Tim Perry

Creator of HTTP Toolkit: powerful tools to debug, test & build with HTTP(S).

Passionate tech speaker, open-source contributor, and maintainer of Loglevel, Git‑Confirm and notes.

As of February 14th 2024, RFC 9512 formally registers application/yaml as the media type for all YAML content, and adds +yaml as a standard structured suffix for all YAML-based more specific media types. With this registration, it's now included in the official media types list maintained by the IANA. Media types like this (also known as the MIME t...
The X-Forwarded-For (XFF) HTTP header provides crucial insight into the origin of web requests. The header works as a mechanism for conveying the original source IP addresses of clients, and not just across one hop, but through chains of multiple intermediaries. This list of IPv4 and IPv6 addresses is helpful to understand where requests have reall...
Idempotency is when doing an operation multiple times is guaranteed to have the same effect as doing it just once. When working with APIs this is exceptionally helpful on slow or unreliable internet connections, or when dealing with particularly sensitive actions such as payments, because it makes retrying operations safe and reliable. This is why ...
It's hard to work on APIs without hearing about OpenAPI. OpenAPI is an API description format, which is essentially metadata that describes an HTTP API: where it lives, how it works, what data is available, and how it's authenticated. Additional keywords can be used to provide all sorts of validation information, adding a type system to what would ...
Everything crashes. Sometimes things crash when they're running inside a Docker container though, and then all of a sudden it can get much more difficult to work out why, or what the hell to do next. Docker's great, but it's an extra layer of complexity that means you can't always easily poke your app up close any more, and that can really hinder d...
A couple of weeks ago I published a post about changes in Android 14 that fundamentally break existing approaches to installing system-level CA certificates, even with root access. This has triggered some fascinating discussion! I highly recommend a skim through the debate on Mastodon and Hacker News. Since that was posted, quite a few people have ...
Update: This post sparked a lot of excellent discussion and debate on workarounds, and there are now multple working solutions to allow certificate injection on Android 14, despite the restrictions discussed here. See the update post for more details. When Android was initially announced in 2007 by the Open Handset Alliance (headed by Google) their...
There's been a lot of concern recently about the Web Environment Integrity proposal, developed by a selection of authors from Google, and apparently being prototyped in Chromium. There's good reason for anger here (though I'm not sure yelling at people on GitHub is necessarily the best outlet). This proposal amounts to attestation on the web, limit...
Caching is hard. Unfortunately though, caching is quite important. Hosted caching & CDNs offer incredible powers that can provide amazing performance boosts, cost savings & downtime protection, essential for most modern sites with any serious volume of users. Unfortunately, while there are strict standards for how caching is supposed to work with H...
This week, at long last, GitHub announced granular access tokens for npm. This is a big deal! It's great for security generally, but also particularly useful if you maintain any npm packages, as it removes the main downside of automating npm publishing, by allowing you to give CI jobs only a very limited token instead of full 2FA-free access to you...
As you may have seen, Docker Hub made a dramatic shift in policy this week, and effectively gave a 30 day eviction notice to almost all community-run images. They've now made an apology to 'clarify' a few details, and helpfully take some of the hard edges off, but this still highlights a big problem. Fortunately, there are solutions. As initially d...
HTTP Toolkit has been selected to receive another round of open-source funding from the EU! This aims to improve interception of HTTPS traffic from mobile apps, making it easier for both security/privacy researchers and normal technical users to inspect & manipulate the data that any app they use sends & receives. This funding will directly support...
HTTP is important on the web, but as other alternative protocols grow popular in networked applications, it's often important to be able to capture, debug and mock those too. I've been working on expanding HTTP Toolkit's support for this over the past year (as one part of a project funded by EU Horizon's Next Generation Internet initiative), to ext...
