Solid Start 2.0.0-rc.0: custom serialization adapters emitted into Solid’s SSR stream run before hydrate() installs the adapter map — uncaught `$_TSR.t is undefined`

[TylerRick]

Which project does this relate to?

Start

Describe the bug

With a custom serialization adapter registered in start.ts and a route whose loader primes a query through @tanstack/solid-router-ssr-query, every page load throws:

TypeError: Cannot read properties of undefined (reading 'get')

The dehydrated query state reaches Solid's own SSR resource stream, not just the router's pipeline, so the adapter expression is emitted twice:

• inside Solid's stream script (_$HY.r["0"] = …) as a bare $_TSR.t.get("Money")(1234) — no $_TSR.p(...) wrapper, and ahead of the router's $tsr-stream-barrier script that defines self.$_TSR. Solid's stream scripts run at parse time, so this one throws (or reports $_TSR is not defined when it parses before the router's bootstrap);
• inside the router's barrier script, correctly wrapped in $_TSR.p(...) and buffered until hydrate() installs the adapter map.

A loader that simply returns the adapter-typed value does NOT reproduce it — that path is serialized by the router's pipeline alone. It takes the ssr-query dehydration path, which is the ordinary shape for an app reading session or loader data through the query cache.

Complete minimal reproducer

https://github.com/TylerRick/tanstack-solid-ssr-query-adapter-repro

Steps to Reproduce the Bug or Issue

1. pnpm install
2. pnpm dev
3. Open http://localhost:5597 with the console visible — one uncaught TypeError per load.
4. Optional confirmation in the served HTML: the same $_TSR.t.get("Money")(…) expression appears once unbuffered inside _$HY.r[...], and once inside $_TSR.p(...) in the barrier script.

Expected behavior

Adapter expressions emitted into Solid's SSR stream are buffered the way the router's own chunks are — or the adapter map is installed before any stream script can run — so a page that streams adapter-typed data through ssr-query loads without an uncaught error.

Screenshots or Videos

No response

Platform

• Router / Start Version: @tanstack/solid-start, @tanstack/solid-router, @tanstack/solid-router-ssr-query 2.0.0-rc.0; @tanstack/solid-query 6.0.0-rc.0; @tanstack/router-core 1.171.16
• solid-js / @solidjs/web: 2.0.0-rc.0
• OS: Linux
• Browser: Chromium 141
• Bundler: vite 8.2.1 (vite-plugin-solid 3.0.0-next.27)

Additional context

Ours carries a Temporal.PlainDate on the session, so every page load for a user with that field set threw. Workaround we ship: an inline head script, rendered first, that installs $_TSR as an accessor with a passthrough t map, so nothing throws whichever script parses first and hydrate()'s real map still wins.

Related: #5737 (closed, different cause), #7706 (adapter deserialization broken by calling a server fn from the client entry).

[Fnine59]

Fixed by #8105. Solid SSR hydration payloads that use custom serialization adapters now wait for the router adapter map, including when they arrive before the router bootstrap.

[schiller-manuel]

please provide an actual reproducer project as a git repo. this is required. also don't paste your AI output here. write a concise description instead.
future issues not following this will be closed

[TylerRick]

Added a reproducer repo and shortened the description, per the note on #8107: https://github.com/TylerRick/tanstack-solid-ssr-query-adapter-repro