0.8.0

0.8.0

Published 10 April 2026

Major Features

• Spring AI Integration: Added comprehensive Spring AI support with ChatMemoryRepository and VectorStore integration for seamless persistence and retrieval (#1719, #1763)
• Amazon Bedrock AgentCore Memory: Introduced ChatHistoryProvider backed by Amazon Bedrock AgentCore Memory for managed conversation state (#1758)
• DataDog LLM Observability: Added DataDog LLM Observability exporter with response metadata forwarding to inference spans (#1591)

Improvements

• Native structured output for Claude 4.5+: Added JSON Schema support for Claude 4.5+ series models across Anthropic, Bedrock, and Vertex AI providers (#1593)
• Mermaid diagram support for nested subgraphs: Enhanced Mermaid diagram generator to visualize subgraphs and nested subgraphs (#1745)
• RAG-based abstractions:LongTermMemory feature now uses cleaner abstractions from rag-base for better modularity (#1785)
• LLMClient constructor decoupling: Decoupled LLMClient constructors from Ktor for improved flexibility (#1742)
• Customizable field names: Added support for customized field names in AdditionalPropertiesFlatteningSerializer (#1626)
• GPT-5.4 models: Added support for GPT-5.4Mini and GPT-5.4Nano models (#1837)
• Google models update: Updated Google models capabilities and deprecated older model versions (#1827)
• Environment creation abstraction: Extracted environment creation into prepareEnvironment method in agent implementations for better extensibility (#1790)
• Reasoning prompt refactoring: Moved reasoning prompt configuration to strategy parameters for better encapsulation (#1789)
• JSON schema capabilities: Added JSON schema capabilities to OpenAI models (#1822)
• Add missing JavaAPI for history compression inside write session: Added replaceHistoryWithTLDR as non-suspend method of AIAgentWriteSession (#1839)

Bug Fixes

• Agent message handling: Corrected description of Koog agent message handling (#1010)
• History compression with chat memory: Fixed missed prompt messages when chat memory feature is enabled (#1835)
• Reasoning messages: Added IDs for reasoning messages and improved reasoning process to fix status 400 errors from OpenAI (#1779)
• Ollama embedding: Check HTTP status before deserializing Ollama embedding response to prevent parsing errors (#1702)
• Ktor parameter shadowing: Renamed registerTools parameter in koog-ktor to avoid Builder.build() shadowing (#1705, #1721)
• Opus 4.6 token limit: Corrected maxOutputTokens from 1M to 128K for Claude Opus 4.6 (#1825)
• Java AIAgentLLMWriteSession: Added Java support for AIAgentLLMWriteSession compress history functionality

Breaking Changes

• LLMProvider singletons restored: Restored LLMProvider singletons and fixed reified type inference (potentially breaking for custom provider implementations) (#1800)

Examples

• Spring AI Examples Add comprehensive examples of Koog + Spring AI integration

Documentation

• Java API documentation: Add Java code snippets for Agent Events documentation (#1833)
• DataDog documentation: add DataDog exporter documentation (#1801)
• Java API documentation: Add Java code snippets for tracing feature (#1821)
• Java API documentation: Add missing Java snippets for Persistence (#1818)
• Java API documentation: Add java snippets for model capabilities docs (#1815)
• Java API documentation: Add java snippets for content moderation docs (#1814)
• Java API documentation: Add missing Java snippets for read/write LLM sessions (#1808)
• Java API documentation: Predefined strategies Java snippets (#1796)
• Java API documentation: Update streaming docs with Java snippets (#1792)
• Fixed broken formatting: fix code snippets to remove leaking includes (#1759)
• Improve wording: Update wording in History compression and Predefined nodes and components (#1699)

0.7.3

Published 26 March 2026

New Features

• Bedrock prompt caching: Added CacheControl property on Assistant, User, and System messages within the Prompt and integrated explicit cache blocks in the Bedrock Converse API (#1583)

