People sign in with an existing Bluesky or other AT Protocol account and keep a public, LinkedIn-style professional profile, which also gathers their activity from other apps; they can follow and endorse one another.
03–01Belowcompute, networks and resources are not recorded per app
Every layer above links to what it rests on. The figure counts the EU, the EEA, Switzerland and the UK as European, as the landscape does.
How it is run
nine questions
ArchitectureWho holds your account and posts?
Open protocol, through Bluesky Social PBC
open protocol: yes
move your account and keep your followers: yes
hub: Bluesky Social PBC
Sifa profiles are AT Protocol records kept in each member's own account, so any compatible app can read them, and an account can move to another provider with its DID, followers and records. Sifa runs its own AppView, fed by Jetstream from Eurosky, microcosm and Bluesky. The hub is coded as Bluesky because most members' accounts are on Bluesky, identities resolve through Bluesky's PLC directory, and visitors' browsers call Bluesky's public AppView and image CDN.
Sifa credits, data sourcesWe also depend on free public infrastructure that others run at their own costread 28 Sep 2026
Business modelWho pays, and for what?
No revenue yet
Sifa is free and carries no ads, and its founder funds Singi Labs himself, with no investors. No revenue plan is stated, and Sifa says it has no premium tiers.
Singi Labs, aboutBuilt in The Netherlands, hosted in the EU, funded by no one but me.read 28 Sep 2026
control: Guido X Jansen, sole founder of Singi Labs (legal form and registry number not disclosed)
Singi Labs is a one-person studio with no outside investors. Its terms allow for Singi Labs being acquired or handing Sifa to another operator, with 30 days' notice to users.
Singi Labs, aboutSingi Labs is just me, Guido, in The Netherlands.read 28 Sep 2026
Sifa has no home feed yet: its main views are profiles, search and each member's own activity timeline, and it says it has no algorithmic feed. Nothing is ranked by the operator, so the map groups it with the unranked feeds; that is our coding. A feed of followed people's activity ("Stream") is on the roadmap as "coming soon".
Singi Labs handles reports and can hide content or suspend profiles on Sifa, and users can appeal by email. Removals only change what Sifa shows, because the records stay in members' own accounts. The policies mention no third-party or user-chosen moderation services.
Ruled out by Sifa's own signal. Its robots.txt declares Content-Signal train=no, though the same file still lets GPTBot, Google-Extended, CCBot and other AI crawlers read profile pages. The terms and privacy policy do not mention AI training, and the licence Sifa takes covers display, caching, indexing and featuring. Sifa says it has no AI features and uses AI only to build the product.
This counts profiles claimed by their owners, from Sifa's live counter, which the launch release displays. Sifa also shows unclaimed profiles, built from public data, for any AT Protocol account, and these are not counted.
07Shared servicesWhat does it lean on but not run?
Bluesky Social PBC · United States
also Eurosky · Netherlands: one of the Jetstream feeds Sifa's AppView reads
also microcosm · country not established: a second Jetstream feed, and the Slingshot record cache
Sifa runs its own AppView, fed by Jetstream from Eurosky, microcosm and Bluesky. Visitors' browsers also call Bluesky's public AppView and image CDN, both served through Bunny.net (SI). Accounts resolve through the PLC directory, which runs on AWS in Ohio.
07VerificationWho checks users' identity, age or account?
None
ID needed to post: no
No identity check. Signing in takes an existing AT Protocol account and a self-declared age of 16+. Sifa verifies linked GitHub and ORCID accounts, and shows verification badges issued by Bluesky and by Mu's trusted verifiers.
No AI features in the product. AI is used only to build it, and training on Sifa content is refused by default.
Sifa creditsWe use AI only to build the product; Sifa itself has no AI features (yet).read 24 Sep 2026
05DataWhere does the data sit?
Singi Labs · Germany
also Bluesky Social PBC · United States: hosts most members' AT Protocol accounts (bsky.social), where their profile records live
where: Sifa's servers, database and logs are at Hetzner in Germany, and its analytics are self-hosted in the Netherlands. But the profile records themselves live on each member's own account host, which for most members is Bluesky's.
transfers: None stated; both named sub-processors, Hetzner and Scaleway, are in the EU. Observed but undisclosed are Fastmail (AU) for mail to sifa.id, Cloudflare in front of the analytics script, and Google's favicon service in visitors' browsers.
Served straight from Hetzner through Caddy. Sifa's trust page says there is no CDN; the one exception observed is the analytics script, which arrives with Cloudflare headers.