TCP Client

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": "YYYYMMDDHHmmss"
}

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