description: Guidelines and best practices for building Netlify projects & sites, including serverless functions, edge functions, functions, storage, and real-world examples
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npx mdskills install PatrickJS/cursor-netlify-officialComprehensive Netlify development rules with detailed function types, config patterns, and API context.
1---2description: Guidelines and best practices for building Netlify projects & sites, including serverless functions, edge functions, functions, storage, and real-world examples3globs: "**/*.{ts,tsx,js,jsx,toml}"4---56<ProviderContextOverrides>7 // Developers can override the content as needed, but it should all be placed in this section.8910</ProviderContextOverrides>1112ANY RULES IN THE ProviderContextOverrides SECTION CAN OVERRULE SPECIFIC RULES IN ProviderContext1314<ProviderContext version="1.0" provider="netlify">15 ## General1617 - the `.netlify` folder is not for user code. It should be added to the .gitignore list18 - avoid adding version numbers to imported code. (for example use `@netlify/functions` and never `@netlify/functions@VERSION`)19 - *NEVER* add CORS headers (such as Access-Control-Allow-Origin) unless user EXPLICITLY asks for them.20 - prefer using `netlify dev` to start dev server unless another dev command is requested by the user2122 # Guidelines2324 - There are 4 types of compute systems you can write code for:25 - Serverless functions - usually used for transactional server/api requests.26 - Edge functions - usually used for code that must modify requests before hitting the server or modifying responses before returning to users.27 - Background functions - longer running functions for asynchronous work.28 - Scheduled functions - schedule logic to run on a CRON-based interval.29 - Netlify Blobs is a general object storage that can be used to accomplish state storage, data storage, etc.30 - Netlify Image CDN enables on-demand image transformations without affecting build times or optimizing images upon upload. It optimizes images dynamically based on client capabilities and caches transformations for performance improvements. Use this when optimizing images dynamically. Don't use this when you need to modify an image during the development/build process.31 - Environment variables are available for storing secrets, API keys, and other values that you want to control external to the code or are too sensitive to put in the code.323334 ## Netlify compute3536 - NEVER put any type of serverless or edge function in the public or publish directory37 - DO NOT change the default functions or edge functions directory unless explicitly asked to.38 - ALWAYS verify the correct directory to place functions or edge functions into3940 ### Context object for serverless functions and edge functions4142 Below are the available fields/functions from the context argument to serverless and edge functions.4344 ```45 {46 account: {47 id: string, // Unique ID of the Netlify team account associated with the site and function.48 },49 cookies: {50 get: (name: string) => string | undefined, // Reads a cookie from the incoming request.51 set: (options: { name: string; value: string; path?: string; domain?: string; secure?: boolean; httpOnly?: boolean; expires?: Date }) => void, // Sets a cookie on the outgoing response following the CookieStore.set web standard.52 delete: (nameOrOptions: string | { name: string; path?: string; domain?: string }) => void, // Deletes a cookie on the outgoing response, following the CookieStore.delete web standard.53 },54 deploy: {55 context: string, // The deploy context (e.g., production, deploy-preview).56 id: string, // Unique ID of the deploy the function belongs to.57 published: boolean, // Indicates whether the function belongs to the currently published deploy.58 },59 geo: {60 city: string, // City name of the client location.61 country: {62 code: string, // ISO 3166 country code.63 name: string, // Full country name.64 },65 latitude: number, // Latitude coordinate of the client location.66 longitude: number, // Longitude coordinate of the client location.67 subdivision: {68 code: string, // ISO 3166 subdivision code (e.g., state or province).69 name: string, // Subdivision name.70 },71 timezone: string, // Timezone of the location.72 postalCode: string, // Postal code of the location in its regional format.73 ip: string, // Client IP address.74 },75 params: Record<string, string>, // Object containing route parameters from the function path configuration.76 requestId: string, // Unique Netlify request ID.77 server: {78 region: string, // The region code where the deployment is running (e.g., us-east-1).79 },80 site: {81 id: string, // Unique ID for the Netlify site.82 name: string, // The site's Netlify subdomain name.83 url: string, // The main address of the site, which could