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 base64ct::{Base64, Encoding};
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_ORDER,
42        API_ACCOUNT_MAX_WITHDRAWAL,
43    },
44    borrow_lend::API_BORROW_LEND_POSITIONS,
45    capital::{API_CAPITAL, API_COLLATERAL, API_DEPOSIT_ADDRESS, API_DEPOSITS, API_WITHDRAWALS},
46    futures::API_FUTURES_POSITION,
47    history::API_FILLS_HISTORY,
48    order::{API_ORDER, API_ORDERS},
49    rfq::{API_RFQ, API_RFQ_QUOTE},
50    user::API_USER_2FA,
51};
52use serde::Serialize;
53use serde_json::Value;
54use std::{
55    borrow::Cow,
56    collections::BTreeMap,
57    time::{SystemTime, UNIX_EPOCH},
58};
59
60pub mod error;
61
62mod routes;
63
64#[cfg(feature = "ws")]
65mod ws;
66
67/// Re-export of the Backpack Exchange API types.
68pub use bpx_api_types as types;
69
70/// Re-export of the custom `Error` type and `Result` alias for error handling.
71pub use error::{Error, Result};
72
73use crate::routes::rfq::{API_RFQ_ACCEPT, API_RFQ_CANCEL, API_RFQ_REFRESH};
74
75const API_USER_AGENT: &str = "bpx-rust-client";
76const API_KEY_HEADER: &str = "X-API-Key";
77
78const DEFAULT_WINDOW: u32 = 5000;
79
80const SIGNATURE_HEADER: &str = "X-Signature";
81const TIMESTAMP_HEADER: &str = "X-Timestamp";
82const WINDOW_HEADER: &str = "X-Window";
83
84const JSON_CONTENT: &str = "application/json; charset=utf-8";
85
86/// The official base URL for the Backpack Exchange REST API.
87pub const BACKPACK_API_BASE_URL: &str = "https://api.backpack.exchange";
88
89/// The official WebSocket URL for real-time data from the Backpack Exchange.
90pub const BACKPACK_WS_URL: &str = "wss://ws.backpack.exchange";
91
92/// Type alias for custom HTTP headers passed to `BpxClient` during initialization.
93pub type BpxHeaders = reqwest::header::HeaderMap;
94
95/// A client for interacting with the Backpack Exchange API.
96#[derive(Debug, Clone)]
97pub struct BpxClient {
98    signing_key: Option<SigningKey>,
99    verifying_key: Option<VerifyingKey>,
100    base_url: Url,
101    #[cfg_attr(not(feature = "ws"), allow(dead_code))]
102    ws_url: Url,
103    client: reqwest::Client,
104}
105
106impl std::ops::Deref for BpxClient {
107    type Target = reqwest::Client;
108
109    fn deref(&self) -> &Self::Target {
110        &self.client
111    }
112}
113
114impl std::ops::DerefMut for BpxClient {
115    fn deref_mut(&mut self) -> &mut Self::Target {
116        &mut self.client
117    }
118}
119
120impl AsRef<reqwest::Client> for BpxClient {
121    fn as_ref(&self) -> &reqwest::Client {
122        &self.client
123    }
124}
125
126// Public functions.
127impl BpxClient {
128    pub fn builder() -> BpxClientBuilder {
129        BpxClientBuilder::new()
130    }
131
132    /// Initializes a new client with the given base URL, API secret, and optional headers.
133    ///
134    /// This sets up the signing and verification keys, and creates a `reqwest` client
135    /// with default headers including the API key and content type.
136    pub fn init(base_url: String, secret: &str, headers: Option<BpxHeaders>) -> Result<Self> {
137        BpxClientBuilder::new()
138            .base_url(base_url)
139            .secret(secret)
140            .headers(headers.unwrap_or_default())
141            .build()
142    }
143
144    /// Initializes a new client with WebSocket support.
145    #[cfg(feature = "ws")]
146    #[deprecated(
147        note = "Use BpxClient::builder() instead to configure the client with a custom websocket URL."
