# \#cowboy **URL:** https://erlangforums.com/tag/cowboy/253.md [Latest](https://erlangforums.com/latest.md) · [Categories](https://erlangforums.com/categories.md) · [Tags](https://erlangforums.com/tags.md) --- ## [Roadrunner - Pure-Erlang HTTP and WebSocket server](https://erlangforums.com/t/roadrunner-pure-erlang-http-and-websocket-server/5623)
**Author:** [@williamthome](https://erlangforums.com/u/williamthome)\ **Replies:** 24\ **Last updated:** [October 27, 2026, 10:32pm UTC](https://erlangforums.com/t/roadrunner-pure-erlang-http-and-websocket-server/5623 "2026-10-27T22:32:17Z")
Hey folks, Wanted to share a project I’ve been working on for a while: Roadrunner, a pure-Erlang HTTP/1.1 + HTTP/2 + WebSocket server, built from scratch with TDD as the HTTP layer for Arizona. Why another HTTP server?… --- ## [Arizona - a web framework for Erlang/OTP](https://erlangforums.com/t/arizona-a-web-framework-for-erlang-otp/4529)
**Author:** [@williamthome](https://erlangforums.com/u/williamthome)\ **Replies:** 29\ **Last updated:** [October 26, 2026, 3:10am UTC](https://erlangforums.com/t/arizona-a-web-framework-for-erlang-otp/4529 "2026-10-26T03:10:57Z")
Hello Erlang community! I’m excited to share Arizona, a new web framework for Erlang designed to simplify building modern web applications. Arizona leverages stateful views, WebSocket communication, and efficient DOM p… --- ## [High-Throughput, Low-Latency Authorization Handling](https://erlangforums.com/t/high-throughput-low-latency-authorization-handling/5486)
**Author:** [@PCOM](https://erlangforums.com/u/PCOM)\ **Replies:** 6\ **Last updated:** [March 12, 2026, 3:40pm UTC](https://erlangforums.com/t/high-throughput-low-latency-authorization-handling/5486 "2026-03-12T15:40:20Z")
Hi all! Simple question, really just want to get a feel for what everyone else is doing here. When it comes to, well, exactly what the title says, are most of you guys just isolating your distributed nodes within a vpc … --- ## [Conditional proxying in Cowboy based on request headers](https://erlangforums.com/t/conditional-proxying-in-cowboy-based-on-request-headers/5190)
**Author:** [@zabrane](https://erlangforums.com/u/zabrane)\ **Replies:** 2\ **Last updated:** [October 30, 2025, 6:00am UTC](https://erlangforums.com/t/conditional-proxying-in-cowboy-based-on-request-headers/5190 "2025-10-30T06:00:19Z")
Hi All, I’m using Cowboy 2.14.2 and would like to implement conditional request forwarding to an upstream server based on specific conditions (e.g., User-Agent header value). Use case: When a request arrives with a spe… --- ## [Cowboy 2.13.0 performance bottleneck at 8.7K RPS on Erlang 28.0.2](https://erlangforums.com/t/cowboy-2-13-0-performance-bottleneck-at-8-7k-rps-on-erlang-28-0-2/5004)
**Author:** [@zabrane](https://erlangforums.com/u/zabrane)\ **Replies:** 15\ **Last updated:** [August 29, 2025, 5:50am UTC](https://erlangforums.com/t/cowboy-2-13-0-performance-bottleneck-at-8-7k-rps-on-erlang-28-0-2/5004 "2025-08-29T05:50:23Z")
Hi Folks, I’m seeing unexpectedly poor performance with Cowboy 2.13.0 on Erlang 28.0.2. Load testing shows only 8.7K RPS with 1-second average response times for simple GET requests serving static content (a small 33-b… --- ## [Standard Process For Authenticating Cowboy Requests](https://erlangforums.com/t/standard-process-for-authenticating-cowboy-requests/4859)
