Documentation

ai.wire.prompt_parts

A rendered prompt message's parts for a client that SENDS cache delimiters: the same parts as `message.parts`, with each delimiter made a clean boundary between two content blocks.

Reference version

Signature

function ai.wire.prompt_parts(
default_cache_args: baml.json.json = …
) -> ai.PromptPart[] throws never

A rendered prompt message's parts for a client that SENDS cache delimiters: the same parts as message.parts, with each delimiter made a clean boundary between two content blocks.

  • Text directly before a delimiter is end-trimmed and text directly after one is start-trimmed, and a part left empty is dropped — the treatment text around a media part already gets. The marker sits between two blocks on the wire, so the whitespace that separated them in the template has no block to belong to.
  • A delimiter whose args is null (${cache()}) takes default_cache_args, which the caller passes from its client's default_cache_args(). The delimiter returned carries the resolved value, so the caller never sees a null args.
  • When that default is null too, the delimiter is removed and the text around it is joined, untrimmed: there is nothing to send for it, so it is as if it had not been written.

What the caller does with a delimiter is its own business (a sibling block, a field on the block before); the positions are as written, and so is every args that was not null.

Source:<builtin>/ai/ns_wire/wire.bamlbytes 20892–23090