- Maintain non-tool-result content blocks at their original indices in `AlignClaudeToolResults` instead of moving them after results.
- Reorder tool results in-place into their original slot indices based on preceding tool use IDs.
Closes: #5484
- Ensure Gemini, AI Studio, Vertex, and Antigravity requests end with a user turn to prevent upstream errors when trailing with model content.
- Preserve trailing turns that contain a function response and skip trailing adjustments for `countTokens` actions or Claude models.
- Introduce boundary normalization helpers to validate both leading and trailing turn roles.
Closes: #5358
- Fall back to request payload input items or `previous_response_id` during websocket compaction when transcript snapshot is empty.
- Preserve `previous_response_id` in prepared request body for xAI execution.
Closes: #5205
- Add payload detection and preparation helpers for compaction triggers and summary generation.
- Implement AES-GCM sealing and unsealing to store and restore opaque compaction capsules across turns.
- Support expanding compaction capsules into developer context for downstream turns.
- Provide summary text extraction across Gemini, Claude, and OpenAI response formats.
- Add builders for compaction non-stream JSON responses and SSE stream frames.
Closes: #5094
- Add HTTPWireProfile to sdk/pluginapi on HTTPRequest with wire_profile JSON tag
- Decode wire_profile in host callbacks for flat and nested RPC payloads
- Match header casing in httpwire ordered_conn and allow non-HTTP handshakes
- Apply wire profile settings (HTTP/1.1 enforcement, auto compression disable, header ordering) in plugin host HTTP client
- Preserve proxy configuration, custom TLS dialers, redirect handling, and connection lifecycle
Closes: #5062
- Add `upsertAuthResult` to incrementally update only affected model shards after request completion.
- Cache supported model sets per auth using registry epoch tracking to avoid redundant lookups.
- Preserve full shard synchronization for auth lifecycle events and credential-scoped results.
Closes: #5061
- Reuse coresession.ExtractSessionInfo across HTTP headers and request payloads to unify canonical session prefix namespaces with the scheduler.
- Extract hierarchical session identities in two phases: initial extraction from request headers on entry, and authoritative deep extraction once request payloads and metadata are available.
- Support Claude Code multi-level subagents (X-Claude-Code-Agent-Id, metadata.agent_id) and Codex thread fork lineages.
- Propagate SessionID and ParentSessionID across ClientRequestMetadata, UsageReporter, and coreusage.Record without root_session_id.
- Include session_id and parent_session_id in queuedUsageDetail for Home LPushUsage forwarding and Redis consumption with self-loop guards.
- Add comprehensive test coverage for canonical headers, body extraction, ghost parent elimination, and self-referential loop guards.
- Mark Codex usage limit errors as credential-scoped across HTTP and WebSocket executors.
- Support both top-level and nested error structures with case-insensitive matching when parsing retry-after resets.
- Propagate prevalidated candidate context to session affinity and built-in selectors during auth selection.
Closes: #5529
- Detect advisor tool calls and advisor results in conversation history.
- Preserve forwarded system prompt blocks in top-level system instead of splicing them into message turns or prepending reminders.
- Prevent message index shifts that break layout bindings for encrypted advisor results and trigger upstream 400 errors.
Closes: #5470
- Track auth revisions and file observations to detect changes that occur while background auth scans are in flight.
- Invalidate and drop stale scanned auth records in `refreshAuthState` when concurrent file modifications or deletions are observed.
- Reject out-of-order delayed snapshot updates in `dispatchAuthUpdates` using watcher-local revision counters.
Closes: #5528
- Retain `supported_reasoning_levels` as an empty array instead of deleting the key when no reasoning levels are supported or compatible.
- Continue deleting `default_reasoning_level` when reasoning levels are empty.
- Add `gpt-6-astra` model specifications and capabilities to registry models.
- Update Codex client models configuration and instructions for `gpt-6-astra`.
- Bump default Codex client version and user-agent to `0.153.3` in model fetcher tool.
- Responses API: only hoist developer/system messages before conversation starts to systemInstruction, keeping token 0 cache prefix immutable. Demote mid-session developer messages to user role and merge consecutive user turns via MergeAdjacentGeminiUserContents without crossing functionResponse boundaries.
- Tool Call Buffer: buffer mid-session developer messages during pending function calls and emit after functionResponse, preserving valid tool pairing and reason replay.
- Chat Completions API: apply the same leading/mid-session distinction for system/developer messages and guard against empty parts.
- Claude Messages API: align role: "developer" in messages with role: "system", demoting to <system-reminder> user turns and avoiding upstream 400s.
- Validation: update ValidateGeminiFunctionCallPairing to allow intervening user turns before functionResponse, matching upstream Antigravity tolerance.
