feat: Add explicit SSE event names for local v3 streaming

Author: stainless-app[bot]

.stats.yml

@@ -1,4 +1,4 @@
 configured_endpoints: 8
-openapi_spec_url: https://storage.googleapis.com/stainless-sdk-openapi-specs/browserbase%2Fstagehand-975ca868b31b1e45fb00b31a53d9df1ceec8663f6c2851bf40fdaa84171afadc.yml
-openapi_spec_hash: 37891379e0f47e5c69769fbaa1064dab
-config_hash: 0209737a4ab2a71afececb0ff7459998
+openapi_spec_url: https://storage.googleapis.com/stainless-sdk-openapi-specs/browserbase%2Fstagehand-a4a5ea048bb50d06460d81d6828b53b12b19e9224121ee6338dcd1f0781e22a1.yml
+openapi_spec_hash: 9b81c0ae04576318d13d7a80d4ab7b5a
+config_hash: d6c6f623d03971bdba921650e5eb7e5f

src/SSEStream.php

@@ -29,33 +29,9 @@ private function parsedGenerator(): \Generator
             return;
         }
 
-        $done = false;
         foreach ($this->stream as $row) {
-            // @phpstan-ignore if.alwaysFalse
-            if ($done) {
-                // Iterate through the whole stream
-                continue;
-            }
-
             switch ($row['event'] ?? null) {
-                case null:
-                    if ($data = $row['data'] ?? '') {
-                        $decoded = Util::decodeJson($data);
-
-                        yield Conversion::coerce($this->convert, value: $decoded);
-                    }
-
-                    break;
-            }
-
-            if ($data = $row['data'] ?? '') {
-                if (str_starts_with($data, needle: '{"data":{"status":"finished"')) {
-                    $done = true;
-
-                    continue;
-                }
-
-                if (str_starts_with($data, needle: 'error')) {
+                case 'error':
                     if ($data = $row['data'] ?? '') {
                         $json = Util::decodeJson($data);
                         $message = Util::prettyEncodeJson($json);
@@ -69,8 +45,19 @@ private function parsedGenerator(): \Generator
                         throw $exn;
                     }
 
-                    continue;
-                }
+                    break;
+
+                case 'starting':
+                case 'connected':
+                case 'running':
+                case 'finished':
+                    if ($data = $row['data'] ?? '') {
+                        $decoded = Util::decodeJson($data);
+
+                        yield Conversion::coerce($this->convert, value: $decoded);
+                    }
+
+                    break;
             }
         }
     }

src/Sessions/StreamEvent.php

@@ -12,7 +12,7 @@
 use Stagehand\Sessions\StreamEvent\Type;
 
 /**
- * Server-Sent Event emitted during streaming responses. Events are sent as `data: <JSON>\n\n`. Key order: data (with status first), type, id.
+ * Server-Sent Event emitted during streaming responses. Events are sent as `event: <status>\ndata: <JSON>\n\n`, where the JSON payload has the shape `{ data, type, id }`.
  *
  * @phpstan-import-type DataVariants from \Stagehand\Sessions\StreamEvent\Data
  * @phpstan-import-type DataShape from \Stagehand\Sessions\StreamEvent\Data