diff --git a/src/emu/stream.c b/src/emu/stream.c
index ddfe2b6..52f0b59 100644
--- a/src/emu/stream.c
+++ b/src/emu/stream.c
@@ -71,41 +71,22 @@ load_stream_fd(struct stream *stream, int fd)
 	return 0;
 }
 
-int
-stream_load(struct stream *stream, const char *tracedir, const char *relpath)
+static int
+load_obs(struct stream *stream, const char *path)
 {
-	memset(stream, 0, sizeof(struct stream));
-
-	if (snprintf(stream->path, PATH_MAX, "%s/%s", tracedir, relpath) >= PATH_MAX) {
-		err("path too long: %s/%s", tracedir, relpath);
-		return -1;
-	}
-
-	/* Allow loading a trace with empty relpath */
-	path_remove_trailing(stream->path);
-
-	if (snprintf(stream->relpath, PATH_MAX, "%s", relpath) >= PATH_MAX) {
-		err("path too long: %s", relpath);
-		return -1;
-	}
-
-	dbg("loading %s", stream->relpath);
-
 	int fd;
-	if ((fd = open(stream->path, O_RDWR)) == -1) {
-		err("open %s failed:", stream->path);
+	if ((fd = open(path, O_RDWR)) == -1) {
+		err("open %s failed:", path);
 		return -1;
 	}
 
 	if (load_stream_fd(stream, fd) != 0) {
-		err("load_stream_fd failed for stream '%s'",
-				stream->path);
+		err("load_stream_fd failed for: %s", path);
 		return -1;
 	}
 
 	if (check_stream_header(stream) != 0) {
-		err("stream '%s' has bad header",
-				stream->path);
+		err("stream has bad header: %s", path);
 		return -1;
 	}
 
@@ -132,6 +113,75 @@ stream_load(struct stream *stream, const char *tracedir, const char *relpath)
 	return 0;
 }
 
+static JSON_Object *
+load_json(const char *path)
+{
+	JSON_Value *vmeta = json_parse_file_with_comments(path);
+	if (vmeta == NULL) {
+		err("json_parse_file_with_comments() failed");
+		return NULL;
+	}
+
+	JSON_Object *meta = json_value_get_object(vmeta);
+	if (meta == NULL) {
+		err("json_value_get_object() failed");
+		return NULL;
+	}
+
+	return meta;
+}
+
+/** Loads a stream from disk.
+ *
+ * The relpath must be pointing to a directory with the stream.json and
+ * stream.obs files.
+ */
+int
+stream_load(struct stream *stream, const char *tracedir, const char *relpath)
+{
+	memset(stream, 0, sizeof(struct stream));
+
+	if (snprintf(stream->path, PATH_MAX, "%s/%s", tracedir, relpath) >= PATH_MAX) {
+		err("path too long: %s/%s", tracedir, relpath);
+		return -1;
+	}
+
+	/* Allow loading a trace with empty relpath */
+	path_remove_trailing(stream->path);
+
+	if (snprintf(stream->relpath, PATH_MAX, "%s", relpath) >= PATH_MAX) {
+		err("path too long: %s", relpath);
+		return -1;
+	}
+
+	dbg("loading %s", stream->relpath);
+
+	char path_json[PATH_MAX];
+	char path_obs[PATH_MAX];
+
+	if (path_append(path_json, stream->path, "stream.json") != 0) {
+		err("path_append failed");
+		return -1;
+	}
+
+	if ((stream->meta = load_json(path_json)) == NULL) {
+		err("load_json failed for: %s", path_json);
+		return -1;
+	}
+
+	if (path_append(path_obs, stream->path, "stream.obs") != 0) {
+		err("path_append failed");
+		return -1;
+	}
+
+	if (load_obs(stream, path_obs) != 0) {
+		err("load_obs failed");
+		return -1;
+	}
+
+	return 0;
+}
+
 void
 stream_data_set(struct stream *stream, void *data)
 {
@@ -144,6 +194,12 @@ stream_data_get(struct stream *stream)
 	return stream->data;
 }
 
+JSON_Object *
+stream_metadata(struct stream *stream)
+{
+	return stream->meta;
+}
+
 int
 stream_clkoff_set(struct stream *stream, int64_t clkoff)
 {
diff --git a/src/emu/stream.h b/src/emu/stream.h
index 2bbfd13..8acee0c 100644
--- a/src/emu/stream.h
+++ b/src/emu/stream.h
@@ -1,4 +1,4 @@
-/* Copyright (c) 2021-2023 Barcelona Supercomputing Center (BSC)
+/* Copyright (c) 2021-2024 Barcelona Supercomputing Center (BSC)
  * SPDX-License-Identifier: GPL-3.0-or-later */
 
 #ifndef STREAM_H
@@ -8,6 +8,7 @@
 #include <stdint.h>
 #include "common.h"
 #include "heap.h"
+#include "parson.h"
 struct ovni_ev;
 
 struct stream {
@@ -34,6 +35,8 @@ struct stream {
 	int64_t offset;
 
 	double progress;
+
+	JSON_Object *meta;
 };
 