The world of decentralized web applications is an exciting place that has exploded in recent years, with technologies such as IPFS and Ethereum opening up possibilities for a peer-to-peer web - creating applications that live outside the traditional client/server model, where users to interact and control their own data directly. At the same time, ...
Comment by Tim Perry on Certificate of http-toolkit proxy is not trusted in iOS browser
Hmm, that's very unusual! Have you definitely enabled "Full trust" in the iOS settings? Do you have any other ...
Answer by Tim Perry for Can we get result from http-toolkit programmatically?
There is an internal API for HTTP Toolkit that's used within the Electron app, but it's not officially support...
Can't install the module using node:21
Sponsorship options
Next step is fully automated integration of these scripts into HTTP Toolkit (http://httptoolkit.com) - watch t...
Next step is fully automated integration of these scripts into HTTP Toolkit (http://httptoolkit.com) - watch t...
I've been testing on & off for a few days now - this lets you intercept, inspect & modify HTTPS fr...
I've been testing on & off for a few days now - this lets you intercept, inspect & modify HTTPS fr...
The README on GitHub has an intro & the specific commands, but as a quick guide:* You need a device with F...
The README on GitHub has an intro & the specific commands, but as a quick guide:* You need a device with F...
Using #Frida on iOS?Want to precisely intercept all HTTPS traffic from a single target app, with one command, ...
Using #Frida on iOS?Want to precisely intercept all HTTPS traffic from a single target app, with one command, ...
[Feature]: Support listing and/or searching with @puppeteer/browsers
Will be interesting in practice - I think HTTP Toolkit will be mildly affected (but as a microenterprise - sim...
Will be interesting in practice - I think HTTP Toolkit will be mildly affected (but as a microenterprise - sim...
I'm actually quite impressed by the EU's new updates to the Cyber Resilience Act! #CRA Formal recognit...
I'm actually quite impressed by the EU's new updates to the Cyber Resilience Act! #CRA Formal recognit...
Answer by Tim Perry for How can I print information about a NET:HTTP request for debug purposes?
If you want to see & debug exactly what your app is sending, not just see its log output, I've just released a...
Composeable content decoding & transformation tools
Comment by Tim Perry on Issue with http toolkit and proxifier integration - Seeking Assistance
HTTP Toolkit does support proxy authentication, you just need to include the parameters in the proxy URL like ...
Comment by Tim Perry on Issue with http toolkit and proxifier integration - Seeking Assistance
Can you explain in much more detail what "the integration does not seem to be working as expected" means? Plea...
Comment by Tim Perry on Why did HTTP Toolkit suddenly fails for app?
Can you file a bug at github.com/httptoolkit/httptoolkit/issues? I'm the maintainer, this sounds like a bug ra...
Would be nice if it was more accessible though, with a non-video format like a little shareable web page or so...
Would be nice if it was more accessible though, with a non-video format like a little shareable web page or so...
Of the many many 'wrapped' stats nowadays (this year even my shopping list app gave me a trendy end-of...
Of the many many 'wrapped' stats nowadays (this year even my shopping list app gave me a trendy end-of...
Comment by Tim Perry on ReferenceError: __dirname is not defined in ES module scope
Just to be explicit: this works nicely cross-platform too! On windows both are set to Windows-format paths (C:...
https://blog.postman.com/download-mobile-game-postman-api-first-journey/*Blinking*I... I really don't know...
https://blog.postman.com/download-mobile-game-postman-api-first-journey/*Blinking*I... I really don't know...
Guess I can probably delete this then 😂
Guess I can probably delete this then 😂
https://tuta.com/blog/chat-control is really fantastic news. Great not just to see sanity prevail over #ChatCo...
https://tuta.com/blog/chat-control is really fantastic news. Great not just to see sanity prevail over #ChatCo...
Answer by Tim Perry for Why does repeating intercepted API calls in Charles Proxy work, but exporting them as a cURL and running them fails?
It's hard to know without being able to see the specific code, but one possibility is TLS fingerprinting. I've...
Answer by Tim Perry for How can I see the entire HTTP request that's being sent by my Python application?
You can use HTTP Toolkit to do exactly this. It's especially useful if you need to do this quickly, with no co...