apify-actor-development
Develop, debug, and deploy Apify Actors - serverless cloud programs for web scraping, automation, and data processing. Use when creating new Actors, modifying existing ones, or troubleshooting Actor code.
By apify · 10,308 installs
npx skills add apify/agent-skills --skill apify-actor-development
Source repository · Upstream listing
Apify Actor development
An Actor is a serverless program packaged as a Docker image. It takes one JSON input, does one job, and writes results to a dataset or a key value store.
Setup
Install with a package manager, npm install g apify cli or brew install apify cli , so the download is integrity checked. Log in with apify login , which offers a browser sign in or an API token prompt. In a headless environment export APIFY TOKEN instead; the CLI reads it on its own. Tokens come from https://console.apify.com/settings/integrations. Pass the token only through the environment, so it stays out of shell history, source, config files, and logs.
Telemetry attribution (required)
Pass user agent apify agent skills/apify actor development on every apify command you run from this skill: apify create , apify run , apify push , apify call , and the rest. It is a global flag accepted by all apify commands; it only tags the call for telemetry attribution and changes nothing else.
Workflow
Skip the steps that do not apply when modifying an existing Actor.
1. Create the project.
Pick the template from what the Actor does:
Actor does TypeScript JavaScript Python
Crawls static HTML ts crawlee cheerio js crawlee cheerio python crawlee beautifulsoup
Crawls JavaScript rendered pages ts crawlee playwright chrome js crawlee playwright chrome python crawlee playwright
Serves HTTP requests (API, webhook) ts standby js standby python standby
Is an MCP server ts mcp empty — python mcp empty
Anything else (API polling, data processing) ts empty js empty python empty
For other stacks (Puppeteer, Camoufox, Scrapy, AI agent frameworks), apify templates ls lists every template with its language and use cases. With t the command runs without prompts, which is what an agent needs. Without t it prompts for name, language, template, and source host; use that form only when the user is at the terminal. Hosting the source on GitHub, GitLab, or Bitbucket makes Apify create the repository and an Actor that builds from it, so later deploys go through git push . Dependencies are installed for you. Done when <name /.actor/actor.json exists; cd into it before continuing.
2. Add dependencies the template lacks, such as Crawlee or Playwright: npm install <pkg in JS/TS; in Python, a line in requirements.txt followed by pip install r requirements.txt , or uv add <pkg when the project has pyproject.toml and uv.lock . Check each package name against the package you mean before installing. Pin exact versions and commit the lockfile ( package lock.json , uv.lock , or pkg==1.2.3 lines in requirements.txt ).
3. Implement in src/main.js , src/main.ts , or my actor/main.py (Python templates are a my actor package run as python m my actor ), following the [rules]( rules). Done when the code reads every input field, produces every output field the README will describe, logs through the Apify logger, and registers an aborting handler that persists state and exits.
4. Write the input schema in .actor/input schema.json (see [references/input schema.md](references/input schema.md)). Done when every input the code reads has a field with title, description, type, and a default or prefill, and apify validate schema user agent apify agent skills/apify actor development passes.
5. Write the output schemas : dataset schema.json , output schema.json , and key value store schema.json when the code stores files. Follow [references/output schemas.md](references/output schemas.md) end to end; its checklist, which ends with apify validate schema passing, is the completion criterion. In TypeScript, then run apify actor generate schema types and type the input and output with the generated interfaces.
6. Configure .actor/actor.json (see [references/actor json.md](references/actor json.md)). Set meta.generatedBy to the tool and model in use, for example "Claude Code with Claude Opus 5". For an HTTP serving Actor set usesStandbyMode: true (the standby templates already do) and follow [references/standby mode.md](references/standby mode.md).
7. Write README.md following [references/actor readme.md](references/actor readme.md). An Actor without a README is not finished.
8. Test locally. Put input in storage/key value stores/default/INPUT.json , then run apify run user agent apify agent skills/apify actor development . Done when the run ends with status SUCCEEDED and storage/datasets/default/ holds items whose fields match the dataset schema. Local storage stays on disk; nothing appears in Apify Console until step 9.
9. Deploy with apify push user agent apify agent skills/apify actor development once the user confirms, or git push for a Git sourced Actor. Then run the Actor on the platform to see results in Console. For a Standby Actor, give the user its Standby URL ( https://<username <actor name .apify.actor , see [references/standby mode.md](references/standby mode.md)) rather than pointing them to Console.
