- Wire parity: align Connect-RPC Sentry-Trace, User-Agent suppression, float32 double pattern, and dynamic 732-char hex device fingerprint
- Session ordinal & cache: implement process-scoped Field 15.2 with bounded LRU (5000 entries) and Field 15.4=14 user boundary; prioritize stable session_id over previous_interaction_id to preserve prompt caching
- Streaming robustness: unblock hung TCP reads on client cancellation via context watcher; accurately propagate stream read errors and trailer errors instead of swallowing truncated frames
- Thought signature & reasoning: emit raw delta signatures directly in active thought steps; eliminate redundant tail base64 re-encoding; ensure 1:1 assistant signature and thinking alignment across multi-turn history
- Tool call de-multiplexing: route parallel tool calls by tc.Index in both streaming step events and non-streaming aggregations
- Security & transport: escape OAuth callback error HTML against reflected XSS, enforce strict state validation, and isolate Devin HTTP transport with tr.Clone()
- Register static model definitions for devin/gemini-3-8-flash (1M context, Google) and devin/grok-4-6 (500k context, xAI).
- Support gemini38Efforts (low/medium/high) and grok46Efforts (low/medium/high/xhigh) in ResolveDevinChatModelUID, supporting both colon and parenthesis suffix parsing.
- Recognize Gemini Tink thought signatures (AY-prefix / 0x01 Tink header) in detectSignatureType and parseSignatureBytes.
- Add unit tests for both models in registry and devin_models.
- Add example payload filter rules in `config.example.yaml` for stripping tools from both flat and nested `additional_tools` Codex request payloads.
Closes: #5792
- Derive billing fingerprint message text from the first user message to prevent prompt cache invalidation across turns.
- Centralize continuity tag resolution to maintain stable prompt IDs and request references across requests.
Closes: #5730
- Inspect `input` items for the latest `configuration_update` reasoning effort before falling back to top-level configuration.
- Route `codex`, `xai`, and `openai-response` providers through usage-specific thinking config extraction.
- Support `none`, `auto`, and explicit reasoning level modes from in-turn updates.
Closes: #5714
- Add `BaseURL` field to usage records and host auth file entries.
- Extract `base_url` from auth attributes and metadata during usage reporting.
- Propagate `base_url` through plugin usage adapters and runtime auth callbacks.
Closes: #5693
- Retain `cache_control` blocks with 1h TTL and `extended-cache-ttl` beta header when explicitly requested by subagents.
- Detect 1h TTL configuration from request payloads and incoming Anthropic-Beta headers.
- Ensure `extended-cache-ttl` beta header is preserved or injected when 1h TTL is present.
Closes: #5629
- Initialize `util.SessionIDResolver` to resolve session IDs from request contexts, metadata, and headers.
- Ensure canonical session metadata is injected into execution options across execution flows.
- Propagate session context in executors to support `$CPA-SESSION-ID` expansion in custom headers.
- Sync cleared or updated session identities back to execution contexts during conductor execution.
Closes: #5690
- Check for \u in fast-path check to prevent JSON Unicode escapes from bypassing inspection.
- Inspect regex keys under patternProperties and drop keys with unsupported Unicode property escapes.
- Add tests covering Unicode escape representations (\u005c, \u0070, \u0050) and patternProperties keys.
- Add HasUnsupportedUnicodePropertyEscape in internal/util to detect \p{...} / \P{...} escapes that fail Python re compilation.
- Strip incompatible pattern attributes during tool parameter normalization in codex/claude and openai/claude translators.
- Provide schema-aware fallback stripping in codex executor helps to protect downstream Codex requests without mutating non-schema user data.
- Export unified schema keyword lists in internal/util to eliminate duplication.
- Add comprehensive unit tests covering Artifact fixtures, lookaheads, and user data preservation.
Closes: #5644
- Emit an OpenAI-compatible trailing usage chunk with an empty choices array on `message_stop`.
- Include `cache_write_tokens` in prompt token details for OpenAI response translations.
- Parse usage from `message.usage` and buffer Claude stream usage across chunks to merge input and output token counts.
- Ensure observed streaming usage details are published on completion or stream failure.
Closes: #5617
- Route `openai-response` source format requests to dedicated streaming and non-streaming responses handlers.
- Add upstream URL resolution for Kimi Responses API endpoints based on auth attributes.
- Normalize `openai-response` provider format to codex during thinking parameter resolution.
Closes: #5400#5571
advanced-tool-use-2025-11-20 is sent only while tool search or another
advanced tool-use feature is on the wire, or when the caller asks for it;
2.1.258 no longer attaches it to plain tool declarations (measured: 158
inline tools, no beta). A caller-supplied afk-mode-2026-01-31 is forwarded
between fast-mode and extended-cache-ttl and is an insertion boundary for
the advisor beta.
2.1.258 Haiku helpers offer the same full compression set as the main
thread and never send X-Stainless-Async. x-client-request-id is attached
only when the client's base URL is api.anthropic.com, so the helper
transport check accepts an empty value or a valid UUID and rejects only a
malformed one.
- Normalize complex constant `oneOf` and `anyOf` tool parameter schemas into equivalent enums to prevent upstream aborts.
- Escape property keys containing dots and colons during schema updates to prevent invalid path splitting.
- Identify terminal `response.incomplete` events with zero output tokens and no content as upstream failures.
Closes: #5551
- Configure upstream connection pool under antigravity.connection-pool with enabled: false by default.
- In short connection mode, set MaxIdleConnsPerHost = -1 with DisableKeepAlives = false, ensuring immediate TCP termination after response body completion without leaking Connection: close request headers.
- When pooling is explicitly enabled (enabled: true), cap idle-conn-timeout at 210s (leaving a 30s safety buffer below Google Frontend's 240s Keep-Alive cutoff) and default max-idle-conns-per-host to 2 (bounded at 100).
- Refactor TransportCache to execute CloseIdleConnections outside the mutex lock during LRU eviction and matching closes.
- Proactively evict and close idle connections on 429 quota exhaustion across Execute, ExecuteStream, and CountTokens.
- Wire hot-reload diff detection and server reload purge hooks for graceful transport pool updates.
- 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
- 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
- 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.
- 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.
- 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.
