472    }
473}
474
475async fn get_models(api_token: String, client: Arc<dyn HttpClient>) -> Result<Vec<Model>> {
476    let all_models = request_models(api_token, client).await?;
477
478    let mut models: Vec<Model> = all_models
479        .into_iter()
480        .filter(|model| {
481            // Ensure user has access to the model; Policy is present only for models that must be
482            // enabled in the GitHub dashboard
483            model.model_picker_enabled
484                && model
485                    .policy
486                    .as_ref()
487                    .is_none_or(|policy| policy.state == "enabled")
488        })
489        // The first model from the API response, in any given family, appear to be the non-tagged
490        // models, which are likely the best choice (e.g. gpt-4o rather than gpt-4o-2024-11-20)
491        .dedup_by(|a, b| a.capabilities.family == b.capabilities.family)
492        .collect();
493
494    if let Some(default_model_position) =
495        models.iter().position(|model| model.id == DEFAULT_MODEL_ID)
496    {
497        let default_model = models.remove(default_model_position);
498        models.insert(0, default_model);
499    }
500
501    Ok(models)
502}
503
504async fn request_models(api_token: String, client: Arc<dyn HttpClient>) -> Result<Vec<Model>> {
505    let request_builder = HttpRequest::builder()
506        .method(Method::GET)
507        .uri(COPILOT_CHAT_MODELS_URL)
508        .header("Authorization", format!("Bearer {}", api_token))
509        .header("Content-Type", "application/json")
510        .header("Copilot-Integration-Id", "vscode-chat");
511
512    let request = request_builder.body(AsyncBody::empty())?;
513
514    let mut response = client.send(request).await?;
515
516    if response.status().is_success() {
517        let mut body = Vec::new();
518        response.body_mut().read_to_end(&mut body).await?;
519
520        let body_str = std::str::from_utf8(&body)?;
521
522        let models = serde_json::from_str::<ModelSchema>(body_str)?.data;
523
524        Ok(models)
525    } else {
526        Err(anyhow!("Failed to request models: {}", response.status()))
527    }
528}
529
530async fn request_api_token(oauth_token: &str, client: Arc<dyn HttpClient>) -> Result<ApiToken> {
531    let request_builder = HttpRequest::builder()
532        .method(Method::GET)
533        .uri(COPILOT_CHAT_AUTH_URL)
534        .header("Authorization", format!("token {}", oauth_token))
535        .header("Accept", "application/json");
536
537    let request = request_builder.body(AsyncBody::empty())?;
538
539    let mut response = client.send(request).await?;
540
541    if response.status().is_success() {
542        let mut body = Vec::new();
543        response.body_mut().read_to_end(&mut body).await?;
544
545        let body_str = std::str::from_utf8(&body)?;
546
547        let parsed: ApiTokenResponse = serde_json::from_str(body_str)?;
548        ApiToken::try_from(parsed)
549    } else {
550        let mut body = Vec::new();
551        response.body_mut().read_to_end(&mut body).await?;
552
553        let body_str = std::str::from_utf8(&body)?;
554
555        Err(anyhow!("Failed to request API token: {}", body_str))
556    }
557}
558
559fn extract_oauth_token(contents: String) -> Option<String> {
560    serde_json::from_str::<serde_json::Value>(&contents)
561        .map(|v| {
562            v.as_object().and_then(|obj| {
563                obj.iter().find_map(|(key, value)| {
564                    if key.starts_with("github.com") {
565                        value["oauth_token"].as_str().map(|v| v.to_string())
566                    } else {
567                        None
568                    }
569                })
570            })
571        })
572        .ok()
573        .flatten()
574}
575
576async fn stream_completion(
577    client: Arc<dyn HttpClient>,
578    api_key: String,
579    request: Request,
580) -> Result<BoxStream<'static, Result<ResponseEvent>>> {
581    let request_builder = HttpRequest::builder()
582        .method(Method::POST)
583        .uri(COPILOT_CHAT_COMPLETION_URL)
584        .header(
585            "Editor-Version",
586            format!(
587                "Zed/{}",
588                option_env!("CARGO_PKG_VERSION").unwrap_or("unknown")
589            ),
590        )
591        .header("Authorization", format!("Bearer {}", api_key))
592        .header("Content-Type", "application/json")
593        .header("Copilot-Integration-Id", "vscode-chat")
594        .header("Copilot-Vision-Request", "true");
595
596    let is_streaming = request.stream;
597
598    let json = serde_json::to_string(&request)?;
599    let request = request_builder.body(AsyncBody::from(json))?;
600    let mut response = client.send(request).await?;
601
602    if !response.status().is_success() {
603        let mut body = Vec::new();
604        response.body_mut().read_to_end(&mut body).await?;
