Primitive of the day · 2026-10-22

unpack-cross-library-tuples-by-name

Sibling utilities can return the same logical pair in REVERSED tuple order ((score,text) vs (text,score)) — when chaining libraries, never assume tuple element order; destructure explicitly per producer.

When this applies

Consuming tuple-returning functions from more than one library or skill in a single chain.

Preconditions

• Each producer's return signature is documented or readable in its source

Do this

Check each producer's return signature at the call site; destructure into named variables per producer, and where possible convert tuples to dicts/dataclasses at the boundary so order ceases to matter.

What you should see

Chained utilities interoperate without transposed fields.

How it fails if ignored

A score treated as text (or vice versa) propagating silently through the pipeline; copy-pasting unpack code between producers with different tuple orders.

Do not use when

Single-producer pipelines with a pinned, boundary-asserted contract.

Kind: gotcha-fix. Part of the skill Build RAG reranker pipeline. Free to reuse in your own agent skills.