diff --git a/CHANGELOG.adoc b/CHANGELOG.adoc
index e9be2e2b..eb00a647 100644
--- a/CHANGELOG.adoc
+++ b/CHANGELOG.adoc
@@ -20,6 +20,7 @@ https://github.com/oxidecomputer/progenitor/compare/v0.1.1\...HEAD[Full list of
 * Derive `Debug` for `Client` and builders for the various operations (#145)
 * Builders for `struct` types (#171)
 * Add a prelude that include the `Client` and any extension traits (#176)
+* Added `Error::IoError` variant for channel connection failures (breaks `match` exhaustivity)
 
 == 0.1.1 (released 2022-05-13)
 
diff --git a/Cargo.lock b/Cargo.lock
index e835b576..1c9d3e33 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -985,6 +985,12 @@ version = "0.3.24"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "58893f751c9b0412871a09abd62ecd2a00298c6c83befa223ef98c52aef40cbe"
 
+[[package]]
+name = "ppv-lite86"
+version = "0.2.16"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "eb9f9e6e233e5c4a35559a617bf40a4ec447db2e84c20b55a6f83167b7e57872"
+
 [[package]]
 name = "proc-macro-error"
 version = "1.0.4"
@@ -1026,6 +1032,7 @@ dependencies = [
  "chrono",
  "clap",
  "futures",
+ "http",
  "openapiv3",
  "percent-encoding",
  "progenitor-client",
@@ -1036,6 +1043,7 @@ dependencies = [
  "schemars",
  "serde",
  "serde_json",
+ "tokio",
  "uuid",
 ]
 
@@ -1043,13 +1051,17 @@ dependencies = [
 name = "progenitor-client"
 version = "0.1.2-dev"
 dependencies = [
+ "base64",
  "bytes",
  "futures-core",
+ "http",
  "percent-encoding",
+ "rand",
  "reqwest",
  "serde",
  "serde_json",
  "serde_urlencoded",
+ "tokio",
 ]
 
 [[package]]
@@ -1100,6 +1112,36 @@ dependencies = [
  "proc-macro2",
 ]
 
+[[package]]
+name = "rand"
+version = "0.8.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "34af8d1a0e25924bc5b7c43c079c942339d8f0a8b57c39049bef581b46327404"
+dependencies = [
+ "libc",
+ "rand_chacha",
+ "rand_core",
+]
+
+[[package]]
+name = "rand_chacha"
+version = "0.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e6c10a63a0fa32252be49d21e7709d4d4baf8d231c2dbce1eaa8141b9b127d88"
+dependencies = [
+ "ppv-lite86",
+ "rand_core",
+]
+
+[[package]]
+name = "rand_core"
+version = "0.6.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d34f1408f55294453790c48b2f1ebbb1c5b4b7563eb1f418bcfcfdbb06ebb4e7"
+dependencies = [
+ "getrandom",
+]
+
 [[package]]
 name = "redox_syscall"
 version = "0.2.10"
diff --git a/progenitor-client/Cargo.toml b/progenitor-client/Cargo.toml
index ed770a75..1c3403ff 100644
--- a/progenitor-client/Cargo.toml
+++ b/progenitor-client/Cargo.toml
@@ -9,8 +9,16 @@ description = "An OpenAPI client generator - client support"
 [dependencies]
 bytes = "1.2.1"
 futures-core = "0.3.23"
+http = "0.2"
 percent-encoding = "2.1"
 reqwest = { version = "0.11", default-features = false, features = ["json", "stream"] }
 serde = "1.0"
 serde_json = "1.0"
 serde_urlencoded = "0.7.1"
+
+# deps for websocket support
+base64 = "0.13"
+rand = "0.8"
+# reqwest wraps hyper, but does not expose a read/write socket for us to work with,
+# so we must make direct socket connections.
+tokio = { version = "1.0", features = ["net"] }
diff --git a/progenitor-client/src/progenitor_client.rs b/progenitor-client/src/progenitor_client.rs
index 7096294c..8be5c9a5 100644
--- a/progenitor-client/src/progenitor_client.rs
+++ b/progenitor-client/src/progenitor_client.rs
@@ -5,6 +5,7 @@
 //! Support code for generated clients.
 
 use std::ops::{Deref, DerefMut};
+use std::str::FromStr;
 
 use bytes::Bytes;
 use futures_core::Stream;
@@ -14,6 +15,9 @@ use serde::{de::DeserializeOwned, Serialize};
 type InnerByteStream =
     std::pin::Pin<Box<dyn Stream<Item = reqwest::Result<Bytes>> + Send + Sync>>;
 
+// used for Websockets requests
+type HttpBareRequest = http::Request<()>;
+
 /// Untyped byte stream used for both success and error responses.
 pub struct ByteStream(InnerByteStream);
 
@@ -195,6 +199,65 @@ impl<T: std::fmt::Debug> std::fmt::Debug for ResponseValue<T> {
     }
 }
 
+/// Value returned by generated client methods for Websocket channels.
+///
+/// Currently, the only interface available for Dropshot websocket channels is
+/// providing their raw, unmodeled form (that is, Dropshot does not yet define
+/// higher-level constructs for modeling the structure of Websocket messages
+/// themselves).
+///
+/// The user is responsible for passing it to a websocket implementation, i.e.:
+/// ```ignore
+/// let (request, tcp_stream) = my_progenitor_client
+///     .my_websocket_channel()
+///     .answer(42)
+///     .send()
+///     .await?
+///     .into_request_and_tcp_stream();
+/// let ws_client = tokio_tungstenite::client_async(request, tcp_stream).await?;
+/// ```
+///
+/// (As no request has been *made*, returning a [ResponseValue] would be inappropriate.)
+pub struct WebsocketReactants {
+    request: HttpBareRequest,
+    tcp_stream: tokio::net::TcpStream,
+}
+
+impl WebsocketReactants {
+    pub fn new<T>(
+        rqw: reqwest::Request,
+        tcp_stream: tokio::net::TcpStream,
+    ) -> Result<Self, Error<T>> {
+        // rebuild as http::Request, which tungstenite re-exports as its
+        // "IntoClientRequest" type.
+        // FIXME: this is obviously a hack, the better thing to do would be to
+        // implement using http::Request::builder() in the proc macro
+        let mut rb = http::Request::builder()
+            .method(rqw.method())
+            .version(rqw.version())
+            .uri(
+                http::Uri::from_str(rqw.url().as_str())
+                    .map_err(|e| Error::InvalidRequest(format!("{:?}", e)))?,
+            );
+        for (k, v) in rqw.headers().iter() {
+            rb = rb.header(k, v);
+        }
+        let request = rb
+            .body(())
+            .map_err(|e| Error::InvalidRequest(e.to_string()))?;
+        Ok(Self {
+            request,
+            tcp_stream,
+        })
+    }
+
+    pub fn into_request_and_tcp_stream(
+        self,
+    ) -> (HttpBareRequest, tokio::net::TcpStream) {
+        (self.request, self.tcp_stream)
+    }
+}
+
 /// Error produced by generated client methods.
 ///
 /// The type parameter may be a struct if there's a single expected error type
@@ -207,6 +270,9 @@ pub enum Error<E = ()> {
     /// A server error either due to the data, or with the connection.
     CommunicationError(reqwest::Error),
 
