fix(anthropic): make max_tokens optional for count_tokens endpoint#105
Open
juslintek wants to merge 4 commits intojwadow:mainfrom
Open
fix(anthropic): make max_tokens optional for count_tokens endpoint#105juslintek wants to merge 4 commits intojwadow:mainfrom
juslintek wants to merge 4 commits intojwadow:mainfrom
Conversation
The prompt_tokens reported to clients (used by Claude Code's /context command) were wildly inaccurate because they were derived from Kiro's contextUsagePercentage, which returns unreliable values. Instead, count tokens from the complete serialized Kiro request payload using tiktoken. This includes system prompt, messages, tools, and all other payload fields — matching what actually gets sent to the API. - Replace request_messages/request_tools params with pre-counted prompt_tokens across all streaming functions - Count tokens from full kiro_request_body in both OpenAI and Anthropic route handlers - Remove dependency on contextUsagePercentage for token counting - Update tests to match new function signatures
Claude Code calls this endpoint before each request to check conversation size and decide whether to trigger compaction. Without it, the gateway returns 404, Claude Code cannot estimate context usage, and long conversations eventually hit the upstream CONTENT_LENGTH_EXCEEDS_THRESHOLD error (400). The endpoint builds the full Kiro payload and counts tokens on the serialized JSON using tiktoken, consistent with the token counting approach used in the messages endpoint. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Replace validate_tool_names (400 error) with deterministic truncation for tool names exceeding 64-char Kiro API limit. Names are shortened to 55 chars + '_' + 8-char md5 hash. Mapping is reversed in responses so clients receive original names. Fixes MCP plugins with auto-generated names like mcp__plugin_cloudflare_cloudflare-docs__search_cloudflare_documentation
…s endpoint Claude Code sends /v1/messages/count_tokens without max_tokens since it only needs token counting, not generation. The required max_tokens field caused 422 validation errors, breaking context usage tracking and preventing conversation compaction.
|
Thanks for the PR! 🎉 Before merge, we need a one-time CLA confirmation. Full CLA text: Please reply once with: You need to write once, all further messages from me can be ignored. |
Author
|
I have read the CLA and I accept its terms |
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
3 participants
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.
Problem
Claude Code calls
/v1/messages/count_tokensto track context usage and trigger conversation compaction. This endpoint reusesAnthropicMessagesRequestwhich requiresmax_tokens: int.Since count_tokens only counts tokens (no generation), Claude Code doesn't send
max_tokens. Every call fails with 422:This breaks context tracking entirely — Claude Code can't estimate context usage, leading to conversations hitting
CONTENT_LENGTH_EXCEEDS_THRESHOLDerrors.Solution
Give
max_tokensa default value of 4096 inAnthropicMessagesRequest, making it optional. The messages endpoint still works identically (clients always send it), while count_tokens no longer requires it.Depends on