Lib Curl, Twitter API & “Expect: 100-continue” PAIN and How To Fix it

by Jeremy Schoemaker on December 29, 2008 · 76 comments

*this post will probably not be worthwhile for 99% of the normal readers. But for those having the same issue it will be priceless.*

I have been working on a new twitter app for a couple months and at approximately 5pm on December 23rd 2008 (3 days ago) it all went boom.

All of my php curl (lib curl) requests started returning:

HTTP/1.1 417 Expectation Failed

and the exact html returned is:

<title>417 Expectation Failed</title>
<h1>Expectation Failed</h1>
<p>The expectation given in the Expect request-header
field could not be met by this server.</p>
<p>The client sent<pre>
Expect: 100-continue
but we only allow the 100-continue expectation.</p>

It appears Twitter started being super anal about requests being sent and in particular the http/1.1 RFC post requests.

Anyway it took be a long time searching the web and trying various things until I figured out the solution by looking at some of the lib curl compilation files.

Just add:

[php]curl_setopt($ch, CURLOPT_HTTPHEADER, array(‘Expect:’));[/php]

and you will be fixed!

full disclosure

About the author...

– who has written 2896 posts on

Jeremy "ShoeMoney" Schoemaker is the founder & CEO of the ShoeMoney Blog, Elite Retreat Internet Conference, & the PAR Program. In 2013 Jeremy released his #1 Amazon Best selling Autobiography titled "Nothing's Changed But My Change" - The ShoeMoney Story. Jeremy currently lives in Lincoln Nebraska with his wife and 2 daughters.

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1 jtGraphic

Seriously… I love when you post nerdy stuff :) This stuff is sooo useful. Thanks.

2 meethere

can’t wait to see your twitter tool/site… :D

3 jtGraphic

Thanks. I’ll keep people posted!

4 Steven-Sanders

Good to know. Thanks for the great info!

5 The Poker Jerk

I’m just as interested in this as the post above ^^^^^

6 Taris Janitens

LOL oh poker jerk – you as such a jerk hehehe

7 SEO Tips South Africa

Heheheheh….that will be MISTER JERK to you…..

8 Internet Marketing Access

I think I am now more interested in the twitter app that you have been working on for the past few months. lol What does it do or is that a secret?

9 jtGraphic


10 Brennan

I know many people who will be able to use this. I haven’t really gotten into the whole Twitter thing yet but it seems like every blogger is saying how great it is so I might just have to join in on it.

11 Taris Janitens

You and me both – I just don’t wanna be tied to my phone 24-7 personally which is why I am avoiding it

12 SEO Tips South Africa

I’ve also been avoiding twitter, but it seems that the mainstream pressure is going to force me to re-appraise and try to get into it!

13 Internet Marketing Industry

I have to agree with the above – definitely interested in learning about this new app – glad to see you found the solution – maybe the issue happened because of all of the apps being built for twitter now a days -looking forward to what you have to share.

14 Jason

Thanks for the heads-up! Just getting my feet wet now with the Twitter API…

15 Day

That’s so you can’t say Expect-100: gimme(document.cookie)

16 Taris Janitens

Thanks for the heads up!! I’m sure someone will be able to use this, ableit not me :)

17 Mark

Long time reader, first time poster. I know enough about Twitter to be dangerous and I got myself banned tonight by signing up with a service called Twauter that creates auto follows. Anyway I do have a twitter app that is pretty cool called ObamaTweet at . It pulls all Tweets with the word Obama from the Twitter DB and displays a realtime Obama River. I’m getting it ready for a big marketing push before the swearing in. Any tips would be appreciated.

18 Affiliate Showdown

Im now starting to wonder what you got cooking over there.

19 Wesley

I’ve used the twitter api with curl as well and never had to do this, this is definitely weird.

20 Blog And Make Cash

Nice trick, I was looking for it since days! curl rocks, definitely.

21 Work At Home

Wow.. I would have give up doing this work by now. Well done

22 Hyder

Thanks for this info my developer might need to know this, it’s all Greek to me, for a twitter widget we’re building.

23 Learn English Online

Thanks a million for the knowledge.

24 Owen

That come just in time. Working on a Twitter thingy at the moment!

25 Joe Tech

Nice error. I just use the API rather than curl, but that has its limitations. I assume you’re making requests that don’t require the user’s twitter account to be authenticated.

26 Kyle Irwin

Welcome to curl101. Retards.

27 RockaFeller

Wow, earning so much money and… YOU STILL CODE?!

28 Juuso

Nice… but where’s the super affiliate post? :)

29 Dick

I ‘ve got interested in the information laying-out. ’tis good to know it.

