foundry_common/provider/
runtime_transport.rs

1//! Runtime transport that connects on first request, which can take either of an HTTP,
2//! WebSocket, or IPC transport. Retries are handled by a client layer (e.g.,
3//! `RetryBackoffLayer`) when used.
4
5use crate::{DEFAULT_USER_AGENT, REQUEST_TIMEOUT};
6use alloy_json_rpc::{RequestPacket, ResponsePacket};
7use alloy_pubsub::{PubSubConnect, PubSubFrontend};
8use alloy_rpc_types::engine::{Claims, JwtSecret};
9use alloy_transport::{
10    Authorization, BoxTransport, TransportError, TransportErrorKind, TransportFut,
11};
12use alloy_transport_http::Http;
13use alloy_transport_ipc::IpcConnect;
14use alloy_transport_ws::WsConnect;
15use reqwest::header::{HeaderName, HeaderValue};
16use std::{fmt, path::PathBuf, str::FromStr, sync::Arc};
17use thiserror::Error;
18use tokio::sync::RwLock;
19use tower::Service;
20use url::Url;
21
22/// An enum representing the different transports that can be used to connect to a runtime.
23/// Only meant to be used internally by [RuntimeTransport].
24#[derive(Clone, Debug)]
25pub enum InnerTransport {
26    /// HTTP transport
27    Http(Http<reqwest::Client>),
28    /// WebSocket transport
29    Ws(PubSubFrontend),
30    /// IPC transport
31    Ipc(PubSubFrontend),
32}
33
34/// Error type for the runtime transport.
35#[derive(Error, Debug)]
36pub enum RuntimeTransportError {
37    /// Internal transport error
38    #[error("Internal transport error: {0} with {1}")]
39    TransportError(TransportError, String),
40
41    /// Invalid URL scheme
42    #[error("URL scheme is not supported: {0}")]
43    BadScheme(String),
44
45    /// Invalid HTTP header
46    #[error("Invalid HTTP header: {0}")]
47    BadHeader(String),
48
49    /// Invalid file path
50    #[error("Invalid IPC file path: {0}")]
51    BadPath(String),
52
53    /// Invalid construction of Http provider
54    #[error(transparent)]
55    HttpConstructionError(#[from] reqwest::Error),
56
57    /// Invalid JWT
58    #[error("Invalid JWT: {0}")]
59    InvalidJwt(String),
60}
61
62/// Runtime transport that only connects on first request.
63///
64/// A runtime transport is a custom [`alloy_transport::Transport`] that only connects when the
65/// *first* request is made. When the first request is made, it will connect to the runtime using
66/// either an HTTP WebSocket, or IPC transport depending on the URL used.
67/// Retries for rate-limiting and timeout-related errors are handled by an external
68/// client layer (e.g., `RetryBackoffLayer`) when configured.
69#[derive(Clone, Debug)]
70pub struct RuntimeTransport {
71    /// The inner actual transport used.
72    inner: Arc<RwLock<Option<InnerTransport>>>,
73    /// The URL to connect to.
74    url: Url,
75    /// The headers to use for requests.
76    headers: Vec<String>,
77    /// The JWT to use for requests.
78    jwt: Option<String>,
79    /// The timeout for requests.
80    timeout: std::time::Duration,
81    /// Whether to accept invalid certificates.
82    accept_invalid_certs: bool,
83    /// Whether to disable automatic proxy detection.
84    no_proxy: bool,
85}
86
87/// A builder for [RuntimeTransport].
88#[derive(Debug)]
89pub struct RuntimeTransportBuilder {
90    url: Url,
91    headers: Vec<String>,
92    jwt: Option<String>,
93    timeout: std::time::Duration,
94    accept_invalid_certs: bool,
95    no_proxy: bool,
96}
97
98impl RuntimeTransportBuilder {
99    /// Create a new builder with the given URL.
100    pub fn new(url: Url) -> Self {
101        Self {
102            url,
103            headers: vec![],
104            jwt: None,
105            timeout: REQUEST_TIMEOUT,
106            accept_invalid_certs: false,
107            no_proxy: false,
108        }
109    }
110
111    /// Set the URL for the transport.
112    pub fn with_headers(mut self, headers: Vec<String>) -> Self {
113        self.headers = headers;
114        self
115    }
116
117    /// Set the JWT for the transport.
118    pub fn with_jwt(mut self, jwt: Option<String>) -> Self {
119        self.jwt = jwt;
120        self
121    }
122
123    /// Set the timeout for the transport.
124    pub fn with_timeout(mut self, timeout: std::time::Duration) -> Self {
125        self.timeout = timeout;
126        self
127    }
128
129    /// Set whether to accept invalid certificates.
130    pub fn accept_invalid_certs(mut self, accept_invalid_certs: bool) -> Self {
131        self.accept_invalid_certs = accept_invalid_certs;
132        self
133    }
134
135    /// Set whether to disable automatic proxy detection.
136    ///
137    /// This can help in sandboxed environments (e.g., Cursor IDE sandbox, macOS App Sandbox)
138    /// where system proxy detection via SCDynamicStore causes crashes.
