René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"bug: mcpServers field incorrectly required","articleBody":"## Current Behavior\n\n```python\n# This fails with ValidationError\nrequest = NewSessionRequest(cwd=\"/tmp\")\n# Error: Field required [type=missing]\n```\n\n## Expected Behavior\n\n```python\n# Should work per spec\nrequest = NewSessionRequest(cwd=\"/tmp\")\nrequest = NewSessionRequest(cwd=\"/tmp\", mcp_servers=[])\n```\n\nhttps://github.com/agentclientprotocol/python-sdk/blob/main/src/acp/schema.py#L1339-L1345\nhttps://github.com/agentclientprotocol/python-sdk/blob/main/src/acp/schema.py#L1987-L1993\n\nSet the default for these two to None.\n\n\n### Reproduction steps\n\neasy to Reproduction\n\n### Expected result\n\nkeep the same behavior with spec\n\n### Actual result\n\nmcpServers field incorrectly required\n\n### Versions / environment\n\n0.7\n\n### Logs \u0026 screenshots\n\n```shell\n\n```\n\n### Open to submitting a fix?\n\n- [x] I’m willing to open a PR for this bug.","author":{"url":"https://github.com/Smityz","@type":"Person","name":"Smityz"},"datePublished":"2026-01-07T17:45:32.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":0},"url":"https://github.com/55/python-sdk/issues/55"}