mirror of
https://github.com/hwchase17/langchain.git
synced 2026-07-13 03:42:57 +00:00
bd8ab5520b
Many provider integrations (notably Anthropic's `input_json_delta`
path) attach the tool-call `id` and `name` only to the first
`tool_use` chunk; subsequent per-chunk slices carry `id=None,
name=None` and just the fresh `args` segment. The compat bridge
forwarded those `None` values verbatim, producing wire payloads like
`{"type": "tool_call_chunk", "id": null, "name": null, "args": "..."}`.
Consumers that fold deltas via a naive `{...target, ...delta}` spread
(e.g. the langgraph-js SDK's `MessageAssembler.applyContentDelta`)
interpret those as "identifier reset to null" and lose the id/name
captured from `content-block-start`. Downstream extractors then drop
the chunk until the final `content-block-finish` arrives — visible to
end users as tool-call cards appearing all-at-once at the end of a
turn instead of streaming in incrementally (the Deep Agent example
rendering four subagents in a single flicker rather than one after
another).
Introduce `_to_protocol_delta_block` and route every
`content-block-delta` emission (sync / async chunk streams and the
`message_to_events` replay path) through it. For `tool_call_chunk`
and `server_tool_call_chunk` shapes, drop `id` / `name` keys when
they would serialize to `null`. This matches the wire shape produced
by langgraph-js's `toProtocolDeltaBlock`, where identifiers are only
surfaced when they carry a real value.