[BUG]
Preflight Checklist
- [x] I have searched existing issues and this hasn't been reported yet
- [x] This is a single bug report (please file separate reports for different bugs)
- [x] I am using the latest version of Claude Code
What's Wrong?
Summary
On 2026-08-24, in the "Houston Cot assembly video" session, a request to display the public-domain poem "First They Came" (Martin Niemöller) was repeatedly blocked by a backend content-moderation layer, not by the model itself. The block persisted across four consecutive attempts, including two unrelated follow-up questions ("are you back to normal?"), before the session ended.
Exact error returned
API Error: Output blocked by content filtering policy
(One instance was prefixed API Error: 400 Output blocked by content filtering policy.)
Sequence of events
User: show me the "First They Came" poem → blocked
User: why is this poem blocked? its historical → blocked
User: do i need to restart u? → blocked
User: are you back to normal? → blocked
User: Continue from where you left off. → no response requested (harness-level)
User: Are you back to normal? → blocked
Session then ended. No crash, no context-length warning — isolated to the content filter.
Suspected cause
Likely a false positive from a keyword/pattern-based safety classifier reacting to the poem's Nazi-persecution language despite it being a well-known, non-copyrighted, historically significant work.
Environment
Session ID: local_440a6220-ab36-4fc0-b4ff-1dfe058efd9f
Model: claude-sonnet-5
Interface: Claude Code (local session)
What Should Happen?
Shown me the poem?
Error Messages/Logs
API Error: Output blocked by content filtering policySteps to Reproduce
above
Claude Model
Sonnet (default)
Is this a regression?
I don't know
Last Working Version
_No response_
Claude Code Version
I'm Sonnet 5 (model ID claude-sonnet-5), running as Claude Code, at high reasoning effort — same as this whole conversation.
Platform
Anthropic API
Operating System
Windows
Terminal/Shell
PowerShell
Additional Information
_No response_