Bug Fixes

• Agent deadlock fix: Fixed deadlock when agent.run() is called from within executor.submit — when the agent was invoked from a worker thread of the configured ExecutorService, runBlocking(context) would dispatch the coroutine back onto that executor and park the calling thread (KG-750, #1716)
• AIAgentTool for simple agents: Fixed AIAgentTool to support simple agents that accept primitives as input by introducing AIAgentToolInput wrapper (#1729)
• MCP custom transport: Fixed runtime crash when using non-default custom MCP transports in MCPToolRegistryProvider (#1740)
• Anthropic tool error reporting: Added is_error flag for failed tool calls in the Anthropic client so the model is properly informed of tool execution failures (#1700)
• DeepSeek reasoning with tool calls: Ensured reasoningContent is preserved and merged with tool calls to satisfy DeepSeek API requirements (#1614)

Breaking Changes

• ToolRegistry.Builder removed: Unified everything under expect/actual ToolRegistryBuilder. Removed tools(Any) overload that was interfering with tools(List) and causing unexpected bugs (#1746)

Build

• Removed stale coreLibrariesVersion override: The convention plugins were setting coreLibrariesVersion = "2.1.21" which made published POMs declare kotlin-stdlib 2.1.21, mismatching the actual 2.3.x compiler version. Removed the override so the POM picks up the real compiler version (#1697, #1722)

Documentation

• Updated serialization documentation with Java snippets (#1732)
• Added Java implementation for custom subgraphs documentation (KG-770, #1730)
• Added Java implementation for OpenTelemetry, Langfuse, and Weave integration documentation (KG-760, #1696)
• Moved "Chat agent with memory" tutorial under "Chat memory" feature section (#1686)

0.7.2

Published 19 March 2026

Bug Fixes

• Java API for OpenTelemetry extensions: Fixed Java API inside OpenTelemetryConfig class annotated with @JavaOverride
  that relied on Kotlin Duration class, causing all further attributes to be skipped by the compiler in Langfuse and Weave extensions (KG-754, #1682)
• System prompt preservation in agent builder: Fixed systemPrompt method in agent builders to preserve previously configured messages, id, and params in the prompt (KG-747, #1671)
• LLMParams copy overloads: Added correct override fun copy() to all LLMParams subclasses (GoogleParams, AnthropicParams, OpenAIChatParams, etc.) so that Prompt.withUpdatedParams preserves provider-specific fields instead of silently dropping them. Also fixed BedrockConverseParams.copy() missing parameters and DashscopeParams incorrect super.copy() call (KG-742, #1668)

Breaking Changes

• Removed input parameter from AIAgentFunctionalContext.subtask: The input parameter was not actually used; taskDescription is the right way to specify the task. Related methods and builders updated accordingly (#1667)

Documentation

• Started porting rest of the documentation to Java (#1669)

0.7.1

Published 17 March 2026

Major Features

• Java API: Introduced comprehensive Java interoperability across the framework:
  • Java API for creating and running agents from pure Java projects (#1185)
  • Builder-based Java API for graph strategies (#1581, #1617, #1366)
  • Java-friendly API for AIAgentStorage with JVM-specific methods (#1600)
  • Blocking API builders for PromptExecutor and LLMClient for Java (#1555, #1604)
  • Jackson as the default serializer for Java API (#1630)
  • Weave and Langfuse integrations now available from Java (#1616)
  • Centralized Java/Kotlin time conversion utilities (TimeUtils, toKotlinDuration, etc.) (#1620)
• Spring AI Integration: Added two new Spring Boot starters (koog-spring-ai-starter-model-chat and koog-spring-ai-starter-model-embedding) to integrate Spring AI ChatModel and EmbeddingModel implementations as Koog LLM backends, enabling support for the wide range of providers available in Spring AI (KG-109, #1587)
• Chat Memory: Introduced persistent chat memory with multiple storage backend options:
  • Core ChatMemory feature and ChatHistoryProvider abstraction (#1511)
  • Exposed-ORM based providers for PostgreSQL, MySQL, and H2 (#1584)
  • Pure JDBC ChatHistoryProvider for PostgreSQL, MySQL, and H2 with no ORM dependency (#1597)
  • JDBC-based PersistenceStorageProvider (#1612)
• Long-term Memory: Added LongTermMemory feature that augments prompts with relevant memory records from storage and extracts/ingests new memories from agent conversations (#1490)
• Library-Agnostic Serialization API: Introduced a JSONSerializer abstraction to support pluggable serialization libraries. Two implementations provided: KotlinxSerializer (default) and the new JacksonSerializer in a separate serialization-jackson module. Tools API migrated to this new abstraction (#1588)

