Azure Cosmos DB Blog
The latest news, updates and technical insights from the Azure Cosmos DB team
Featured posts
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 b...
Latest posts
Announcing the Public Preview of Integrated Embeddings in Azure Cosmos DB: Build AI Apps With Embeddings That Stay in Sync
AI applications built on Azure Cosmos DB depend on embeddings for grounded results. Keeping them in sync with your data is the hard part: it means building and operating a separate data pipeline to track changes, call an embedding model, and write the results back to Azure Cosmos DB. In practice, that pipeline also has to handle failures and retries, throttling, scaling, and monitoring as your data and traffic grow. Integrated Embeddings in Azure Cosmos DB, now in Public Preview, removes that heavy lifting. Azure Cosmos DB automatically generates and maintains the embeddings for you as items are written and upda...
Introducing OmniVec: An Open-Source Embedding Platform for AI Apps on Azure
Today we are open-sourcing OmniVec, a platform for building and operating the embedding pipelines that keep the vector representation of your operational data in sync as it changes. You register data sources, embedding model(s), vector stores (destination), and OmniVec does the rest: initial backfill, change tracking, model invocation to geenrate, and writing them back to your vector store. We are shipping this with support for Azure Cosmos DB, PostgreSQL, SQL Server (source and destination), and Azure Blob Storage (destination). You deploy OmniVec in your own Azure subscription, and use the web UI, CLI, or the ...
Azure Cosmos DB All Versions and Deletes Change Feed Mode is Now Generally Available
Modern applications don't just write data and move on. They react to it. A new order triggers an inventory update. A profile change syncs to a search index. A deleted record kicks off a compliance workflow. Azure Cosmos DB's change feed makes this possible by giving you a real-time stream of every change happening in your container, and it's one of the most powerful capabilities of the platform. Today, we're excited to announce that all versions and deletes change feed mode is generally available in Azure Cosmos DB for NoSQL! This mode gives you the full picture of what's changing in your data, including deletes ...
Change Partition Keys in Azure Cosmos DB is Now Generally Available
We're excited to announce the general availability of Change Partition Key in Azure Cosmos DB for NoSQL, now with online copy support. You can repartition containers directly in the Azure portal with near-zero downtime and without stopping writes to the source container. Why Partition Key Choice Matters In Azure Cosmos DB, the partition key is one of the most important design choices you make. It affects how data is distributed across physical partitions, how queries are routed, and how well your application performs at scale. But applications change over time. A partition key that worked well at launch can ...
Public Preview: AI-powered Azure Cosmos DB Migration Assistant for RDBMS to NoSQL
Today, we are excited to announce the public preview of the Azure Cosmos DB Migration Assistant for RDBMS to NoSQL, now available in the Azure Cosmos DB extension for Visual Studio Code. 📈 Modernize with confidence Why migrate from RDBMS to Azure Cosmos DB? Modernizing relational workloads has traditionally been complex, time-consuming, and risky. This new AI-assisted, phase-based workflow replaces manual analysis with structured recommendations and helps you navigate key design choices such as denormalization, partitioning, and NoSQL data modeling. It helps you move from relational databases (SQL Se...
Announcing the General Availability of Per Partition Automatic Failover for Azure Cosmos DB NoSQL
Today, we are excited to announce the General Availability of Per Partition Automatic Failover (PPAF) for Azure Cosmos DB NoSQL API. PPAF is a significant advancement in how Azure Cosmos DB delivers availability and resilience for mission-critical workloads running on single-write-region accounts. If you rely on Azure Cosmos DB to be always on for your mission-critical applications — PPAF is built for you. With PPAF, Azure Cosmos DB can automatically recover affected partitions by failing over writes to a secondary region within 3 minutes at P99, without requiring application changes. A smarter, more granu...
Azure Cosmos DB MCP Toolkit Is Now Generally Available — Bringing Your Database to AI Agents at Scale
Since we introduced the Azure Cosmos DB MCP Toolkit at Ignite 2025 in preview, the response has been clear: developers want a straightforward way to connect AI agents to their production databases. Customers asked for stability, broader embedding provider support, and a smoother path from experimentation to production. Today, we're announcing the general availability of the Azure Cosmos DB MCP Toolkit (v1.1.2), now with deeper Microsoft Foundry integration, multi-provider embedding support, and the reliability improvements you asked for. The Problem: Getting AI Agents to Talk to Your Data Is Harder Than I...
Announcing General availability of the Azure Cosmos DB vNext emulator
The Azure Cosmos DB vNext emulator is generally available today. It ships as a Docker image that runs on Linux, macOS, and Windows, on both x64 and ARM64 architectures, giving you a local Cosmos DB instance you can develop and test against. Use it for inner-loop development on your laptop, in CI integration tests, and anywhere else you’d rather not use a live account. You can get started right away with a couple of simple commands: A lot has shipped since the preview announcement: broader feature and API coverage, an embedded shell, vector search, and OpenTelemetry support. The rest of this post walks throu...
Announcing the Public Preview of Semantic Reranker in Azure Cosmos DB for NoSQL
Today we’re thrilled to announce the public preview of Semantic Reranker in Azure Cosmos DB for NoSQL,a new AI-powered capability that improves the relevancy of your search results with just a few lines of code. If you’ve ever run a vector, full-text, or hybrid search and wished the most relevant documents bubbled to the very top, this one’s for you. Semantic Reranker uses an AI model to score and reorder the results of any query based on how well each document matches the user’s intent. It’s built right into the Azure Cosmos DB SDKs (Python, .NET, and Java), so you can reorder results from any container with ...
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...