--- title: Apache Flink Agents 0.4.0 Release Announcement | daily.dev description: Apache Flink Agents 0.4.0 ships as the final planned preview release before a production-ready 1.0. It adds sub-agents that delegate tasks to other agents, a... canonical: https://daily.dev/posts/apache-flink-agents-0-4-0-release-announcement-71ffd5vqc twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: Apache Flink Agents 0.4.0 Release Announcement | daily.dev og:description: Apache Flink Agents 0.4.0 ships as the final planned preview release before a production-ready 1.0. It adds sub-agents that delegate tasks to other agents, a... og:url: https://daily.dev/posts/apache-flink-agents-0-4-0-release-announcement-71ffd5vqc og:image: https://api.daily.dev/og/posts/71fFd5Vqc.png og:image:alt: Apache Flink Agents 0.4.0 Release Announcement og:image:width: 1200 og:image:height: 630 og:locale: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # Apache Flink Agents 0.4.0 Release Announcement **[Flink](https://daily.dev/sources/flink)** · 13 min read · 0 upvotes · 0 comments ## Summary Apache Flink Agents 0.4.0 ships as the final planned preview release before a production-ready 1.0. It adds sub-agents that delegate tasks to other agents, a unified Decision Model API (TypeSafe, OpenAI, Alibaba Cloud Model Studio), model routing, multimodal messages, and expanded structured output. Observability gets a new Trace Log and richer built-in metrics. The release carries more breaking changes than usual: max-retries defaults change from 3 to 0, Action State Store data from 0.3 is incompatible, and default models shift to gpt-4o-mini and claude-sonnet-4-6. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Questions this post answers ### What breaking changes come with upgrading Apache Flink Agents from 0.3 to 0.4.0? Action State Store data written by Flink Agents 0.3 is not compatible with 0.4, so saved Action execution history cannot be reused across the upgrade. The max-retries default also changes from 3 to 0, error-handling-strategy is removed, Event Log is replaced by Trace Log with renamed configuration keys, and several Java and Python APIs for actions, messages, and tool results change. _Teams planning this upgrade can track Flink Agents breaking changes on daily.dev before touching production state._ ### What are the default LLM models in Flink Agents 0.4 for OpenAI and Anthropic? The Python OpenAI default model changes from gpt-3.5-turbo to gpt-4o-mini, and the Anthropic default changes from claude-sonnet-4-20250514 to claude-sonnet-4-6 in Apache Flink Agents 0.4.0. Applications relying on implicit defaults should configure their intended model explicitly rather than depend on the framework's defaults. _Developers picking default models for streaming agent apps can follow these changes on daily.dev._ ### How do sub-agents work in Apache Flink Agents 0.4? Sub-agents let an agent delegate tasks to other agents within the same Flink job or to integrated external agent services, then continue processing with the results. Delegation can happen explicitly in code or the model can choose a sub-agent itself. Calls support durable execution, so recorded results can be reused during recovery. _Engineers designing multi-agent streaming pipelines can follow sub-agent patterns like this on daily.dev._ ## Similar posts on daily.dev - [Apache Flink 2.2.0: Advancing Real-Time Data \+ AI and Empowering Stream Processing for the AI Era](https://daily.dev/posts/apache-flink-2-2-0-advancing-real-time-data-ai-and-empowering-stream-processing-for-the-ai-era-vyfow5bk8) · Flink · 5 upvotes · 0 comments - [Releasing Airflow AI Provider 1.0: Agents, Sandboxes, Human Approval and Smarter Retries](https://daily.dev/posts/releasing-airflow-ai-provider-1-0-agents-sandboxes-human-approval-and-smarter-retries-kf8gteqvn) · Apache Airflow · 7 upvotes · 0 comments - [Apache Flink CDC 3.7.0 Release Announcement](https://daily.dev/posts/apache-flink-cdc-3-7-0-release-announcement-fuum4pygz) · Flink · 5 upvotes · 0 comments --- Tags: [#ai-agents](https://daily.dev/tags/ai-agents), [#llm](https://daily.dev/tags/llm), [#java](https://daily.dev/tags/java), [#apache-flink](https://daily.dev/tags/apache-flink) [View this post on daily.dev](https://daily.dev/posts/apache-flink-agents-0-4-0-release-announcement-71ffd5vqc) ```json {"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://daily.dev/#organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180},"sameAs":["https://twitter.com/dailydotdev","https://github.com/dailydotdev","https://www.linkedin.com/company/daily-dev-ltd"]},{"@type":"WebSite","@id":"https://daily.dev/#website","url":"https://daily.dev","name":"daily.dev","publisher":{"@id":"https://daily.dev/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://daily.dev/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]} {"@context":"https://schema.org","@type":"TechArticle","headline":"Apache Flink Agents 0.4.0 Release Announcement","url":"https://daily.dev/posts/apache-flink-agents-0-4-0-release-announcement-71ffd5vqc","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/apache-flink-agents-0-4-0-release-announcement-71ffd5vqc"},"datePublished":"2026-10-30T08:06:35.047Z","dateModified":"2026-10-30T08:07:05.260Z","description":"Apache Flink Agents 0.4.0 ships as the final planned preview release before a production-ready 1.0. 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