Bugs reach production. Fixwire finds them first: errors, traces, logs and AI agent runs in one place, an AI debugger on every plan, and your data kept in the region you choose.

Fixwire SDK for edge runtimes

Welcome to @fixwire/edge, the official SDK for Fixwire on edge runtimes: Cloudflare Workers, Vercel Edge Functions and Next.js middleware, Deno Deploy and Netlify Edge Functions. It captures errors, traces, release health, cron monitor check-ins, user feedback and AI agent runs. It is part of the Fixwire SDK for JavaScript, whose README has the full guide.

📦 Getting started

Prerequisites

• A Fixwire account and project: sign up at fixwire.io.
• An edge runtime with fetch: Cloudflare Workers (with nodejs_compat for node:async_hooks), Vercel Edge, Deno Deploy or Netlify Edge Functions.

Installation

npm install @fixwire/edge
pnpm add @fixwire/edge
yarn add @fixwire/edge

Basic configuration

On Cloudflare Workers, wrap the module; the SDK starts on the first invocation, with FIXWIRE_DSN, FIXWIRE_RELEASE and FIXWIRE_ENVIRONMENT from env filling unset options:

import { AsyncLocalStorage } from "node:async_hooks";
import * as Fixwire from "@fixwire/edge";

export default Fixwire.withFixwire(
  (env) => ({
    dsn: env.FIXWIRE_DSN, // https://<publishable key>@ingest.eu.fixwire.io
    release: "[email protected]",
    environment: "production",
    tracesSampleRate: 0.2, // record 20% of traces
    asyncLocalStorage: AsyncLocalStorage, // scopes per request
    // redact: false, // turn off masking of secrets and personal data
  }),
  {
    async fetch(request, env, ctx) {
      return new Response("ok");
    },
  },
);

On Vercel Edge Functions and Next.js middleware, Deno and Netlify Edge Functions, call init() and wrap each handler:

import { waitUntil } from "@vercel/functions";
import * as Fixwire from "@fixwire/edge";

Fixwire.init({ dsn: process.env.FIXWIRE_DSN, release: "[email protected]" });

export const GET = Fixwire.wrapRequestHandler(async (request) => Response.json(await load()), {
  waitUntil,
});

In Next.js middleware, pass event.waitUntil; on Netlify, context.waitUntil. Without waitUntil the handler waits for delivery before returning. The DSN is your project's publishable key and the ingest host, https://<publishable key>@<host>; without one, the SDK does nothing. init() never throws: a broken DSN or option is said in a warning on the console and the SDK stays off.

Quick usage example

Fixwire.captureMessage("Hello Fixwire!"); // an info-level message in your project

try {
  JSON.parse("{ not json");
} catch (err) {
  Fixwire.captureException(err); // the error, with its stack, causes and breadcrumbs
}

An error a wrapped handler throws is reported, then thrown on.

✨ Why Fixwire

• Secrets stay in your worker. Secrets and personal data are masked before sending, with the same rules as the Fixwire server; request headers come from an allowlist, never cookies or authorization.
• Sent after the response. Errors and spans travel as OpenTelemetry (OTLP/HTTP JSON), gzipped and sent through the runtime's waitUntil, so the isolate isn't stopped first.
• It never gets in your app's way. init() and captures never throw, deliveries follow no redirect and time out after 10 seconds, and queues, strings and retries all have fixed limits.
• Your data stays where you want it. Fixwire keeps it in the region you choose for your project: the EU today, more regions soon.

🧩 Integrations

| Integration | What it does | How to use | |---|---|---| | Cloudflare Workers | Fetch handlers, cron triggers (scheduled) and queue consumers (queue): a scope, a segment and error reporting each; other handlers pass through | Fixwire.withFixwire((env) => options, handlers) | | Vercel Edge, Next.js middleware, Deno, Netlify Edge | A scope and a segment per request, the caller's trace (W3C traceparent and tracestate) continued, errors reported | Fixwire.wrapRequestHandler(handler, { waitUntil }) | | Per-request scopes | setUser, setTag and breadcrumbs stay with the request that set them, through the runtime's AsyncLocalStorage (found on its own on Vercel Edge; pass it elsewhere) | asyncLocalStorage option | | fetch | Calls become child spans with a breadcrumb, and carry trace headers to tracePropagationTargets | On by default | | OpenAI, Anthropic, AI agents | Model calls, agent runs and tool calls as spans | Fixwire.wrapOpenAI(), Fixwire.wrapAnthropic(), Fixwire.ai.agent(), ai.chat(), ai.tool() |

⚙️ Configuration

All options are listed in the repository README. The ones you'll reach for first:

| Option | Default | What it does | |---|---|---| | dsn, release, environment | FIXWIRE_DSN, FIXWIRE_RELEASE, FIXWIRE_ENVIRONMENT (then "production") | Where data goes, and which release and environment it belongs to; read from env in withFixwire, else from process.env where the runtime has it | | asyncLocalStorage | found on its own where it can be | The runtime's AsyncLocalStorage; without one, requests an isolate serves at the same time share their scope | | tracesSampleRate | none | Share of traces recorded, 0 to 1; unset: tracing is off | | tracePropagationTargets | none | Where fetch calls carry trace headers: "example.com" is that host and its subdomains ("example.com:8443" on that port only), a string with :// a URL prefix, a RegExp is searched for in the URL without its query and fragment | | maxValueLength | 1024 | Longest string sent, in bytes of UTF-8, ... included | | beforeSend | none | Changes or drops an event before it is sent | | autoSessionTracking | true | Each request, cron trigger and queue batch is a session for crash-free rates (needs release); users are sent only as hashes | | useEnvironment | true | Read FIXWIRE_* variables from process.env, where the runtime has it |

wrapRequestHandler takes flushTimeoutMs (default 2000): the longest wait for queued events.

🧪 Examples

The examples show the Node.js and browser SDKs; the samples above are the edge setup.

📚 Documentation

The full guide lives in the repository README and the examples.

• Configuration
• Examples
• Changelog
• Security policy
• Contributing guide

🚧 Coming from another error tracker?

The API follows the shape most error-tracking SDKs share: init, captureException, captureMessage, setUser, setTag, addBreadcrumb, withScope and startSpan. Moving over is mostly a change of package and DSN. Trace headers go nowhere until you list tracePropagationTargets.

🙌 Want to contribute?

We'd love your help, whether it's a bug report, a fix or a new integration. Start with the contributing guide, then pick from the open issues or the good first issues.

🛟 Need help?

• Questions: ask on Discord or Slack.
• Bugs: open a GitHub issue.
• Found a security issue? Please don't open an issue; follow the security policy.

🔗 Resources

• Website
• Pricing
• Discord
• Slack
• X
• Changelog
• Examples
• Security policy

📃 License

The SDK is open source under the MIT license; see LICENSE. Parts are derived from other MIT-licensed SDKs; see NOTICE.

😘 Contributors

Thanks to everyone who helps make Fixwire better!