Openrouter is not supported with claude code

[SaiSanthosh1508]

For the past week i've been working on a project, i was able to use openrouter model by configuring claude code but right now its not wokring its thorwing me this error.How do i resolve this?

API Error: 400 {"error":{"message":"No endpoints available that
support Anthropic's context management features (context-management-2025-06-27). Context management requires a
supported provider (Anthropic).","code":400}}

import asyncio
import os
from typing import Any
from dotenv import load_dotenv
from claude_agent_sdk import query, ClaudeAgentOptions, tool, create_sdk_mcp_server

load_dotenv()

@tool(
    name="summarize_file",
    description="Summarizes the content of a file. Input is a file path, output is a concise summary of the file's content.",
    input_schema={"file_path": str},
)
async def summarize_file(args: dict[str, Any]) -> dict[str, Any]:
    file_path = args["file_path"]

    if not os.path.isfile(file_path):
        return {
            "content": [{"type": "text", "text": f"Error: File '{file_path}' does not exist."}],
            "is_error": True,
        }

    try:
        with open(file_path, "r") as f:
            content = f.read()
        summary = content[:100] + "..." if len(content) > 100 else content
        return {"content": [{"type": "text", "text": summary}]}
    except Exception as e:
        return {
            "content": [{"type": "text", "text": f"Error reading file '{file_path}': {str(e)}"}],
            "is_error": True,
        }

file_server = create_sdk_mcp_server(name="file_server", tools=[summarize_file])

async def run_agent(user_prompt: str):
    options = ClaudeAgentOptions(
        setting_sources=["project"],
        allowed_tools=["Read", "Write", "Bash", "LS", "Search", "mcp__file_server__*"],
        mcp_servers={"file_server": file_server},
        model="minimax/minimax-m2.7",
        betas=[]
    )

    async for message in query(prompt=user_prompt, options=options):
        print(message)

if __name__ == "__main__":
    prompt = "Run the summarize_file tool on main.py"
    asyncio.run(run_agent(prompt))

[majdyz]

We're hitting this in production at AutoGPT (Significant-Gravitas/AutoGPT). We've been pinned to claude-agent-sdk==0.1.45 (CLI 2.1.63) since PR #12294 because every version above introduces a 400 against OpenRouter.

There are actually two distinct OpenRouter regressions stacked here:

1. tool_reference content blocks (CLI 2.1.69, fixed in CLI 2.1.70 via the proxy detection in tool_search). This was the original break that forced our pin.
2. The context-management-2025-06-27 beta header described in this issue, which appears in some CLI version after 2.1.91. We attempted upgrades to 0.1.55 and 0.1.56 (via Dependabot) and both had to be rolled back.

Concrete impact for us:

• We're 13 patch versions behind on the SDK and locked out of exclude_dynamic_sections (0.1.57), AssistantMessage.usage per-turn token tracking (0.1.49), task_budget (0.1.51), get_context_usage() (0.1.52), and the MCP large-tool-result truncation fix in 0.1.55 / CLI 2.1.91 — all of which directly affect our cost-attribution and prompt-caching work.
• Various stability fixes since 2.1.63 are also out of reach: the MCP HTTP/SSE 50 MB/hr buffer leak fix in 2.1.97, the 429 retry exponential-backoff fix in 2.1.97, the --resume cache miss regression fix in 2.1.90, and the per-turn JSON.stringify perf fix in 2.1.90.

Two asks if upstream can help triage:

1. Confirmation of which CLI version introduced the context-management-2025-06-27 header — this would let us bisect to a known-good CLI version higher than 2.1.63 in the meantime.
2. An option to opt out of the context-management-2025-06-27 beta at the SDK / CLI level when ANTHROPIC_BASE_URL points to a non-Anthropic gateway (mirroring how tool_search does proxy detection in 2.1.70).

Happy to run tests against any candidate fix. Adding a +1 from a production user — this is genuinely blocking us from taking ~6 months of bug fixes and several SDK features that we'd otherwise want.