Improvements

• OpenTelemetry:
  • Added OpenTelemetry support for functional agent pipelines (KG-677, #1447)
  • Added OpenTelemetry spans for MCP tool calls (#1421)
• Planner improvements:
  • Added AIAgentPlannerContext and AIAgentFunctionalContextBase for better context hierarchy and planner-specific APIs (#1480)
  • Added planner-specific pipeline interceptors: onPlanCreationStarting/Completed, onStepExecutionStarting/Completed, onPlanCompletionEvaluationStarting/Completed (KG-672, #1550)
  • GOAP strategies now have typed input/output and a dedicated GoapAgentState (#1498)
• OpenRouter embedding support: Implemented LLMEmbeddingProvider for OpenRouter, enabling access to 21+ embedding models (KG-659, #1398)
• Swift Package Manager support: Added XCFramework build and distribution infrastructure for iOS/macOS development via SPM (KG-682, #1485)

New LLM Models

• Anthropic Claude Opus 4.6: Added support via Anthropic and Bedrock executors (#1513)
• Google Gemini 3 Flash Preview: New model with extended capabilities and high-speed processing (#1621)
• OpenAI GPT-5.x series: Added GPT-5.1-Codex-Max, GPT-5.2-Codex, GPT-5.3-Codex, GPT-5.4, and GPT-5.4-Pro (#1595)
• Moonshot Kimi K2 Thinking: Added support via the Bedrock Converse API (#1436)
• Ollama thinking support: Added think=true request parameter and streaming reasoning delta support for Ollama models (#1532)

Bug Fixes

• Persistence checkpoints: Fixed last successful node being re-executed when restoring from a checkpoint; changed lastInput to lastOutput in checkpoint structure (#1308)
• Ollama streaming: Fixed Ollama client to use preparePost(...).execute for proper streaming instead of buffering the full response (#1497)
• OpenRouter streaming: Fixed missing reasoning and reasoningDetails fields in OpenRouterStreamDelta causing deserialization errors (#1504)
• Dashscope streaming: Fixed tool call argument merging for streaming responses in DashscopeLLMClient (KG-658, #1590)
• agents-ext dependency leak: Moved agents-ext from commonMain api to jvmTest implementation in agents-test to prevent transitive compile-time dependency leakage (#1506)
• Streaming exception handling: executeStreaming now properly propagates exceptions from LLM clients and requires StreamFrame.End to signal stream completion (KG-550, #1580)
• Debugger feature: Extended to support functional agents in addition to graph-based agents by dispatching appropriate strategy starting events (KG-741, #1637)

