TCP Client for VS Code

Talk to any TCP server from inside VS Code. Send text or binary, frame with HL7 or custom envelopes, interpolate variables.

Quick Start

1. Open the Command Palette → TCP Client: Open Panel
2. Enter host:port and click Connect
3. Pick an Envelope (default: None / raw)
4. Type your message — use escape sequences for binary, {{name}} for variables
5. Press Send or Ctrl+Enter. Click the yellow ? for syntax help.

Connection state is shown by a status dot (grey / amber / green). Every response is logged with a timestamp and round-trip time in ms. Form state survives panel close and VS Code restarts.

Message Syntax

Escape sequences

Use \{ and \} to send literal {{name}} in a message.

Variables

Reference {{name}} in the message area. The text is resolved before encoding and framing.

Add your own in the Variables section (or directly in settings.json):

{
  "tcpClient.variables.custom": [
    { "name": "user.name", "value": "ryu" },
    { "name": "session.id", "value": "abc-123" }
  ],
  "tcpClient.variables.timestampFormat": "YYYY-MM-DDTHH:mm:ss.sssZ"
}

Unknown {{name}} references are left in the output and a warning is logged to the developer console — the send is not blocked. The pipe in {{name|anything}} is silently ignored for seq, uuid, and user variables.

Envelopes

An envelope wraps your message with prefix/suffix bytes before it's written to the socket — useful for HL7 v2 / MLLP, NRPE-style line framing, and any protocol with a well-known start/end marker.

Pick one from the dropdown, or define your own:

{
  "tcpClient.envelopes.custom": [
    {
      "id": "stx-etx",
      "label": "STX/ETX framed",
      "prefix": "\\x02",
      "suffix": "\\x03"
    },
    {
      "id": "stx-etx-line",
      "label": "STX/ETX per line",
      "prefix": "\\x02",
      "suffix": "\\x03",
      "linePrefix": ">",
      "lineSuffix": "<"
    }
  ]
}

Fields:

• id (required) — unique identifier
• label (required) — shown in the dropdown
• prefix / suffix — bytes prepended / appended (escape-sequence string)
• linePrefix / lineSuffix — wrap each \n-separated line of the payload (for protocols that frame every line). Default empty — leave both empty for single-wrap behaviour.

When you select a custom envelope in the panel, its prefix, suffix, linePrefix, and lineSuffix are exposed as inline fields so you can tweak them without editing settings.json.

Settings

All settings live under tcpClient.* in settings.json:

Keyboard

License

MIT