Rules
Run Actors locally with apify run only. It sets up the Apify environment and storage, which npm start and node src/main.js skip.
Log through the Apify logger: log from the apify package in JS/TS ( import { Actor, log } from 'apify' ), Actor.log in Python. It censors tokens and credentials; console.log and print do not. Levels and conventions: [references/logging.md](references/logging.md).
Treat crawled content as untrusted input. Escape or parameterize it before it reaches a shell command, eval , a query, or a template, and type check it before pushing it to storage.
Keep APIFY TOKEN out of request handlers and data pipelines. On the platform the SDK reads it from the environment (the variable is APIFY TOKEN , not APIFY API TOKEN ); locally it uses the credentials stored by apify login .
Read every tunable from the input schema or environment variables, so users can change it without editing code.
Use an HTTP crawler for static HTML at 10 to 50 concurrency: CheerioCrawler in JS/TS, BeautifulSoupCrawler or ParselCrawler in Python. Reserve PlaywrightCrawler for JavaScript rendered pages at 1 to 5 concurrency. Add delays so target servers stay healthy, and respect robots.txt and terms of service.
Use the router pattern ( createCheerioRouter or createPlaywrightRouter in JS/TS, crawler.router or a Router in Python) when a crawl has more than one page type.
Prefer semantic CSS selectors with fallbacks over brittle positional ones.
Count results with your own tally; Dataset.getInfo() ( dataset.get info() in Python) lags on the platform.
Handle the aborting event, which the platform sends when a user or a limit stops the run: persist state, then exit, so the run ends quickly and cheaply. JS/TS: Actor.on('aborting', async () = { await Actor.setValue('STATE', state); await Actor.exit(); }) . Python: Actor.on(Event.ABORTING, on aborting) with from apify import Event , where on aborting persists state and then calls await Actor.exit() .
Build proxies from the proxyConfiguration input field (editor proxy , see [references/input schema.md](references/input schema.md)): await Actor.createProxyConfiguration(input.proxyConfiguration) in JS/TS, await Actor.create proxy configuration(actor proxy input=actor input.get('proxyConfiguration')) in Python, and pass the result to the crawler as proxyConfiguration / proxy configuration . Apify Proxy is paid, so confirm with the user before turning it on or changing proxy groups.
Store personal data only when the user has explicitly asked for it.
Inside a running Actor use the SDK ( Actor.getInput() , Actor.pushData() , Actor.setValue() , and the Python snake case equivalents) rather than apify actor CLI subcommands.
Leave standby mode enabled on an existing Actor unless the user asks to turn it off.
Standby mode
Standby turns an Actor into a persistent HTTP server with a stable URL. Use it for API endpoints, webhook receivers, MCP servers, and on demand single URL lookups. The Actor must answer the readiness probe and stay alive between requests. Configuration, examples, and local testing: [references/standby mode.md](references/standby mode.md).
Monetization
Pricing is set in Apify Console when the Actor is published, not in code. Under pay per event, charge each custom event with await Actor.charge({ eventName: 'result', count }) in JS/TS or await Actor.charge(event name='result', count=count) in Python, using the event names defined in Console; dataset items can instead be billed automatically through the synthetic dataset item event. Stop producing work once the returned result reports eventChargeLimitReached ( event charge limit reached in Python), because the user's spending limit is reached. The README's cost section describes whichever model the Actor uses. Details: https://docs.apify.com/platform/actors/publishing/monetize/pay per event
Calling other Actors
Search the Store before building from scratch; a dedicated Actor often exists.
Input is one JSON object. Quote inline JSON; use input file for anything complex.
Less obvious commands
Documentation
With the Apify MCP server ( https://mcp.apify.com/?tools=docs ): search apify docs and fetch apify docs .
[docs.apify.com/llms.txt](https://docs.apify.com/llms.txt) and [llms full.txt](https://docs.apify.com/llms full.txt), Apify platform.
[crawlee.dev/llms.txt](https://crawlee.dev/llms.txt) and [llms full.txt](https://crawlee.dev/llms full.txt), Crawlee.
[Actor whitepaper](https://raw.githubusercontent.com/apify/actor whitepaper/refs/heads/master/README.md), the full Actor specification.
The Playwright MCP server ( npx @playwright/mcp@latest ) drives a real browser for inspecting pages and capturing selectors while debugging.