# CEL Published articles for CEL. This is one page of public article previews, not the complete archive. Follow Next page to continue. Summaries are not the original full articles. ## 【kube-apiserver】Mutating / Validating Webhook：timeout、failurePolicy 与可用性门 DevFeed: [【kube-apiserver】Mutating / Validating Webhook：timeout、failurePolicy 与可用性门]() Original publisher: [Read original article]() Author: Liao Tonglang Published: 2026-08-28T00:00:00Z Content type: tutorial Language: zh Sources: [土法炼钢 - 系统与基础设施]() Topics: [Kubernetes](), [configuration](), [dry-run](), [TLS (Transport Layer Security)](), [API]() Tags: [admission](), [api](), [apiserver](), [cel](), [configuration](), [distributed](), [kubernetes](), [kyverno](), [mutating](), [timeout](), [tls](), [v1-30-3](), [validating](), [webhook]() ### AI overview A tutorial on configuring and troubleshooting Kubernetes v1.30.3 mutating and validating admission webhooks. It explains configuration fields, timeout and failurePolicy behavior, production availability requirements, reinvocation and idempotency, CEL ValidatingAdmissionPolicy boundaries, and an evidence-based troubleshooting approach. It emphasizes that slow webhooks add latency to the admission path rather than indicating etcd lag. ### Source excerpt 钉 K8s v1.30.3 的 MutatingWebhookConfiguration / ValidatingWebhookConfiguration v1：timeoutSeconds、failurePolicy、sideEffects、reinvocationPolicy 字段语义；webhook 慢如何表现为写路径延迟而非 etcd lag；生产可用性门选取；CEL ValidatingAdmissionPolicy 作为内置替代路径；排障证据包。 ## Securing the agentic era: Introducing formal verification for CEL DevFeed: [Securing the agentic era: Introducing formal verification for CEL]() Original publisher: [Read original article]() Author: Google Open Source (noreply@blogger.com) Published: 2026-08-18T18:30:00Z Content type: release Language: en Sources: [Google Open Source Blog]() Topics: [Formal verification](), [Automated reasoning](), [Testing](), [Artificial Intelligence]() Tags: [agent](), [ai](), [ai-agent](), [automated-reasoning](), [cel](), [common-expression-language](), [formal-verification](), [open-source](), [security](), [testing](), [verification](), [z3]() ### AI overview Google's Common Expression Language (CEL) Formal Verification Framework is available for proving the correctness of CEL expressions and policies. Powered by the Z3 theorem prover, it complements heuristic testing by using mathematical proofs to identify logic flaws, equivalence issues, and potentially unsafe policy behavior. ### Source excerpt by Sean Huh, Common Expression Language Team We are rapidly entering an era where AI agents can autonomously draft, refactor, and deploy policies that protect our users and our systems. But this velocity introduces a vital question: How do we trust AI-generated policies? Unit tests may fail to cover the infinite set of possible inputs that occur in production; thus, an AI agent that overfits its policy to existing tests may fail spectacularly in production. To secure automated policy authoring, we must combine heuristic testing with mathematical proofs. We are thrilled to announce the Common Expression Language (CEL) Formal Verification Framework is now available. Powered by the Z3 theorem prover, this framework allows you to prove the correctness of your CEL expressions and policies, serving as the ultimate safety net for the agentic policy. Automated reasoning definitively answers questions like: "Is there any combination of inputs that allows an unapproved request into production?" "Are we absolutely certain this AI-refactored policy matches the original behavior?" "Can a bad actor manipulate this rule to force an evaluation error?" Formal verification establishes mathematical certainty across the infinite spectrum of inputs. Proven policies protect your users and system while giving auditors clear proof of compliance. To see these capabilities in action, watch our video demonstrating how the CEL Verifier REPL catches subtle logic flaws in seconds: Proving rules from the ground up Getting started with formal verification doesn't require learning complex architectures right away. You can evaluate simple standalone CEL expressions to catch edge cases that tests easily miss. (Note: The examples below use our interactive REPL syntax--check out the REPL documentation to follow along!) 1. Catching logic bugs in simple expressions (Equivalence) How do you guarantee a refactored rule behaves identically to the original? Suppose we have a policy that allows ports 80 or 443 ## CEL repositories move to the dedicated cel-expr GitHub organization DevFeed: [CEL repositories move to the dedicated cel-expr GitHub organization]() Original publisher: [Read original article]() Author: Google Open Source (noreply@blogger.com) Published: 2026-06-16T18:30:00Z Content type: release Language: en Sources: [Google Open Source Blog]() Topics: [GitHub](), [Git]() Tags: [announce](), [brand-identity](), [c-plus-plus](), [cel](), [common-expression-language](), [consistency](), [dependencies](), [dependency-management](), [development](), [discoverability](), [github](), [go](), [java](), [pull-requests](), [python]() ### AI overview The official Common Expression Language (CEL) repositories have moved from the Google organization to the dedicated cel-expr GitHub organization. The move centralizes the language specification and implementations, while redirects preserve existing links and repository history. ### Source excerpt by Olena Huang, CEL (Common Expression Language) team We're excited to announce that the official Common Expression Language (CEL) repositories have moved to a dedicated GitHub organization. Visit the new cel-expr repository now! Why the move? This move is a key step in strengthening the CEL ecosystem. By centralizing our projects, including the language specification, Go, C++, C, Java, and Python implementations, under the cel-expr organization, we aim to: Enhance Branding: Create a clear and unified brand identity for CEL. Improve Discoverability: Make it easier for users and contributors to find all official CEL resources in one place. Ensure Consistency: Foster consistency across all CEL projects. Streamline Development: Simplify our development and release processes. What's Changing? The following repositories now reside in the cel-expr organization: google/cel-spec is now cel-expr/cel-spec google/cel-cpp is now cel-expr/cel-cpp google/cel-go is now cel-expr/cel-go google/cel-java is now cel-expr/cel-java cel-expr/cel-python and cel-expr/cel-c have already been in the cel-expr namespace All future development, issues, and pull requests for these projects will take place in their new homes within the cel-expr organization. This is a non-breaking change, due to automatic redirects, but you should update your URLs where possible. What Stays the Same? We've worked to make this transition as seamless as possible: Automatic Redirects: GitHub will automatically redirect all web traffic and git operations from the old google/cel-* URLs to the new cel-expr/cel-* locations. Your existing links and git remote configurations pointing to the old URLs should continue to work for cloning and fetching. Preserved History: The full commit history, issues, and pull requests for each repository have been migrated and are available in the new locations. Action Required: Update Your Dependencies While existing links and git remote configurations pointing to the old URLs should conti