Fix: IndexError when streaming with multiple content blocks (#1192)#1251
Open
Adityakk9031 wants to merge 1 commit intoanthropics:mainfrom
Open
Fix: IndexError when streaming with multiple content blocks (#1192)#1251Adityakk9031 wants to merge 1 commit intoanthropics:mainfrom
Adityakk9031 wants to merge 1 commit intoanthropics:mainfrom
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
1 participant
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Fix-#1192
Problem
An IndexError: list index out of range is raised at current_snapshot.content[event.index] inside both
accumulate_event
(line 465) and
build_events
(line 407) when streaming responses with multiple content blocks.
The root cause is content_block_start blindly calling .append() without validating event.index against the current list length — a known gap flagged by a # TODO: check index comment at that line. If the server sends a non-contiguous index, the list is shorter than expected, and any subsequent content_block_delta or content_block_stop for that index crashes.
Fix
5 changes in
src/anthropic/lib/streaming/_messages.py
:
content_block_start — resolve the TODO: validate event.index; if ahead of the list, pad with empty placeholder blocks and emit a RuntimeWarning.
content_block_delta in
accumulate_event
— early-return if event.index >= len(content).
content_block_stop in
accumulate_event
— same guard.
content_block_delta in
build_events
— same guard.
content_block_stop in
build_events
— same guard.