Breaking Changes

• Serialization API: All encode/decode methods in Tool now accept a second JSONSerializer parameter. Automatic ToolDescriptor generation for primitive argument types (Tool<String, String>) is no longer supported without a custom descriptor. AIAgentFeature.createInitialConfig now takes an agentConfig: AIAgentConfig parameter. JSON types in pipeline events changed from kotlinx.serialization to ai.koog.serialization (#1588)
• TypeToken replaces KType: Nodes and agent features now work with ai.koog.serialization.TypeToken instead of kotlin.reflect.KType. All typeOf<Foo>() usages should be replaced with typeToken<Foo>() (#1581)
• Global JSON schema registries removed: RegisteredStandardJsonSchemaGenerators and RegisteredBasicJsonSchemaGenerators removed. getStructuredRequest and StructureFixingParser moved to ai.koog.prompt.executor.model package (KG-698, #1517)
• LLMDescription.description renamed to value: The description field of LLMDescription has been renamed to value for Java compatibility (#1607)
• Deprecated kotlinx.datetime imports replaced with kotlin.time equivalents (Clock, Instant) (#1533)
• Retired Anthropic/Bedrock models: Removed Sonnet_3_7, Haiku_3_5, Sonnet_3_5, and Opus_3 from Anthropic models; removed several AI21, Bedrock, and legacy Anthropic models. Haiku_3 marked as deprecated (#1526)

Documentation

• Added documentation for Java API and Java examples (#1610)
• Added documentation for Spring AI integration (KG-109, #1627)
• Added documentation for custom feature creation (#1295)
• Reworked Getting Started, agent types, and Chat Memory tutorials (#1349, #1552)
• Improved Prompts and Planner agent documentation (#1302, #1301)
• Added nightly builds documentation (#1433)

Examples

• Added Java example for JavaOne 2026 (#1641)
• Added full Spring Boot Java API example (#1350)
• Added example for calling a Koog agent from JavaScript code, including browser (TypeScript webapp) and Node.js usage with AbortSignal support (#1500)

0.6.4

Major Features

• LLM Client Router: Added support for routing requests across multiple LLM clients with pluggable load balancing strategies. Includes a built-in round-robin router and fallback handling when a provider is unavailable (#1503)

Improvements

• Anthropic models list: Implemented models() for the Anthropic LLM client, consistent with other supported providers (KG-527, #1460)
• Dependency updates: Updated io.lettuce:lettuce-core from 6.5.5.RELEASE to 7.2.1.RELEASE (#1304)

Breaking Changes

• OllamaModels relocation: OllamaModels and OllamaEmbeddingModels moved from prompt-llm to prompt-executor-ollama-client module (KG-121, #1470)

0.6.3

Improvements

• Streaming reasoning support: Models with reasoning capabilities (like Claude Sonnet 4.5 or GPT-o1) now stream their reasoning process in real-time, allowing you to see how the model thinks through problems as it generates responses (KG-592, #1264)
• LLModel API enhancement: LLM clients now return List<LLModel> instead of List<String> for improved type safety and direct access to model metadata (#1452)
• Multiple event handlers per feature: Features can register multiple handlers for the same event type, enabling more flexible event processing (KG-678, #1446)
• Dependency updates: Updated Kotlin libraries (KG-544, #1475):
  • Kotlin from 2.2.21 to 2.3.10
  • kotlinx-serialization from 1.8.1 to 1.10.0
  • kotlinx-datetime from 0.6.2 to 0.7.1

Bug Fixes

• OpenRouter streaming: Fixed parsing errors when receiving reasoning content from models with reasoning capabilities by adding missing reasoning and reasoningDetails fields to the streaming response (#854)
• ReadFileTool: Fixed incorrect binary file detection for empty files (KG-533, #1340)
• DevstralMedium model: Added missing LLMCapability.Document capability (#1482)
• Ktor integration: Fixed custom timeout values being ignored when configuring LLM providers in application.yaml (KTOR-8881, #807)

Breaking Changes

• Streaming API redesign: Restructured StreamFrame types to distinguish between delta frames (incremental content like TextDelta, ReasoningDelta) and complete frames (full content like TextComplete, ReasoningComplete). Added End frame type to signal stream completion (#1264)
• Kotlin version update: Migrated from Kotlin 2.2.21 to 2.3.10; replaced kotlinx.datetime.Clock/Instant with kotlin.time.Clock/Instant (#1475)
• LLModel API changes: LLMClient.models() now returns List<LLModel> instead of List<String>; LLModel.capabilities and LLModel.contextLength are now nullable (#1452)

Documentation

• Updated documentation for the singleRunStrategy API and AIAgentService class.

