# mitmproxy v12.2.1 — mitmproxy 12.2.1

- Product: mitmproxy (https://whatsnew.fyi/product/mitmproxy)
- Vendor: mitmproxy
- Date: 2025-11-24
- Version: v12.2.1
- Original notes: https://github.com/mitmproxy/mitmproxy/releases/tag/v12.2.1
- Permalink: https://whatsnew.fyi/product/mitmproxy/releases/v12.2.1
- Labels: Platforms: Desktop

What's New is an index, not a publisher: every entry below links to the vendor's own release notes, which are the authoritative source. Entries are labelled where they are hand-curated sample data, pre-releases, or drawn from a secondary source such as a developer blog.

Reuse: the summaries, labels and curation here are © What's New. Quote freely with attribution and a link back; wholesale republication of the corpus is not permitted — terms: https://whatsnew.fyi/terms. The vendors' own release notes remain their publishers'.

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- **added** — Make TCP inactivity timeout configurable through a new tcp_timeout option with a default of 600 seconds
- **added** — Add example addon to spoof DNS responses
- **changed** — Flush flow file after each flow to allow further processing
- **changed** — Fallback to UTF-8 for more content types in infer_content_encoding
- **changed** — Improve is_mostly_bin check to support Chinese characters
- **changed** — mitmweb is now built with Vite
- **fixed** — Remove bless from hex editors to avoid issues with macOS
- **fixed** — Fix various issues in infer_content_encoding
- **fixed** — Gracefully handle decoding of raw binary payloads that previously caused errors
- **fixed** — Show query parameters for empty-body requests in the mitmproxy console
- **fixed** — Fix URL of mitmweb when --web-host is an IPv6 address
- **fixed** — Fix event loop leak when running tests
- **fixed** — Fix TypeScript build by adding React types and removing obsolete directives

- Make TCP inactivity timeout configurable through a new `tcp_timeout` option (default: 600 seconds).
  Previously, the timeout was hardcoded to 10 minutes for all TCP connections.
  ([#7909](https://github.com/mitmproxy/mitmproxy/pull/7909), @keshavkrishnadav)
- Flush flow file after each flow to allow further processing.
  ([#7967](https://github.com/mitmproxy/mitmproxy/pull/7967), @caiquejjx)
- infer_content_encoding: Fallback to UTF-8 for more content types
  ([#7961](https://github.com/mitmproxy/mitmproxy/pull/7961), @xu-cheng)
- Remove `bless` from hex editors to avoid issues with macOS
  ([#7937](https://github.com/mitmproxy/mitmproxy/pull/7937), @caiquejjx)
- Improves `is_mostly_bin` check to support chinese characters
  ([#7933](https://github.com/mitmproxy/mitmproxy/pull/7933), @caiquejjx, @mhils)
- Fix various issues in infer_content_encoding
  ([#7928](https://github.com/mitmproxy/mitmproxy/pull/7928), @xu-cheng)
- Add example addon to spoof DNS responses.
  ([#7973](https://github.com/mitmproxy/mitmproxy/pull/7973), @mhils)
- Gracefully handle decoding of raw binary payloads that previously caused
  "Raw cannot decode" or "failed to parse as JSON" errors
  ([#7940](https://github.com/mitmproxy/mitmproxy/pull/7940), @AdityaPatadiya)
- Show query parameters for empty-body requests in the mitmproxy console.
  ([#7923](https://github.com/mitmproxy/mitmproxy/pull/7923), @lups2000)
- mitmweb is now built with Vite, improving the development workflow.
  ([#7971](https://github.com/mitmproxy/mitmproxy/pull/7971), @sleeyax, @mhils)
- Fix URL of mitmweb when --web-host is an IPv6 address.
  ([#7963](https://github.com/mitmproxy/mitmproxy/pull/7963), @Julien00859)
- Fix event loop leak when running tests
  ([#7982](https://github.com/mitmproxy/mitmproxy/pull/7982), @DNEGEL3125)
- Fix TypeScript build by adding React types and removing obsolete `@ts-expect-error` directives.
  ([#7988](https://github.com/mitmproxy/mitmproxy/pull/7988), @DNEGEL3125)