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::general_purpose::STANDARD, Engine};
37use ed25519_dalek::{Signature, Signer, SigningKey, VerifyingKey};
38use reqwest::{header::CONTENT_TYPE, IntoUrl, Method, Request, Response, StatusCode};
39use routes::{
40    account::{API_ACCOUNT, API_ACCOUNT_CONVERT_DUST, API_ACCOUNT_MAX_BORROW, API_ACCOUNT_MAX_WITHDRAWAL},
41    borrow_lend::API_BORROW_LEND_POSITIONS,
42    capital::{API_CAPITAL, API_COLLATERAL, API_DEPOSITS, API_DEPOSIT_ADDRESS, API_WITHDRAWALS},
43    futures::API_FUTURES_POSITION,
44    order::{API_ORDER, API_ORDERS},
45    rfq::{API_RFQ, API_RFQ_QUOTE},
46    user::API_USER_2FA,
47};
48use serde::Serialize;
49use serde_json::Value;
50use std::{
51    borrow::Cow,
52    collections::BTreeMap,
53    time::{SystemTime, UNIX_EPOCH},
54};
55
56pub mod error;
57
58mod routes;
59
60#[cfg(feature = "ws")]
61mod ws;
62
63/// Re-export of the Backpack Exchange API types.
64pub use bpx_api_types as types;
65
66/// Re-export of the custom `Error` type and `Result` alias for error handling.
67pub use error::{Error, Result};
68
69const API_USER_AGENT: &str = "bpx-rust-client";
70const API_KEY_HEADER: &str = "X-API-Key";
71
72const DEFAULT_WINDOW: u32 = 5000;
73
74const SIGNATURE_HEADER: &str = "X-Signature";
75const TIMESTAMP_HEADER: &str = "X-Timestamp";
76const WINDOW_HEADER: &str = "X-Window";
77
78const JSON_CONTENT: &str = "application/json; charset=utf-8";
79
80/// The official base URL for the Backpack Exchange REST API.
81pub const BACKPACK_API_BASE_URL: &str = "https://api.backpack.exchange";
82
83/// The official WebSocket URL for real-time data from the Backpack Exchange.
84pub const BACKPACK_WS_URL: &str = "wss://ws.backpack.exchange";
85
86/// Type alias for custom HTTP headers passed to `BpxClient` during initialization.
87pub type BpxHeaders = reqwest::header::HeaderMap;
88
89/// A client for interacting with the Backpack Exchange API.
90#[derive(Debug, Clone)]
91pub struct BpxClient {
92    signer: SigningKey,
93    verifier: VerifyingKey,
94    base_url: String,
95    #[allow(dead_code)]
96    ws_url: Option<String>,
97    client: reqwest::Client,
98}
99
100impl std::ops::Deref for BpxClient {
101    type Target = reqwest::Client;
102
103    fn deref(&self) -> &Self::Target {
104        &self.client
105    }
106}
107
108impl std::ops::DerefMut for BpxClient {
109    fn deref_mut(&mut self) -> &mut Self::Target {
110        &mut self.client
111    }
112}
113
114impl AsRef<reqwest::Client> for BpxClient {
115    fn as_ref(&self) -> &reqwest::Client {
116        &self.client
117    }
118}
119
120// Public functions.
121impl BpxClient {
122    /// Initializes a new client with the given base URL, API secret, and optional headers.
123    ///
124    /// This sets up the signing and verification keys, and creates a `reqwest` client
125    /// with default headers including the API key and content type.
126    pub fn init(base_url: String, secret: &str, headers: Option<BpxHeaders>) -> Result<Self> {
127        Self::init_internal(base_url, None, secret, headers)
128    }
129
130    /// Initializes a new client with WebSocket support.
131    #[cfg(feature = "ws")]
132    pub fn init_with_ws(base_url: String, ws_url: String, secret: &str, headers: Option<BpxHeaders>) -> Result<Self> {
133        Self::init_internal(base_url, Some(ws_url), secret, headers)
134    }
135
136    /// Internal helper function for client initialization.
137    fn init_internal(
138        base_url: String,
139        ws_url: Option<String>,
140        secret: &str,
141        headers: Option<BpxHeaders>,
142    ) -> Result<Self> {
143        let signer = STANDARD
144            .decode(secret)?
