Use SendGrid and Google App Engine to create a Trello card via Email
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LICENSE
README.md
app.yaml
email-trello.py

README.md

abandonware, use at your own risk

Google App Engine has changed, so the instructions are out of date. For example, the newer Google Cloud SDK will run as 'gcloud preview app deploy' after you authenticate and set your project.

Utilize SendGrid and App Engine to Email yourself TODO cards on Trello

This code released under Creative Commons Attribution-Sharealike 3.0: http://creativecommons.org/licenses/by-sa/3.0/

See the LICENSE file for additional license information including a copyright from another author.


This project was a proof-of-concept project I built for a talk at PyCon Canada in November of 2012.

Some buddies at SoapBox were using Trello but during PyCon they were constantly sending "To-Do" Emails to one another, and add them as R&D spikes on Trello for an upcoming sprint of work. I had the idea that with a few API calls, we could rig up a way to let them send an Email through SendGrid's "Inbound Parse" mechanism to POST data to a URL somewhere, and write a new Trello card for themselves.

After a brief search, not only did I not find any existing open source that handled this, I found a service that would charge you $10/month for a similar service. Knowing that the quotas that App Engine provides (before maxing out the 200 (at the time) Emails per day of a free SendGrid developer account) would be free for hosting, I set out to write a handler.

I found py-trello on GitHub and due props belong to them for the initial work they did to set up a basic communication setup with Trello for fetching and writing data. The only problem was that the code wouldn't work natively with Google App Engine (for one, GAE doesn't support httplib2 which py-trello used for their http communications). Long story short, I rewrote a significant chunk of their code, removed some bits, and here we are.

Original code I used and modified:

There are some key requirements here before you can get started:

  • A Domain Name
  • Access to modify DNS records for that domain name

Sign up for Google App Engine (free)


  1. Sign up for a Google App Engine account. Read more about it here: https://appengine.google.com/ You can set up a free account with them.

  2. Set up a new application. Follow Google's instructions for adding a new application.

Sign up for Trello (free)


  1. Sign up for a free Trello account (if you don't already have one)

  2. Get your API key, and get a "permanent read/write token" curl "https://trello.com/1/authorize?key=YOURAPIKEYGOESHERE&name=My+Application&expiration=never&response_type=token"

Modify my code (free)


  1. Modify app.yaml Set your Google App Engine application name at the top of the app.yaml file. Feel free to change the version number, but everything else can stay the same.

  2. Modify the email-trello.py file Put your API key and permanent token at the top of the script.

Sign up for SendGrid (free)


  1. Get a free account You can get a free "developer" account via http://sendgrid.com/user/signup to send up to 200 messages per day. Once you reach your 200 message limit per day, it will block you from sending any additional messages until they reset your credits for the next day.

  2. Once your SendGrid account is provisioned, follow the instructions to set up the "Inbound Parse" feature: http://sendgrid.com/docs/API%20Reference/Webhooks/parse.html

This will require that you add a subdomain on your current domain. You might want to call call it "trello.yourdomain.com" or "todo.yourdomain.com". Per the SendGrid instructions, you will need to add an MX record for that subdomain to point to mx.sendgrid.net

  1. Set up your Parse API url for POST operations Visit http://sendgrid.com/developer/reply (once you're logged into SendGrid) and add your subdomain and App Engine application URL (ie http://yourprojectname.appspot.com/postit). This step will require that the DNS settings for your subdomain and its associated MX record have propagated around the world enough that SendGrid can detect it.

At this point, your App Engine application should be running, SendGrid is all set up and provisioned, Trello is ready and waiting. Now all you need to do is try to send a sample Email in this format:

trello_board_name-board_list_name@subdomain.yourdomain.com

Let's break this down and explain a few things:

"trello_board_name" Trello allows you to have multiple "boards" where you can post lists of "cards". This first portion of the Email recipient address will be the name of this board, without spaces or dashes. For example, "To-Do" would simply become "todo". "Brilliant Ideas" would become "brilliantideas" and so on.

"board_list_name" Since each board can have multiple lists, this portion of the address will indicate which list will get the card data. Like the board name, dashes and spaces will be removed, so "To-Do" would become "todo", "Current Sprint" would become "currentsprint" and so on.

To clarify, your Trello boards and lists can have spaces and dashes, but the address you send a message to cannot have these spaces or dashes. The board name and list name are separated with a dash, like "board-list" (your App Engine application will parse it this way).

If you have a board called "To Do" and a list called "Grocery shopping", the recipient Email address you would use would start out with todo-groceryshopping@

@subdomain.yourdomain.com This is the subdomain you set up at SendGrid. SendGrid won't care about the username of the recipient Email address, but any messages it receives at subdomain.yourdomain.com will trigger a POST of data to your App Engine application.

The App Engine application will then parse the POST data that SendGrid sends, find the "From" address, and strip it down to just the username of the Email address (ie, joe.smith@address.com would become just "joe.smith"). It should handle full "named" sender addresses as well, so a header that looks like this: From: Ian Douglas ian.douglas@iandouglas.com ... should parse down to just "ian.douglas"

The application will perform a similar strip-down of the recipient address to break down the target board/list names.

Since Trello's API does not include a way to retrieve a list of all boards your API key will have access to (as of November 2012), I had to do an alpha/numeric search. And since their search could do partial searches, the code will actually iterate through string.lowercase() + string.digits(), fetch data for each Board name it finds, makes sure it gets added to a unique list, then checks if any of those board names (lowercased, stripped of spaces and dashes) match the first fragment of the recipient Email address.

If it finds a match for the board name, it then fetches all lists (open and closed) for that Board from Trello to find a matching list name (also lowercased and stripped of spaces and dashes). If a match is found there as well, then the subject line and body of the message are written into a new card within that Board/List.

Either way, unless there's a script error at App Engine, SendGrid will receive a "200" status code and consider the transaction finished.


Things you may want to do with this:

If you find this useful, please fork the project and contribute code back to it. This was literally an evening hack, and there are likely better/cleaner ways to do things. Also, since I had to hack the py-trello code, there may be enhancements and changes there (plus newer versions of the Trello API) that may need updating.

Since App Engine can handle OAuth, you may or may not want to look at setting up a proper OAuth system between App Engine and Trello to work for multiple users. Hey, you could even start up a service to charge people $10/month for it...


It goes without saying that while this code works perfectly for me (my wife uses it to send messages to my "Honey Do" list on a "Family" board), your mileage may vary and this may not work for you. I also haven't modified it or tweaked it other than some simple PEP8 conventions and a lot more documentation.

I hold no liability or responsibility for your use of this code. I'm happy to support you as best I can, but you're mostly on your own.

My employer at the time, SendGrid Inc, is not liable in any way for your use of this code, nor am I.