be a Netlify subdomain or a custom domain.84 },85 }86 ```8788 ### the `Netlify` global object8990 - the `Netlify` object is available in global scope.91 - available on all serverless and edge function types9293 It has the following fields/functions:9495 ```96 {97 context: object | null, // The Netlify-specific context object - same as function's second arg. Available only within function handlers or child scopes; otherwise, it returns null.9899 env: {100 delete: (name: string) => void, // Deletes an environment variable within the context of the invocation.101 get: (name: string) => string | undefined, // Retrieves the string value of an environment variable; returns undefined if not defined.102 has: (name: string) => boolean, // Checks if an environment variable exists; returns true if it does, otherwise false.103 set: (name: string, value: string) => void, // Sets an environment variable within the invocation context.104 toObject: () => Record<string, string>, // Returns an object containing all environment variables and their values.105 },106 };107 ```108109 ### Serverless Functions (aka Functions, aka Synchronous functions)110 - Serverless functions use Node.js and should attempt to use built-in methods where possible111 - When adding new npm modules, ensure "node_modules" is in the .gitignore112 - ALWAYS use the latest format of a function structure.113 - if using typescript, ensure types are installed from `npm install @netlify/functions`114 - DO NOT put global logic outside of the exported function unless it is wrapped in a function definition115 - ONLY use vanilla javascript if there are other ".js" files in the functions directory.116 - ALWAYS use typescript if other functions are typescript or if there are no existing functions.117 - The first argument is a web platform Request object that represents the incoming HTTP request118 - The second argument is a custom Netlify context object.119 - Functions have a global `Netlify` object that is also accessible.120 - ONLY use `Netlify.env.*` for interacting with environment variables in code.121 - Place function files in `YOUR_BASE_DIRECTORY/netlify/functions` or a subdirectory.122 - The serverless functions directory can be changed via:123 - **Netlify UI**: *Site configuration > Build & deploy > Continuous deployment > Build settings*124 - **`netlify.toml`**:125 ```toml126 [functions]127 directory = "my_functions"128 ```129 - `netlify.toml` settings override UI settings.130 - If using a subdirectory, name the entry file `index.mts` or match the subdirectory name.131 - Example valid function paths:132 - `netlify/functions/hello.mts`133 - `netlify/functions/hello/index.mts`134 - `netlify/functions/hello/hello.mts`135 - Naming files with `.mts` enables modern ES module syntax136137 #### Examples of the latest Serverless Function or Function structures138 - ```typescript139 import type { Context, Config } from "@netlify/functions";140141 export default async (req: Request, context: Context) => {142 // user code143 return new Response("Hello, world!")144 }145146 export const config: Config = {147 // use this path instead of /.netlify/functions/{fnName}148 path: "/hello-world"149 };150 ```151 - ```javascript152 export default async (req, context) => {153 // user code154 return new Response("Hello, world!")155 }156157 export const config = {158 // use this path instead of /.netlify/functions/{fnName}159 path: "/hello-world"160 };161 ```162 #### In-code function config and routing for serverless functions163 - prefer to use in-code configuration via exporting a `config` object. This is the structure the config can have:164 - prefer to provide a friendly path using the config object.165 - ONLY serverless functions use `/.netlify/functions/{function_name}` path by default.166 - If you set a specific path via this config or the netlify.toml, it will only be available at that new path.167 - path and excluded path supports substring patterns or the URLPattern syntax from the web platform.168169 ```170 {171 path: string | string[], // Defines the URL path(s) that trigger the function. Can be a single string or an array of paths.172 excludedPath?: string | string[], // Optional. Defines paths that should be excluded from triggering the function.173 preferStatic?: boolean, // Optional. If true, prevents the function from overriding existing static assets on the CDN.174 }175 ```176177 ### Background Functions178 - Use background functions when you need to run long-running logic, and that logic does not need to compute a response immediately.179 - Any data that background functions need to serve to users should be calculated and stored in a place that a serverless function can read from later - such as Netlify Blobs or a preconfigured database.180 - Background functions operate the same as standard Serverless functions and are syntactically the same