Error

local Error = require("@game/ReplicatedStorage/Twill").Error

local errors = Error.Install(Log.new("Unhandled"))

Scope.Framework():Add(errors, "Destroy")

ScriptContext.Error reports script failures as they happen, and this module turns each one into Log lines carrying the trace.

Nothing is re-thrown. The error already happened, and raising it again would double the report.

For how this sits alongside deliberate reporting, see See what your game is doing.

What each failure writes

Two lines per failure, at two levels.

Level	Content
Error	The full name of the script that failed, then the message.
Debug	The trace.

Splitting them means a server running at Info records that something broke without carrying the whole stack.

Webhook

Passing a webhook URL posts each report there as well, as a JSON body with a content field, which is the shape a Discord webhook takes. A report is the script name, the message, and the trace, cut to 1900 characters.

Discord refuses requests from Roblox game servers, so a Discord webhook given directly works only from Studio. Install warns when the URL names Discord. Post through a proxy that forwards to it.

Posting is metered at one post every five seconds, and a post refused by the meter is dropped rather than queued. The point is to be told that something broke, not to receive every instance of it.

Posting happens only on the server. Installing with a webhook on the client is not an error, and nothing is posted.

A failed post is reported through the same logger at Warn rather than raised, so an unreachable webhook does not itself become an error.

A webhook URL is a credential. Keep it in the server half, in ServerScriptService.Twill or your own server folder, never in ReplicatedStorage. Anything that can read it can post to the channel.

API

Error.Install

[Server] | [Client]

Wires a logger to every script error the runtime reports.

function Error.Install(logger: Log.Logger, options: Options?): Handle

export type Options = {
  Webhook: string?,
}

export type Handle = {
  Destroy: (self: Handle) -> (),
}

Parameters

Name	Type	Description
logger	Log.Logger	Where each error and its trace is written.
options	Options?	Somewhere to post reports to, when they should leave the server.

Returns

Handle - Stops the listening when destroyed.

Throws when no logger is given.

Install once per side. A second install listens twice and reports every failure twice.

Example

function ObservabilityService.Init()
  local errors = Twill.Error.Install(Twill.Log.new("Unhandled"))

  Twill.Scope.Framework():Add(errors, "Destroy")
end

Deliberate errors

This module catches failures nobody handled. For errors raised on purpose, call logger:Error(...), or Log.SetErrorHandler to route all of them somewhere.

Limits

Limit	Value
Webhook posts	1 every 5 seconds
Report length	1900 characters