Ross ROSS = Recommend OSS · open-source software intelligence for agents

twitter-archive/diffy

Find potential bugs in your services with Diffy observed · 2026-08-28

github.com/twitter-archive/diffy · homepage · Scala · Apache-2.0 (permissive) · archived observed · 2026-08-28

Health v2 · maintenance only

10/100

  • Activity 0
  • Release rhythm 35
  • Longevity 100

Flags: no_releases archived

How is this computed?

round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10) — computed 2026-09-03. Adoption (stars, forks) is never an input.

  • gap_med: n/a
  • age_days: 4039
  • days_rel: n/a
  • days_push: 2254
  • n_releases_24m: 0

Full methodology

Adoption not part of the score

3811 stars · 360 forks observed · 2026-08-28

What it is AI-extracted, prompt v1, taxonomy v1, 2026-08-29, confidence not recorded

Diffy is a proxy-based differential testing tool from Twitter that multicasts incoming requests to a candidate service and two known-good service instances, then compares responses to surface regressions. It filters out non-deterministic noise by measuring differences between two identical known-good instances.

Use cases

  • find regressions in a new version of my service without writing tests
  • compare responses between old and new service implementations side by side
  • detect bugs in my API by diffing candidate and known-good instances
  • filter out noisy non-deterministic fields when comparing service responses
  • run automated differential testing against microservices
  • validate a rewritten service behaves equivalently to the original

When to avoid

  • the original repo is archived and unmaintained - use the community fork Opendiffy instead
  • you need to test stateful services where side effects make response comparison unreliable
  • you don't have the ability to run multiple instances of your service simultaneously

Facets

service · maturity abandoned

testing proxy middleware http-server testing developer-tools apis backend jvm self-hosted differential-testing regression-detection service-comparison scala twitter-archive mirror-testing docker

1 source

Member repositories

RepositoryRoleHealth v2
twitter-archive/diffymain10

For agents

markdown · JSON · MCP: product_card(name="twitter-archive/diffy")

Data as of 2026-08-30T08:39:29.467469+00:00 · Report a problem