139    pub fn no_proxy(mut self, no_proxy: bool) -> Self {
140        self.no_proxy = no_proxy;
141        self
142    }
143
144    /// Builds the [RuntimeTransport] and returns it in a disconnected state.
145    /// The runtime transport will then connect when the first request happens.
146    pub fn build(self) -> RuntimeTransport {
147        RuntimeTransport {
148            inner: Arc::new(RwLock::new(None)),
149            url: self.url,
150            headers: self.headers,
151            jwt: self.jwt,
152            timeout: self.timeout,
153            accept_invalid_certs: self.accept_invalid_certs,
154            no_proxy: self.no_proxy,
155        }
156    }
157}
158
159impl fmt::Display for RuntimeTransport {
160    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
161        write!(f, "RuntimeTransport {}", self.url)
162    }
163}
164
165impl RuntimeTransport {
166    /// Connects the underlying transport, depending on the URL scheme.
167    pub async fn connect(&self) -> Result<InnerTransport, RuntimeTransportError> {
168        match self.url.scheme() {
169            "http" | "https" => self.connect_http(),
170            "ws" | "wss" => self.connect_ws().await,
171            "file" => self.connect_ipc().await,
172            _ => Err(RuntimeTransportError::BadScheme(self.url.scheme().to_string())),
173        }
174    }
175
176    /// Creates a new reqwest client from this transport.
177    pub fn reqwest_client(&self) -> Result<reqwest::Client, RuntimeTransportError> {
178        let mut client_builder = reqwest::Client::builder()
179            .timeout(self.timeout)
180            .danger_accept_invalid_certs(self.accept_invalid_certs);
181
182        // Disable automatic proxy detection if requested. This helps in sandboxed environments
183        // (e.g., Cursor IDE sandbox, macOS App Sandbox) where system proxy detection via
184        // SCDynamicStore causes crashes. See: https://github.com/foundry-rs/foundry/issues/12733
185        if self.no_proxy {
186            client_builder = client_builder.no_proxy();
187        }
188
189        let mut headers = reqwest::header::HeaderMap::new();
190
191        // If there's a JWT, add it to the headers if we can decode it.
192        if let Some(jwt) = self.jwt.clone() {
193            let auth =
194                build_auth(jwt).map_err(|e| RuntimeTransportError::InvalidJwt(e.to_string()))?;
195
196            let mut auth_value: HeaderValue =
197                HeaderValue::from_str(&auth.to_string()).expect("Header should be valid string");
198            auth_value.set_sensitive(true);
199
200            headers.insert(reqwest::header::AUTHORIZATION, auth_value);
201        };
202
203        // Add any custom headers.
204        for header in &self.headers {
205            let make_err = || RuntimeTransportError::BadHeader(header.to_string());
206
207            let (key, val) = header.split_once(':').ok_or_else(make_err)?;
208
209            headers.insert(
210                HeaderName::from_str(key.trim()).map_err(|_| make_err())?,
211                HeaderValue::from_str(val.trim()).map_err(|_| make_err())?,
212            );
213        }
214
215        if !headers.contains_key(reqwest::header::USER_AGENT) {
216            headers.insert(
217                reqwest::header::USER_AGENT,
218                HeaderValue::from_str(DEFAULT_USER_AGENT)
219                    .expect("User-Agent should be valid string"),
220            );
221        }
222
223        client_builder = client_builder.default_headers(headers);
224
225        Ok(client_builder.build()?)
226    }
227
228    /// Connects to an HTTP [alloy_transport_http::Http] transport.
229    fn connect_http(&self) -> Result<InnerTransport, RuntimeTransportError> {
230        let client = self.reqwest_client()?;
231        Ok(InnerTransport::Http(Http::with_client(client, self.url.clone())))
232    }
233
234    /// Connects to a WS transport.
235    async fn connect_ws(&self) -> Result<InnerTransport, RuntimeTransportError> {
236        let auth = self.jwt.as_ref().and_then(|jwt| build_auth(jwt.clone()).ok());
237        let mut ws = WsConnect::new(self.url.to_string());
238        if let Some(auth) = auth {
239            ws = ws.with_auth(auth);
240        };
241        let service = ws
242            .into_service()
243            .await
244            .map_err(|e| RuntimeTransportError::TransportError(e, self.url.to_string()))?;
245        Ok(InnerTransport::Ws(service))
246    }
247
248    /// Connects to an IPC transport.
249    async fn connect_ipc(&self) -> Result<InnerTransport, RuntimeTransportError> {
250        let path = url_to_file_path(&self.url)
251            .map_err(|_| RuntimeTransportError::BadPath(self.url.to_string()))?;
252        let ipc_connector = IpcConnect::new(path.clone());
253        let ipc = ipc_connector.into_service().await.map_err(|e| {
254            RuntimeTransportError::TransportError(e, path.clone().display().to_string())
255        })?;
256        Ok(InnerTransport::Ipc(ipc))
257    }
258
259    /// Sends a request using the underlying transport.