+    /// A fundamental input/output error has occurred (e.g. unable to make a socket connection)
+    IoError(std::io::Error),
+
     /// A documented, expected error response.
     ErrorResponse(ResponseValue<E>),
 
@@ -225,6 +291,7 @@ impl<E> Error<E> {
         match self {
             Error::InvalidRequest(_) => None,
             Error::CommunicationError(e) => e.status(),
+            Error::IoError(_) => None,
             Error::ErrorResponse(rv) => Some(rv.status()),
             Error::InvalidResponsePayload(e) => e.status(),
             Error::UnexpectedResponse(r) => Some(r.status()),
@@ -239,6 +306,7 @@ impl<E> Error<E> {
         match self {
             Error::InvalidRequest(s) => Error::InvalidRequest(s),
             Error::CommunicationError(e) => Error::CommunicationError(e),
+            Error::IoError(e) => Error::IoError(e),
             Error::ErrorResponse(ResponseValue {
                 inner: _,
                 status,
@@ -262,6 +330,12 @@ impl<E> From<reqwest::Error> for Error<E> {
     }
 }
 
+impl<E> From<std::io::Error> for Error<E> {
+    fn from(e: std::io::Error) -> Self {
+        Self::IoError(e)
+    }
+}
+
 impl<E> std::fmt::Display for Error<E>
 where
     ResponseValue<E>: ErrorFormat,
@@ -274,6 +348,9 @@ where
             Error::CommunicationError(e) => {
                 write!(f, "Communication Error: {}", e)
             }
+            Error::IoError(e) => {
+                write!(f, "Input/Output Error: {}", e)
+            }
             Error::ErrorResponse(rve) => {
                 write!(f, "Error Response: ")?;
                 rve.fmt_info(f)
@@ -377,3 +454,8 @@ impl<E> RequestBuilderExt<E> for RequestBuilder {
             })?))
     }
 }
+
+#[doc(hidden)]
+pub fn generate_websocket_key() -> String {
+    base64::encode(rand::random::<[u8; 16]>())
+}
diff --git a/progenitor-impl/Cargo.toml b/progenitor-impl/Cargo.toml
index 33a1368c..1a592b8e 100644
--- a/progenitor-impl/Cargo.toml
+++ b/progenitor-impl/Cargo.toml
@@ -23,7 +23,7 @@ thiserror = "1.0"
 # To publish, use a numbered version
 #typify = "0.0.9"
 typify = { git = "https://github.com/oxidecomputer/typify" }
-unicode-ident = "1.0.3"
+unicode-ident = "1.0.2"
 
 [dev-dependencies]
 dropshot = { git = "https://github.com/oxidecomputer/dropshot", default-features = false }
diff --git a/progenitor-impl/src/lib.rs b/progenitor-impl/src/lib.rs
index 49882108..5a23821e 100644
--- a/progenitor-impl/src/lib.rs
+++ b/progenitor-impl/src/lib.rs
@@ -26,6 +26,8 @@ pub enum Error {
     UnexpectedFormat(String),
     #[error("invalid operation path {0}")]
     InvalidPath(String),
+    #[error("invalid dropshot extension use: {0}")]
+    InvalidExtension(String),
     #[error("internal error {0}")]
     InternalError(String),
 }
@@ -213,7 +215,13 @@ impl Generator {
         let file = quote! {
             // Re-export ResponseValue and Error since those are used by the
             // public interface of Client.
-            pub use progenitor_client::{ByteStream, Error, ResponseValue};
+            pub use progenitor_client::{
+                ByteStream,
+                Error,
+                ResponseValue,
+                WebsocketReactants,
+                generate_websocket_key,
+            };
             #[allow(unused_imports)]
             use progenitor_client::{encode_path, RequestBuilderExt};
 
@@ -319,10 +327,12 @@ impl Generator {
                 #[allow(unused_imports)]
                 use super::{
                     encode_path,
+                    generate_websocket_key,
                     ByteStream,
                     Error,
                     RequestBuilderExt,
                     ResponseValue,
+                    WebsocketReactants,
                 };
                 #[allow(unused_imports)]
                 use std::convert::TryInto;
@@ -358,11 +368,15 @@ impl Generator {
                 #[allow(unused_imports)]
                 use super::{
                     encode_path,
+                    generate_websocket_key,
                     ByteStream,
                     Error,
                     RequestBuilderExt,
                     ResponseValue,
+                    WebsocketReactants,
                 };
+                #[allow(unused_imports)]
+                use std::convert::TryInto;
 
                 #(#builder_struct)*
 
diff --git a/progenitor-impl/src/method.rs b/progenitor-impl/src/method.rs
index a8c1b628..201176f4 100644
--- a/progenitor-impl/src/method.rs
+++ b/progenitor-impl/src/method.rs
@@ -29,6 +29,7 @@ pub(crate) struct OperationMethod {
     params: Vec<OperationParameter>,
     responses: Vec<OperationResponse>,
     dropshot_paginated: Option<DropshotPagination>,
+    dropshot_websocket: bool,
 }
 
 enum HttpMethod {
@@ -449,9 +450,20 @@ impl Generator {
             });
         }
 
+        // TODO: should dropshot::{WEBSOCKET_EXTENSION, PAGINATION_EXTENSION} be pub for these?
         let dropshot_paginated =
             self.dropshot_pagination_data(operation, &params, &responses);
 
+        let dropshot_websocket =
+            operation.extensions.get("x-dropshot-websocket").is_some();
+
+        if dropshot_websocket && dropshot_paginated.is_some() {
+            return Err(Error::InvalidExtension(format!(
+                "conflicting extensions in {:?}",
+                operation_id
+            )));
+        }
+
         Ok(OperationMethod {
             operation_id: sanitize(operation_id, Case::Snake),
             tags: operation.tags.clone(),
@@ -465,6 +477,7 @@ impl Generator {
             params,
             responses,
             dropshot_paginated,
+            dropshot_websocket,
         })
     }
 
@@ -515,15 +528,19 @@ impl Generator {
             body,
         } = self.method_sig_body(method, quote! { self })?;
 
