Teller

Banking APIs for developers

[Teller @teller]

🚨📢 In a head-to-head aggregator test performed by a large consumer fintech, Teller had the most stable connections. Number #2 disconnected 63% more often than Teller.

[Teller @teller]

@dyslexicABC @datarade there will be more from us on this in due course.

[Teller @teller]

@dyslexicABC @datarade we are not enabling accounts for production at this time

[Teller @teller]

@veckdatadriven @datarade we're not accepting new users right now.

[Teller @teller]

@datarade 🫶

[Kumar🇺🇸 @datarade]

Wrote a blog post and mentioned @teller.

They came up with some new tech for reverse engineering mobile apps.

https://t.co/LcJSDe3wXZ

[Teller @teller]

@kyleshirlz @ryanvogel We're better than Plaid.

[Stevie Graham (new account) @stevegraham]

Ok, enough talking.

Introducing Wiretrap: Agentic Mobile App Reverse Engineering.

@teller connects to over 7000 financial institutions, providing developers with a single API to integrate against. We connect using private APIs discovered by reverse engineering their mobile apps.

This is a huge engineering cost (we have to analyze every app update to check for API changes), and obtaining accounts at those banks to be able to use their apps and map out the API interactions we need for our own API clients is an operational nightmare. Both are major blockers to supporting more institutions, countries, and product types, especially ones that are not practical to obtain at every bank, e.g. student loans and mortgages.

Wiretrap solves for both problems.

Wiretrap intercepts network requests a mobile app makes and injects symbolic responses that allow an agent to discover the underlying API contract by simply observing what the app does with them. It can override individual values to trigger different flows, allowing agents to completely map out an entire API without a single request hitting the bank.

Check out this brief video of an agent using phony credentials to log into Chase (the request is intercepted by Wiretrap and never hits Chase's API) to get to the account dashboard. Note the symbolic value "req_058.response.body.bankingAccountOverviews[0].
businessName" displayed in the app UI, representing the request and key path the value originated from allowing the agent to join what is displayed on screen with what "went over the wire".

Everything you see is inferred by observing how the app interacts with Wiretrap's symbolic responses.

Another @teller world first :)

[Stevie Graham (new account) @stevegraham]

.@teller has a tool that can extract an API from any app AND build the SDK for it.

[Stevie Graham (new account) @stevegraham]

So far this new tool has worked on every app we’ve tested it with. Chase, Wells Fargo, BofA, Truist, a bunch of small provincial banks. After 5 months of smashing my head against the wall, to be honest I can’t quite believe it finally works. It works with everything, even stuff aggressively inlined by the compiler (standard on release swift apps). This is probably one the most important things I’ve built in my career.

[Stevie Graham (new account) @stevegraham]

Nobody will care but I’m reasonably confident that a tool I’ve been building is able to maintain all of the integrations we have at @teller. When a new app hits the AppStore, it reverses it in minutes.

We’ve literally spent millions and millions of dollars on humans doing this over the years. Now we can do it faster and for orders of magnitude less cost.

Also, for the first time ever we no longer need accounts at the financial institution. The whole analysis process happens offline.

Two massive bottlenecks on our ability to scale have been obliterated.

The really exciting question is: can it reverse all the other banks we haven’t done yet? Every bank in the world? Where is the limit?

[Dean @Dean__Mauro]

Had fun with this & made an @openclaw skill that buys $1 of stock in every company you shop at

@teller to hook into the bank account
@public for market data & buy orders
@CloudflareDev to host the connection flow & a daily summary

Public is doing some awesome stuff
https://t.co/tteI6BVEfG

[Teller @teller]

@ryanvogel @kyleshirlz What looks sketch?

[Stevie Graham (new account) @stevegraham]

Imagine this was all you needed to fetch and display bank accounts from any bank in an iOS app. (Working code btw)

[Teller @teller]

What's all this about then?

[Stevie Graham (new account) @stevegraham]

Something new is coming…

[Stevie Graham (new account) @stevegraham]

We (@teller) are shipping some incredible stuff this month. Stay tuned!

[Stevie Graham (new account) @stevegraham]

The @teller team has been working on some really cool stuff these past few months and it’s going to fundamentally change how bank data aggregation is done. An unbelievable step change in user privacy is coming.

[Teller @teller]

@karlclement @mikehostetler We do!

[Teller @teller]

https://t.co/9kyncYGgjt

[Teller @teller]

Experiment with @teller in Python, Ruby, Elixir, Go, Java, Node, or PHP with one command that bootstraps runtime env, installs dependencies and starts server https://t.co/9kyncYGgjt