605        let body_str = std::str::from_utf8(&body)?;
606        return Err(anyhow!(
607            "Failed to connect to API: {} {}",
608            response.status(),
609            body_str
610        ));
611    }
612
613    if is_streaming {
614        let reader = BufReader::new(response.into_body());
615        Ok(reader
616            .lines()
617            .filter_map(|line| async move {
618                match line {
619                    Ok(line) => {
620                        let line = line.strip_prefix("data: ")?;
621                        if line.starts_with("[DONE]") {
622                            return None;
623                        }
624
625                        match serde_json::from_str::<ResponseEvent>(line) {
626                            Ok(response) => {
627                                if response.choices.is_empty() {
628                                    None
629                                } else {
630                                    Some(Ok(response))
631                                }
632                            }
633                            Err(error) => Some(Err(anyhow!(error))),
634                        }
635                    }
636                    Err(error) => Some(Err(anyhow!(error))),
637                }
638            })
639            .boxed())
640    } else {
641        let mut body = Vec::new();
642        response.body_mut().read_to_end(&mut body).await?;
643        let body_str = std::str::from_utf8(&body)?;
644        let response: ResponseEvent = serde_json::from_str(body_str)?;
645
646        Ok(futures::stream::once(async move { Ok(response) }).boxed())
647    }
648}
649
650#[cfg(test)]
651mod tests {
652    use super::*;
653
654    #[test]
655    fn test_resilient_model_schema_deserialize() {
656        let json = r#"{
657              "data": [
658                {
659                  "capabilities": {
660                    "family": "gpt-4",
661                    "limits": {
662                      "max_context_window_tokens": 32768,
663                      "max_output_tokens": 4096,
664                      "max_prompt_tokens": 32768
665                    },
666                    "object": "model_capabilities",
667                    "supports": { "streaming": true, "tool_calls": true },
668                    "tokenizer": "cl100k_base",
669                    "type": "chat"
670                  },
671                  "id": "gpt-4",
672                  "model_picker_enabled": false,
673                  "name": "GPT 4",
674                  "object": "model",
675                  "preview": false,
676                  "vendor": "Azure OpenAI",
677                  "version": "gpt-4-0613"
678                },
679                {
680                    "some-unknown-field": 123
681                },
682                {
683                  "capabilities": {
684                    "family": "claude-3.7-sonnet",
685                    "limits": {
686                      "max_context_window_tokens": 200000,
687                      "max_output_tokens": 16384,
688                      "max_prompt_tokens": 90000,
689                      "vision": {
690                        "max_prompt_image_size": 3145728,
691                        "max_prompt_images": 1,
692                        "supported_media_types": ["image/jpeg", "image/png", "image/webp"]
693                      }
694                    },
695                    "object": "model_capabilities",
696                    "supports": {
697                      "parallel_tool_calls": true,
698                      "streaming": true,
699                      "tool_calls": true,
700                      "vision": true
701                    },
702                    "tokenizer": "o200k_base",
703                    "type": "chat"
704                  },
705                  "id": "claude-3.7-sonnet",
706                  "model_picker_enabled": true,
707                  "name": "Claude 3.7 Sonnet",
708                  "object": "model",
709                  "policy": {
710                    "state": "enabled",
711                    "terms": "Enable access to the latest Claude 3.7 Sonnet model from Anthropic. [Learn more about how GitHub Copilot serves Claude 3.7 Sonnet](https://docs.github.com/copilot/using-github-copilot/using-claude-sonnet-in-github-copilot)."
712                  },
713                  "preview": false,
714                  "vendor": "Anthropic",
715                  "version": "claude-3.7-sonnet"
716                }
717              ],
718              "object": "list"
719            }"#;
720
721        let schema: ModelSchema = serde_json::from_str(&json).unwrap();
722
723        assert_eq!(schema.data.len(), 2);
724        assert_eq!(schema.data[0].id, "gpt-4");
725        assert_eq!(schema.data[1].id, "claude-3.7-sonnet");
726    }
727}