+        let ret_type = match method.dropshot_websocket {
+            false => {
+                quote!(Result<ResponseValue<#success_type>, Error<#error_type>>)
+            }
+            true => quote!(Result<#success_type, Error<#error_type>>),
+        };
+
         let method_impl = quote! {
             #[doc = #doc_comment]
             pub async fn #operation_id #bounds (
                 &'a self,
                 #(#params),*
-            ) -> Result<
-                ResponseValue<#success_type>,
-                Error<#error_type>,
-            > {
+            ) -> #ret_type {
                 #body
             }
         };
@@ -705,6 +722,20 @@ impl Generator {
             (query_build, query_use)
         };
 
+        let websock_hdrs = if method.dropshot_websocket {
+            quote! {
+                .header(reqwest::header::CONNECTION, "Upgrade")
+                .header(reqwest::header::UPGRADE, "websocket")
+                .header(reqwest::header::SEC_WEBSOCKET_VERSION, "13")
+                .header(
+                    reqwest::header::SEC_WEBSOCKET_KEY,
+                    generate_websocket_key(),
+                )
+            }
+        } else {
+            quote! {}
+        };
+
         // Generate the path rename map; then use it to generate code for
         // assigning the path parameters to the `url` variable.
         let url_renames = method
@@ -765,6 +796,26 @@ impl Generator {
             OperationResponseStatus::is_success_or_default,
         );
 
+        let execute_request = if method.dropshot_websocket {
+            quote! {
+                let baseurl = #client.baseurl();
+                let uri: reqwest::Url = baseurl.parse()
+                    .map_err(|e| Error::InvalidRequest(format!("Invalid baseurl {:?}: {:?}", baseurl, e)))?;
+                let host = uri.host_str()
+                    .ok_or_else(|| Error::InvalidRequest(format!("No host in baseurl {:?}", baseurl)))?;
+                let port = uri.port_or_known_default()
+                    .ok_or_else(|| Error::InvalidRequest(format!("Cannot determine port from baseurl {:?}", baseurl)))?;
+                let addr = (host, port);
+                let sock_result = tokio::net::TcpStream::connect(addr).await;
+            }
+        } else {
+            quote! {
+                let result = #client.client
+                    .execute(request)
+                    .await;
+            }
+        };
+
         let success_response_matches =
             success_response_items.iter().map(|response| {
                 let pat = match &response.status_code {
@@ -871,6 +922,51 @@ impl Generator {
 
         let method_func = format_ident!("{}", method.method.as_str());
 
+        let wrap_response = if method.dropshot_websocket {
+            quote! {
+                let tcp_stream = sock_result?;
+                Ok(WebsocketReactants::new(request, tcp_stream)?)
+            }
+        } else {
+            quote! {
+                let response = result?;
+                match response.status().as_u16() {
+                    // These will be of the form...
+                    // 201 => ResponseValue::from_response(response).await,
+                    // 200..299 => ResponseValue::empty(response),
+                    // TODO this kind of enumerated response isn't implemented
+                    // ... or in the case of an operation with multiple
+                    // successful response types...
+                    // 200 => {
+                    //     ResponseValue::from_response()
+                    //         .await?
+                    //         .map(OperationXResponse::ResponseTypeA)
+                    // }
+                    // 201 => {
+                    //     ResponseValue::from_response()
+                    //         .await?
+                    //         .map(OperationXResponse::ResponseTypeB)
+                    // }
+                    #(#success_response_matches)*
+
+                    // This is almost identical to the success types except
+                    // they are wrapped in Error::ErrorResponse...
+                    // 400 => {
+                    //     Err(Error::ErrorResponse(
+                    //         ResponseValue::from_response(response.await?)
+                    //     ))
+                    // }
+                    #(#error_response_matches)*
+
+                    // The default response is either an Error with a known
+                    // type if the operation defines a default (as above) or
+                    // an Error::UnexpectedResponse...
+                    // _ => Err(Error::UnexpectedResponse(response)),
+                    #default_response
+                }
+            }
+        };
+
         let body_impl = quote! {
             #url_path
             #query_build
@@ -879,49 +975,12 @@ impl Generator {
                 . #method_func (url)
                 #(#body_func)*
                 #query_use
+                #websock_hdrs
                 .build()?;
             #pre_hook
-            let result = #client.client
-                .execute(request)
-                .await;
+            #execute_request
             #post_hook
-
-            let response = result?;
-
-            match response.status().as_u16() {
-                // These will be of the form...
-                // 201 => ResponseValue::from_response(response).await,
-                // 200..299 => ResponseValue::empty(response),
-                // TODO this kind of enumerated response isn't implemented
-                // ... or in the case of an operation with multiple
-                // successful response types...
-                // 200 => {
-                //     ResponseValue::from_response()
-                //         .await?
-                //         .map(OperationXResponse::ResponseTypeA)
-                // }
-                // 201 => {
-                //     ResponseValue::from_response()
-                //         .await?
-                //         .map(OperationXResponse::ResponseTypeB)
-                // }
-                #(#success_response_matches)*
-
-                // This is almost identical to the success types except
-                // they are wrapped in Error::ErrorResponse...
-                // 400 => {
-                //     Err(Error::ErrorResponse(
-                //         ResponseValue::from_response(response.await?)
-                //     ))
-                // }
-                #(#error_response_matches)*
-
-                // The default response is either an Error with a known
-                // type if the operation defines a default (as above) or
-                // an Error::UnexpectedResponse...
-                // _ => Err(Error::UnexpectedResponse(response)),
-                #default_response
-            }
+            #wrap_response
         };
 
         Ok(MethodSigBody {
@@ -936,6 +995,18 @@ impl Generator {
         method: &'a OperationMethod,
         filter: fn(&OperationResponseStatus) -> bool,
     ) -> (Vec<&'a OperationResponse>, TokenStream) {
+        if method.dropshot_websocket {
+            return (
+                vec![],
+                // hack: we want to unconditionally return a generic error
+                // presently, as we don't model anything more sophisticated
+                match filter(&OperationResponseStatus::Code(200)) {
+                    true => quote!(WebsocketReactants),
+                    false => quote!(types::Error),
+                },
+            );
+        }
+
         let mut response_items = method
             .responses
             .iter()
@@ -1485,6 +1556,11 @@ impl Generator {
                 }
             };
 
+        let ret_type = match method.dropshot_websocket {
+            false => quote!(Result<ResponseValue<#success>, Error<#error>>),
+            true => quote!(Result<#success, Error<#error>>),
+        };
+
         Ok(quote! {
             #[doc = #struct_doc]
             #derive
@@ -1504,10 +1580,7 @@ impl Generator {
                 #( #param_impls )*
 