 USE_RET int stream_load(struct stream *stream, const char *tracedir, const char *relpath);
@@ -46,5 +49,6 @@ USE_RET int64_t stream_lastclock(struct stream *stream);
         void stream_allow_unsorted(struct stream *stream);
         void stream_data_set(struct stream *stream, void *data);
 USE_RET void *stream_data_get(struct stream *stream);
+USE_RET JSON_Object *stream_metadata(struct stream *stream);
 
 #endif /* STREAM_H */
diff --git a/src/emu/trace.c b/src/emu/trace.c
index 4b8bd49..96aa414 100644
--- a/src/emu/trace.c
+++ b/src/emu/trace.c
@@ -27,7 +27,7 @@ add_stream(struct trace *trace, struct stream *stream)
 }
 
 static int
-load_stream(struct trace *trace, const char *path)
+load_stream(struct trace *trace, const char *json_path)
 {
 	struct stream *stream = calloc(1, sizeof(struct stream));
 
@@ -36,6 +36,14 @@ load_stream(struct trace *trace, const char *path)
 		return -1;
 	}
 
+	/* The json_path must end in .../stream.json, so remove it */
+	char path[PATH_MAX];
+	if (path_copy(path, json_path) != 0) {
+		err("path_copy failed");
+		return -1;
+	}
+	path_dirname(path);
+
 	int offset = (int) strlen(trace->tracedir);
 	const char *relpath = path + offset;
 
@@ -53,46 +61,16 @@ load_stream(struct trace *trace, const char *path)
 }
 
 static int
-has_suffix(const char *str, const char *suffix)
+is_stream(const char *fpath)
 {
-	if (!str || !suffix)
-		return 0;
+	const char *filename = path_filename(fpath);
 
-	int lenstr = (int) strlen(str);
-	int lensuffix = (int) strlen(suffix);
-
-	if (lensuffix > lenstr)
-		return 0;
-
-	const char *p = str + lenstr - lensuffix;
-	if (strncmp(p, suffix, (size_t) lensuffix) == 0)
+	if (strcmp(filename, "stream.json") == 0)
 		return 1;
 
 	return 0;
 }
 
-static int
-is_stream(const char *fpath)
-{
-	if (has_suffix(fpath, OVNI_STREAM_EXT))
-		return 1;
-
-	/* For compatibility load the old streams too */
-	const char *filename = path_filename(fpath);
-
-	const char prefix[] = "thread.";
-	if (!path_has_prefix(filename, prefix))
-		return 0;
-
-	const char *tid = filename + strlen(prefix);
-	for (int i = 0; tid[i]; i++) {
-		if (tid[i] < '0' || tid[i] > '9')
-			return 0;
-	}
-
-	return 1;
-}
-
 static int
 cb_nftw(const char *fpath, const struct stat *sb,
 		int typeflag, struct FTW *ftwbuf)
diff --git a/src/rt/ovni.c b/src/rt/ovni.c
index 0cec34d..523dfea 100644
--- a/src/rt/ovni.c
+++ b/src/rt/ovni.c
@@ -104,17 +104,34 @@ void ovni_version_check_str(const char *version)
 	/* Ignore the patch number */
 }
 
+static void
+create_thread_dir(void)
+{
+	char path[PATH_MAX];
+
+	int written = snprintf(path, PATH_MAX, "%s/thread.%d",
+			rproc.procdir, rthread.tid);
+
+	if (written >= PATH_MAX)
+		die("path too long: %s/thread.%d", rproc.procdir, rthread.tid);
+
+	/* The procdir must have been created earlier */
+	if (mkdir(path, 0755) != 0)
+		die("mkdir(%s) failed:", path);
+}
+
 static void
 create_trace_stream(void)
 {
 	char path[PATH_MAX];
 
-	int written = snprintf(path, PATH_MAX, "%s/thread.%d%s",
-			rproc.procdir, rthread.tid, OVNI_STREAM_EXT);
+	int written = snprintf(path, PATH_MAX, "%s/thread.%d/stream.obs",
+			rproc.procdir, rthread.tid);
 
-	if (written >= PATH_MAX)
-		die("thread trace path too long: %s/thread.%d%s",
-				rproc.procdir, rthread.tid, OVNI_STREAM_EXT);
+	if (written >= PATH_MAX) {
+		die("path too long: %s/thread.%d/stream.obs",
+				rproc.procdir, rthread.tid);
+	}
 
 	rthread.streamfd = open(path, O_WRONLY | O_CREAT, 0644);
 
@@ -465,11 +482,11 @@ static void
 thread_metadata_store(void)
 {
 	char path[PATH_MAX];
-	int written = snprintf(path, PATH_MAX, "%s/thread.%d.json",
+	int written = snprintf(path, PATH_MAX, "%s/thread.%d/stream.json",
 			rproc.procdir, rthread.tid);
 
 	if (written >= PATH_MAX)
-		die("thread trace path too long: %s/thread.%d.json",
+		die("thread trace path too long: %s/thread.%d/stream.json",
 				rproc.procdir, rthread.tid);
 
 	if (json_serialize_to_file_pretty(rthread.meta, path) != JSONSuccess)
@@ -578,6 +595,7 @@ ovni_thread_init(pid_t tid)
 	if (rthread.evbuf == NULL)
 		die("malloc failed:");
 
+	create_thread_dir();
 	create_trace_stream();
 	write_stream_header();