Development

WebSocket Frame Decoder

Decode raw WebSocket frames (hex or base64) byte by byte per RFC 6455: FIN/RSV/opcode, MASK bit, extended lengths, masking key, unmasked payload, close codes, and protocol-violation warnings.

html· HTML resultOpen tool

Quick start

Call this tool from your code in three languages.

cURL

curl -X POST 'https://api.elysiatools.com/en/api/tools/websocket-frame-decoder' \
  -H 'Content-Type: application/json' \
  -d '{"frames":"81 85 37 fa 21 3d 7f 9f 4d 51 58 89 00 88 05 03 e8 62 79 65","inputFormat":"auto","maxPayloadBytes":256}'

API reference

Send a POST request with your inputs as JSON. File parameters require a separate upload first.

Endpoint

HTTP

POST https://api.elysiatools.com/en/api/tools/websocket-frame-decoder

Parameters

Name	Type	Required	Description
frames	textarea	Yes	—
inputFormat	select	No	—
maxPayloadBytes	number	No	—

Response format

HTML result

JSON

{
  "result": "<div>Processed HTML content</div>",
  "error": "Error message (optional)",
  "message": "Notification message (optional)",
  "metadata": {
    "key": "value"
  }
}

MCP integration

Add this tool to your Model Context Protocol server so AI agents can list and call it.

Server configuration

Add this block to your MCP client configuration:

mcp.json

{
  "mcpServers": {
    "elysiatools-websocket-frame-decoder": {
      "name": "websocket-frame-decoder",
      "description": "Decode raw WebSocket frames (hex or base64) byte by byte per RFC 6455: FIN/RSV/opcode, MASK bit, extended lengths, masking key, unmasked payload, close codes, and protocol-violation warnings.",
      "baseUrl": "https://api.elysiatools.com/mcp/sse?toolId=websocket-frame-decoder",
      "command": "",
      "args": [],
      "env": {},
      "isActive": true,
      "type": "sse"
    }
  }
}

List available tools

After connecting to the SSE endpoint, list the exposed tools:

tools/list

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/list"
}

Call this tool

Invoke the tool by its id, passing arguments built from its parameters:

tools/call

{
  "jsonrpc": "2.0",
  "id": 2,
  "method": "tools/call",
  "params": {
    "name": "websocket-frame-decoder",
    "arguments": {
  "frames": "81 85 37 fa 21 3d 7f 9f 4d 51 58 89 00 88 05 03 e8 62 79 65",
  "inputFormat": "auto",
  "maxPayloadBytes": 256
}
  }
}

Chain multiple tools in one session with a comma-separated toolId list, e.g. /mcp/sse?toolId=png-to-webp,jpg-to-webp,gif-to-webp (max 20).

Questions or issues? Contact [email protected]

Browse tools Open tool

curl -X POST 'https://api.elysiatools.com/en/api/tools/websocket-frame-decoder' \ -H 'Content-Type: application/json' \ -d '{"frames":"81 85 37 fa 21 3d 7f 9f 4d 51 58 89 00 88 05 03 e8 62 79 65","inputFormat":"auto","maxPayloadBytes":256}'

Name

Type

Required

Description

frames

textarea

Yes

—

inputFormat

select

—

maxPayloadBytes

number

—

{ "mcpServers": { "elysiatools-websocket-frame-decoder": { "name": "websocket-frame-decoder", "description": "Decode raw WebSocket frames (hex or base64) byte by byte per RFC 6455: FIN/RSV/opcode, MASK bit, extended lengths, masking key, unmasked payload, close codes, and protocol-violation warnings.", "baseUrl": "https://api.elysiatools.com/mcp/sse?toolId=websocket-frame-decoder", "command": "", "args": [], "env": {}, "isActive": true, "type": "sse" } } }

{ "jsonrpc": "2.0", "id": 2, "method": "tools/call", "params": { "name": "websocket-frame-decoder", "arguments": { "frames": "81 85 37 fa 21 3d 7f 9f 4d 51 58 89 00 88 05 03 e8 62 79 65", "inputFormat": "auto", "maxPayloadBytes": 256 } } }