                 #[doc = #send_doc]
-                pub async fn send(self) -> Result<
-                    ResponseValue<#success>,
-                    Error<#error>,
-                > {
+                pub async fn send(self) -> #ret_type {
                     // Destructure the builder for convenience.
                     let Self {
                         client,
diff --git a/progenitor-impl/tests/output/buildomat-builder-tagged.out b/progenitor-impl/tests/output/buildomat-builder-tagged.out
index fe9815cf..c8804fad 100644
--- a/progenitor-impl/tests/output/buildomat-builder-tagged.out
+++ b/progenitor-impl/tests/output/buildomat-builder-tagged.out
@@ -1,6 +1,8 @@
 #[allow(unused_imports)]
 use progenitor_client::{encode_path, RequestBuilderExt};
-pub use progenitor_client::{ByteStream, Error, ResponseValue};
+pub use progenitor_client::{
+    generate_websocket_key, ByteStream, Error, ResponseValue, WebsocketReactants,
+};
 pub mod types {
     use serde::{Deserialize, Serialize};
     #[allow(unused_imports)]
@@ -1500,7 +1502,12 @@ impl Client {
 pub mod builder {
     use super::types;
     #[allow(unused_imports)]
-    use super::{encode_path, ByteStream, Error, RequestBuilderExt, ResponseValue};
+    use super::{
+        encode_path, generate_websocket_key, ByteStream, Error, RequestBuilderExt, ResponseValue,
+        WebsocketReactants,
+    };
+    #[allow(unused_imports)]
+    use std::convert::TryInto;
     ///Builder for [`Client::control_hold`]
     ///
     ///[`Client::control_hold`]: super::Client::control_hold
diff --git a/progenitor-impl/tests/output/buildomat-builder.out b/progenitor-impl/tests/output/buildomat-builder.out
index e1d4c58a..a926f1d3 100644
--- a/progenitor-impl/tests/output/buildomat-builder.out
+++ b/progenitor-impl/tests/output/buildomat-builder.out
@@ -1,6 +1,8 @@
 #[allow(unused_imports)]
 use progenitor_client::{encode_path, RequestBuilderExt};
-pub use progenitor_client::{ByteStream, Error, ResponseValue};
+pub use progenitor_client::{
+    generate_websocket_key, ByteStream, Error, ResponseValue, WebsocketReactants,
+};
 pub mod types {
     use serde::{Deserialize, Serialize};
     #[allow(unused_imports)]
@@ -1500,7 +1502,10 @@ impl Client {
 pub mod builder {
     use super::types;
     #[allow(unused_imports)]
-    use super::{encode_path, ByteStream, Error, RequestBuilderExt, ResponseValue};
+    use super::{
+        encode_path, generate_websocket_key, ByteStream, Error, RequestBuilderExt, ResponseValue,
+        WebsocketReactants,
+    };
     #[allow(unused_imports)]
     use std::convert::TryInto;
     ///Builder for [`Client::control_hold`]
diff --git a/progenitor-impl/tests/output/buildomat-positional.out b/progenitor-impl/tests/output/buildomat-positional.out
index 6a039bb2..87567a85 100644
--- a/progenitor-impl/tests/output/buildomat-positional.out
+++ b/progenitor-impl/tests/output/buildomat-positional.out
@@ -1,6 +1,8 @@
 #[allow(unused_imports)]
 use progenitor_client::{encode_path, RequestBuilderExt};
-pub use progenitor_client::{ByteStream, Error, ResponseValue};
+pub use progenitor_client::{
+    generate_websocket_key, ByteStream, Error, ResponseValue, WebsocketReactants,
+};
 pub mod types {
     use serde::{Deserialize, Serialize};
     #[allow(unused_imports)]
diff --git a/progenitor-impl/tests/output/keeper-builder-tagged.out b/progenitor-impl/tests/output/keeper-builder-tagged.out
index 00f1772b..73139c7b 100644
--- a/progenitor-impl/tests/output/keeper-builder-tagged.out
+++ b/progenitor-impl/tests/output/keeper-builder-tagged.out
@@ -1,6 +1,8 @@
 #[allow(unused_imports)]
 use progenitor_client::{encode_path, RequestBuilderExt};
-pub use progenitor_client::{ByteStream, Error, ResponseValue};
+pub use progenitor_client::{
+    generate_websocket_key, ByteStream, Error, ResponseValue, WebsocketReactants,
+};
 pub mod types {
     use serde::{Deserialize, Serialize};
     #[allow(unused_imports)]
@@ -829,7 +831,12 @@ impl Client {
 pub mod builder {
     use super::types;
     #[allow(unused_imports)]
-    use super::{encode_path, ByteStream, Error, RequestBuilderExt, ResponseValue};
+    use super::{
+        encode_path, generate_websocket_key, ByteStream, Error, RequestBuilderExt, ResponseValue,
+        WebsocketReactants,
+    };
+    #[allow(unused_imports)]
+    use std::convert::TryInto;
     ///Builder for [`Client::enrol`]
     ///
     ///[`Client::enrol`]: super::Client::enrol
diff --git a/progenitor-impl/tests/output/keeper-builder.out b/progenitor-impl/tests/output/keeper-builder.out
index bb334b2c..9e5e682b 100644
--- a/progenitor-impl/tests/output/keeper-builder.out
+++ b/progenitor-impl/tests/output/keeper-builder.out
@@ -1,6 +1,8 @@
 #[allow(unused_imports)]
 use progenitor_client::{encode_path, RequestBuilderExt};
-pub use progenitor_client::{ByteStream, Error, ResponseValue};
+pub use progenitor_client::{
+    generate_websocket_key, ByteStream, Error, ResponseValue, WebsocketReactants,
+};
 pub mod types {
     use serde::{Deserialize, Serialize};
     #[allow(unused_imports)]
@@ -829,7 +831,10 @@ impl Client {
 pub mod builder {
     use super::types;
     #[allow(unused_imports)]
-    use super::{encode_path, ByteStream, Error, RequestBuilderExt, ResponseValue};
+    use super::{
+        encode_path, generate_websocket_key, ByteStream, Error, RequestBuilderExt, ResponseValue,
+        WebsocketReactants,
+    };
     #[allow(unused_imports)]
     use std::convert::TryInto;
     ///Builder for [`Client::enrol`]
diff --git a/progenitor-impl/tests/output/keeper-positional.out b/progenitor-impl/tests/output/keeper-positional.out
index 6a3bf9c8..4b4d6611 100644
--- a/progenitor-impl/tests/output/keeper-positional.out
+++ b/progenitor-impl/tests/output/keeper-positional.out
@@ -1,6 +1,8 @@
 #[allow(unused_imports)]
 use progenitor_client::{encode_path, RequestBuilderExt};
-pub use progenitor_client::{ByteStream, Error, ResponseValue};
+pub use progenitor_client::{
+    generate_websocket_key, ByteStream, Error, ResponseValue, WebsocketReactants,
+};
 pub mod types {
     use serde::{Deserialize, Serialize};
     #[allow(unused_imports)]
diff --git a/progenitor-impl/tests/output/nexus-builder-tagged.out b/progenitor-impl/tests/output/nexus-builder-tagged.out
index 4c1f9f1b..ee928fe7 100644
--- a/progenitor-impl/tests/output/nexus-builder-tagged.out
+++ b/progenitor-impl/tests/output/nexus-builder-tagged.out
@@ -1,6 +1,8 @@
 #[allow(unused_imports)]
 use progenitor_client::{encode_path, RequestBuilderExt};
-pub use progenitor_client::{ByteStream, Error, ResponseValue};
+pub use progenitor_client::{
+    generate_websocket_key, ByteStream, Error, ResponseValue, WebsocketReactants,
+};
 pub mod types {
     use serde::{Deserialize, Serialize};
     #[allow(unused_imports)]
@@ -13617,7 +13619,12 @@ impl ClientVpcsExt for Client {
 pub mod builder {
     use super::types;
     #[allow(unused_imports)]
-    use super::{encode_path, ByteStream, Error, RequestBuilderExt, ResponseValue};