**Author:** [@PCOM](https://erlangforums.com/u/PCOM)\ **Replies:** 7\ **Last updated:** [July 10, 2025, 11:29pm UTC](https://erlangforums.com/t/standard-process-for-authenticating-cowboy-requests/4859 "2025-07-10T23:29:03Z")
Hi everyone–question title says it all. What’s the best way to authenticate REST requests to a cowboy server existing on the public internet? (Meaning: NOT shielded within a private VPC/API Gateway–requests are made dir… --- ## [Cowboy Failing With 'Already Running' Process When Moved From Main App Level To Supervised Worker?](https://erlangforums.com/t/cowboy-failing-with-already-running-process-when-moved-from-main-app-level-to-supervised-worker/4848)
**Author:** [@PCOM](https://erlangforums.com/u/PCOM)\ **Replies:** 3\ **Last updated:** [June 28, 2025, 10:36am UTC](https://erlangforums.com/t/cowboy-failing-with-already-running-process-when-moved-from-main-app-level-to-supervised-worker/4848 "2025-06-28T10:36:43Z")
Hi all. Cowboy is killing me. When I follow their documentation and place the cowboy compilation code application-level, it works. Dispatch = cowboy\_router:compile(\[ {'\_', \[ {"/", reservationhandler,… --- ## [How to serve multiple website files on the same server from Cowboy](https://erlangforums.com/t/how-to-serve-multiple-website-files-on-the-same-server-from-cowboy/4386)
**Author:** [@PCOM](https://erlangforums.com/u/PCOM)\ **Replies:** 4\ **Last updated:** [January 15, 2025, 8:54am UTC](https://erlangforums.com/t/how-to-serve-multiple-website-files-on-the-same-server-from-cowboy/4386 "2025-01-15T08:54:43Z")
Hi all! I am trying to point multiple domain’s DNS records to my private server. This server will be running cowboy which will, hopefully, grab the hostname included within the request and serve the appropriate website … --- ## [New Erlang OSS Discord server run by creator of Cowboy](https://erlangforums.com/t/new-erlang-oss-discord-server-run-by-creator-of-cowboy/4215)
**Author:** [@juhlig](https://erlangforums.com/u/juhlig)\ **Replies:** 5\ **Last updated:** [November 27, 2024, 10:58am UTC](https://erlangforums.com/t/new-erlang-oss-discord-server-run-by-creator-of-cowboy/4215 "2024-11-27T10:58:03Z")
Last week, @essen (creator and maintainer of cowboy, ranch, gun, erlang.mk and other related projects) announced the Erlang OSS Discord server. While created for the purpose of ninenines-related projects, it is open to … --- ## [Handling High Parallel Requests and Large Bodies in Cowboy HTTP Server](https://erlangforums.com/t/handling-high-parallel-requests-and-large-bodies-in-cowboy-http-server/3971)
**Author:** [@onex-rahul](https://erlangforums.com/u/onex-rahul)\ **Replies:** 4\ **Last updated:** [September 10, 2024, 11:10am UTC](https://erlangforums.com/t/handling-high-parallel-requests-and-large-bodies-in-cowboy-http-server/3971 "2024-09-10T11:10:07Z")
Hello, I’m currently working with the Cowboy HTTP server in an Erlang application, and I’m encountering a performance issue. My setup involves handling approximately 2,000 parallel requests, each with a body size of 0.2… --- ## [Which webserver do you use?](https://erlangforums.com/t/which-webserver-do-you-use/1911)
**Author:** [@AstonJ](https://erlangforums.com/u/AstonJ)\ **Replies:** 23\ **Last updated:** [September 9, 2024, 11:42am UTC](https://erlangforums.com/t/which-webserver-do-you-use/1911 "2024-09-09T11:42:16Z")
We had a thread on EF recently that mentioned webservers in PHP, and it got me curious about the options in the BEAM world and what everyone is using. Which webservers do you use or plan to use in your apps? :003: You c… --- ## [Is there an open source cowboy framework implementation of the rtmpt protocol](https://erlangforums.com/t/is-there-an-open-source-cowboy-framework-implementation-of-the-rtmpt-protocol/2797)
