Expander reference

Use QueryExpander to broaden a user query into alternative phrasings before retrieval. The expander calls Claude Haiku to generate 3–5 rephrased versions of the original query, improving recall when the query has low surface-level overlap with target documents. Any API error falls back to the original query unchanged.

Classes

Class	Description
`QueryExpander`	Expands a query into alternative phrasings using Claude Haiku.

`QueryExpander`

from attune_rag.expander import QueryExpander

Constructor

Parameters	Type	Default
`model`	`str`	`'claude-haiku-4-5'`
`api_key`	`str	None`
`cache`	`bool`	`True`

Methods

Method	Parameters	Returns	Description
`expand`	`query: str`	`list[str]`	Expands a query into alternative phrasings synchronously.
`expand_async`	`query: str`	`list[str]`	Expands a query into alternative phrasings asynchronously.

Constants

Constant	Type	Value
`_SYSTEM`	`str`	`"You expand developer queries for a documentation retrieval system.\nGiven a query about developer workflows and tooling, return 3-5 alternative\nphrasings as a JSON array of strings. Expose the user's actual intent:\nfeature names, tool categories, workflow synonyms, and developer jargon.\nReturn ONLY the JSON array — no explanation, no markdown fences."`

Source files

src/attune_rag/expander.py