+    use super::{
+        encode_path, generate_websocket_key, ByteStream, Error, RequestBuilderExt, ResponseValue,
+        WebsocketReactants,
+    };
+    #[allow(unused_imports)]
+    use std::convert::TryInto;
     ///Builder for [`ClientDisksExt::disk_view_by_id`]
     ///
     ///[`ClientDisksExt::disk_view_by_id`]: super::ClientDisksExt::disk_view_by_id
diff --git a/progenitor-impl/tests/output/nexus-builder.out b/progenitor-impl/tests/output/nexus-builder.out
index 46857e82..6ec722f3 100644
--- a/progenitor-impl/tests/output/nexus-builder.out
+++ b/progenitor-impl/tests/output/nexus-builder.out
@@ -1,6 +1,8 @@
 #[allow(unused_imports)]
 use progenitor_client::{encode_path, RequestBuilderExt};
-pub use progenitor_client::{ByteStream, Error, ResponseValue};
+pub use progenitor_client::{
+    generate_websocket_key, ByteStream, Error, ResponseValue, WebsocketReactants,
+};
 pub mod types {
     use serde::{Deserialize, Serialize};
     #[allow(unused_imports)]
@@ -13437,7 +13439,10 @@ impl Client {
 pub mod builder {
     use super::types;
     #[allow(unused_imports)]
-    use super::{encode_path, ByteStream, Error, RequestBuilderExt, ResponseValue};
+    use super::{
+        encode_path, generate_websocket_key, ByteStream, Error, RequestBuilderExt, ResponseValue,
+        WebsocketReactants,
+    };
     #[allow(unused_imports)]
     use std::convert::TryInto;
     ///Builder for [`Client::disk_view_by_id`]
diff --git a/progenitor-impl/tests/output/nexus-positional.out b/progenitor-impl/tests/output/nexus-positional.out
index 916cfb75..d8e14e97 100644
--- a/progenitor-impl/tests/output/nexus-positional.out
+++ b/progenitor-impl/tests/output/nexus-positional.out
@@ -1,6 +1,8 @@
 #[allow(unused_imports)]
 use progenitor_client::{encode_path, RequestBuilderExt};
-pub use progenitor_client::{ByteStream, Error, ResponseValue};
+pub use progenitor_client::{
+    generate_websocket_key, ByteStream, Error, ResponseValue, WebsocketReactants,
+};
 pub mod types {
     use serde::{Deserialize, Serialize};
     #[allow(unused_imports)]
diff --git a/progenitor-impl/tests/output/test_default_params_builder.out b/progenitor-impl/tests/output/test_default_params_builder.out
index cc576a97..4329e0a2 100644
--- a/progenitor-impl/tests/output/test_default_params_builder.out
+++ b/progenitor-impl/tests/output/test_default_params_builder.out
@@ -1,6 +1,8 @@
 #[allow(unused_imports)]
 use progenitor_client::{encode_path, RequestBuilderExt};
-pub use progenitor_client::{ByteStream, Error, ResponseValue};
+pub use progenitor_client::{
+    generate_websocket_key, ByteStream, Error, ResponseValue, WebsocketReactants,
+};
 pub mod types {
     use serde::{Deserialize, Serialize};
     #[allow(unused_imports)]
@@ -236,7 +238,10 @@ impl Client {
 pub mod builder {
     use super::types;
     #[allow(unused_imports)]
-    use super::{encode_path, ByteStream, Error, RequestBuilderExt, ResponseValue};
+    use super::{
+        encode_path, generate_websocket_key, ByteStream, Error, RequestBuilderExt, ResponseValue,
+        WebsocketReactants,
+    };
     #[allow(unused_imports)]
     use std::convert::TryInto;
     ///Builder for [`Client::default_params`]
diff --git a/progenitor-impl/tests/output/test_default_params_positional.out b/progenitor-impl/tests/output/test_default_params_positional.out
index 9eadbcab..8b7365e5 100644
--- a/progenitor-impl/tests/output/test_default_params_positional.out
+++ b/progenitor-impl/tests/output/test_default_params_positional.out
@@ -1,6 +1,8 @@
 #[allow(unused_imports)]
 use progenitor_client::{encode_path, RequestBuilderExt};
-pub use progenitor_client::{ByteStream, Error, ResponseValue};
+pub use progenitor_client::{
+    generate_websocket_key, ByteStream, Error, ResponseValue, WebsocketReactants,
+};
 pub mod types {
     use serde::{Deserialize, Serialize};
     #[allow(unused_imports)]
diff --git a/progenitor-impl/tests/output/test_freeform_response.out b/progenitor-impl/tests/output/test_freeform_response.out
index 97216ca1..d9b8a395 100644
--- a/progenitor-impl/tests/output/test_freeform_response.out
+++ b/progenitor-impl/tests/output/test_freeform_response.out
@@ -1,6 +1,8 @@
 #[allow(unused_imports)]
 use progenitor_client::{encode_path, RequestBuilderExt};
-pub use progenitor_client::{ByteStream, Error, ResponseValue};
+pub use progenitor_client::{
+    generate_websocket_key, ByteStream, Error, ResponseValue, WebsocketReactants,
+};
 pub mod types {
     use serde::{Deserialize, Serialize};
     #[allow(unused_imports)]
diff --git a/progenitor-impl/tests/output/test_renamed_parameters.out b/progenitor-impl/tests/output/test_renamed_parameters.out
index 8f13e283..6b95b98d 100644
--- a/progenitor-impl/tests/output/test_renamed_parameters.out
+++ b/progenitor-impl/tests/output/test_renamed_parameters.out
@@ -1,6 +1,8 @@
 #[allow(unused_imports)]
 use progenitor_client::{encode_path, RequestBuilderExt};
-pub use progenitor_client::{ByteStream, Error, ResponseValue};
+pub use progenitor_client::{
+    generate_websocket_key, ByteStream, Error, ResponseValue, WebsocketReactants,
+};
 pub mod types {
     use serde::{Deserialize, Serialize};
     #[allow(unused_imports)]
diff --git a/progenitor/Cargo.toml b/progenitor/Cargo.toml
index 8d50909d..9c42f436 100644
--- a/progenitor/Cargo.toml
+++ b/progenitor/Cargo.toml
@@ -24,3 +24,5 @@ regress = "0.4.1"
 reqwest = { version = "0.11", features = ["json", "stream"] }
 schemars = { version = "0.8.10", features = ["uuid1"] }
 uuid = { version = "1.0", features = ["serde", "v4"] }
+tokio = { version = "1", features = ["net"] }
+http = "0.2.8"
diff --git a/progenitor/tests/build_propolis.rs b/progenitor/tests/build_propolis.rs
new file mode 100644
index 00000000..3eba2d31
--- /dev/null
+++ b/progenitor/tests/build_propolis.rs
@@ -0,0 +1,24 @@
+// Copyright 2022 Oxide Computer Company
+
+// ensure that the websocket channel used for serial console compiles.
+mod propolis_client {
+    progenitor::generate_api!(
+        spec = "../sample_openapi/propolis-server.json",
+        interface = Builder,
+        tags = Merged,
+    );
+}
+
+use propolis_client::Client;
+
+pub fn _ignore() {
+    let _ = async {
+        let (_req, _tcp): (http::Request<()>, tokio::net::TcpStream) =
+            Client::new("")
+                .instance_serial()
+                .send()
+                .await
+                .unwrap()
+                .into_request_and_tcp_stream();
+    };
+}
diff --git a/sample_openapi/propolis-server.json b/sample_openapi/propolis-server.json
new file mode 100644
index 00000000..ee6ba4e4
--- /dev/null
+++ b/sample_openapi/propolis-server.json
@@ -0,0 +1,850 @@
+{
+  "openapi": "3.0.3",
+  "info": {
+    "title": "Oxide Propolis Server API",
+    "description": "API for interacting with the Propolis hypervisor frontend.",
+    "contact": {
+      "url": "https://oxide.computer",
+      "email": "api@oxide.computer"
+    },
+    "version": "0.0.1"
+  },
+  "paths": {
+    "/instance": {
+      "get": {