145            .try_into()
146            .map(|s| SigningKey::from_bytes(&s))
147            .map_err(|_| Error::SecretKey)?;
148
149        let verifier = signer.verifying_key();
150
151        let mut headers = headers.unwrap_or_default();
152        headers.insert(API_KEY_HEADER, STANDARD.encode(verifier).parse()?);
153        headers.insert(CONTENT_TYPE, JSON_CONTENT.parse()?);
154
155        let client = reqwest::Client::builder()
156            .user_agent(API_USER_AGENT)
157            .default_headers(headers)
158            .build()?;
159
160        Ok(BpxClient {
161            signer,
162            verifier,
163            base_url,
164            ws_url,
165            client,
166        })
167    }
168
169    /// Creates a new, empty `BpxHeaders` instance.
170    pub fn create_headers() -> BpxHeaders {
171        reqwest::header::HeaderMap::new()
172    }
173
174    /// Processes the response to check for HTTP errors and extracts
175    /// the response content.
176    ///
177    /// Returns a custom error if the status code is non-2xx.
178    async fn process_response(res: Response) -> Result<Response> {
179        if let Err(e) = res.error_for_status_ref() {
180            let err_text = res.text().await?;
181            let err = Error::BpxApiError {
182                status_code: e.status().unwrap_or(StatusCode::INTERNAL_SERVER_ERROR),
183                message: err_text.into(),
184            };
185            return Err(err);
186        }
187        Ok(res)
188    }
189
190    /// Sends a GET request to the specified URL and signs it before execution.
191    pub async fn get<U: IntoUrl>(&self, url: U) -> Result<Response> {
192        let req = self.build_and_maybe_sign_request::<(), _>(url, Method::GET, None)?;
193        tracing::debug!("req: {:?}", req);
194        let res = self.client.execute(req).await?;
195        Self::process_response(res).await
196    }
197
198    /// Sends a POST request with a JSON payload to the specified URL and signs it.
199    pub async fn post<P: Serialize, U: IntoUrl>(&self, url: U, payload: P) -> Result<Response> {
200        let req = self.build_and_maybe_sign_request(url, Method::POST, Some(&payload))?;
201        tracing::debug!("req: {:?}", req);
202        let res = self.client.execute(req).await?;
203        Self::process_response(res).await
204    }
205
206    /// Sends a DELETE request with a JSON payload to the specified URL and signs it.
207    pub async fn delete<P: Serialize, U: IntoUrl>(&self, url: U, payload: P) -> Result<Response> {
208        let req = self.build_and_maybe_sign_request(url, Method::DELETE, Some(&payload))?;
209        tracing::debug!("req: {:?}", req);
210        let res = self.client.execute(req).await?;
211        Self::process_response(res).await
212    }
213
214    /// Sends a PATCH request with a JSON payload to the specified URL and signs it.
215    pub async fn patch<P: Serialize, U: IntoUrl>(&self, url: U, payload: P) -> Result<Response> {
216        let req = self.build_and_maybe_sign_request(url, Method::PATCH, Some(&payload))?;
217        tracing::debug!("req: {:?}", req);
218        let res = self.client.execute(req).await?;
219        Self::process_response(res).await
220    }
221
222    /// Returns a reference to the `VerifyingKey` used for request verification.
223    pub const fn verifier(&self) -> &VerifyingKey {
224        &self.verifier
225    }
226
227    /// Returns a reference to the underlying HTTP client.
228    pub const fn client(&self) -> &reqwest::Client {
229        &self.client
230    }
231}
232
233// Private functions.
234impl BpxClient {
235    /// Signs a request by generating a signature from the request details
236    /// and appending necessary headers for authentication.
237    ///
238    /// # Arguments
239    /// * `req` - The mutable reference to the request to be signed.
