bpx_api_client/
lib.rs

1//! Backpack Exchange API Client
2//!
3//! This module provides the `BpxClient` for interacting with the Backpack Exchange API.
4//! It includes functionality for authenticated and public endpoints,
5//! along with utilities for error handling, request signing, and response processing.
6//!
7//! ## Features
8//! - Request signing and authentication using ED25519 signatures.
9//! - Supports both REST and WebSocket endpoints.
10//! - Includes modules for managing capital, orders, trades, and user data.
11//!
12//! ## Example
13//! ```no_run
14//! # // We depend on tokio only when the `ws` feature is enabled.
15//! # #[cfg(feature = "ws")]
16//! # {
17//! use bpx_api_client::{BACKPACK_API_BASE_URL, BpxClient};
18//!
19//! #[tokio::main]
20//! async fn main() {
21//!     let base_url = BACKPACK_API_BASE_URL.to_string();
22//!     let secret = "your_api_secret_here";
23//!     let headers = None;
24//!
25//!     let client = BpxClient::init(base_url, secret, headers)
26//!         .expect("Failed to initialize Backpack API client");
27//!
28//!     match client.get_open_orders(Some("SOL_USDC")).await {
29//!         Ok(orders) => println!("Open Orders: {:?}", orders),
30//!         Err(err) => tracing::error!("Error: {:?}", err),
31//!     }
32//! }
33//! # }
34//! ```
35
36use base64::{Engine, engine::general_purpose::STANDARD};
37use ed25519_dalek::{Signature, Signer, SigningKey, VerifyingKey};
38use reqwest::{IntoUrl, Method, Request, Response, StatusCode, Url, header::CONTENT_TYPE};
39use routes::{
40    account::{
41        API_ACCOUNT, API_ACCOUNT_CONVERT_DUST, API_ACCOUNT_MAX_BORROW, API_ACCOUNT_MAX_WITHDRAWAL,
42    },
43    borrow_lend::API_BORROW_LEND_POSITIONS,
44    capital::{API_CAPITAL, API_COLLATERAL, API_DEPOSIT_ADDRESS, API_DEPOSITS, API_WITHDRAWALS},
45    futures::API_FUTURES_POSITION,
46    history::API_FILLS_HISTORY,
47    order::{API_ORDER, API_ORDERS},
48    rfq::{API_RFQ, API_RFQ_QUOTE},
49    user::API_USER_2FA,
50};
51use serde::Serialize;
52use serde_json::Value;
53use std::{
54    borrow::Cow,
55    collections::BTreeMap,
56    time::{SystemTime, UNIX_EPOCH},
57};
58
59pub mod error;
60
61mod routes;
62
63#[cfg(feature = "ws")]
64mod ws;
65
66/// Re-export of the Backpack Exchange API types.
67pub use bpx_api_types as types;
68
69/// Re-export of the custom `Error` type and `Result` alias for error handling.
70pub use error::{Error, Result};
71
72const API_USER_AGENT: &str = "bpx-rust-client";
73const API_KEY_HEADER: &str = "X-API-Key";
74
75const DEFAULT_WINDOW: u32 = 5000;
76
77const SIGNATURE_HEADER: &str = "X-Signature";
78const TIMESTAMP_HEADER: &str = "X-Timestamp";
79const WINDOW_HEADER: &str = "X-Window";
80
81const JSON_CONTENT: &str = "application/json; charset=utf-8";
82
83/// The official base URL for the Backpack Exchange REST API.
84pub const BACKPACK_API_BASE_URL: &str = "https://api.backpack.exchange";
85
86/// The official WebSocket URL for real-time data from the Backpack Exchange.
87pub const BACKPACK_WS_URL: &str = "wss://ws.backpack.exchange";
88
89/// Type alias for custom HTTP headers passed to `BpxClient` during initialization.
90pub type BpxHeaders = reqwest::header::HeaderMap;
91
92/// A client for interacting with the Backpack Exchange API.
93#[derive(Debug, Clone)]
94pub struct BpxClient {
95    signing_key: Option<SigningKey>,
96    verifying_key: Option<VerifyingKey>,
97    base_url: Url,
98    #[cfg_attr(not(feature = "ws"), allow(dead_code))]
99    ws_url: Url,
100    client: reqwest::Client,
101}
102
103impl std::ops::Deref for BpxClient {
104    type Target = reqwest::Client;
105
106    fn deref(&self) -> &Self::Target {
107        &self.client
108    }
109}
110
111impl std::ops::DerefMut for BpxClient {
112    fn deref_mut(&mut self) -> &mut Self::Target {
113        &mut self.client
114    }
115}
116
117impl AsRef<reqwest::Client> for BpxClient {
118    fn as_ref(&self) -> &reqwest::Client {
119        &self.client
120    }
121}
122
123// Public functions.