+        "operationId": "instance_get",
+        "responses": {
+          "200": {
+            "description": "successful operation",
+            "content": {
+              "application/json": {
+                "schema": {
+                  "$ref": "#/components/schemas/InstanceGetResponse"
+                }
+              }
+            }
+          },
+          "4XX": {
+            "$ref": "#/components/responses/Error"
+          },
+          "5XX": {
+            "$ref": "#/components/responses/Error"
+          }
+        }
+      },
+      "put": {
+        "operationId": "instance_ensure",
+        "requestBody": {
+          "content": {
+            "application/json": {
+              "schema": {
+                "$ref": "#/components/schemas/InstanceEnsureRequest"
+              }
+            }
+          },
+          "required": true
+        },
+        "responses": {
+          "201": {
+            "description": "successful creation",
+            "content": {
+              "application/json": {
+                "schema": {
+                  "$ref": "#/components/schemas/InstanceEnsureResponse"
+                }
+              }
+            }
+          },
+          "4XX": {
+            "$ref": "#/components/responses/Error"
+          },
+          "5XX": {
+            "$ref": "#/components/responses/Error"
+          }
+        }
+      }
+    },
+    "/instance/disk/{id}/snapshot/{snapshot_id}": {
+      "post": {
+        "summary": "Issue a snapshot request to a crucible backend",
+        "operationId": "instance_issue_crucible_snapshot_request",
+        "parameters": [
+          {
+            "in": "path",
+            "name": "id",
+            "required": true,
+            "schema": {
+              "type": "string",
+              "format": "uuid"
+            },
+            "style": "simple"
+          },
+          {
+            "in": "path",
+            "name": "snapshot_id",
+            "required": true,
+            "schema": {
+              "type": "string",
+              "format": "uuid"
+            },
+            "style": "simple"
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "successful operation",
+            "content": {
+              "application/json": {
+                "schema": {
+                  "title": "Null",
+                  "type": "string",
+                  "enum": [
+                    null
+                  ]
+                }
+              }
+            }
+          },
+          "4XX": {
+            "$ref": "#/components/responses/Error"
+          },
+          "5XX": {
+            "$ref": "#/components/responses/Error"
+          }
+        }
+      }
+    },
+    "/instance/migrate/status": {
+      "get": {
+        "operationId": "instance_migrate_status",
+        "requestBody": {
+          "content": {
+            "application/json": {
+              "schema": {
+                "$ref": "#/components/schemas/InstanceMigrateStatusRequest"
+              }
+            }
+          },
+          "required": true
+        },
+        "responses": {
+          "200": {
+            "description": "successful operation",
+            "content": {
+              "application/json": {
+                "schema": {
+                  "$ref": "#/components/schemas/InstanceMigrateStatusResponse"
+                }
+              }
+            }
+          },
+          "4XX": {
+            "$ref": "#/components/responses/Error"
+          },
+          "5XX": {
+            "$ref": "#/components/responses/Error"
+          }
+        }
+      }
+    },
+    "/instance/serial": {
+      "get": {
+        "operationId": "instance_serial",
+        "responses": {
+          "default": {
+            "description": "",
+            "content": {
+              "*/*": {
+                "schema": {}
+              }
+            }
+          }
+        },
+        "x-dropshot-websocket": {}
+      }
+    },
+    "/instance/state": {
+      "put": {
+        "operationId": "instance_state_put",
+        "requestBody": {
+          "content": {
+            "application/json": {
+              "schema": {
+                "$ref": "#/components/schemas/InstanceStateRequested"
+              }
+            }
+          },
+          "required": true
+        },
+        "responses": {
+          "204": {
+            "description": "resource updated"
+          },
+          "4XX": {
+            "$ref": "#/components/responses/Error"
+          },
+          "5XX": {
+            "$ref": "#/components/responses/Error"
+          }
+        }
+      }
+    },
+    "/instance/state-monitor": {
+      "get": {
+        "operationId": "instance_state_monitor",
+        "requestBody": {
+          "content": {
+            "application/json": {
+              "schema": {
+                "$ref": "#/components/schemas/InstanceStateMonitorRequest"
+              }
+            }
+          },
+          "required": true
+        },
+        "responses": {
+          "200": {
+            "description": "successful operation",
+            "content": {
+              "application/json": {
+                "schema": {
+                  "$ref": "#/components/schemas/InstanceStateMonitorResponse"
+                }
+              }
+            }
+          },
+          "4XX": {
+            "$ref": "#/components/responses/Error"
+          },
+          "5XX": {
+            "$ref": "#/components/responses/Error"
+          }
+        }
+      }
+    }
+  },
+  "components": {
+    "responses": {
+      "Error": {
+        "description": "Error",
+        "content": {
+          "application/json": {
+            "schema": {
+              "$ref": "#/components/schemas/Error"
+            }
+          }
+        }
+      }
+    },
+    "schemas": {
+      "CrucibleOpts": {
+        "type": "object",
+        "properties": {
+          "cert_pem": {
+            "nullable": true,
+            "type": "string"
+          },
+          "control": {
+            "nullable": true,
+            "type": "string"
+          },
+          "flush_timeout": {
+            "nullable": true,
+            "type": "integer",
+            "format": "uint32",
+            "minimum": 0
+          },
+          "id": {
+            "type": "string",
+            "format": "uuid"
+          },
+          "key": {
+            "nullable": true,
+            "type": "string"
+          },
+          "key_pem": {
+            "nullable": true,
+            "type": "string"
+          },
+          "lossy": {
+            "type": "boolean"
+          },
+          "read_only": {
+            "type": "boolean"
+          },
+          "root_cert_pem": {
+            "nullable": true,
+            "type": "string"
+          },
+          "target": {
+            "type": "array",
+            "items": {
+              "type": "string"
+            }
+          }
+        },
+        "required": [
+          "id",
+          "lossy",