148    )]
149    pub fn init_with_ws(
150        base_url: String,
151        ws_url: String,
152        secret: &str,
153        headers: Option<BpxHeaders>,
154    ) -> Result<Self> {
155        BpxClientBuilder::new()
156            .base_url(base_url)
157            .ws_url(ws_url)
158            .secret(secret)
159            .headers(headers.unwrap_or_default())
160            .build()
161    }
162
163    /// Processes the response to check for HTTP errors and extracts
164    /// the response content.
165    ///
166    /// Returns a custom error if the status code is non-2xx.
167    async fn process_response(res: Response) -> Result<Response> {
168        if let Err(e) = res.error_for_status_ref() {
169            let err_text = res.text().await?;
170            let err = Error::BpxApiError {
171                status_code: e.status().unwrap_or(StatusCode::INTERNAL_SERVER_ERROR),
172                message: err_text.into(),
173            };
174            return Err(err);
175        }
176        Ok(res)
177    }
178
179    /// Sends a GET request to the specified URL and signs it before execution.
180    pub async fn get<U: IntoUrl>(&self, url: U) -> Result<Response> {
181        let req = self.build_and_maybe_sign_request::<(), _>(url, Method::GET, None)?;
182        tracing::debug!(?req, "GET request");
183        let res = self.client.execute(req).await?;
184        Self::process_response(res).await
185    }
186
187    /// Sends a POST request with a JSON payload to the specified URL and signs it.
188    pub async fn post<P: Serialize, U: IntoUrl>(&self, url: U, payload: P) -> Result<Response> {
189        let req = self.build_and_maybe_sign_request(url, Method::POST, Some(&payload))?;
190        tracing::debug!(?req, "POST request");
191        let res = self.client.execute(req).await?;
192        Self::process_response(res).await
193    }
194
195    /// Sends a DELETE request with a JSON payload to the specified URL and signs it.
196    pub async fn delete<P: Serialize, U: IntoUrl>(&self, url: U, payload: P) -> Result<Response> {
197        let req = self.build_and_maybe_sign_request(url, Method::DELETE, Some(&payload))?;
198        tracing::debug!(?req, "DELETE request");
199        let res = self.client.execute(req).await?;
200        Self::process_response(res).await
201    }
202
203    /// Sends a PATCH request with a JSON payload to the specified URL and signs it.
204    pub async fn patch<P: Serialize, U: IntoUrl>(&self, url: U, payload: P) -> Result<Response> {
205        let req = self.build_and_maybe_sign_request(url, Method::PATCH, Some(&payload))?;
206        tracing::debug!(?req, "PATCH request");
207        let res = self.client.execute(req).await?;
208        Self::process_response(res).await
209    }
210
211    /// Returns a reference to the [`VerifyingKey`] used for request verification.
212    /// Return will be [`Some`] if the client was initialised with a secret key, otherwise [`None`].
213    pub const fn verifying_key(&self) -> Option<&VerifyingKey> {
214        self.verifying_key.as_ref()
215    }
216
217    /// Returns a reference to the underlying HTTP client.
218    pub const fn client(&self) -> &reqwest::Client {
219        &self.client
220    }
221}
222
223// Private functions.
224impl BpxClient {
225    /// Signs a request by generating a signature from the request details
226    /// and appending necessary headers for authentication.
227    ///
228    /// # Arguments
229    /// * `req` - The mutable reference to the request to be signed.