260    /// If this is the first request, it will connect to the appropriate transport depending on the
261    /// URL scheme. Retries are performed by an external client layer (e.g., `RetryBackoffLayer`),
262    /// if such a layer is configured by the caller.
263    /// For sending the actual request, this action is delegated down to the
264    /// underlying transport through Tower's [tower::Service::call]. See tower's [tower::Service]
265    /// trait for more information.
266    pub fn request(&self, req: RequestPacket) -> TransportFut<'static> {
267        let this = self.clone();
268        Box::pin(async move {
269            let mut inner = this.inner.read().await;
270            if inner.is_none() {
271                drop(inner);
272                {
273                    let mut inner_mut = this.inner.write().await;
274                    if inner_mut.is_none() {
275                        *inner_mut =
276                            Some(this.connect().await.map_err(TransportErrorKind::custom)?);
277                    }
278                }
279                inner = this.inner.read().await;
280            }
281
282            // SAFETY: We just checked that the inner transport exists.
283            match inner.clone().expect("must've been initialized") {
284                InnerTransport::Http(mut http) => http.call(req),
285                InnerTransport::Ws(mut ws) => ws.call(req),
286                InnerTransport::Ipc(mut ipc) => ipc.call(req),
287            }
288            .await
289        })
290    }
291
292    /// Convert this transport into a boxed trait object.
293    pub fn boxed(self) -> BoxTransport
294    where
295        Self: Sized + Clone + Send + Sync + 'static,
296    {
297        BoxTransport::new(self)
298    }
299}
300
301impl tower::Service<RequestPacket> for RuntimeTransport {
302    type Response = ResponsePacket;
303    type Error = TransportError;
304    type Future = TransportFut<'static>;
305
306    #[inline]
307    fn poll_ready(
308        &mut self,
309        _cx: &mut std::task::Context<'_>,
310    ) -> std::task::Poll<Result<(), Self::Error>> {
311        std::task::Poll::Ready(Ok(()))
312    }
313
314    #[inline]
315    fn call(&mut self, req: RequestPacket) -> Self::Future {
316        self.request(req)
317    }
318}
319
320impl tower::Service<RequestPacket> for &RuntimeTransport {
321    type Response = ResponsePacket;
322    type Error = TransportError;
323    type Future = TransportFut<'static>;
324
325    #[inline]
326    fn poll_ready(
327        &mut self,
328        _cx: &mut std::task::Context<'_>,
329    ) -> std::task::Poll<Result<(), Self::Error>> {
330        std::task::Poll::Ready(Ok(()))
331    }
332
333    #[inline]
334    fn call(&mut self, req: RequestPacket) -> Self::Future {
335        self.request(req)
336    }
337}
338
339fn build_auth(jwt: String) -> eyre::Result<Authorization> {
340    // Decode jwt from hex, then generate claims (iat with current timestamp)
341    let secret = JwtSecret::from_hex(jwt)?;
342    let claims = Claims::default();
343    let token = secret.encode(&claims)?;
344
345    let auth = Authorization::Bearer(token);
346
347    Ok(auth)
348}
349
350#[cfg(windows)]
351fn url_to_file_path(url: &Url) -> Result<PathBuf, ()> {
352    const PREFIX: &str = "file:///pipe/";
353
354    let url_str = url.as_str();
355
356    if let Some(pipe_name) = url_str.strip_prefix(PREFIX) {
357        let pipe_path = format!(r"\\.\pipe\{pipe_name}");
358        return Ok(PathBuf::from(pipe_path));
359    }
360
361    url.to_file_path()
362}
363
364#[cfg(not(windows))]
365fn url_to_file_path(url: &Url) -> Result<PathBuf, ()> {
366    url.to_file_path()
367}
368
369#[cfg(test)]
370mod tests {
371    use super::*;
372    use reqwest::header::HeaderMap;
373
374    #[tokio::test]
375    async fn test_user_agent_header() {
376        let listener = tokio::net::TcpListener::bind("127.0.0.1:0").await.unwrap();
377        let url = Url::parse(&format!("http://{}", listener.local_addr().unwrap())).unwrap();
378
379        let http_handler = axum::routing::get(|actual_headers: HeaderMap| {
380            let user_agent = HeaderName::from_str("User-Agent").unwrap();
381            assert_eq!(actual_headers[user_agent], HeaderValue::from_str("test-agent").unwrap());
382
383            async { "" }
384        });
385
386        let server_task = tokio::spawn(async move {
387            axum::serve(listener, http_handler.into_make_service()).await.unwrap()
388        });
389
390        let transport = RuntimeTransportBuilder::new(url.clone())
391            .with_headers(vec!["User-Agent: test-agent".to_string()])
392            .build();
393        let inner = transport.connect_http().unwrap();
394
395        match inner {
396            InnerTransport::Http(http) => {
397                let _ = http.client().get(url).send().await.unwrap();
398
399                // assert inside http_handler
400            }
401            _ => unreachable!(),
402        }
403
404        server_task.abort();
405    }
406}
foundry_common/provider/runtime_transport.rs

foundry_common/provider/
runtime_transport.rs