+          "read_only",
+          "target"
+        ]
+      },
+      "DiskAttachment": {
+        "type": "object",
+        "properties": {
+          "disk_id": {
+            "type": "string",
+            "format": "uuid"
+          },
+          "generation_id": {
+            "type": "integer",
+            "format": "uint64",
+            "minimum": 0
+          },
+          "state": {
+            "$ref": "#/components/schemas/DiskAttachmentState"
+          }
+        },
+        "required": [
+          "disk_id",
+          "generation_id",
+          "state"
+        ]
+      },
+      "DiskAttachmentState": {
+        "oneOf": [
+          {
+            "type": "string",
+            "enum": [
+              "Detached",
+              "Destroyed",
+              "Faulted"
+            ]
+          },
+          {
+            "type": "object",
+            "properties": {
+              "Attached": {
+                "type": "string",
+                "format": "uuid"
+              }
+            },
+            "required": [
+              "Attached"
+            ],
+            "additionalProperties": false
+          }
+        ]
+      },
+      "DiskRequest": {
+        "type": "object",
+        "properties": {
+          "device": {
+            "type": "string"
+          },
+          "gen": {
+            "type": "integer",
+            "format": "uint64",
+            "minimum": 0
+          },
+          "name": {
+            "type": "string"
+          },
+          "read_only": {
+            "type": "boolean"
+          },
+          "slot": {
+            "$ref": "#/components/schemas/Slot"
+          },
+          "volume_construction_request": {
+            "$ref": "#/components/schemas/VolumeConstructionRequest"
+          }
+        },
+        "required": [
+          "device",
+          "gen",
+          "name",
+          "read_only",
+          "slot",
+          "volume_construction_request"
+        ]
+      },
+      "Error": {
+        "description": "Error information from a response.",
+        "type": "object",
+        "properties": {
+          "error_code": {
+            "type": "string"
+          },
+          "message": {
+            "type": "string"
+          },
+          "request_id": {
+            "type": "string"
+          }
+        },
+        "required": [
+          "message",
+          "request_id"
+        ]
+      },
+      "Instance": {
+        "type": "object",
+        "properties": {
+          "disks": {
+            "type": "array",
+            "items": {
+              "$ref": "#/components/schemas/DiskAttachment"
+            }
+          },
+          "nics": {
+            "type": "array",
+            "items": {
+              "$ref": "#/components/schemas/NetworkInterface"
+            }
+          },
+          "properties": {
+            "$ref": "#/components/schemas/InstanceProperties"
+          },
+          "state": {
+            "$ref": "#/components/schemas/InstanceState"
+          }
+        },
+        "required": [
+          "disks",
+          "nics",
+          "properties",
+          "state"
+        ]
+      },
+      "InstanceEnsureRequest": {
+        "type": "object",
+        "properties": {
+          "cloud_init_bytes": {
+            "nullable": true,
+            "type": "string"
+          },
+          "disks": {
+            "default": [],
+            "type": "array",
+            "items": {
+              "$ref": "#/components/schemas/DiskRequest"
+            }
+          },
+          "migrate": {
+            "nullable": true,
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/InstanceMigrateInitiateRequest"
+              }
+            ]
+          },
+          "nics": {
+            "default": [],
+            "type": "array",
+            "items": {
+              "$ref": "#/components/schemas/NetworkInterfaceRequest"
+            }
+          },
+          "properties": {
+            "$ref": "#/components/schemas/InstanceProperties"
+          }
+        },
+        "required": [
+          "properties"
+        ]
+      },
+      "InstanceEnsureResponse": {
+        "type": "object",
+        "properties": {
+          "migrate": {
+            "nullable": true,
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/InstanceMigrateInitiateResponse"
+              }
+            ]
+          }
+        }
+      },
+      "InstanceGetResponse": {
+        "type": "object",
+        "properties": {
+          "instance": {
+            "$ref": "#/components/schemas/Instance"
+          }
+        },
+        "required": [
+          "instance"
+        ]
+      },
+      "InstanceMigrateInitiateRequest": {
+        "type": "object",
+        "properties": {
+          "migration_id": {
+            "type": "string",
+            "format": "uuid"
+          },
+          "src_addr": {
+            "type": "string"
+          },
+          "src_uuid": {
+            "type": "string",
+            "format": "uuid"
+          }
+        },
+        "required": [
+          "migration_id",
+          "src_addr",
+          "src_uuid"
+        ]
+      },
+      "InstanceMigrateInitiateResponse": {
+        "type": "object",
+        "properties": {
+          "migration_id": {
+            "type": "string",
+            "format": "uuid"
+          }
+        },
+        "required": [
+          "migration_id"
+        ]
+      },
+      "InstanceMigrateStatusRequest": {
+        "type": "object",
+        "properties": {
+          "migration_id": {
+            "type": "string",
+            "format": "uuid"
+          }
+        },
+        "required": [
+          "migration_id"
+        ]
+      },
+      "InstanceMigrateStatusResponse": {
+        "type": "object",
+        "properties": {
+          "state": {
+            "$ref": "#/components/schemas/MigrationState"
+          }
+        },
+        "required": [
+          "state"
+        ]
+      },
+      "InstanceProperties": {
+        "type": "object",
+        "properties": {
+          "bootrom_id": {
+            "description": "ID of the bootrom used to initialize this Instance.",
+            "type": "string",
+            "format": "uuid"
+          },
+          "description": {
+            "description": "Free-form text description of an Instance.",
+            "type": "string"
+          },
+          "id": {
+            "description": "Unique identifier for this Instance.",
+            "type": "string",
+            "format": "uuid"
+          },
+          "image_id": {
+            "description": "ID of the image used to initialize this Instance.",
+            "type": "string",
+            "format": "uuid"
+          },
+          "memory": {
+            "description": "Size of memory allocated to the Instance, in MiB.",
+            "type": "integer",
+            "format": "uint64",
+            "minimum": 0
+          },
+          "name": {
