diff --git a/aos/vision/debug/tcp-source.cc b/aos/vision/debug/tcp-source.cc
new file mode 100644
index 0000000..28feff3
--- /dev/null
+++ b/aos/vision/debug/tcp-source.cc
@@ -0,0 +1,137 @@
+#include "aos/vision/debug/debug_framework.h"
+
+#include <gdk/gdk.h>
+#include <gtk/gtk.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <cstdlib>
+#include <fstream>
+#include <functional>
+#include <string>
+
+#include "aos/vision/blob/codec.h"
+#include "aos/vision/events/tcp_client.h"
+
+namespace aos {
+namespace vision {
+
+class BufferedLengthDelimReader {
+ public:
+  union data_len {
+    uint32_t len;
+    char buf[4];
+  };
+  BufferedLengthDelimReader() {
+    num_read_ = 0;
+    img_read_ = -1;
+  }
+  template <typename Lamb>
+  void up(int fd, Lamb lam) {
+    ssize_t count;
+    if (img_read_ < 0) {
+      count = read(fd, &len_.buf[num_read_], sizeof(len_.buf) - num_read_);
+      if (count < 0) return;
+      num_read_ += count;
+      if (num_read_ < 4) return;
+      num_read_ = 0;
+      img_read_ = 0;
+      data_.clear();
+      if (len_.len > 200000) {
+        printf("bad size: %d\n", len_.len);
+        exit(-1);
+      }
+      data_.resize(len_.len);
+    } else {
+      count = read(fd, &data_[img_read_], len_.len - img_read_);
+      if (count < 0) return;
+      img_read_ += count;
+      if (img_read_ < (int)len_.len) return;
+      lam(DataRef{&data_[0], len_.len});
+      img_read_ = -1;
+    }
+  }
+
+ private:
+  data_len len_;
+  int num_read_;
+  std::vector<char> data_;
+  int img_read_;
+};
+
+bool ParsePort(const std::string &port, int *portno) {
+  if (port.empty()) return false;
+  int value = 0;
+  if (port[0] == '0') return false;
+  for (char item : port) {
+    if (item < '0' || item > '9') return false;
+    value = value * 10 + (item - '0');
+  }
+  *portno = value;
+  return true;
+}
+
+class TCPImageSource : public ImageSource {
+ public:
+  class Impl : public aos::events::TcpClient {
+   public:
+    Impl(const std::string &hostname, int portno,
+         DebugFrameworkInterface *interface)
+        : aos::events::TcpClient(hostname.c_str(), portno), interface_(interface) {}
+
+    void ReadEvent() override {
+      read_.up(fd(), [&](DataRef data) {
+        BlobList blobl;
+        const char *buf = data.data();
+        buf += sizeof(uint32_t);
+
+        ImageFormat fmt;
+        Int64Codec::Read(&buf);
+        fmt.w = Int32Codec::Read(&buf);
+        fmt.h = Int32Codec::Read(&buf);
+        buf = ParseBlobList(&blobl, buf);
+        interface_->NewBlobList(blobl, fmt);
+      });
+    }
+
+    BufferedLengthDelimReader read_;
+    DebugFrameworkInterface *interface_ = nullptr;
+  };
+
+  void Init(const std::string &addr_and_port,
+            DebugFrameworkInterface *interface) override {
+    auto it = addr_and_port.rfind(':');
+    if (it == std::string::npos) {
+      fprintf(stderr, "usage is: tcp:hostname:port\n");
+      exit(-1);
+    }
+    auto hostname = addr_and_port.substr(0, it);
+    auto port = addr_and_port.substr(it + 1);
+    int portno = 0;
+    if (!ParsePort(port, &portno)) {
+      fprintf(stderr, "usage is: tcp:hostname:port\n");
+      exit(-1);
+    }
+
+    impl_.reset(new Impl(hostname, portno, interface));
+
+    interface->Loop()->Add(impl_.get());
+
+    interface->InstallKeyPress([this](uint32_t /*keyval*/) {});
+  }
+
+  const char *GetHelpMessage() override {
+    return &R"(
+    format_spec is in ipaddr:port format.
+    This viewer soure connects to a target_sender binary and views the live
+    blob-stream.
+)"[1];
+  }
+
+ private:
+  std::unique_ptr<Impl> impl_;
+};
+
+REGISTER_IMAGE_SOURCE("tcp", TCPImageSource);
+
+}  // namespace vision
+}  // namespace aos