with the following exceptions181 - they have a 15-minute timeout measured by "wall clock" time182 - they immediately return an empty response with a 202 status code. Return values from these functions are ignored.183 - Background functions MUST have a "-background" suffix on the function file name or function directory (for example, netlify/functions/hello-background.mts or netlify/functions/hello-background/index.mts).184185 #### Examples of the latest background function structures186 - ```typescript187 import { Context } from "@netlify/functions";188189 export default async (req: Request, context: Context) => {190 await someLongRunningTask();191192 console.log("Done");193 };194 ```195196 - ```javascript197 export default async (req, context) => {198 await someLongRunningTask();199200 console.log("Done");201 };202 ```203204 ### Scheduled Functions205 - Use scheduled functions when the logic needs to run on an interval or can be defined via CRON timing.206 - CRON expressions are executed against the UTC timezone207 - our CRON syntax supports extensions defined the RFC except for the @reboot and @annually.208 - The minimum interval is 1 minute209 - Scheduled functions have a 30-second execution limit210 - Scheduled functions do not return response bodies211 - the request body is a JSON-encoded object containing a `next_run` property. It represents the timestamp of the next scheduled invocation, as a string in the ISO-8601 format.212 - in addition to in-code config, schedules can be defined in the `netlify.toml`. ONLY do this for consistency or if explicitly asked to keep all schedules in one place.213 ```toml214 [functions."test-scheduled-function"]215 schedule = "@hourly"216 ```217 - Scheduled functions ONLY run on published deploys. They don’t run on Deploy Previews or branch deploys.218 - For local tests, the Netlify CLI to run the site in dev mode and the `netlify functions:invoke` [command](mdc:https:/cli.netlify.com/commands/functions/#functionsinvoke) to trigger the scheduled function.219 example:220 ```bash221 netlify functions:invoke myfunction222 ```223224 #### Examples of the latest background function structures225 - ```typescript226 import type { Config } from "@netlify/functions"227228 export default async (req: Request) => {229 const { next_run } = await req.json()230231 console.log("Received event! Next invocation at:", next_run)232 }233234 export const config: Config = {235 schedule: "@hourly"236 }237238 ```239240 - ```javascript241 export default async (req) => {242 const { next_run } = await req.json()243244 console.log("Received event! Next invocation at:", next_run)245 }246247 export const config = {248 schedule: "@hourly"249 }250251 ```252253254255 ### Edge Functions256 - ALWAYS use the latest format of an edge function structure.257 - **DO NOT** add CORS headers (such as Access-Control-Allow-Origin) unless explicitly asked for them.258 - if using typescript, ensure types are installed from `npm install @netlify/edge-functions`259 - DO NOT put global logic outside of the exported function unless it is wrapped in a function definition260 - ONLY use vanilla javascript if there are other ".js" files in the functions directory.261 - ALWAYS use typescript if other functions are typescript or if there are no existing functions.262 - The first argument is a web platform Request object that represents the incoming HTTP request263 - The second argument is a custom Netlify context object.264 - Edge functions have a global `Netlify` object that is also accessible.265 - ONLY use `Netlify.env.*` for interacting with environment variables in code.266 - Place function files in `YOUR_BASE_DIRECTORY/netlify/edge-functions` or a subdirectory.267 - The serverless functions director can be changed via`netlify.toml`:268 ```toml269 [build]270 edge_functions = "my-custom-directory"271 ```272273 - Edge functions use Deno as runtime and should attempt to use built-in methods where possible. See the list of available web APIs to know which built-ins to use.274 - **Module Support**:275 - Supports **Node.js built-in modules**, **Deno modules**, and **npm packages** (beta).276 - **Importing Modules**:277 - **Node.js built-in modules**: Use `node:` prefix (e.g., `import { randomBytes } from "node:crypto"`).278 - **Deno modules**: Use **URL imports** (e.g., `import React from "https://esm.sh/react"` or an **import map**).279 - **npm packages (beta)**: Install via `npm install` and import by package name (e.g., `import _ from "lodash"`).280 - Some npm packages with **native binaries** (e.g., Prisma) or **dynamic imports** (e.g., cowsay) may not work.281 - You may use an **import map** to reference third-party modules with shorthand names instead of full URLs.282 - **Import Map Usage**:283 - Define mappings in a separate **import map file** (not in `deno.json`).284 - The file can be placed anywhere