230    fn build_and_maybe_sign_request<P: Serialize, U: IntoUrl>(
231        &self,
232        url: U,
233        method: Method,
234        payload: Option<&P>,
235    ) -> Result<Request> {
236        let url = url.into_url()?;
237        let instruction = match url.path() {
238            API_CAPITAL if method == Method::GET => "balanceQuery",
239            API_DEPOSITS if method == Method::GET => "depositQueryAll",
240            API_DEPOSIT_ADDRESS if method == Method::GET => "depositAddressQuery",
241            API_WITHDRAWALS if method == Method::GET => "withdrawalQueryAll",
242            API_WITHDRAWALS if method == Method::POST => "withdraw",
243            API_USER_2FA if method == Method::POST => "issueTwoFactorToken",
244            API_ORDER if method == Method::GET => "orderQuery",
245            API_ORDER if method == Method::POST => "orderExecute",
246            API_ORDER if method == Method::DELETE => "orderCancel",
247            API_ORDERS if method == Method::GET => "orderQueryAll",
248            API_ORDERS if method == Method::DELETE => "orderCancelAll",
249            API_RFQ if method == Method::POST => "rfqSubmit",
250            API_RFQ_QUOTE if method == Method::POST => "quoteSubmit",
251            API_RFQ_ACCEPT if method == Method::POST => "quoteAccept",
252            API_RFQ_CANCEL if method == Method::POST => "rfqCancel",
253            API_RFQ_REFRESH if method == Method::POST => "rfqRefresh",
254            API_FUTURES_POSITION if method == Method::GET => "positionQuery",
255            API_BORROW_LEND_POSITIONS if method == Method::GET => "borrowLendPositionQuery",
256            API_COLLATERAL if method == Method::GET => "collateralQuery",
257            API_ACCOUNT if method == Method::GET => "accountQuery",
258            API_ACCOUNT_MAX_BORROW if method == Method::GET => "maxBorrowQuantity",
259            API_ACCOUNT_MAX_ORDER if method == Method::GET => "maxOrderQuantity",
260            API_ACCOUNT_MAX_WITHDRAWAL if method == Method::GET => "maxWithdrawalQuantity",
261            API_ACCOUNT if method == Method::PATCH => "accountUpdate",
262            API_ACCOUNT_CONVERT_DUST if method == Method::POST => "convertDust",
263            API_FILLS_HISTORY if method == Method::GET => "fillHistoryQueryAll",
264            _ => {
265                let req = self.client().request(method, url);
266                if let Some(payload) = payload {
267                    return Ok(req.json(payload).build()?);
268                } else {
269                    return Ok(req.build()?);
270                }
271            }
272        };
273
274        let Some(signing_key) = &self.signing_key else {
275            return Err(Error::NotAuthenticated);
276        };
277
278        let query_params = url
279            .query_pairs()
280            .collect::<BTreeMap<Cow<'_, str>, Cow<'_, str>>>();
281        let body_params = if let Some(payload) = payload {
282            let s = serde_json::to_value(payload)?;
283            match s {
284                Value::Object(map) => map
285                    .into_iter()
286                    .map(|(k, v)| (k, v.to_string()))
287                    .collect::<BTreeMap<_, _>>(),
288                _ => {
289                    return Err(Error::InvalidRequest(
290                        "payload must be a JSON object".into(),
291                    ));
292                }
293            }
294        } else {
295            BTreeMap::new()
296        };
297
298        let timestamp = now_millis();
299        let mut signee = format!("instruction={instruction}");
300        for (k, v) in query_params {
301            signee.push_str(&format!("&{k}={v}"));
302        }
303        for (k, v) in body_params {
304            let v = v.trim_start_matches('"').trim_end_matches('"');
305            signee.push_str(&format!("&{k}={v}"));
306        }
307        signee.push_str(&format!("&timestamp={timestamp}&window={DEFAULT_WINDOW}"));
308        tracing::debug!("signee: {}", signee);
309
310        let signature: Signature = signing_key.sign(signee.as_bytes());
311        let signature = Base64::encode_string(&signature.to_bytes());
312
313        let mut req = self.client().request(method, url);
314        if let Some(payload) = payload {
315            req = req.json(payload);
316        }
317        let mut req = req.build()?;
318        req.headers_mut()
319            .insert(SIGNATURE_HEADER, signature.parse()?);
320        req.headers_mut()
321            .insert(TIMESTAMP_HEADER, timestamp.to_string().parse()?);
322        req.headers_mut()
323            .insert(WINDOW_HEADER, DEFAULT_WINDOW.to_string().parse()?);
324        if matches!(req.method(), &Method::POST | &Method::DELETE) {
325            req.headers_mut()
326                .insert(CONTENT_TYPE, JSON_CONTENT.parse()?);
327        }
328        Ok(req)
329    }
330}
331
332#[derive(Debug, Default)]
333pub struct BpxClientBuilder {
334    base_url: Option<String>,
335    ws_url: Option<String>,
336    secret: Option<String>,
337    headers: Option<BpxHeaders>,
338}
339
340impl BpxClientBuilder {
341    pub fn new() -> Self {
342        Default::default()
343    }
344
345    /// Sets the base URL for the Backpack Exchange API.