Refactoring

• Module restructuring: Moved file-system abstractions (GlobPattern, FileSize, FileSystemEntry, FileSystemEntryBuilders) from agents-ext to rag-base module to reduce transitive dependencies (#1278)

Examples

• Added the ACP (Agent Communication Protocol) agent example project (#1438)

0.6.2

Published 10 February 2026

Improvements

• Structured output with examples: Include examples in the prompt with StructuredRequest.Native to help LLMs better understand desired data format (#1328, #1396)

Bug fixes

• Kotlin/Wasm support: Applied workaround for Kotlin/Wasm compiler bug which produced invalid Wasm files (KT-83728, #1365)

0.6.1

Published 28 January 2026

Major Features

Block of changes:

• Converse API support in Bedrock LLM client: Added support for the Converse API in the Bedrock LLM client, enabling richer prompt-based interactions (KG-543, #1384)
• Tool choice heuristics: Introduced heuristic-based required tool selection via LLMBasedToolCallFixProcessor for models that do not support explicit tool choice (KG-200, #1389)

Improvements

• Prompt parameter preservation: Ensured that LLMParams fields are preserved after calling Prompt.withUpdatedParams (#1194)
• Error handling for tools: Improved error handling for tool argument parsing, result serialization, and subgraph tool execution failures (KG-597, #1329)
• OpenTelemetry:
  • Updated span attributes and names to better align with semantic conventions (KG-646, #1351; KG-647, #1359)
  • Replaced agent data propagation through the coroutine context with the AIAgentContext instance for agent events (KG-178, #1336)
• ACP SDK update: Updated the ACP SDK to version 0.13.1 to enable connections from IntelliJ-based IDE clients (KG-671, #1363)

Bug fixes

• OpenAI client:
  • Restored the minimal option in ReasonEffort within OpenAIDataModels (#1412)
  • Fixed missing token usage information in streaming mode (#1072, #1404)
• Bedrock client:
  • Fixed JSON schema generation for Bedrock tools to correctly handle nested objects (#1259, #1361)
  • Fixed parsing of tool usage in Bedrock Anthropic streaming responses (KG-627, #1310)
• DeepSeek structured output: Fixed structured output handling for DeepSeek (KG-537, #1385)
• Gemini 3.0 tool calls: Fixed thought signature handling for tool calls (KG-596, #1317)
• Subtask completion flow: Ensured that subtasks return after a tool call finishes, before issuing a new LLM request (#1322, #1362)

Examples

• Updated the ACP example to use the latest ACP SDK version (#1363)
• Updated the Compose Demo App to use the latest Koog version (#1227)

0.6.0

Published 22 December 2025

Major Features

• ACP Integration: Introduce initial ACP (Agent Communication Protocol) integration to create ACP-compatible agents in Koog (#1253)
• Planner Agent Type: Introduce new "planner" agent type with iterative planning capabilities. Provide two out-of-the box strategies: simple LLM planner and GOAP (Goal-Oriented Action Planning) (#1232)
• Response Processor: Introduce ResponseProcessor to fix tool call messages from weak models that fail to properly generate tool calls (KG-212, #871)

Improvements

• Event ID Propagation: Integrate event ID and execution info propagation across all pipeline events, agent execution flow, and features including Debugger and Tracing (KG-178)
• Bedrock Enhancements:
  • Add fallback model support and warning mechanism for unsupported Bedrock models with custom families (KG-595, #1224)
  • Add global inference profile prefix support to Bedrock models for improved availability and latency (#1139)
  • Add Bedrock support in Ktor integration for configuring and initializing Bedrock LLM clients (#1141)
  • Improve Bedrock moderation implementation with conditional guardrails API calls (#1105)
• Ollama: Add support for file attachments in Ollama client (#1221)
• Tool Schema: Add extension point for custom tool schemas to allow clients to provide custom schemas or modify existing ones (#1158)
• Google Client:
  • Add support for /models request in Google LLM Client (#1181)
  • Add text embedding support for Google's Gemini models via gemini-embedding-001 (KG-314, #1235)
• HTTP Client: Make KoogHttpClient auto-closable and add clientName parameter (#1184)
• Update MCP SDK version to 0.7.7 (#1154)
• Use SEQUENTIAL mode as default for singleRunStrategy (#1195)

