[PR #82] fix(models): sanitize unknown content block types to prevent 422 errors #79

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opened 2026-02-27 07:17:52 +03:00 by kerem · 0 comments

kerem commented

2026-02-27 07:17:52 +03:00

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📋 Pull Request Information

Original PR: https://github.com/jwadow/kiro-gateway/pull/82
Author: @XuNeo
Created: 2/22/2026
Status: 🔄 Open

Base: main ← Head: fix/sanitize-unknown-content-blocks

📝 Commits (2)

459be05 feat(config): add claude-opus-4.6 to fallback models
a6f95c4 fix(models): sanitize unknown content block types to prevent 422 errors

📊 Changes

2 files changed (+56 additions, -1 deletions)

View changed files

📝 kiro/config.py (+1 -0)
📝 kiro/models_anthropic.py (+55 -1)

📄 Description

Summary

Claude Code's ToolSearch (deferred tool loading) returns tool_reference content blocks inside tool_result messages. These are an internal Claude Code content type not recognized by the Anthropic Messages API schema.
When the conversation history containing these blocks is forwarded through the gateway, Pydantic validation rejects them with a 422 error, breaking all subsequent API calls in the session.
This PR adds model_validator(mode="before") to ToolResultContentBlock and AnthropicMessage that converts unrecognized block types (e.g. tool_reference) into harmless text blocks before Pydantic validation runs.

Example

Before (causes 422):

{"type": "tool_reference", "tool_name": "mcp__gdbmcp__gdb_connect"}

After (passes validation):

{"type": "text", "text": "[tool_reference: mcp__gdbmcp__gdb_connect]"}

Test plan

All 147 existing unit tests pass
Manually verified with Claude Code using ToolSearch to load deferred MCP tools — no more 422 errors

🤖 Generated with Claude Code

_{🔄 This issue represents a GitHub Pull Request. It cannot be merged through Gitea due to API limitations.}

## 📋 Pull Request Information **Original PR:** https://github.com/jwadow/kiro-gateway/pull/82 **Author:** [@XuNeo](https://github.com/XuNeo) **Created:** 2/22/2026 **Status:** 🔄 Open **Base:** `main` ← **Head:** `fix/sanitize-unknown-content-blocks` --- ### 📝 Commits (2) - [`459be05`](https://github.com/jwadow/kiro-gateway/commit/459be0540994724b1e5ac4356b439a9decf54223) feat(config): add claude-opus-4.6 to fallback models - [`a6f95c4`](https://github.com/jwadow/kiro-gateway/commit/a6f95c428f34af87ee8b348f4e94860239159f96) fix(models): sanitize unknown content block types to prevent 422 errors ### 📊 Changes **2 files changed** (+56 additions, -1 deletions) <details> <summary>View changed files</summary> 📝 `kiro/config.py` (+1 -0) 📝 `kiro/models_anthropic.py` (+55 -1) </details> ### 📄 Description ## Summary - Claude Code's `ToolSearch` (deferred tool loading) returns `tool_reference` content blocks inside `tool_result` messages. These are an internal Claude Code content type not recognized by the Anthropic Messages API schema. - When the conversation history containing these blocks is forwarded through the gateway, Pydantic validation rejects them with a 422 error, breaking all subsequent API calls in the session. - This PR adds `model_validator(mode="before")` to `ToolResultContentBlock` and `AnthropicMessage` that converts unrecognized block types (e.g. `tool_reference`) into harmless text blocks before Pydantic validation runs. ## Example Before (causes 422): ```json {"type": "tool_reference", "tool_name": "mcp__gdbmcp__gdb_connect"} ``` After (passes validation): ```json {"type": "text", "text": "[tool_reference: mcp__gdbmcp__gdb_connect]"} ``` ## Test plan - [x] All 147 existing unit tests pass - [x] Manually verified with Claude Code using `ToolSearch` to load deferred MCP tools — no more 422 errors 🤖 Generated with [Claude Code](https://claude.com/claude-code) --- <sub>🔄 This issue represents a GitHub Pull Request. It cannot be merged through Gitea due to API limitations.</sub>