30 Typhoon

Waiting for your new tool..but no idea what you wrote in this post :{}

31 Typhoon

Sorry but shoe didn’t update his blog with this news..
Google Have Updated PageRank of every blog almost..
My blog is a PR3 from PR0

32 Typhoon

By the way what’s the new application all about..Is it coming soon in the new year?

33 memory

ummmm, i guess i’m part of the 99%…’s all greek to me!

34 iskandarX

This is what we call “AMAZING”. Dude you are awsome working for this.

35 Karl hadwen

Thanks for this love nerdy code :)

36 Karl hadwen

Thanks for the code love nerdy stuff like this lol

37 Dick

Let’s call a spade a spade.

38 SEO Tips South Africa

Heheheheheh! And a nerd a nerd, or nerdy stuff, nerdy stuff!

39 BusinessX

I am having to advance my programming skills to do some of the things I want to do (including API). So, I imagine I will be returning to this post someday soon.

40 Dick

I am thinking of the stuff again ready to make some progress in my self-improvement.

41 Dick

I lloked through the stuff again and sopped at the place where there is a photo of your elder daughter. The girl is so cute.She will be a doctor for sure.

42 Mr. School Fundraising ideas

I guess I am not a uber geek because I have no clue what is up with that twitter. The expectation failed but it says that the 100-expect is allowed. What does that mean, crazy stuff, and we wonder if machines will ever take over the human race… sorry to be the let down, they have already.

Mr. School Fundraising Ideas

43 Mr. School Fundraising Ideas

I have heard of Twitter but haven’t quite gotten the whole concept why and how it is a big deal and how it can help you in your business?

44 Personal Development Tips

This is great stuff! I was having this problem exactly! When I searched for 100-continue expectation this is what I found. I added that line and then voila! It worked!

Great job and thanks a bunch!

45 Drew

Thanks for the tip. This is exactly what I needed to make this work at:

46 Mike Peters

Count me in that 1% :-)

We just had a similar issue with php-cgi and Nginx that took a few hours to trace. Turns out php-cgi adds 2 seconds when your POSTed data contains more than 1,000 characters and missing the Expect header.

47 Derek P. Collins

Ah, thank you so much for this! I wasn’t having this issue on my local server, but when I moved my Twitter app onto the production server I got this error. Your solution fixed it right up! Thank you, thank you, thank you!

48 JumpByte

Anybody wanna help me out? I’m using VB.NET and System.Net.ServicePointManager.Expect100Continue = False doesn’t solve my problem :\


49 Rodney Joyce

There’s some hint as to where to add this line but I am not 100% sure:

50 alex

YES! Thanks!

51 mystral-kk

Thanks! Your solution works fine.

52 Al Becs

Oh, you should have done great research. Your solution works perfectly!


53 danish

thanks man … it really worked :)

54 blackwinged

yayy, you saved my day!
wouldn´t have figured this out so quickly on my own.

55 dnuske

god bless you

and all the people like you around the world


56 matthew

THANK YOU!!!! Struggled with this for hours until I found your post and then like magic it was fixed. THANK YOU!

57 Jeans

Thank you very much.It work!

58 Symphony

But for those having the same issue it will be priceless.

Absolutly! It’s really helpful! Thanks a lot!

59 Naval

Thanks a lot it really help me most i was facing same problem.

60 Billy Ellison

Thank you so much! This was really frustrating me

61 Hannes

I was using godaddy and wanted to send messages to twitter. It just failed.

Thanks to you I got it to work. Thanks, mate!

62 mariochampion

god bless the internet! (and you, and all the ships at sea ; )

63 Zx.MYS

Thank you for saving my time!!

64 Electric Guitars

Thanks for this snippet. I just started getting this error message on a new WP plugin that I am writing, and a quick Google search led mw to your website.

Yes it does seem that Twitter has gone a bit “anal” about things, but I guess we have to follow their rules.

Many thanks


65 Kenton Monasterio

What a planet we live in!!?! It just exhibits us all as much as the fools we are…

66 Rosenda Lenoch

Useful submit. Thanks for talk about

67 shiju

thnx a lot for this fix.. buddy

68 Sankha

Thanks man! You gained good Karma (Kamma).
If you want to know a detailed explanation of Kamma then mail to

69 Ravi

Nice time saver

70 Apply for loans for bad credit today

Well, Thanks for sharing your thoughts. After reading your post I think that twitter is really one of the finest site frm where one can get lots of advantage.

71 ear hearing loss

Definitely, what a fantastic website and instructive posts, I surely will bookmark your website.Have an awsome day!

72 Wesley

It just means that curl should send an empty “Expect:” header over to twitter, since otherwise twitter may misinterpret.

73 Abel Perez

Awesome, thanks for sharing such a nice time saver :)

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