**Author:** [@leeyis](https://erlangforums.com/u/leeyis)\ **Replies:** 1\ **Last updated:** [June 11, 2024, 9:49pm UTC](https://erlangforums.com/t/is-there-an-open-source-cowboy-framework-implementation-of-the-rtmpt-protocol/2797 "2024-06-11T21:49:20Z")
Is there an open source cowboy framework implementation of the rtmpt protocol? GitHub - sile/erl-amf: An Erlang library to encode/decode AMF An Erlang library to encode/decode AMF The following ones I know of have no… --- ## [Handle\_continue in Cowboy websocket?](https://erlangforums.com/t/handle-continue-in-cowboy-websocket/3513)
**Author:** [@drathier](https://erlangforums.com/u/drathier)\ **Replies:** 0\ **Last updated:** [April 22, 2024, 9:03pm UTC](https://erlangforums.com/t/handle-continue-in-cowboy-websocket/3513 "2024-04-22T21:03:30Z")
Is there something like handle\_continue in Cowboy websockets? I can’t find it in the docs. Should/can I implement it myself on top of websocket\_info? --- ## [Cowboy only routes the first pattern](https://erlangforums.com/t/cowboy-only-routes-the-first-pattern/3266)
**Author:** [@sillygoose3](https://erlangforums.com/u/sillygoose3)\ **Replies:** 2\ **Last updated:** [February 5, 2024, 5:58pm UTC](https://erlangforums.com/t/cowboy-only-routes-the-first-pattern/3266 "2024-02-05T17:58:02Z")
I’m compiling my routes as such Dispatch = cowboy\_router:compile(\[ {'\_', \[{"/", debug\_handler, \[\]}\]}, {'\_', \[{"/sysinfo", sysinfo\_handler, \[\]}\]}, {'\_', \[{"/proc", proc\_handler, \[\]}\]} … --- ## [WebSocket connection closing prematurely](https://erlangforums.com/t/websocket-connection-closing-prematurely/3244)
**Author:** [@NAR](https://erlangforums.com/u/NAR)\ **Replies:** 2\ **Last updated:** [January 31, 2024, 11:26am UTC](https://erlangforums.com/t/websocket-connection-closing-prematurely/3244 "2024-01-31T11:26:28Z")
Hello! I’m using gun 2.0 to create a WebSocket connection to a webserver implemented with cowboy 2.10.0. I noticed that even if there’s a constant stream of data going through from the client to the server (multiple mes… --- ## [Cowboy: how to stream (Partial Content 206) a video?](https://erlangforums.com/t/cowboy-how-to-stream-partial-content-206-a-video/3055)
**Author:** [@zabrane](https://erlangforums.com/u/zabrane)\ **Replies:** 2\ **Last updated:** [November 26, 2023, 5:43pm UTC](https://erlangforums.com/t/cowboy-how-to-stream-partial-content-206-a-video/3055 "2023-11-26T17:43:48Z")
Hi guys, I’ve a large .mp4 video (~300MB) that I’d like to stream with Cowboy (2.10.0). I tried to put the video and serve is a static file, but Cowboy doesn’t stream it and send it with HTTP response code 200 OK. Is … --- ## [A documented Cowboy Stream Handler reference implementation](https://erlangforums.com/t/a-documented-cowboy-stream-handler-reference-implementation/3001)
**Author:** [@weaver](https://erlangforums.com/u/weaver)\ **Replies:** 4\ **Last updated:** [November 7, 2023, 1:15pm UTC](https://erlangforums.com/t/a-documented-cowboy-stream-handler-reference-implementation/3001 "2023-11-07T13:15:34Z")
Hi everyone! I had to write a cowboy stream handler for work this week, and in the process, I put together this little reference module with comments to use as a jumping off point for when I have to write these in the f… --- ## [Unknown type ranch:ref/0 dialyzer warning in cowboy\_req on Erlang/OTP 26](https://erlangforums.com/t/unknown-type-ranch-ref-0-dialyzer-warning-in-cowboy-req-on-erlang-otp-26/2760)
**Author:** [@unix1](https://erlangforums.com/u/unix1)\ **Replies:** 11\ **Last updated:** [November 2, 2023, 6:06pm UTC](https://erlangforums.com/t/unknown-type-ranch-ref-0-dialyzer-warning-in-cowboy-req-on-erlang-otp-26/2760 "2023-11-02T18:06:59Z")
Hello, I’m seeing 2 new dialyzer warnings in my app that uses cowboy on 26.0 that weren’t there on 25.3: \_build/default/lib/cowboy/src/cowboy\_req.erl Line 134 Column 9: Unknown type ranch:ref/0 Line 152 Column 18: Unkno… --- ## [How to use Cowboy with HTTP/2 instead of HTTP/1.1?](https://erlangforums.com/t/how-to-use-cowboy-with-http-2-instead-of-http-1-1/2918)
