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v1.5.9

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Changelog

This release rebases Bifrost Enterprise on OSS transports v1.6.9. It brings opt-in HTTP/2 PING keepalives for Bedrock streams, tenant-aware OTEL metric attributes (team, customer, business unit, service instance), and a large batch of streaming and provider-fidelity fixes, including two SSE heartbeat regressions that could corrupt or abort raw passthrough streams. There are no enterprise-only feature changes in this release.

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🌎 Open Source Features

  • Bedrock HTTP/2 PING Keepalives - The Bedrock provider can now send HTTP/2 PING frames on idle connections through the new http2_ping_interval_in_seconds config key (0 disables it), so quiet streams survive intermediaries that cut idle connections. Docs
  • Tenant Attributes on OTEL Metrics - Exported metrics now carry a service instance id plus team, customer, and business-unit ids and names, so series can be sliced per tenant without post-processing. Attribute values are also normalized and whitespace-trimmed on export. Docs
  • Adaptive Thinking on Raw Passthrough - For adaptive-only Anthropic models (Opus 4.7+, Opus 4.8, Opus 5, Sonnet 5, Fable 5, Mythos 5), a legacy thinking.type: "enabled" block is now rewritten to the adaptive form on the raw passthrough body, not just on the typed request path.

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🐞 Fixed

  • SSE Heartbeat Mid-Line Corruption - The stream reader now tracks line boundaries under a mutex and will not emit a heartbeat mid-line, fixing corrupted data: payloads on raw passthrough streams.
  • SSE Heartbeat Frame Compatibility - The heartbeat comment frame no longer carries a trailing blank line, so non-conforming SSE decoders (openai-go ssestream before v3.43.0) stop dispatching an empty event and aborting mid-stream.
  • Lost Log Rows on Shared Trace IDs - Concurrent requests that inherit the same W3C trace id no longer overwrite each other’s pending log entry; the join now uses the per-request internal trace id.
  • Budget Counters Reset on Force-Sync - config.json force-sync no longer overwrites live current_usage, last_reset, and the token/request rate-limit counters with file values.
  • Transcription Filename Dropped - The client’s multipart filename is carried through transcription ingress, so non-WAV containers are no longer relabelled audio.mp3 and rejected upstream.
  • Anthropic Mid-Conversation System Messages - A role:"system" turn that cannot be forwarded natively is inlined as a user turn instead of being dropped, and Bedrock’s system-reminder converter keeps its cache_control marker.
  • Bedrock Streaming Correctness - ConverseStream now reports stopReason: tool_use for tool-use turns, message_start carries an all-zero usage object when figures are unknown so @ai-sdk/anthropic accepts the frame, and encrypted reasoning is preserved as a replay signature when translating Responses history.
  • Encrypted Reasoning Fail-Soft - An upstream 400 caused by unverifiable replayed encrypted_content now strips the reasoning content and retries once instead of failing the request.
  • Server-Side Tool Search - tool_search_tool_* types are normalized on the Responses path, and include_server_side_tool_invocations now reaches the Gemini declaration-drop gate.
  • DeepSeek Thinking on Multi-Turn - Thinking is no longer silently disabled for ordinary multi-turn conversations through the OpenAI-compatible surface. Docs
  • Vertex and Gemini Response Fidelity - generateContent keeps candidates[0].safetyRatings and avgLogprobs, and Vertex cached-content methods honour API-key or context-header auth instead of overwriting Authorization.
  • Custom Provider Base Resolution - OpenAI models served through a custom provider now resolve to their built-in base provider before deciding reasoning item-id embedding.
  • MCP Tool Errors Replayed as Success - Failed MCP tool executions are marked as errors instead of being replayed to the model as successful results, covering agent-loop failures, the MCP isError flag, and CodeMode lookup/sandbox failures.
  • Tool-Result Document Blocks - document blocks in tool results survive the Anthropic to Responses conversion with a synthesized filename, and FileURL/FileType propagate through all three chat/responses conversion paths.
  • Stream Termination Edge Cases - A nil delta paired with a non-nil finish reason no longer aborts the stream, and GPT-5-series detection tolerates prefixed model names when resolving reasoning-effort support.

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🗄️ Database Migrations

No new database migrations in this release, in either the OSS transports layer or the enterprise repo.

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🐙 Closed OSS Issues

  • #5206 - Bedrock ConverseStream egress reports stopReason=end_turn for tool-use turns (should be tool_use)
  • #5211 - Bedrock streaming can drop with “unexpected EOF” when an intermediary idle timeout severs a quiet stream
  • #5256 - Concurrent HTTP requests sharing a W3C trace ID lose LLM log rows
  • #5279 - OpenAI /v1/responses to Anthropic drops the tool_search_tool_regex type, so server-side tool_search never runs
  • #5670 - Transcription drops the client’s multipart filename, so non-WAV containers are relabelled audio.mp3 and rejected
  • #5679 - Anthropic Messages does not propagate Gemini mixed server/client tool opt-in
  • #5843 - generateContent (Gemini format) drops candidates[0].safetyRatings and avgLogprobs on Vertex AI responses
  • #5874 - SSE heartbeat frame aborts streams for openai-go ssestream consumers (< v3.43.0) with “unexpected end of JSON input”
  • #5885 - v1.6.8 omits message_start.message.usage on Bedrock-backed providers, breaking @ai-sdk/anthropic streaming
  • #5887 - DeepSeek thinking silently lost on ALL multi-turn requests via OpenAI-compat inbound
  • #5890 - chat completions surface drops tool_result is_error, so failed tool calls replay to the model as successful
  • #5902 - service_tier silently dropped for gpt-5.4 family, priority/fast requests downgrade to default
  • #5905 - v1.6.8 raw passthrough heartbeat can split SSE data lines and corrupt JSON
  • #5925 - config.json force-sync overwrites budget current_usage and last_reset on startup

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📀 Base OSS version

transports/v1.6.9

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🔌 If you are compiling plugin against this release - use following deps