[Bug] Anthropic-compatible endpoint rejects a JSON Schema `pattern` with Unicode property escapes (\p{Cc}) with 400 code 1210, breaking every interactive Claude Code turn

提交前确认 · Pre-submission checklist

• 我已搜索过现有 issue，确认这不是重复 / I searched existing issues and confirmed this isn't a duplicate.
• 我已阅读 CONTRIBUTING.md / I've read CONTRIBUTING.md.

问题类别 · Category

工具调用 / MCP · Tool use / MCP

涉及的 Agent 框架 · Agent framework

Claude Code

严重程度 · Severity

阻塞使用 · Blocking (无法使用核心功能 / core function unusable)

复现频率 · Reproducibility

必现 · Always

问题描述 · Description

Claude Code (interactive mode) pointed at the Anthropic-compatible endpoint with glm-5.3 fails on every turn with:

API Error: 400 [glm/glm-5.3] {"type":"error","error":{"type":"invalid_request_error","code":"1210","message":"[1210][Invalid API parameter, please check the documentation.][<request id>]"}}

claude -p "..." (print mode) works against the same endpoint. Bisecting the two captured request bodies shows the only difference that matters is the tools array: interactive mode includes Claude Code's built-in Artifact tool, and inside its input_schema the field property carries this pattern:

^(?!__.*__$)[^\p{Cc}\p{Cf}\p{Zl}\p{Zp}"\\./[\]]{1,200}$

Removing that single pattern makes the identical request return 200. The other five patterns in the same schema are accepted. So the endpoint's schema validator cannot compile ECMA-262 Unicode property escapes (\p{...}), which are valid in JSON Schema pattern (ECMA-262 dialect), and it rejects the whole request with a generic 1210 rather than naming the parameter.

This affects every Claude Code user on the GLM Coding Plan as soon as they use the interactive CLI (versions 2.1.263, 2.1.265, 2.1.266 all send this tool).

复现步骤 · Steps to reproduce

1. Send any Messages request to the Anthropic-compatible endpoint with a tools entry whose input_schema contains a string property with "pattern": "^[^\\p{Cc}]{1,200}$". Standalone repro (replace the key):

curl -s https://api.z.ai/api/anthropic/v1/messages \
  -H 'content-type: application/json' -H 'anthropic-version: 2023-06-01' -H 'x-api-key: <KEY>' \
  -d '{"model":"glm-5.3","max_tokens":32,"messages":[{"role":"user","content":"Say OK"}],
       "tools":[{"name":"probe","description":"probe","input_schema":{"type":"object","properties":{"field":{"type":"string","pattern":"^[^\\p{Cc}]{1,200}$"}}}}]}'

2. Observe HTTP 400, error code 1210.
3. Send the same request without the pattern keyword: HTTP 200.
4. Real-world path: start interactive Claude Code with ANTHROPIC_BASE_URL set to the endpoint and send any prompt; every turn fails. claude -p succeeds because print mode omits the Artifact tool.

期望表现 · Expected behavior

Either accept ECMA-262 Unicode property escapes in pattern (the JSON Schema dialect Claude Code and the Anthropic API use), or ignore pattern keywords the validator cannot compile instead of rejecting the request. In all cases the 1210 error should name the offending parameter (e.g. tools[32].input_schema.properties.field.pattern) so users can find it without bisecting request bodies.

实际表现 · Actual behavior

HTTP 400 with {"type":"invalid_request_error","code":"1210","message":"[1210][Invalid API parameter, please check the documentation.][...]"}, no indication of which parameter. Interactive Claude Code is unusable on the endpoint; the only workaround found is "permissions": {"deny": ["Artifact"]} in Claude Code's settings.json, which removes the tool from the request.

ZCode 版本 · ZCode version

Not ZCode: Claude Code CLI 2.1.263 / 2.1.265 / 2.1.266 against the Anthropic-compatible API, model glm-5.3

设备 / 系统 / 浏览器 · Device / OS / Browser

macOS 26 (Apple Silicon) / Claude Code CLI / requests reach the endpoint through a local Anthropic-compatible proxy (9router); reproduced with plain curl as well

截图 / 录屏 / 日志 · Screenshots / Recordings / Logs

Upstream request ids for two failing turns: 202609090758534b30326b670343d5 and 202609090759179161046158a5442f (2026-09-09, UTC+3 morning).

Bisection log (same request body, only the named part changed):

• full interactive body: 400 / 1210
• interactive body with print-mode tools: 200
• print-mode body + only the Artifact tool added: 400 / 1210; + AskUserQuestion, EnterPlanMode, ExitPlanMode, SendFeedback individually: 200
• Artifact with its pattern keywords stripped: 200; with each other keyword (propertyNames, prefixItems, additionalProperties, anyOf, const, maxLength) stripped: still 400
• keeping exactly one pattern at a time: only ^(?!__.*__$)[^\p{Cc}\p{Cf}\p{Zl}\p{Zp}"\\./[\]]{1,200}$ fails; the other five pass

Start with the standalone curl reproduction against the Anthropic-compatible endpoint and compare requests with and without the Unicode-property pattern. Trace the schema validation path for the tools input schema; done means the request is accepted or the 1210 response identifies the offending pattern parameter, with the provided Claude Code and curl cases covered.