346    /// If not set, defaults to `BACKPACK_API_BASE_URL`.
347    ///
348    /// # Arguments
349    /// * `base_url` - The base URL
350    ///
351    /// # Returns
352    /// * `Self` - The updated builder instance
353    pub fn base_url(mut self, base_url: impl ToString) -> Self {
354        self.base_url = Some(base_url.to_string());
355        self
356    }
357
358    /// Sets the WebSocket URL for the Backpack Exchange API.
359    /// If not set, defaults to `BACKPACK_WS_URL`.
360    ///
361    /// # Arguments
362    /// * `ws_url` - The WebSocket URL
363    ///
364    /// # Returns
365    /// * `Self` - The updated builder instance
366    #[cfg(feature = "ws")]
367    pub fn ws_url(mut self, ws_url: impl ToString) -> Self {
368        self.ws_url = Some(ws_url.to_string());
369        self
370    }
371
372    /// Sets the API secret for signing requests.
373    /// If not set, the client will be unauthenticated.
374    ///
375    /// # Arguments
376    /// * `secret` - The API secret
377    ///
378    /// # Returns
379    /// * `Self` - The updated builder instance
380    pub fn secret(mut self, secret: impl ToString) -> Self {
381        self.secret = Some(secret.to_string());
382        self
383    }
384
385    /// Sets custom HTTP headers for the client.
386    /// If not set, no additional headers will be included.
387    ///
388    /// # Arguments
389    /// * `headers` - The custom HTTP headers
390    ///
391    /// # Returns
392    /// * `Self` - The updated builder instance
393    pub fn headers(mut self, headers: BpxHeaders) -> Self {
394        self.headers = Some(headers);
395        self
396    }
397
398    /// Builds the `BpxClient` instance with the configured parameters.
399    ///
400    /// # Returns
401    /// * `Result<BpxClient>` - The constructed client or an error if building fails
402    pub fn build(self) -> Result<BpxClient> {
403        let base_url = self.base_url.as_deref().unwrap_or(BACKPACK_API_BASE_URL);
404        let base_url = Url::parse(base_url)?;
405
406        let ws_url = self.ws_url.as_deref().unwrap_or(BACKPACK_WS_URL);
407        let ws_url = Url::parse(ws_url)?;
408
409        let signing_key = if let Some(secret) = self.secret {
410            Some(
411                Base64::decode_vec(&secret)?
412                    .try_into()
413                    .map(|s| SigningKey::from_bytes(&s))
414                    .map_err(|_| Error::SecretKey)?,
415            )
416        } else {
417            None
418        };
419        let verifying_key = signing_key.as_ref().map(|s| s.verifying_key());
420
421        let mut header_map = BpxHeaders::new();
422        if let Some(headers) = self.headers {
423            header_map.extend(headers);
424        }
425
426        header_map.insert(CONTENT_TYPE, JSON_CONTENT.parse()?);
427        if let Some(signing_key) = &signing_key {
428            let verifier = signing_key.verifying_key();
429            header_map.insert(
430                API_KEY_HEADER,
431                Base64::encode_string(&verifier.to_bytes()).parse()?,
432            );
433        }
434
435        let client = BpxClient {
436            signing_key,
437            verifying_key,
438            base_url,
439            ws_url,
440            client: reqwest::Client::builder()
441                .user_agent(API_USER_AGENT)
442                .default_headers(header_map)
443                .build()?,
444        };
445
446        Ok(client)
447    }
448}
449
450/// Returns the current time in milliseconds since UNIX epoch.
451fn now_millis() -> u64 {
452    SystemTime::now()
453        .duration_since(UNIX_EPOCH)
454        .expect("Time went backwards")
455        .as_millis() as u64
456}
bpx_api_client/lib.rs

bpx_api_client/
lib.rs
