Claude CLI v2.1.154 Breaks Local vLLM — One-Line Patch Fixes It

Claude CLI v2.1.154 introduced support for workflows, but in doing so it added three new API message roles (ctx, msg, and system) that broke compatibility with local vLLM servers. The fix is a one-line change to vLLM's Anthropic protocol definitions.

The Problem

Claude CLI versions ≥2.1.154 now send messages with roles beyond user and assistant. vLLM's Anthropic API endpoint only accepted the original two roles, causing requests from the CLI to fail when pointing to a local vLLM instance.

The One-Line Patch

The patch updates the role field in vllm/entrypoints/anthropic/protocol.py to allow the new roles:

--- a/vllm/entrypoints/anthropic/protocol.py
+++ b/vllm/entrypoints/anthropic/protocol.py
@@ -65,7 +65,7 @@ class AnthropicContentBlock(BaseModel):
 class AnthropicMessage(BaseModel):
     """Message structure"""
-    role: Literal["user", "assistant"]
+    role: Literal["user", "assistant", "ctx", "msg", "system"]

That's it. After applying this change, you can use the latest Claude CLI workflows with vLLM-based local models like MiniMax-M2.7 (the only model tested by the author).

If you run a local Anthropic-compatible endpoint on vLLM, apply this patch to keep working with Claude CLI ≥2.1.154.