124impl BpxClient {
125    pub fn builder() -> BpxClientBuilder {
126        BpxClientBuilder::new()
127    }
128
129    /// Initializes a new client with the given base URL, API secret, and optional headers.
130    ///
131    /// This sets up the signing and verification keys, and creates a `reqwest` client
132    /// with default headers including the API key and content type.
133    pub fn init(base_url: String, secret: &str, headers: Option<BpxHeaders>) -> Result<Self> {
134        BpxClientBuilder::new()
135            .base_url(base_url)
136            .secret(secret)
137            .headers(headers.unwrap_or_default())
138            .build()
139    }
140
141    /// Initializes a new client with WebSocket support.
142    #[cfg(feature = "ws")]
143    #[deprecated(
144        note = "Use BpxClient::builder() instead to configure the client with a custom websocket URL."
145    )]
146    pub fn init_with_ws(
147        base_url: String,
148        ws_url: String,
149        secret: &str,
150        headers: Option<BpxHeaders>,
151    ) -> Result<Self> {
152        BpxClientBuilder::new()
153            .base_url(base_url)
154            .ws_url(ws_url)
155            .secret(secret)
156            .headers(headers.unwrap_or_default())
157            .build()
158    }
159
160    /// Processes the response to check for HTTP errors and extracts
161    /// the response content.
162    ///
163    /// Returns a custom error if the status code is non-2xx.
164    async fn process_response(res: Response) -> Result<Response> {
165        if let Err(e) = res.error_for_status_ref() {
166            let err_text = res.text().await?;
167            let err = Error::BpxApiError {
168                status_code: e.status().unwrap_or(StatusCode::INTERNAL_SERVER_ERROR),
169                message: err_text.into(),
170            };
171            return Err(err);
172        }
173        Ok(res)
174    }
175
176    /// Sends a GET request to the specified URL and signs it before execution.
177    pub async fn get<U: IntoUrl>(&self, url: U) -> Result<Response> {
178        let req = self.build_and_maybe_sign_request::<(), _>(url, Method::GET, None)?;
179        tracing::debug!(?req, "GET request");
180        let res = self.client.execute(req).await?;
181        Self::process_response(res).await
182    }
183
184    /// Sends a POST request with a JSON payload to the specified URL and signs it.
185    pub async fn post<P: Serialize, U: IntoUrl>(&self, url: U, payload: P) -> Result<Response> {
186        let req = self.build_and_maybe_sign_request(url, Method::POST, Some(&payload))?;
187        tracing::debug!(?req, "POST request");
188        let res = self.client.execute(req).await?;
189        Self::process_response(res).await
190    }
191
192    /// Sends a DELETE request with a JSON payload to the specified URL and signs it.
193    pub async fn delete<P: Serialize, U: IntoUrl>(&self, url: U, payload: P) -> Result<Response> {
194        let req = self.build_and_maybe_sign_request(url, Method::DELETE, Some(&payload))?;
195        tracing::debug!(?req, "DELETE request");
196        let res = self.client.execute(req).await?;
197        Self::process_response(res).await
198    }
199
200    /// Sends a PATCH request with a JSON payload to the specified URL and signs it.
201    pub async fn patch<P: Serialize, U: IntoUrl>(&self, url: U, payload: P) -> Result<Response> {
202        let req = self.build_and_maybe_sign_request(url, Method::PATCH, Some(&payload))?;
203        tracing::debug!(?req, "PATCH request");
204        let res = self.client.execute(req).await?;
205        Self::process_response(res).await
206    }
207
208    /// Returns a reference to the [`VerifyingKey`] used for request verification.
209    /// Return will be [`Some`] if the client was initialised with a secret key, otherwise [`None`].
210    pub const fn verifying_key(&self) -> Option<&VerifyingKey> {
211        self.verifying_key.as_ref()
212    }
213
214    /// Returns a reference to the underlying HTTP client.
215    pub const fn client(&self) -> &reqwest::Client {
216        &self.client
217    }
218}
219
220// Private functions.