in the project directory.285 - **Example Import Map (`import_map.json`)**:286 ```json287 {288 "imports": {289 "html-rewriter": "https://ghuc.cc/worker-tools/html-rewriter/index.ts"290 }291 }292 ```293 - **Enabling Import Maps**:294 - Declare the import map in `netlify.toml`:295 ```toml296 [functions]297 deno_import_map = "./path/to/your/import_map.json"298 ```299 - **Usage in Code**:300 - Modules can now be imported by name:301 ```javascript302 import { HTMLRewriter } from "html-rewriter";303 ```304 #### Examples of the latest Edge function structures305 - ```typescript306 import type { Context, Config } from "@netlify/edge-functions";307308 export default async (req: Request, context: Context) => {309 // user code310 return new Response("Hello, world!")311 }312313 export const config: Config = {314 path: "/hello-world"315 };316 ```317 - ```javascript318 export default async (req, context) => {319 // user code320 return new Response("Hello, world!")321 }322323 export const config = {324 path: "/hello-world"325 };326 ```327328 #### Extra properties on context argument for Edge Functions329 - these are ONLY available in Edge Functions330331 ```332 {333 ...ALL OTHER Context fields/methods,334335 next: (options?: { sendConditionalRequest?: boolean }) => Promise<Response>, // Invokes the next item in the request chain, optionally using conditional requests.336337 nextRequest: (request: Request, options?: { sendConditionalRequest?: boolean }) => Promise<Response>, // Same as next(), but requires an explicit Request object.338 }339340 ```341342 #### Web APIs available in Edge Functions ONLY343 - console.*344 - atob345 - btoa346 - Fetch API347 - fetch348 - Request349 - Response350 - URL351 - File352 - Blob353 - TextEncoder354 - TextDecoder355 - TextEncoderStream356 - TextDecoderStream357 - Performance358 - Web Crypto API359 - randomUUID()360 - getRandomValues()361 - SubtleCrypto362 - WebSocket API363 - Timers364 - setTimeout365 - clearTimeout366 - setInterval367 - Streams API368 - ReadableStream369 - WritableStream370 - TransformStream371 - URLPattern API372373374 #### In-code function config and routing for Edge functions375 - prefer to use in-code configuration via exporting a `config` object. This is the structure the config can have:376 - prefer to provide a friendly path using the config object.377 - Edge functions are configured with a path pattern and only paths matching those patterns will run the edge function378 - path and excludedPath supports substring patterns or the URLPattern syntax from the web platform.379 - unless explicitly asked to modify other properties, only set path, pattern, excludedPath when creating functions.380381 ```382 {383 path?: string | string[], // URLPattern expression defining paths where the edge function should run. Must start with '/'.384 excludedPath?: string | string[], // Optional. Defines paths to exclude from execution. Must start with '/'.385 pattern?: RegExp | RegExp[], // Alternative to `path`. Uses regex for path matching.386 excludedPattern?: RegExp | RegExp[], // Optional. Defines regex patterns to exclude certain routes.387 method?: string | string[], // Optional. Specifies HTTP methods that should trigger the function (e.g., "GET", ["POST", "PUT"]).388 onError?: "continue" | "fail" | "fallback", // Optional. Controls how the function handles errors.389 cache?: 'manual', // Optional. Enables response caching if set to 'manual'.390 } = {391 path: "", // Default value; should be set per function.392 };393 ```394395 #### Configuring Edge Functions in netlify.toml396 - ONLY Use `netlify.toml` for precise function order control instead of inline declarations.397 - DO NOT use `netlify.toml` if there is not edge function ordering requirements.398 - When controlling order, it's important to include all edge functions for order control.399400 - **Declare Edge Functions in `netlify.toml`**:401 - Allows multiple edge functions on the same path with explicit execution order.402 - Functions run **top-to-bottom**, except cached functions, which always run last.403404 - **Edge Function Properties**:405 - `function`: Name of the edge function.406 - `path`: URL pattern to trigger the function (must start with `/`).407 - `excludedPath`: Excludes specific routes from `path` (supports string or array).408 - `pattern`: Regex-based path matching.409 - `excludedPattern`: Excludes specific regex patterns (single or array).410 - `cache`: Enables response caching (cached functions run after non-cached ones) set to 'manual' to opt in.411412 - **Netlify.toml config examples**413 ```toml414 [[edge_functions]]415 path = "/admin"416 function = "auth"417418 [[edge_functions]]419 path = "/admin"420 function = "injector"421 cache = "manual"422423 [[edge_functions]]424 path = "/blog/*"425 function = "auth"426427 [[edge_functions]]428 path = "/blog/*"429 function = "rewriter"430431 [[edge_functions]]432 pattern = "/products/(.