DNS records put Replit inside 62 funded YC startups, and that changes your hosting risk math

RuntimeWire started from a single Google Cloud address, 34.111.179.208, and finished with 160 Replit-verified hostnames mapped to 63 companies in the Y Combinator directory as of 18 August 2026 ^{[1] [3] [8]}. The 62 companies other than Replit itself have raised approximately $1.91 billion in disclosed funding ^[2], which shifts the question of whether AI coding platforms touch production from vendor testimony to public DNS.

The method is worth reading before the conclusion. An IP match alone was not enough, because shared cloud addresses serve unrelated customers, so RuntimeWire required two signals: the hostname resolving to the Replit-linked address, and a TXT record beginning with `replit-verify=` on the hostname or its root domain ^[9]. That TXT record exists to prove control of a custom domain during a Replit deployment ^[10]. So the finding is narrow and hard: somebody with write access to a company's DNS zone authorized a Replit-hosted endpoint. RuntimeWire is explicit that the records cannot show whether Replit's AI agent wrote the code ^[7].

Fountain is the legible case. Public DNS puts `start.fountain.com` and `tools.fountain.com` on the Replit-linked address while the rest of Fountain's public product infrastructure sits with other providers ^[11]. That split is the shape of the whole dataset: tools, portals, landing pages and application components attached to real domains, not a replacement for the primary engineering stack ^[7].

The capital is concentrated. Roughly three-quarters of the external funding sits with the 10 best-funded companies ^[6], about $1.4 billion of the $1.91 billion total ^[14], against an average of roughly $30.8 million per company across all 62 ^[13]. Aspire says it has raised more than $300 million in equity and debt; Fountain about $219 million; GiveCampus approximately $191 million; Instawork $160 million; Pelago $151 million after its 2024 Series C; Shepherd $67 million after a March 2026 round; Tavus about $64 million; SafetyWing $47 million ^[12]. Qventus has announced investments of $100 million and $105 million since 2022, the latter including a debt component RuntimeWire excluded from its equity calculation ^[15]. Of the 63 companies, YC lists 57 as active, five as inactive and one as acquired ^[4]. Include Replit's own roughly $878 million and the cluster totals about $2.79 billion ^[5].

The operator consequence is not the funding number. It is that RuntimeWire found the platform absent from the public technology stacks of companies whose domains point at it ^[16]. A procurement inventory or an architecture diagram would not surface these endpoints; a zone file audit would. Each of those hostnames is a dependency on one vendor's custom-domain publishing layer, provisioned by whoever held DNS access, which is a different risk profile from a prototyping tool nobody can reach from the open internet.

Two things to check. First, your own zones, for `replit-verify=` TXT records you did not approve, and for any hostname resolving to a deployment layer you have never had an availability conversation about. Second, whether the endpoints belonging to the five inactive companies and the one acquired one keep resolving ^[4], because abandoned custom domains pointed at live shared infrastructure are the part of this pattern that ages badly.