- Role Normalization: ensure functionResponse turns in Antigravity are always normalized to role: "user".
- Require exactly one non-reminder text block matching quota/test/probe/./Hi for probe request matching.
- Identify title helper requests via expanded session title patterns.
- Implement post-payload bidirectional probe reclassification: strip CPA diagnostics and billing tags on probes, while restoring continuity if declassified.
- Preserve caller-owned and payload-supplied diagnostics on probe requests.
- Gate late sensitive-word obfuscation strictly on cloaked requests in Execute and ExecuteStream.
- Add comprehensive end-to-end tests for probe classification, diagnostics isolation, and late cloaking.
- Inject '# Reporting outcomes' system block for Fable 5.1 / Mythos 5.1 models matching Claude Code 2.1.258 tengu_dapper_lagoon behavior.
- Support both string-format and block-array system prompts for Fable reporting injection.
- Add reconcileClaudeCodeFableModelAfterPayload to reconcile model additions when payload rules override model or thinking.
- Reliably re-add reporting block if omitted after payload rules modify system blocks.
- Drop injected thinking.display on Fable models when payload changes thinking type from adaptive to disabled.
- Enhance payload rule path tracking with ancestor target matching in ApplyPayloadConfigWithTrackedPaths.
- Introduce 2.1.258 dynamic betas: thinking-display-updates-2026-08-18, server-side-fallback-2026-06-01, and fallback-credit-2026-03-24.
- Prune effort-2025-11-24 on Haiku models, probes, and when thinking is disabled.
- Prune thinking-display-updates on disabled thinking and probe/helper turns.
- Identify Fable 5.1 / Mythos 5.1 models with boundary checks and inject default fallbacks and adaptive thinking display.
- Strictly pair 1h cache control with extended-cache-ttl-2025-04-11, stripping TTL on probes and subagents.
- 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.
Enforce strict monotonic offset ordering (replacement.start <= last) when
splicing degraded tool provenance IDs to reject unknown zero offsets and
prevent overwriting the payload prefix.
- Implement three-way merge for refreshed and prepared auth updates against base and current runtime state.
- Retain user modifications to metadata, attributes, proxy URL, and error/cooldown status across background refresh operations.
- Guard against stale registration epochs and enforce per-auth generation ordering during persistence.
Closes: #5465
- Recursively inspect JSON schema properties to detect optional fields not listed in the `required` array.
- Downgrade `strict` to false when schemas contain optional properties to prevent backend HTTP 400 rejections.
Closes: #5463
- Prefix colliding tool names (`read_file`, `write_file`, `execute_code`) with `external_` when sending requests upstream to Antigravity models.
- Strip the `external_` prefix from Antigravity responses so clients receive the original tool names.
- Apply the name mapping across tool definitions, tool calls, tool results, and tool choice in both Chat Completions and Responses translators.
Closes: #5462
- Bump plugin schema version to 5 and introduce `SchemaVersionStreamChunkOmitHistory`.
- Omit `HistoryChunks` on payload stream chunks for schema version 5+ to avoid per-chunk cloning and serialization overhead.
- Conditionally accumulate and clone history chunks only when legacy plugins with schema version < 5 are active.
Closes: #5451
- Map Claude `max_tokens` stop reason to `response.incomplete` with `max_output_tokens` incomplete details.
- Propagate `incomplete` status to trailing output items across streaming and non-streaming responses.
- Defer and track output item finalization to ensure correct status and arguments when turns are truncated.
Closes: #5439
- Cache token usage metrics from streaming chunks instead of prematurely finalizing content blocks.
- Defer `message_delta` and `message_stop` emissions until encountering a finish reason, a trailing usage chunk, or stream completion.
Closes: #5419
- Add `writePing` to responses websocket writer to emit Ping control frames.
- Send periodic keep-alive Ping frames based on streaming configuration during response forwarding.
- Reset keep-alive interval upon receiving data chunks and abort session if ping write fails.
Closes: #5413
- Add `codex.orphan-delegation-compatibility` configuration option and mirror it to SDK configuration.
- Convert orphan Codex delegation outputs into standard user messages for requests with `X-Openai-Subagent: collab_spawn`.
- Integrate orphan delegation rewriting into OpenAI responses request handling pipeline.
Closes: #5401
- Add routing.session-affinity-subagents (defaulting to true) to RoutingConfig.
- Unify subagent parent credential inheritance across all providers by removing hardcoded provider/model blacklists.
- When session-affinity-subagents is false, isolate subagents and distribute them via the fallback selector.
- Ensure changing session-affinity-subagents is a no-op when session-affinity is false.
- Preserve alias isolation and failure isolation invariants.
Closes: #5417
