I'm trying to send an email when a user signs up. I tried the mailgun example from https://www.graph.cool/docs/reference/functions/server-side-subscriptions-ahlohd8ohn/ But when the function triggers i get this: "Call to https://wt-graphcool.it.auth0.com/api/run/cj6moe68l0dhw0178sb2qk2xc/cj7f8b37d001c01qpwiib0hys failed with status 400". I don't use Auth0 at all, anybody have a clue why this happens?

You implemented it as a SSS? Does a test run work? Are you seeing anything else in the invocation logs, usually the reason for the 400 follows right after?

Yep, the full error log: {"error":"Call to https://wt-graphcool.it.auth0.com/api/run/cj6moe68l0dhw0178sb2qk2xc/cj7f8b37d001c01qpwiib0hys failed with status 400, response body {\n \"code\": 400,\n \"error\": \"Error when JSON serializing the result of the JavaScript code.\",\n \"details\": \"TypeError: Converting circular structure to JSON\",\n \"name\": \"TypeError\",\n \"message\": \"Converting circular structure to JSON\",\n \"stack\": \"TypeError: Converting circular structure to JSON\\n at Object.stringify (native)\\n at /data/sandbox/lib/sandbox.js82748\\n at /data/io/8c26235693364c19a885a11e92a009f4/webtask.js4633\\n at process._tickDomainCallback (node.js4819)\"\n} and headers [date: Sun, 10 Sep 2017 210618 GMT | Connection: keep-alive | content-type: application/json | x-auth0-stats: {\"worker_pid\":1,\"response\":{\"400\":1},\"time\":539,\"uptime\":509.99,\"memory\":{\"rss\":51757056,\"heapTotal\":31953920,\"heapUsed\":19937968,\"external\":440308}} | x-frame-options: DENY | transfer-encoding: chunked | x-auth0-proxy-stats: {\"proxy_host\":\"172.28.64.50\",\"proxy_pid\":37,\"container_id\":\"01356f3f-2207-46d5-b179-2b8f5667d887\",\"latency\":598,\"uptime\":1128318.306,\"memory\":{\"rss\":97816576,\"heapTotal\":63930112,\"heapUsed\":53273672,\"external\":20004876},\"req_id\":\"1505077577507.764406\"} | x-wt-response-source: sandbox]"}

That error is usually indicative of an error response from the API (in this case, Mailgun)

Ok, hmm, so why does it try to call auth0.com?

That's where the SSS function runs, it's the Auth0 Extend environment that Graphcool uses to run all your functions

Ahh, ok. Thanks for the help!

Instead of returning fetch directly, you can use:

fetch(...)
   .then(response => { ... })
   .catch(error => { ... }

to have more control over the process, and do some console.log() calls in there

Thanks, I'll do that! I probably need to take a closer look at the mailgun api first 🙂

https://documentation.mailgun.com/en/latest/api-intro.html#authentication According to this page, the apikey is used

yep

Good point! https://github.com/graphcool/content/issues/288