221impl BpxClient {
222    /// Signs a request by generating a signature from the request details
223    /// and appending necessary headers for authentication.
224    ///
225    /// # Arguments
226    /// * `req` - The mutable reference to the request to be signed.
227    fn build_and_maybe_sign_request<P: Serialize, U: IntoUrl>(
228        &self,
229        url: U,
230        method: Method,
231        payload: Option<&P>,
232    ) -> Result<Request> {
233        let url = url.into_url()?;
234        let instruction = match url.path() {
235            API_CAPITAL if method == Method::GET => "balanceQuery",
236            API_DEPOSITS if method == Method::GET => "depositQueryAll",
237            API_DEPOSIT_ADDRESS if method == Method::GET => "depositAddressQuery",
238            API_WITHDRAWALS if method == Method::GET => "withdrawalQueryAll",
239            API_WITHDRAWALS if method == Method::POST => "withdraw",
240            API_USER_2FA if method == Method::POST => "issueTwoFactorToken",
241            API_ORDER if method == Method::GET => "orderQuery",
242            API_ORDER if method == Method::POST => "orderExecute",
243            API_ORDER if method == Method::DELETE => "orderCancel",
244            API_ORDERS if method == Method::GET => "orderQueryAll",
245            API_ORDERS if method == Method::DELETE => "orderCancelAll",
246            API_RFQ if method == Method::POST => "rfqSubmit",
247            API_RFQ_QUOTE if method == Method::POST => "quoteSubmit",
248            API_FUTURES_POSITION if method == Method::GET => "positionQuery",
249            API_BORROW_LEND_POSITIONS if method == Method::GET => "borrowLendPositionQuery",
250            API_COLLATERAL if method == Method::GET => "collateralQuery",
251            API_ACCOUNT if method == Method::GET => "accountQuery",
252            API_ACCOUNT_MAX_BORROW if method == Method::GET => "maxBorrowQuantity",
253            API_ACCOUNT_MAX_WITHDRAWAL if method == Method::GET => "maxWithdrawalQuantity",
254            API_ACCOUNT if method == Method::PATCH => "accountUpdate",
255            API_ACCOUNT_CONVERT_DUST if method == Method::POST => "convertDust",
256            API_FILLS_HISTORY if method == Method::GET => "fillHistoryQueryAll",
257            _ => {
258                let req = self.client().request(method, url);
259                if let Some(payload) = payload {
260                    return Ok(req.json(payload).build()?);
261                } else {
262                    return Ok(req.build()?);
263                }
264            }
265        };
266
267        let Some(signing_key) = &self.signing_key else {
268            return Err(Error::NotAuthenticated);
269        };
270
271        let query_params = url
272            .query_pairs()
273            .collect::<BTreeMap<Cow<'_, str>, Cow<'_, str>>>();
274        let body_params = if let Some(payload) = payload {
275            let s = serde_json::to_value(payload)?;
276            match s {
277                Value::Object(map) => map
278                    .into_iter()
279                    .map(|(k, v)| (k, v.to_string()))
280                    .collect::<BTreeMap<_, _>>(),
281                _ => {
282                    return Err(Error::InvalidRequest(
283                        "payload must be a JSON object".into(),
284                    ));
285                }
286            }
287        } else {
288            BTreeMap::new()
289        };
290
291        let timestamp = now_millis();
292        let mut signee = format!("instruction={instruction}");
293        for (k, v) in query_params {
294            signee.push_str(&format!("&{k}={v}"));
295        }
296        for (k, v) in body_params {
297            let v = v.trim_start_matches('"').trim_end_matches('"');
298            signee.push_str(&format!("&{k}={v}"));
299        }
300        signee.push_str(&format!("&timestamp={timestamp}&window={DEFAULT_WINDOW}"));
301        tracing::debug!("signee: {}", signee);
302
303        let signature: Signature = signing_key.sign(signee.as_bytes());
304        let signature = STANDARD.encode(signature.to_bytes());
305
306        let mut req = self.client().request(method, url);
307        if let Some(payload) = payload {
308            req = req.json(payload);
309        }
310        let mut req = req.build()?;
311        req.headers_mut()
312            .insert(SIGNATURE_HEADER, signature.parse()?);
313        req.headers_mut()
314            .insert(TIMESTAMP_HEADER, timestamp.to_string().parse()?);
315        req.headers_mut()
316            .insert(WINDOW_HEADER, DEFAULT_WINDOW.to_string().parse()?);
317        if matches!(req.method(), &Method::POST | &Method::DELETE) {
318            req.headers_mut()
319                .insert(CONTENT_TYPE, JSON_CONTENT.parse()?);
320        }
321        Ok(req)
322    }
323}
324
325#[derive(Debug, Default)]
326pub struct BpxClientBuilder {
327    base_url: Option<String>,
328    ws_url: Option<String>,
329    secret: Option<String>,
330    headers: Option<BpxHeaders>,
331}
332
333impl BpxClientBuilder {
334    pub fn new() -> Self {
335        Default::default()
336    }
337
338    /// Sets the base URL for the Backpack Exchange API.