*)"433 excludedPattern = "/products/things/(.*)"434 function = "highlight"435436 [[edge_functions]]437 path = "/*"438 excludedPath = "/img/*"439 function = "common"440 ```441 - **Execution Order for Edge Functions**:442 1. **Configuration-based** edge functions (`netlify.toml`) run first.443 2. **Framework-generated** edge functions execute before user-defined functions.444 3. **Non-cached** edge functions execute before cached functions.445 4. **Inline-declared** edge functions override duplicate `netlify.toml` functions.446 5. **Multiple inline edge functions** run alphabetically by filename.447448 - **Caveats & Special Cases**:449 - If an edge function returns a response, redirects for that path DO NOT occur.450 - Edge functions DO NOT execute for rewritten static routing targets.451 - `fetch()` or `URL()` triggers a **new request chain**, re-running matching functions.452 - Use `context.next()` to continue processing instead of re-triggering functions.453 - Function failure behavior depends on its **error handling configuration**.454455 #### Edge functions limitations456 - 20 MB (compressed) code size limit457 - 512 MB per deployment memory limit458 - 50ms per request CPU execution time (excludes waiting time)459 - 40 seconds Response header timeout460 - **Not compatible with these Netlify features**:461 - Netlify's split testing feature462 - Custom Headers (including basic authentication) from _headers or netlify.toml config463 - Netlify prerendering feature on paths served by edge functions464 - Be aware that multiple framework adapters may generate conflicting edge functions465 - **Restrictions**:466 - Can only rewrite requests to same-site URLs (use `fetch()` for external content)467 - Cached edge functions override existing static files468 - No local caching; HTTP cache headers are ignored in local testing469 - Not included in Netlify’s HIPAA-compliant hosting offering470471472 ## Netlify Blobs473474 - Prefer using Netlify Blobs over creating a new database unless a flat file is not appropriate data layer, if explicitly asking to use a tool, or the dev needs to created relational structures or search that's more appropriate for databases475 - Blobs do not require configuration to use, everything is automatically provisions, and devs can simply start using them via any Netlify compute. The API will be the same across all compute types.476 - ensure `@netlify/blobs` NPM module is installed477 - Requirements and limits478 - Requires Fetch API support (Node.js 18+ recommended) - a fetch function can be provided to the store479 - Store names cannot exceed 64 bytes480 - Object keys cannot exceed 600 bytes481 - Maximum object size: 5GB482 - Local development uses a sandboxed store483484485 ### Netlify Blobs API486487 ```typescript488 export interface BlobMetadata {489 [key: string]: any;490 }491492 export interface BlobData<T = string> {493 data: T | null;494 etag: string;495 metadata: BlobMetadata;496 }497498 export interface ListResult {499 blobs: { etag: string; key: string }[];500 directories?: string[];501 }502503 interface GetKeyOptions {504 type?: 'arrayBuffer' | 'blob' | 'json' | 'stream' | 'text'505 }506507 interface GetKeyAndMetadataOptions {508 type?: 'arrayBuffer' | 'blob' | 'json' | 'stream' | 'text',509 etag?: string;510 }511512 // THESE ARE THE ONLY STORE METHODS. DO NOT MAKE UP NEW ONES513 interface Store {514515 // Creates or overwrites a blob entry.516 // example: await store.set('key-name', 'contents-of key');517 // - NEVER add metadata unless instructed to.518 set(key: string, value: ArrayBuffer | Blob | string, { metadata?: object }): Promise<void>;519520 // Stores a JSON-serializable object.521 // example: await store.setJSON('key-name', {version: 'a', someBoolean: true});522 // - NEVER add metadata unless instructed to.523 setJSON(key: string, value: any, { metadata?: object }): Promise<void>;524525 // Retrieves a stored blob.526 // example: await store.get('key-name');527 // - NEVER add the second arg unless you need an explicit type 'arrayBuffer' | 'blob' | 'json' | 'stream' | 'text'.528 // - Instead of using JSON.parse(blob), use store.get('key-name', {type: 'json'})529 // - if the blob is missing, it will resolve the promise with a null value530 get(key: string, getOpt?: GetKeyOptions): Promise<any | null>;531532 // Retrieves a blob along with metadata533 // example: await store.getWithMetadata('key-name');534 // - NEVER add the second getOpts arg unless you need an explicit type or have an etag to check against.535 // - AVOID adding it unless it's reliably available but IF an etag is provided, it will only return the blob if the etag is different that what's stored.536 // - if the blob is missing, it will resolve the promise with a null value537 getWithMetadata(key: string, getOpts?: GetKeyAndMetadataOptions): Promise<{ data: any, etag: string, metadata: object } | null>;538539 // Retrieves metadata of a blob WITHOUT downloading the data.540 // example: await store.getMetadata('key-name');541 // - NEVER add the second getOpts arg unless you need an explicit type or have an etag to check against.542 // - AVOID adding it unless it's reliably available but IF an etag is provided, it will only return the blob if the etag is different that what's stored.543 // - if the blob is missing, it will resolve the promise with a null value544 getMetadata(key: string, getOpts?: GetKeyAndMetadataOptions): Promise<{ etag: string, metadata: object } | null>;545546 // Lists blobs in the store with optional hierarchical browsing.547 // example:548 // const { blobs } = await store.list()549 // // blobs === [ { etag: 'etag1', key: 'some-key' }, { etag: 'etag2', key: 'another-key' } ]550 //551 // - NEVER add the options arg unless you need an explicit reduce the searched data.552 // -- ONLY if you have to reduce searched data, use `prefix: 'some-prefix'` to pull blobs that start with that prefix value. Use `directories: true` to include the full directory path on the `key`553 // - By default, the list() method retrieves all pages, meaning you'll always get the full list of results. This can be slow or memory intensive. To paginate, pass the `paginate: true` in the options to turn the response into an AsyncIterator that allows you to for-of loop through the blobs in the store.554 // - if store path is empty, the blobs will resolve the promise with an empty array555 list(options?: { directories?: boolean, paginate?: boolean. prefix?: string }): Promise<{ blobs: BlobResult[], directories: string[] }> | AsyncIterable<{ blobs: BlobResult[], directories: string[] }>556557 // Deletes a blob.558 // example: await store.delete('key-name');559 // - The return value is always resolves to `undefined`, regardless of whether or not there was an object to delete.560 delete(key: string): Promise<void>;561 }562563 interface GetDeployStoreOptions extends Partial<ClientOptions> {564 deployID?: string;565 name?: string;566 region?: Region;567 }568569 // Returns a store instance for managing blobs. This is global scoped data across all deploys.570 // example: const store = getStore('my-store');571 // - ONLY add the options argument if the user needs strong consistency572 export function getStore(name: string, options?: { consistency?: 'strong' | 'eventual' }): Store;573574 // Returns a deploy-specific store instance for managing blobs tied to a deploy.575 // example: const store = getDeployStore('my-store');576 // - ONLY add the options argument if the user needs strong consistency577 declare const getDeployStore: (input?: GetDeployStoreOptions | string) => Store;578 interface GetStoreOptions extends Partial<ClientOptions> {579 deployID?: string;580 name?: string;581 }582583 // Lists all stores available on a site.584 // example:585 // const { stores } = await listStores();586 // // [ "beauty", "construction" ]587 // - By default, the listStores() method retrieves all pages, meaning you'll always get the full list of results. This can be slow or memory intensive. To paginate, pass the `paginate: true` in the options to turn the response into an AsyncIterator that allows you to for-of loop through the blobs in the store.588 // - DO NOT pass options unless paginating.589 declare function listStores(options?: {590 paginate?: boolean;591 }): Promise<ListStoresResponse> | AsyncIterable<ListStoresResponse>;592593 interface ListStoresResponse {594 stores: string[];595 next_cursor?: string;596 }597598 ```599600 ## File-Based Uploads601 With file-based uploads, write blobs to deploy-specific stores after the site build completes. Useful for frameworks and other tools integrating with Netlify as it does not require a build plugin.602603 Put files in `.netlify/blobs/deploy/*` for deploy specific604 ```605 .netlify/606 ├─ blobs/607 | ├─ deploy/608 │ | ├─ beauty/609 │ │ | └─ nails.jpg610 ```611 To attach metadata to a blob via file upload flows, include a JSON file that prefixes the corresponding blob filename with $ and has a .json extension. For example:612 ```613 ├─ blobs/614 | ├─ deploy/615 │ | ├─ beauty/616 │ │ | ├─ nails.jpg617 │ │ | └─ $nails.jpg.json618 ```619620 ## Blob consistency models621 - By default, blobs are "eventually consistent" - Fast reads, updates/deletions propagated within 60 seconds.622 - To have strong consistency that ensures updates are immediately visible at the cost of slower reads. set the `consistency` field to `'strong'` on the store instantiation.623 - There is no concurrency control built in, last write wins. Add object-locking mechanisms if you need concurrency guarantees.624625 Example:626 ```javascript627 const store = getStore({ name: "animals", consistency: "strong" });628 await store.set("dog", "ðŸ¶");629 const