- Assemble x-anthropic-billing-header strictly following official 2.1.258 binary sequence: cc_version -> cc_entrypoint -> cch -> cc_workload -> cc_is_subagent -> cc_prev_req -> cc_prompt_id.
- Track upstream request-id in thread-safe bounded session continuity state and inject into subsequent turns as cc_prev_req.
- Generate and enforce RFC 4122 UUIDv4 cc_prompt_id per user prompt turn, preserving it across tool continuations while suppressing it on probes and title helpers.
- Detect subagents via agent headers and session metadata to emit cc_is_subagent=true.
- Harmonize diagnostics and continuity lifecycles to prevent uncommitted or truncated streams from corrupting state.
- Exclude x-anthropic-billing-header system blocks from sensitive-word zero-width space injection.
Align the remaining measured OAuth wire profiles, including the ordered
connection writer in internal/httpwire that reproduces the observed header
sequence, and the refresh/profile response shapes in internal/auth/claude.
Replay the measured Fast path and keep diagnostic continuity across cloaked and
native requests.
Preserve the native direct token-counting shape so a caller that reaches
count_tokens itself is not reshaped into the cloaked form.
Scope cloak dates to the credential's timezone rather than the host's, so
currentDate matches what the real client would have sent for that account.
