skills: document the managed AI platform path (Lovable, v0, Bolt) — wasm-inline, headless auth, non-`postgres` role

[coderdan]

A Lovable agent implemented CipherStash end-to-end in a Lovable-hosted project and reported what it had to discover for itself. Most of it is documentation, and most of it applies to every managed AI app platform — Lovable, v0, Bolt, Replit — not just this one. The common shape: no shell the developer controls, an edge/Workers runtime, a database role that is not postgres, and database changes only through the platform's migration tool.

Its most costly discovery, in its own words:

I spent a full turn concluding CipherStash was impossible here before learning stash existed.

It knew @cipherstash/protect, inferred "native Rust addon, won't run on Workers" from the -ffi dependency name, and concluded the product was unusable — before finding @cipherstash/stack and the wasm-inline entry. That is a near-miss we should not rely on the next agent surviving.

What to add

A managed-platform section — either in skills/stash-supabase/SKILL.md or as a new skills/stash-lovable / skills/stash-managed-platforms — covering:

1. Edge runtime, up front and unmissable. Edge or Workers? Use @cipherstash/stack with the @cipherstash/stack/wasm-inline entry. @cipherstash/protect is the deprecated predecessor and its native FFI will not load there. This belongs high enough that an agent skimming the first screen cannot miss it — it is the difference between "CipherStash works here" and "CipherStash is impossible here".

2. Headless auth works. stash auth login --json --region <r> runs the device flow with the verification URL emitted as the first NDJSON event, no browser auto-open, and writes to ~/.cipherstash (packages/cli/src/cli/registry.ts:250-285). It works in an ephemeral sandbox. The reporter did not know this, and reached for a raw .sql release asset instead of the CLI on the assumption the CLI could not authenticate. Once it confirmed auth login --json worked, the CLI was the better path throughout.

3. Credentials. stash env --name <x> --write mints the four CS_* vars into a file (registry.ts:561-603); they go into the platform's backend secrets. The reporter: "that part worked flawlessly and is worth codifying." So this is a docs gap, not a product gap — worth recording, because we had it flagged internally as a suspected blocker and it is not one.

4. The database role is not postgres. State it, and route the install through the platform's migration tool via --print-sql (sibling issue) rather than a direct connection. Include what the CLI cannot do from inside these sandboxes and what to hand to the platform instead.

5. What is not available through PostgREST. eq/neq/in/gt/gte/lt/lte do work through the Data API — the adapter encrypts each filter value with the full storage path. Free-text matches() and encrypted-JSON containment/selector predicates do not, because they need eql_v3.query_* casts PostgREST cannot emit. Agents guess wrong in both directions on this; the existing note in skills/stash-supabase/SKILL.md is correct but too deep in the file to be found under time pressure.

6. Server-side client construction. encryptedSupabase needs a Postgres connection for introspection and so cannot be constructed in a Worker (#708). Say so where an agent building on one of these platforms will read it, and point at the supported shape.

Related

• Supabase v3: encryptedSupabaseV3 requires a Postgres connection, so it cannot run in Workers or the browser #708 — encryptedSupabase requires a Postgres connection, so it cannot run in Workers or the browser. The product-side half of point 6.
• stash-supabase skill lacks raw-pg / no-ORM guidance (only covers the encryptedSupabase JS wrapper) #601 — stash-supabase skill lacks raw-pg / no-ORM guidance.
• Document raw-SQL EQL v3 querying: encryptQuery term + ::eql_v3.query_<domain> cast (no-ORM surfaces) #664 — raw-SQL EQL v3 querying, which is what an agent falls back to when the wrapper will not construct.
• Sibling issues in this batch: --print-sql, owner-scoped grants, preflight, TLS.

Per AGENTS.md, skills ship inside the stash tarball and get copied into customer repos, so this needs a stash patch changeset.