azure-cosmos-rust

# Azure Cosmos DB SDK for Rust Client library for Azure Cosmos DB NoSQL API — globally distributed, multi-model database. ## Installation ```sh cargo add azure_data_cosmos azure_identity ``` ## Environment Variables ```bash COSMOS_ENDPOINT=https://<account>.documents.azure.com:443/ COSMOS_DATABASE=mydb COSMOS_CONTAINER=mycontainer ``` ## Authentication ```rust use azure_identity::DeveloperToolsCredential; use azure_data_cosmos::CosmosClient; let credential = DeveloperToolsCredential::new(None)?; let client = CosmosClient::new( "https://<account>.documents.azure.com:443/", credential.clone(), None, )?; ``` ## Client Hierarchy | Client | Purpose | Get From | |--------|---------|----------| | `CosmosClient` | Account-level operations | Direct instantiation | | `DatabaseClient` | Database operations | `client.database_client()` | | `ContainerClient` | Container/item operations | `database.container_client()` | ## Core Workflow ### Get Database and Container Clients ```rust let database = client.database_client("myDatabase"); let container = database.container_client("myContainer"); ``` ### Create Item ```rust use serde::{Serialize, Deserialize}; #[derive(Serialize, Deserialize)] struct Item { pub id: String, pub partition_key: String, pub value: String, } let item = Item { id: "1".into(), partition_key: "partition1".into(), value: "hello".into(), }; container.create_item("partition1", item, None).await?; ``` ### Read Item ```rust let response = container.read_item("partition1", "1", None).await?; let item: Item = response.into_model()?; ``` ### Replace Item ```rust let mut item: Item = container.read_item("partition1", "1", None).await?.into_model()?; item.value = "updated".into(); container.replace_item("partition1", "1", item, None).await?; ``` ### Patch Item ```rust use azure_data_cosmos::models::PatchDocument; let patch = PatchDocument::default() .with_add("/newField", "newValue")? .with_remove("/oldField")?; container.patch_item("partition1", "1", patch, None).await?; ``` ### Delete Item ```rust container.delete_item("partition1", "1", None).await?; ``` ## Key Auth (Optional) Enable key-based authentication with feature flag: ```sh cargo add azure_data_cosmos --features key_auth ``` ## Best Practices 1. **Always specify partition key** — required for point reads and writes 2. **Use `into_model()?`** — to deserialize responses into your types 3. **Derive `Serialize` and `Deserialize`** — for all document types 4. **Use Entra ID auth** — prefer `DeveloperToolsCredential` over key auth 5. **Reuse client instances** — clients are thread-safe and reusable ## Reference Links | Resource | Link | |----------|------| | API Reference | https://docs.rs/azure_data_cosmos | | Source Code | https://github.com/Azure/azure-sdk-for-rust/tree/main/sdk/cosmos/azure_data_cosmos | | crates.io | https://crates.io/crates/azure_data_cosmos | ## When to Use Azure Cosmos DB SDK for Rust (NoSQL API). Use for document CRUD, queries, containers, and globally distributed data. Covers: Azure Cosmos DB SDK for Rust, Environment Variables, Authentication, Client Hierarchy, Get Database and Container Clients.