Bug Fixes

• Streaming: Fix streaming + tool call issues for Google and OpenRouter clients - Google client now passes tools parameter, OpenRouter uses CIO engine for SSE, improved SSE error handling (KG-616, #1262)
• Tool Calling: Fix requestLLMOnlyCallingTools ignoring tool calls after reasoning messages from models with Chain of Thought (KG-545, #1198)
• File Tools:
  • Handle empty filters in ListDirectoryTool (KG-628, #1285)
  • Fix directory collapse in ListDirectoryUtil (KG-583, #1260)
  • Clamp endLine to file length and add warnings for overflow in ReadFileTool (KG-534, #1182)
• Model-Specific Fixes:
  • Pass jsonObject as responseFormat for DeepSeek to fix JSON mode (KG-537, #1258)
  • Remove LLMCapability.Temperature from GPT-5 model capabilities (#1277)
  • Fix OpenAI streaming with tools in Responses API (KG-584, #1255)
  • Fix Bedrock timeout setting propagation to BedrockRuntimeClient.HttpClient (#1190)
  • Add handler for GooglePart.InlineData to support binary content responses (KG-487, #1094)
• Other Fixes:
  • Fix reasoning message handling in provided simple strategies (#1166)
  • Fix empty list condition check in onMultipleToolResults and onMultipleAssistantMessages (#1192)
  • Fix timeout not respected in executor because join() was called before timeout check (#1005)
  • Fix ContentPartsBuilder to flush whenever textBuilder is not empty (KG-504, #1123)
  • Fix and simplify McpTool to properly support updated Tool serialization (#1128)
  • Fix OpenAIConfig.moderationsPath to be mutable (var instead of val) (#1097)
  • Finalize pipeline feature processors after agent run for StatefulSingleUseAIAgent (KG-576)

Breaking Changes

• Persistence: Remove requirement for unique graph node names in Persistence feature, migrate to node path usage (#1288)
• Tool API: Update Tool API to fix name and descriptor discrepancy - moved configurable tool properties to constructors, removed doExecute in favor of execute (KG-508, #1226)
• OpenAI Models: GPT-5-Codex and GPT-5.1 reasoning models moved from Chat section to Reasoning section (KG-562, #1146)
• Structured Output: Rename structured output classes - StructuredOutput → StructuredRequest, StructuredData → Structure, JsonStructuredData → JsonStructure (#1107)
• Module Organization: Move LLMChoice from prompt-llm to prompt-executor-model module (#1109)

0.5.4

Published 03 December 2025

Improvements

• LLM clients: better error reporting (#1149). Potential breaking change: LLM clients now throw LLMClientException instead of IllegalStateException (KG-552)
• Add support for OpenAI GPT-5.1 and GPT-5 pro (#1121) and (#1113) and Anthropic Claude Opus 4.5 (#1199)
• Add Bedrock support in Ktor for configuring and initializing Bedrock LLM clients. (#1141)
• Improve Bedrock moderation implementation (#1105)
• Add handler for GooglePart.InlineData in GoogleLLMClient (#1094) (KG-487)
• Improvements in ReadFileTool (#1182) and (#1213)

Bug Fixes

• Fix and simplify McpTool to properly support updated Tool serialization (#1128)
• Fix file tools to properly use newer API to provide textual tool result representation (#1201)
• Fix empty list condition check in onMultipleToolResults and onMultipleAssistantMessages (#1192)
• Fix reasoning message handling in strategy (#1166)
• Fix timeout in JvmShellCommandExecutor (#1005)