Azure Cosmos DB Blog
The latest news, updates and technical insights from the Azure Cosmos DB team
Latest posts
Announcing General Availability of Azure Cosmos DB Global Secondary Indexes
Have you ever needed to evolve your read patterns without losing efficiency? Maybe your app started with one access pattern, but now you need three, and the queries that don't hit your partition key are getting slower and more expensive every month. We built global secondary indexes (GSIs) for exactly this, and today we're thrilled to announce they're generally available in Azure Cosmos DB! A GSI is an automatically synced copy of your data with a different partition key, so you can query it efficiently for more read patterns. The problem GSI solves Azure Cosmos DB scales by distributing data across physical ...
New Toolkits for Agent Memories and Agentic Retrieval in Azure Cosmos DB
Today we’re thrilled to announce the public preview of two new toolkits for Azure Cosmos DB: the Agent Memory Toolkit and the Agentic Retrieval Toolkit. If you’re building AI agents and retrieval-augmented generation (RAG) apps, these toolkits are designed to take you from prototype to production faster, giving your agents durable memory and your RAG pipelines the ability to reason over evidence in multiple passes, all backed by the database you already know and love. Both toolkits build on the same foundation: Azure Cosmos DB for NoSQL as a unified store for documents, vectors, and full-text data, with vector...
Announcing Public Preview of Safe Key Rotation in Azure Cosmos DB
In our previous post, we introduced the private preview of Safe Key Rotation, a feature that helps Azure Cosmos DB customers avoid service disruptions during key rotations. By showing when each account key was last used, it helps teams make informed decisions before rotating keys or moving to Entra ID. This capability addresses a common challenge: keys that appear unused may still support critical applications, which can lead to unexpected outages if they are rotated too soon. What is new? With public preview, we are expanding this capability to give you even more control and confidence when managing you...
Announcing the Public Preview of the Azure Cosmos DB Cost Estimator for NoSQL
Today, we're thrilled to announce the public preview of the Azure Cosmos DB Cost Estimator, a new sizing and pricing experience that takes developers from a blank page to a defensible monthly cost estimate in minutes. Sizing an Azure Cosmos DB workload has always been one of the first questions a team has to answer, and historically one of the hardest.  Every one of those decisions changes the number, and most teams need that number before they've written a single line of code. AI workloads have made this harder, not easier. RAG pipelines, AI chat sessions, vector embeddi...
Announcing Public Preview of Distributed Transactions in Azure Cosmos DB for NoSQL
In modern cloud-native applications, correctness is often hardest to maintain at the exact moment a workflow crosses boundaries. A checkout flow writes an order in one place; decrements inventory in another and emits an audit event somewhere else. A money movement workflow debits one account, credits another, and records the transfer for compliance. An AI workflow updates state across multiple services while coordinating retries, handoffs, and downstream actions. Each step is individually straightforward. Keeping the entire workflow correct under partial failures, concurrent updates, retries, and regional events ...
From Intent to Insight: AI Meets Azure Cosmos DB in VS Code (Public Preview)
The Problem Every Developer Knows Too Well You're building a feature. You know exactly what data you need all orders from the last week over $500, grouped by region. The logic is clear in your head. But between you and that data sits a query language, a documentation tab (or three), and fifteen minutes of trial and error before you get the syntax right. Now multiply that across a team. New developers ramping up on Cosmos DB spend days learning query patterns. Senior developers’ context-switch between writing application logic and debugging queries. Product managers wait for data answers that a developer mus...
Azure Cosmos DB Agent Kit now battle tested for GA
Back in January, we shipped the Azure Cosmos DB Agent kit in preview with 45 rules and a hypothesis: if we package Azure Cosmos DB expertise into a format that AI coding agents understand, developers will stop making the same expensive mistakes. That hypothesis held up. What surprised us was how much the rules themselves needed to evolve once we started systematically testing them. Today the Agent Kit is generally available . It now contains 120+ rules across 12 categories. But the number that matters more: we've run over 200 automated test iterations where AI agents build real applications from scratch using ...
Announced at MS Build 2026: Azure Cosmos DB MCP Toolkit, Semantic Reranking, Global Secondary Indexes, and more!
Microsoft Build 2026 has officially started and we’re excited to announce new capabilities for Azure Cosmos DB! We’ve launched new features to help developers build AI-powered applications and agents more easily, improve application resilience, and accelerate developer productivity. These announcements span every stage of the development lifecycle, from local development with the Azure Cosmos DB Linux Emulator, to advanced retrieval and agent memory capabilities for AI applications, to enterprise-grade operational features such as Global Secondary Indexes, Per-Partition Automatic Failover, Distributed Transact...
I’m Starting a New Cosmos DB App. What Security Do I Actually Need?
You just created a Cosmos DB account. The portal handed you two keys and a connection string, it worked, and you moved on. That's what most developers do, and it causes problems later. This post is a guide for developers launching a new Cosmos DB app who want a secure default setup without enterprise-grade complexity. It focuses on the decisions that matter on day one. The honest two-minute threat model Before diving into setup, it is worth noting what actually goes wrong in real apps. Most security issues in any workload are not advanced attacks. There are simple mistakes that create unnecessary risk...