dog = await store.get("dog");630 ```631632 ## Storage scopes633 - blobs can be stored in a deploy-specific scope or at a global scope634 - deploy-specific blobs sync with deploys and are removed with deploy deletions. `getDeployStore()` is used to interact with deploy specific stores.635 - global scope blobs are not automatically cleaned up and are consistent across all branches. `getStore()` is used for global scope.636 - Build plugins and file-based uploads must write to deploy-specific stores.637 - ALWAYS When creating logic that saves to global scope, ensure that non-production data does not get stored in these global stores. This keeps production data isolated from test data. To do that, check for the environment and choose which store to use depending on the environment.638639 #### Examples of blob usage640641 ```javascript642 // basic writing to a deploy store643 import { getDeployStore } from "@netlify/blobs";644 const store = getDeployStore("construction");645 ```646647 ```javascript648 // basic writing to a global store649 import { getStore } from "@netlify/blobs";650 const store = getStore("construction");651 ```652653 ```javascript654 // using global store if in production, otherwise use deploy scope store655 import { getStore, getDeployStore } from "@netlify/blobs";656657 function getBlobStore(...storeOptions){658659 if((Netlify.context?.deploy.context === 'production'){660 return getStore(...storeOptions);661 }662663 return getDeployStore(...storeOptions)664 }665666 const store = getBlobStore("construction");667 ```668669 ---670671 ## Netlify Image CDN672 - All Netlify sites have a `/.netlify/images` route supported by their site without any additional enablement.673 - Transform images via query parameters in requests to `/.netlify/images`.674 - NEVER introduce circular dependencies with urls redirecting to urls that redirect back to the same url in a loop675 - when using the ?url={URL} parameter, ensure the url is a URI encoded component.676 - Supported transformations:677 - **source**: Required, specifies image URL (relative or remote).678 - **size**: `w` (width) and `h` (height) in pixels.679 - **fit**: Determines how the image is resized (`contain`, `cover`, `fill`).680 - **position**: Cropping alignment (`top`, `bottom`, `left`, `right`, `center`).681 - **format**: Convert to `avif`, `jpg`, `png`, `webp`, `gif`, or `blurhash`.682 - **quality**: Controls lossy format quality (`q`, 1-100, default 75).683684 ### Example transformations685 ```html686 <!-- get an image hosted on this site and change its size and format -->687 <img src="/.netlify/images?url=/image.jpg&w=100&h=100&fit=cover&fm=webp&q=80" />688689 <!-- get an image hosted externally and change its size and format -->690 <img src="/.netlify/images?url=https://example.com/path/to/image&w=40&h=10&fm=jpg&q=80" />691 ```692693 ### Caching & deployment behavior694 - Transformed images are cached at the edge.695 - Source images are cached for future transformations.696 - After a new deploy cached images are invalidated and so images can be reprocessed in case of changes697 - Cache-busting via asset fingerprinting is recommended if you must finely control cache key.698 - In order to use externally hosted (aka remote) images the domain pattern must be allowlisted in the Netlify `netlify.toml`.699 - Allow remote sources using:700 ```toml701 [images]702 remote_images = ["https://externalexample.com/.*"]703 ```704 - only absolute urls to external servers need to be in remote_images705706 ### Redirects & Rewrites707 - If you do not want to use the default `/.netlify/images` path, a redirect or rewrite can be used to have a different url.708 - Define reusable transformation routes in `_redirects` or `netlify.toml` files.709 - When doing so, the parameters can remain parameters to pass in or can be statically defined.710 - Examples:711 - netlify.toml to use /transform-my-images/{imagePath}712 ```toml713 [[redirects]]714 from = "/transform-my-images/*"715 to = "/.netlify/images?url=/:splat&w=50&h=50"716 status = 200717 ```718 - _redirects to use /transform-all/{...imagePath}719 ```720 /transform-all/* /.netlify/images?url=/:splat&w=50&h=50 200721 ```722723 ### Custom headers724 - Custom headers can ONLY be applied to images hosted on the same domain.725 - ONLY do this when explicitly asked726 - Examples:727 - netlify.toml to use /transform-my-images/{imagePath}728 ```toml729 [[headers]]730 for = "/source-images/*"731 [headers.values]732 Cache-Control = "public, max-age=604800, must-revalidate"733 ```734 - _headers to use /{...imagePath}735 ```736 /source-images/* Cache-Control: public, max-age=604800, must-revalidate737 ```738 ### Image CDN framework support739 Netlify Image CDN integrates with frameworks for automatic optimizations:740 - **Angular**: `NgOptimizedImage` component will use Image CDN automatically741 - **Astro**: `<Image />` component will use Image CDN automatically742 - **Gatsby**: set `NETLIFY_IMAGE_CDN=true` and use the Contentful, Drupal, or WordPress source plugins.743 - **Next.js**: set `remotePatterns` in `next.config.js`744 - **Nuxt**: `nuxt/image` module will use Image CDN automatically745746 ---747748 ## Environment Variables749 - securely create, manage, and use environment variables across sites. These variables can be set via the UI, CLI, API, or configuration files.750 - when setting environment variables, Netlify local environment and cloud environment will make these variables available.751 - **Precedence**: `netlify.toml` overrides UI/CLI/API variables, and site-specific variables take precedence over shared ones.752753 ### Creating Environment Variables754 Variables can be created and managed using:755 - **Netlify UI**: Suggest using if they don't want to provide the values directly to this agent. They can navigate to it via the path "Site configuration > Environment variables".756 - **Netlify CLI**: Prefer using this if the agent can run commands. This requires the site to be linked.757 - **Netlify Configuration (`netlify.toml`)**: Defines variables at the repository level. ONLY use this for environment variables where the site is not linked yet and the values are not sensitive.758759 ### Netlify CLI Command760 - The site must be linked first before the CLI will add variables. See the rules for initializing and linking sites for how to do this.761 - Use `env:set` for changes, `env:unset` to delete. `env:import` to import from a dotenv`.env` file.762763 #### Example usage of env var CLI764 - Basic setting an environment variable for the site765 ```sh766 netlify env:set API_KEY "not-a-secret"767 ```768 - Setting an environment variable that should be treated as a secret769 ```sh770 netlify env:set API_KEY "secret-value" --secret771 ```772773 ### Example `netlify.toml` Configuration774 - Using the netlify.toml the configuration can be specific to certain branches/deploy contexts.775 - examples776 ```toml777 # Production context: all deploys from the Production branch778 # set in your site’s Branches settings in the UI will inherit779 # these settings. You can define environment variables780 # here but we recommend using the Netlify UI for sensitive781 # values to keep them out of your source repository.782 [context.production]783 publish = "output/"784 command = "make publish"785 environment = { NODE_VERSION = "14.15.3" }786787 # Here is an example of how to define context-specific788 # environment variables. Be mindful when using this789 # option and avoid committing sensitive values to public790 # source repositories.791 [context.deploy-preview.environment]792 NOT_PRIVATE_ITEM = "not so secret"793794 # Branch Deploy context: all deploys that are not from795 # a pull/merge request or from the Production branch796 # will inherit these settings.797 [context.branch-deploy.environment]798 NODE_ENV = "development"799800 # Dev context: environment variables set here801 # are available for local development environments802 # run using Netlify Dev. These values can be803 # overwritten on branches that have a more specific804 # branch context configured.805 [context.dev.environment]806 NODE_ENV = "development"807808 # Specific branch context: all deploys from809 # this specific branch will inherit these settings.810 [context.staging.environment] # “staging†is a branch name811 NODE_ENV = "development"812 ```813814 ### `.env` File Handling815 - Netlify builds do not read `.env` files directly816 - Import `.env` variables into Netlify using the UI or CLI (`netlify env:import .env`).817 - Export Netlify variables to `.env` files via UI or CLI (`env:list`).818819 ### Export `.env` Variables820 ```sh821 # list the production deploy context values in .env format822 netlify env:list --plain --context production823824 # list the production deploy context values in .env format825 # and pipe results into a .env file826 netlify env:list --plain --context production > .env827 ```828829 ---830831 # Creating new sites832833 - do not add redirects to netlify.toml or _redirects unless requested834 - do not add custom headers to the netlify.toml or _headers unless requested835836 # Initializing sites or linking them837 - determine if a site is linked by checking if `PROJECT_FOLDER/.netlify/state.json` file exists and it has a populated `siteId` value.838 - if the site is not linked, run `netlify init` to allow the user to set up the site with Netlify. If the user deploys manually, it will set up the site to use Netlify automatically. If the user decides to set up a repo, they might have to set up the repo first. If the site is already set up on netlify then run `netlify link` for the user to input the credentials to link.839840</ProviderContext>841
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