Describe the bug

Self-referencing table embeds behave inconsistently depending on whether the relationship hint is a column name or a foreign key constraint name.

Table:

CREATE TABLE public.lab (
  id     uuid PRIMARY KEY DEFAULT gen_random_uuid(),
  name   text,
  type   text,
  parent uuid REFERENCES lab(id) ON DELETE CASCADE,  -- constraint: lab_parent_fkey
  main   uuid REFERENCES lab(id) ON DELETE CASCADE   -- constraint: lab_main_fkey
);

Case 1 — column name hint (!parent)

const query = supabase.from("lab").select("*,lab!parent(name,id)").eq("type", "board");

• Runtime response: correct, lab is returned as an array of children.
• Inferred type: incorrect — lab is typed as { name: string | null; id: string } | null instead of an array.

Case 2 — foreign key constraint name hint (!lab_parent_fkey)

const query = supabase.from("lab").select("*,lab!lab_parent_fkey(name,id)").eq("type", "board");

• Inferred type: correct — lab: { name: string | null; id: string }[].
• Runtime response: fails with PGRST200:

{
    "code": "PGRST200",
    "details": "Searched for a foreign key relationship between 'lab' and 'lab' using the hint 'lab_parent' in the schema 'public', but no matches were found.",
    "hint": null,
    "message": "Could not find a relationship between 'lab' and 'lab' in the schema cache"
}

Note that the hint received by PostgREST is lab_parent, not lab_parent_fkey as written in the query. Confirmed via the browser Network tab that the actual outgoing request also has the truncated hint — this is not a typo in our code. The _fkey suffix appears to be stripped somewhere in the select-string building for self-referencing embeds.

Expected behavior

• lab!lab_parent_fkey(name,id) should send the full constraint name lab_parent_fkey to PostgREST and resolve as one-to-many (array).
• lab!parent(name,id) should infer the correct array type at compile time, matching runtime behavior.

Library affected

supabase-js

Reproduction

No response

Steps to reproduce

1. Create a table with two self-referencing foreign keys as above.
2. Run both queries shown.
3. Compare inferred TS types vs actual runtime response, and inspect the outgoing request URL for Case 2.

System Info

supabase-js version: 2.110.2

Used Package Manager

pnpm

Logs

No response

Validations

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• The provided reproduction is a minimal reproducible example of the bug.