**Author:** [@Ostap](https://erlangforums.com/u/Ostap)\ **Replies:** 2\ **Last updated:** [September 30, 2023, 7:00pm UTC](https://erlangforums.com/t/how-to-use-cowboy-with-http-2-instead-of-http-1-1/2918 "2023-09-30T19:00:38Z")
When I open http://127.0.0.1:8080/ in the browser, I can see it uses HTTP/1.1. How can I make it use HTTP/2.0 instead and prefer it over HTTP/1.1? My current code: hello\_server\_app.erl -module(hello\_server\_app). -… --- ## [How to convert the misultin API to cowboy API](https://erlangforums.com/t/how-to-convert-the-misultin-api-to-cowboy-api/2795)
**Author:** [@leeyis](https://erlangforums.com/u/leeyis)\ **Replies:** 3\ **Last updated:** [August 11, 2023, 1:06am UTC](https://erlangforums.com/t/how-to-convert-the-misultin-api-to-cowboy-api/2795 "2023-08-11T01:06:24Z")
I want to achieve a RTMP service, found on the web GitHub - windock/erlyvideo: Erlang RTMP server, It doesn’t work under erlang/otp 25 anymore, And it doesn’t update misultin anymore So, I’m going to copy all the rtmp… --- ## [Cowboy parse\_qs only returning first value](https://erlangforums.com/t/cowboy-parse-qs-only-returning-first-value/2605)
**Author:** [@morguee](https://erlangforums.com/u/morguee)\ **Replies:** 2\ **Last updated:** [May 18, 2023, 3:08pm UTC](https://erlangforums.com/t/cowboy-parse-qs-only-returning-first-value/2605 "2023-05-18T15:08:06Z")
PROBLEM - parse\_qs should return a list of all variables according to documentation, but only returns the first one. --- ## [Keep getting: Connection attempt from node 'AAAAAA@AAAAAAA' rejected since it cannot handle \["BIG\_CREATION"\]](https://erlangforums.com/t/keep-getting-connection-attempt-from-node-aaaaaa-aaaaaaa-rejected-since-it-cannot-handle-big-creation/2544)
**Author:** [@leeyis](https://erlangforums.com/u/leeyis)\ **Replies:** 6\ **Last updated:** [April 19, 2023, 2:00am UTC](https://erlangforums.com/t/keep-getting-connection-attempt-from-node-aaaaaa-aaaaaaa-rejected-since-it-cannot-handle-big-creation/2544 "2023-04-19T02:00:25Z")
In my open source project , I receive such errors all the time. I don’t know why I receive similar errors. How can I solve the problem? error.log: 2023-04-17 20:03:12.420 UTC \[error\] \<0.2886.6\> \*\* 'imboy@127.0.0.1': C… --- ## [Adding elixir dependencies to an Erlang+Cowboy application](https://erlangforums.com/t/adding-elixir-dependencies-to-an-erlang-cowboy-application/2461)
**Author:** [@mau5atron](https://erlangforums.com/u/mau5atron)\ **Replies:** 2\ **Last updated:** [March 22, 2023, 11:15pm UTC](https://erlangforums.com/t/adding-elixir-dependencies-to-an-erlang-cowboy-application/2461 "2023-03-22T23:15:07Z")
Hi everyone, I’m hoping someone may be able to chime in with a specific problem I am having. I recently took on the task of adding two elixir libraries/dependencies (Crawly and Floki) as I would like to web scrape some … --- ## [Running a cowboy server in the google cloud](https://erlangforums.com/t/running-a-cowboy-server-in-the-google-cloud/2012)
**Author:** [@olegzil](https://erlangforums.com/u/olegzil)\ **Replies:** 8\ **Last updated:** [November 6, 2022, 5:36pm UTC](https://erlangforums.com/t/running-a-cowboy-server-in-the-google-cloud/2012 "2022-11-06T17:36:21Z")
I’ve written a server using Cowboy. The server responds fine when running on my desktop. I can connect to it from my phone and receive expected data. But, after I moved it to a VM in the Google Cloud it is unreachable. T… --- ## [Erlang SIP - how can I link it with jssip or flutter-webrtc/dart-sip-ua?](https://erlangforums.com/t/erlang-sip-how-can-i-link-it-with-jssip-or-flutter-webrtc-dart-sip-ua/1648)
