feat: increase default buffer size to 10MB and improve error messages #416
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
- Increase _DEFAULT_MAX_BUFFER_SIZE from 1MB to 10MB to accommodate modern MCP tools (e.g., Puppeteer evaluate() with DOM data, large file contents) - Add warning when buffer reaches 80% capacity to help users debug before hitting the limit - Improve error message with clearer guidance on increasing max_buffer_size - Enhance documentation for ClaudeAgentOptions.max_buffer_size with examples Background: The 1MB default was too small for real-world MCP tool responses. Puppeteer's evaluate() can return 5-7MB when extracting computed CSS styles from DOM elements. This caused frequent crashes with 'JSON message exceeded maximum buffer size' errors. The max_buffer_size parameter was already configurable but: 1. The 1MB default was too conservative 2. Documentation didn't mention it clearly 3. Users resorted to hackish fixes (modifying site-packages directly) This change makes the SDK work better out-of-the-box while maintaining full backwards compatibility. Users can still override via ClaudeAgentOptions.
Author
|
Withdrawing this PR. After further consideration, the existing max_buffer_size parameter already provides the needed functionality. Users can configure it as needed for their use cases. |
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Outdated suggestions cannot be applied.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.
Summary
Increases the default JSON buffer size from 1MB to 10MB to accommodate modern MCP tools that may return large responses, and improves error messages to help users debug buffer overflow issues.
Problem
The current 1MB default buffer size is too small for real-world MCP tool responses. For example:
This causes frequent crashes with buffer overflow errors, forcing users to modify installed packages directly.
Solution
Testing
✅ Tested with real Puppeteer MCP scenarios (6.8 MB responses)
✅ Backward compatible
✅ No breaking changes
Impact