339    /// If not set, defaults to `BACKPACK_API_BASE_URL`.
340    ///
341    /// # Arguments
342    /// * `base_url` - The base URL
343    ///
344    /// # Returns
345    /// * `Self` - The updated builder instance
346    pub fn base_url(mut self, base_url: impl ToString) -> Self {
347        self.base_url = Some(base_url.to_string());
348        self
349    }
350
351    /// Sets the WebSocket URL for the Backpack Exchange API.
352    /// If not set, defaults to `BACKPACK_WS_URL`.
353    ///
354    /// # Arguments
355    /// * `ws_url` - The WebSocket URL
356    ///
357    /// # Returns
358    /// * `Self` - The updated builder instance
359    #[cfg(feature = "ws")]
360    pub fn ws_url(mut self, ws_url: impl ToString) -> Self {
361        self.ws_url = Some(ws_url.to_string());
362        self
363    }
364
365    /// Sets the API secret for signing requests.
366    /// If not set, the client will be unauthenticated.
367    ///
368    /// # Arguments
369    /// * `secret` - The API secret
370    ///
371    /// # Returns
372    /// * `Self` - The updated builder instance
373    pub fn secret(mut self, secret: impl ToString) -> Self {
374        self.secret = Some(secret.to_string());
375        self
376    }
377
378    /// Sets custom HTTP headers for the client.
379    /// If not set, no additional headers will be included.
380    ///
381    /// # Arguments
382    /// * `headers` - The custom HTTP headers
383    ///
384    /// # Returns
385    /// * `Self` - The updated builder instance
386    pub fn headers(mut self, headers: BpxHeaders) -> Self {
387        self.headers = Some(headers);
388        self
389    }
390
391    /// Builds the `BpxClient` instance with the configured parameters.
392    ///
393    /// # Returns
394    /// * `Result<BpxClient>` - The constructed client or an error if building fails
395    pub fn build(self) -> Result<BpxClient> {
396        let base_url = self.base_url.as_deref().unwrap_or(BACKPACK_API_BASE_URL);
397        let base_url = Url::parse(base_url)?;
398
399        let ws_url = self.ws_url.as_deref().unwrap_or(BACKPACK_WS_URL);
400        let ws_url = Url::parse(ws_url)?;
401
402        let signing_key = if let Some(secret) = self.secret {
403            Some(
404                STANDARD
405                    .decode(secret)?
406                    .try_into()
407                    .map(|s| SigningKey::from_bytes(&s))
408                    .map_err(|_| Error::SecretKey)?,
409            )
410        } else {
411            None
412        };
413        let verifying_key = signing_key.as_ref().map(|s| s.verifying_key());
414
415        let mut header_map = BpxHeaders::new();
416        if let Some(headers) = self.headers {
417            header_map.extend(headers);
418        }
419
420        header_map.insert(CONTENT_TYPE, JSON_CONTENT.parse()?);
421        if let Some(signing_key) = &signing_key {
422            let verifier = signing_key.verifying_key();
423            header_map.insert(API_KEY_HEADER, STANDARD.encode(verifier).parse()?);
424        }
425
426        let client = BpxClient {
427            signing_key,
428            verifying_key,
429            base_url,
430            ws_url,
431            client: reqwest::Client::builder()
432                .user_agent(API_USER_AGENT)
433                .default_headers(header_map)
434                .build()?,
435        };
436
437        Ok(client)
438    }
439}
440
441/// Returns the current time in milliseconds since UNIX epoch.
442fn now_millis() -> u64 {
443    SystemTime::now()
444        .duration_since(UNIX_EPOCH)
445        .expect("Time went backwards")
446        .as_millis() as u64
447}
bpx_api_client/lib.rs

bpx_api_client/
lib.rs