+            "description": "Human-readable name of the Instance.",
+            "type": "string"
+          },
+          "vcpus": {
+            "description": "Number of vCPUs to be allocated to the Instance.",
+            "type": "integer",
+            "format": "uint8",
+            "minimum": 0
+          }
+        },
+        "required": [
+          "bootrom_id",
+          "description",
+          "id",
+          "image_id",
+          "memory",
+          "name",
+          "vcpus"
+        ]
+      },
+      "InstanceState": {
+        "description": "Current state of an Instance.",
+        "type": "string",
+        "enum": [
+          "Creating",
+          "Starting",
+          "Running",
+          "Stopping",
+          "Stopped",
+          "Rebooting",
+          "Migrating",
+          "Repairing",
+          "Failed",
+          "Destroyed"
+        ]
+      },
+      "InstanceStateMonitorRequest": {
+        "type": "object",
+        "properties": {
+          "gen": {
+            "type": "integer",
+            "format": "uint64",
+            "minimum": 0
+          }
+        },
+        "required": [
+          "gen"
+        ]
+      },
+      "InstanceStateMonitorResponse": {
+        "type": "object",
+        "properties": {
+          "gen": {
+            "type": "integer",
+            "format": "uint64",
+            "minimum": 0
+          },
+          "state": {
+            "$ref": "#/components/schemas/InstanceState"
+          }
+        },
+        "required": [
+          "gen",
+          "state"
+        ]
+      },
+      "InstanceStateRequested": {
+        "type": "string",
+        "enum": [
+          "Run",
+          "Stop",
+          "Reboot",
+          "MigrateStart"
+        ]
+      },
+      "MigrationState": {
+        "type": "string",
+        "enum": [
+          "Sync",
+          "RamPush",
+          "Pause",
+          "RamPushDirty",
+          "Device",
+          "Arch",
+          "Resume",
+          "RamPull",
+          "Finish",
+          "Error"
+        ]
+      },
+      "NetworkInterface": {
+        "type": "object",
+        "properties": {
+          "attachment": {
+            "$ref": "#/components/schemas/NetworkInterfaceAttachmentState"
+          },
+          "name": {
+            "type": "string"
+          }
+        },
+        "required": [
+          "attachment",
+          "name"
+        ]
+      },
+      "NetworkInterfaceAttachmentState": {
+        "oneOf": [
+          {
+            "type": "string",
+            "enum": [
+              "Detached",
+              "Faulted"
+            ]
+          },
+          {
+            "type": "object",
+            "properties": {
+              "Attached": {
+                "$ref": "#/components/schemas/Slot"
+              }
+            },
+            "required": [
+              "Attached"
+            ],
+            "additionalProperties": false
+          }
+        ]
+      },
+      "NetworkInterfaceRequest": {
+        "type": "object",
+        "properties": {
+          "name": {
+            "type": "string"
+          },
+          "slot": {
+            "$ref": "#/components/schemas/Slot"
+          }
+        },
+        "required": [
+          "name",
+          "slot"
+        ]
+      },
+      "Slot": {
+        "description": "A stable index which is translated by Propolis into a PCI BDF, visible to the guest.",
+        "type": "integer",
+        "format": "uint8",
+        "minimum": 0
+      },
+      "VolumeConstructionRequest": {
+        "oneOf": [
+          {
+            "type": "object",
+            "properties": {
+              "block_size": {
+                "type": "integer",
+                "format": "uint64",
+                "minimum": 0
+              },
+              "id": {
+                "type": "string",
+                "format": "uuid"
+              },
+              "read_only_parent": {
+                "nullable": true,
+                "allOf": [
+                  {
+                    "$ref": "#/components/schemas/VolumeConstructionRequest"
+                  }
+                ]
+              },
+              "sub_volumes": {
+                "type": "array",
+                "items": {
+                  "$ref": "#/components/schemas/VolumeConstructionRequest"
+                }
+              },
+              "type": {
+                "type": "string",
+                "enum": [
+                  "volume"
+                ]
+              }
+            },
+            "required": [
+              "block_size",
+              "id",
+              "sub_volumes",
+              "type"
+            ]
+          },
+          {
+            "type": "object",
+            "properties": {
+              "block_size": {
+                "type": "integer",
+                "format": "uint64",
+                "minimum": 0
+              },
+              "id": {
+                "type": "string",
+                "format": "uuid"
+              },
+              "type": {
+                "type": "string",
+                "enum": [
+                  "url"
+                ]
+              },
+              "url": {
+                "type": "string"
+              }
+            },
+            "required": [
+              "block_size",
+              "id",
+              "type",
+              "url"
+            ]
+          },
+          {
+            "type": "object",
+            "properties": {
+              "block_size": {
+                "type": "integer",
+                "format": "uint64",
+                "minimum": 0
+              },
+              "gen": {
+                "type": "integer",
+                "format": "uint64",
+                "minimum": 0
+              },
+              "opts": {
+                "$ref": "#/components/schemas/CrucibleOpts"
+              },
+              "type": {
+                "type": "string",
+                "enum": [
+                  "region"
+                ]
+              }
+            },
+            "required": [
+              "block_size",
+              "gen",
+              "opts",
+              "type"
+            ]
+          },
+          {
+            "type": "object",
+            "properties": {
+              "block_size": {
+                "type": "integer",
+                "format": "uint64",
+                "minimum": 0
+              },
+              "id": {
+                "type": "string",
+                "format": "uuid"
+              },
+              "path": {
+                "type": "string"
+              },
+              "type": {
+                "type": "string",
+                "enum": [
+                  "file"
+                ]
+              }
+            },
+            "required": [
+              "block_size",
+              "id",
+              "path",
+              "type"
+            ]
+          }
+        ]
+      }
+    }
+  }
+}
\ No newline at end of file