diff --git a/tests/async/_snaps/http-sse.md b/tests/async/_snaps/http-sse.md
new file mode 100644
index 00000000..91dc73cb
--- /dev/null
+++ b/tests/async/_snaps/http-sse.md
@@ -0,0 +1,127 @@
+# parse_sse_event
+
+    Code
+      parse_sse_event(charToRaw(txt))
+    Output
+        foo 
+      "bar" 
+
+---
+
+    Code
+      parse_sse_event(charToRaw(txt))
+    Output
+        foo 
+      "bar" 
+
+---
+
+    Code
+      parse_sse_event(charToRaw(txt))
+    Output
+           foo      baz      and 
+         "bar" "foobar"   "last" 
+
+# chunk_sse_events
+
+    Code
+      chunk_sse_events(charToRaw(txt))
+    Output
+      $events
+      list()
+      
+      $rest
+       [1] 66 6f 6f 3a 20 62 61 72 0a 62 61 7a 3a 20 66 6f 6f 0a
+      
+
+---
+
+    Code
+      chunk_sse_events(charToRaw(txt))
+    Output
+      $events
+      $events[[1]]
+           foo      baz 
+         "bar" "foobar" 
+      
+      $events[[2]]
+      another 
+      "event" 
+      
+      $events[[3]]
+            and 
+      "another" 
+      
+      
+      $rest
+      raw(0)
+      
+
+---
+
+    Code
+      chunk_sse_events(charToRaw(txt))
+    Output
+      $events
+      $events[[1]]
+           foo      baz 
+         "bar" "foobar" 
+      
+      $events[[2]]
+      another 
+      "event" 
+      
+      $events[[3]]
+            and 
+      "another" 
+      
+      
+      $rest
+      raw(0)
+      
+
+---
+
+    Code
+      chunk_sse_events(charToRaw(txt))
+    Output
+      $events
+      $events[[1]]
+           foo      baz 
+         "bar" "foobar" 
+      
+      $events[[2]]
+      another 
+      "event" 
+      
+      
+      $rest
+       [1] 61 6e 64 3a 61 6e 6f 74 68 65 72 0a
+      
+
+# sse
+
+    Code
+      events
+    Output
+      [[1]]
+                        event                 message 
+                          "1" "live long and prosper" 
+      
+      [[2]]
+                        event                 message 
+                          "2" "live long and prosper" 
+      
+      [[3]]
+                        event                 message 
+                          "3" "live long and prosper" 
+      
+      [[4]]
+                        event                 message 
+                          "4" "live long and prosper" 
+      
+      [[5]]
+                        event                 message 
+                          "5" "live long and prosper" 
+      
+
diff --git a/tests/async/test-http-events.R b/tests/async/test-http-events.R
new file mode 100644
index 00000000..5d5c6eaf
--- /dev/null
+++ b/tests/async/test-http-events.R
@@ -0,0 +1,55 @@
+test_that("end event", {
+  done <- NULL
+  do <- function() {
+    p1 <- http_get(http$url("/get"))
+    p2 <- p1$then(function() done <<- c(done, "done"))
+    p1$event_emitter$listen_on("end", function(...) {
+      done <<- c(done, "end")
+    })
+    p2
+  }
+
+  synchronise(do())
+  expect_equal(done, c("end", "done"))
+})
+
+test_that("data event", {
+  skip_on_cran()
+  chunks <- NULL
+  called <- 0L
+  do <- function() {
+    p1 <- http_get(http$url("/drip?duration=1&numbytes=10"))
+    p1$event_emitter$listen_on("data", function(bytes) {
+      chunks <<- c(chunks, list(bytes))
+    })
+    p1$event_emitter$listen_on("data", function(bytes) {
+      called <<- called + 1L
+    })
+    p1
+  }
+
+  # there is an extra zero-length chunk currently, but let's not
+  # rely on that
+  synchronise(do())
+  expect_true(length(chunks) >= 10)
+  expect_equal(length(unlist(chunks)), 10)
+  expect_true(called >= 10)
+})
+
+test_that("multiple end events", {
+  done <- NULL
+  do <- function() {
+    p1 <- http_get(http$url("/get"))
+    p2 <- p1$then(function() done <<- c(done, "done"))
+    p1$event_emitter$listen_on("end", function(...) {
+      done <<- c(done, "end1")
+    })
+    p1$event_emitter$listen_on("end", function(...) {
+      done <<- c(done, "end2")
+    })
+    p2
+  }
+
+  synchronise(do())
+  expect_equal(done, c("end1", "end2", "done"))
+})
diff --git a/tests/async/test-http-sse.R b/tests/async/test-http-sse.R
new file mode 100644
index 00000000..b2c73713
--- /dev/null
+++ b/tests/async/test-http-sse.R
@@ -0,0 +1,59 @@
+test_that("parse_sse_event", {
+  testthat::local_edition(3)
+
+  txt <- "foo: bar"
+  expect_snapshot(parse_sse_event(charToRaw(txt)))
+
+  txt <- "foo:bar"
+  expect_snapshot(parse_sse_event(charToRaw(txt)))
+
+  txt <- "foo: bar\nbaz:foobar\nand:last"
+  expect_snapshot(parse_sse_event(charToRaw(txt)))
+})
+
+test_that("chunk_sse_events", {
+  testthat::local_edition(3)
+
+  # no events yet
+  txt <- "foo: bar\nbaz: foo\n"
+  expect_snapshot(chunk_sse_events(charToRaw(txt)))
+
+  txt <- "foo: bar\nbaz: foobar\n\nanother: event\n\nand:another\n\n"
+  expect_snapshot(chunk_sse_events(charToRaw(txt)))
+
+  # slightly bad separators
+  txt <- paste0(
+    "\n\n\n",
+    "foo: bar\nbaz: foobar",
+    "\n\n\n\n\n",
+    "another: event",
+    "\n\n",
+    "and:another",
+    "\n\n"
+  )
+  expect_snapshot(chunk_sse_events(charToRaw(txt)))
+
+  # incomplete last event
+  txt <- "foo: bar\nbaz: foobar\n\nanother: event\n\nand:another\n"
+  expect_snapshot(chunk_sse_events(charToRaw(txt)))
+
+})
+
+test_that("sse", {
+  testthat::local_edition(3)
+  server <- webfakes::new_app_process(sseapp())
+  url <- server$url("/sse")
+
+  events <- NULL
+  do <- function() {
+    p1 <- http_get(url)
+    evs <- sse_events$new(p1)
+    evs$listen_on("event", function(ev) {
+      events <<- c(events, list(ev))
+    })
+    p1
+  }
+
+  synchronise(do())
+  expect_snapshot(events)
+})