**Author:** [@leeyis](https://erlangforums.com/u/leeyis)\ **Replies:** 0\ **Last updated:** [July 15, 2022, 6:59am UTC](https://erlangforums.com/t/erlang-sip-how-can-i-link-it-with-jssip-or-flutter-webrtc-dart-sip-ua/1648 "2022-07-15T06:59:07Z")
my project is imboy/websocket\_handler.erl at main · imboy-pub/imboy · GitHub How to use poroh/ersip as the server and flutter-webrtc/dart-sip-ua as the client I have clone poroh/piraha running on macOS. How can I link … --- ## [Serving static html file with Cowboy on erlang.mk release](https://erlangforums.com/t/serving-static-html-file-with-cowboy-on-erlang-mk-release/1541)
**Author:** [@mau5atron](https://erlangforums.com/u/mau5atron)\ **Replies:** 4\ **Last updated:** [June 15, 2022, 1:23pm UTC](https://erlangforums.com/t/serving-static-html-file-with-cowboy-on-erlang-mk-release/1541 "2022-06-15T13:23:12Z")
I’ve been attempting to serve a simple index.html file using cowboy (and failing). After 12 hours of searching around, and seeing many examples online of similar content being served by cowboy, I’ve come up empty on my … --- ## [How to Run a Released App in the Background with Rebar3/Cowboy?](https://erlangforums.com/t/how-to-run-a-released-app-in-the-background-with-rebar3-cowboy/1255)
**Author:** [@sey](https://erlangforums.com/u/sey)\ **Replies:** 6\ **Last updated:** [March 27, 2022, 4:31am UTC](https://erlangforums.com/t/how-to-run-a-released-app-in-the-background-with-rebar3-cowboy/1255 "2022-03-27T04:31:05Z")
Hi all, Rebar3 looks release cycle is confusing to me as for now I want to run the released app in the background on the server side. Steps I took: Develop an app with the cowboy and I can ‘rebar3 shell’ and access it… --- ## [Openroad - cowboy response middleware](https://erlangforums.com/t/openroad-cowboy-response-middleware/918)
**Author:** [@fancycade](https://erlangforums.com/u/fancycade)\ **Replies:** 0\ **Last updated:** [January 10, 2022, 3:39am UTC](https://erlangforums.com/t/openroad-cowboy-response-middleware/918 "2022-01-10T03:39:59Z")
Hello, Erlang community! I would like to share a small library that I’ve created to make building cowboy web apps a little more convenient. It provides a data-centric api to make html, json, text, or other data type res… --- ## [Issue with rebar3\_auto and ranch (cowboy)](https://erlangforums.com/t/issue-with-rebar3-auto-and-ranch-cowboy/842)
**Author:** [@fancycade](https://erlangforums.com/u/fancycade)\ **Replies:** 3\ **Last updated:** [December 20, 2021, 10:18pm UTC](https://erlangforums.com/t/issue-with-rebar3-auto-and-ranch-cowboy/842 "2021-12-20T22:18:02Z")
Hi there! I’m running into a problem while using the rebar3\_auto plugin with a cowboy application. Basically on the recompile ranch throws an error. I ran into this issue a year and a half ago and hoped it would magica… --- ## [Cowboy and OTP 24](https://erlangforums.com/t/cowboy-and-otp-24/483)
**Author:** [@pshort](https://erlangforums.com/u/pshort)\ **Replies:** 5\ **Last updated:** [November 7, 2021, 10:44am UTC](https://erlangforums.com/t/cowboy-and-otp-24/483 "2021-11-07T10:44:33Z")
I am building a small RESTful API in cowboy. So far so good… but every now and then when I make things crash, the stack traces really arent telling me anything. I thought “well I guess stack traces maybe aren’t a big Erl… [Next page](https://erlangforums.com/tag/cowboy/253.md?match_all_tags=true&page=1&tags%5B%5D=cowboy)