240    fn build_and_maybe_sign_request<P: Serialize, U: IntoUrl>(
241        &self,
242        url: U,
243        method: Method,
244        payload: Option<&P>,
245    ) -> Result<Request> {
246        let url = url.into_url()?;
247        let instruction = match url.path() {
248            API_CAPITAL if method == Method::GET => "balanceQuery",
249            API_DEPOSITS if method == Method::GET => "depositQueryAll",
250            API_DEPOSIT_ADDRESS if method == Method::GET => "depositAddressQuery",
251            API_WITHDRAWALS if method == Method::GET => "withdrawalQueryAll",
252            API_WITHDRAWALS if method == Method::POST => "withdraw",
253            API_USER_2FA if method == Method::POST => "issueTwoFactorToken",
254            API_ORDER if method == Method::GET => "orderQuery",
255            API_ORDER if method == Method::POST => "orderExecute",
256            API_ORDER if method == Method::DELETE => "orderCancel",
257            API_ORDERS if method == Method::GET => "orderQueryAll",
258            API_ORDERS if method == Method::DELETE => "orderCancelAll",
259            API_RFQ if method == Method::POST => "rfqSubmit",
260            API_RFQ_QUOTE if method == Method::POST => "quoteSubmit",
261            API_FUTURES_POSITION if method == Method::GET => "positionQuery",
262            API_BORROW_LEND_POSITIONS if method == Method::GET => "borrowLendPositionQuery",
263            API_COLLATERAL if method == Method::GET => "collateralQuery",
264            API_ACCOUNT if method == Method::GET => "accountQuery",
265            API_ACCOUNT_MAX_BORROW if method == Method::GET => "maxBorrowQuantity",
266            API_ACCOUNT_MAX_WITHDRAWAL if method == Method::GET => "maxWithdrawalQuantity",
267            API_ACCOUNT if method == Method::PATCH => "accountUpdate",
268            API_ACCOUNT_CONVERT_DUST if method == Method::POST => "convertDust",
269            _ => {
270                let req = self.client().request(method, url);
271                if let Some(payload) = payload {
272                    return Ok(req.json(payload).build()?);
273                } else {
274                    return Ok(req.build()?);
275                }
276            }
277        };
278
279        let query_params = url.query_pairs().collect::<BTreeMap<Cow<'_, str>, Cow<'_, str>>>();
280        let body_params = if let Some(payload) = payload {
281            let s = serde_json::to_value(payload)?;
282            match s {
283                Value::Object(map) => map
284                    .into_iter()
285                    .map(|(k, v)| (k, v.to_string()))
286                    .collect::<BTreeMap<_, _>>(),
287                _ => return Err(Error::InvalidRequest("payload must be a JSON object".into())),
288            }
289        } else {
290            BTreeMap::new()
291        };
292
293        let timestamp = now_millis();
294        let mut signee = format!("instruction={instruction}");
295        for (k, v) in query_params {
296            signee.push_str(&format!("&{k}={v}"));
297        }
298        for (k, v) in body_params {
299            let v = v.trim_start_matches('"').trim_end_matches('"');
300            signee.push_str(&format!("&{k}={v}"));
301        }
302        signee.push_str(&format!("&timestamp={timestamp}&window={DEFAULT_WINDOW}"));
303        tracing::debug!("signee: {}", signee);
304
305        let signature: Signature = self.signer.sign(signee.as_bytes());
306        let signature = STANDARD.encode(signature.to_bytes());
307
308        let mut req = self.client().request(method, url);
309        if let Some(payload) = payload {
310            req = req.json(payload);
311        }
312        let mut req = req.build()?;
313        req.headers_mut().insert(SIGNATURE_HEADER, signature.parse()?);
314        req.headers_mut()
315            .insert(TIMESTAMP_HEADER, timestamp.to_string().parse()?);
316        req.headers_mut()
317            .insert(WINDOW_HEADER, DEFAULT_WINDOW.to_string().parse()?);
318        if matches!(req.method(), &Method::POST | &Method::DELETE) {
319            req.headers_mut().insert(CONTENT_TYPE, JSON_CONTENT.parse()?);
320        }
321        Ok(req)
322    }
323}
324
325/// Returns the current time in milliseconds since UNIX epoch.
326fn now_millis() -> u64 {
327    SystemTime::now()
328        .duration_since(UNIX_EPOCH)
329        .expect("Time went backwards")
330        .as_millis() as u64
331}
bpx_api_client/lib.rs

bpx_api_client/
lib.rs
