Sticky or rotating for an agent?

Sticky, almost always. An agent is a sequence of steps that expects to be one visitor. Rotating is for the stateless fetches around it: each new connection can get a different exit IP. Both come from the same credentials — the only difference is whether the username carries a _session- handle.

How long can a session be held?

As long as the task needs. _sesstime- is minutes: the same _session- handle returns the same exit IP for up to that long. On ARC Basic, Fast and Ultra the hold is best effort with no hard cap — the dashboard generator offers 1 minute to 24 hours, and the API's session_ttl takes 60 to 86,400 seconds. On ARC Mobile a sticky session can be set to 5 to 60 minutes. An exit can go offline before the time is up, so treat a changed IP as normal, not as an error.

Can several agents share one handle?

They can, but they will then share one IP and one rate limit. Mint one handle per concurrent task — any string works, no registration step.

Does Fast Mode cost extra?

No. It is a per-connection token (_fastmode-true) that prefers the fastest nodes in the pool. It is free on every rotating plan; only gigabytes are billed.

I use a hosted browser platform. Can I still use this?

If the platform lets you set a proxy URL — most do — yes: give it the same http://user:pass@host:port string. You then pay the platform for the browser and us for the bandwidth, by the gigabyte, with no expiry.

Can my coding agent set this up on its own?

Yes. The API serves llms.txt — a single markdown file with every endpoint, the request shapes, the error envelope and working examples. The API reference in the dashboard has the same content for people.

Anything unlawful, plus the specific list in the acceptable use policy: fraud, account takeover and credential stuffing, spam, malware, DDoS, and circumventing access controls on non-public data. Public data, your own accounts and your own systems are fine.

Use case · AI agents

Residential proxies for AI agents.

Agents get blocked and rate-limited from datacenter IPs, and hosted browser platforms bill residential bandwidth on top of the browser. Bring your own: one sticky session per task, country and city in the string, an API to mint endpoints, and gigabytes that never expire.

Get started Jump to the snippets

Pay per GB · No subscription · Prices in EUR, excl. VAT

browser-use — one sticky session per task8 lines

browser = Browser(    proxy=ProxySettings(        server="http://proxy.arcproxies.io:8000",        username="USERNAME_pool-arcfast_country-us_session-k3f9a1x2_sesstime-30",        password="PASSWORD",    ))agent = Agent(task="…", llm=llm, browser=browser)

€2.00
per GB on ARC Fast, excl. VAT: −44%
at 1 TB (€1.12 / GB): 185+
countries, city targeting: Never
expires — no subscription

The problem

What goes wrong without the right IPs

None of these are exotic. They are the ordinary reasons an agent run that worked on your laptop fails in production.

Cloud IPs get a different page

Many sites serve a reduced page, a consent wall or a challenge to well-known datacenter ranges. The agent then reasons about a page a person would never see, and loops. A residential exit gets the page a visitor gets.

One limit stops the whole fleet

When every agent leaves from the same egress address, the first rate limit stops all of them at once. One exit IP per task contains a limit to one task.

The IP changes mid-task

Carts, multi-step forms and search sessions expect one visitor. A rotating exit between steps resets that state. A sticky session holds one IP for as long as the task runs — 10 minutes or 6 hours, your call.

Wrong country, wrong answer

Prices, stock, language, shipping options and cookie banners differ by market. An agent that should be in Germany but exits in Virginia collects a different reality. Country and city are two tokens in the username.

Bundled bandwidth is priced like a browser

Hosted browser platforms often charge residential traffic on top of the browser minutes, and most of them let you bring your own proxy. Separating the two makes the bandwidth line a line you can read.

Every tool takes the proxy somewhere else

browser-use wants a ProxySettings object, Playwright a launch option, Playwright MCP a config file, Crawl4AI a run config, n8n a node option. The snippets below are one per tool, from each tool's own docs.

Setup

Recommended setup

Start every agent on ARC Fast with a sticky session. Escalate the few targets that need it, and push plain HTTP fetches down to ARC Basic.

Plan	Role	Session	Targeting	Price
ARC Fast Rotating residential	Default Real residential exits, one per task, and the steepest volume ladder we sell. Nearly every agent workload lives here.	Sticky, 10–30 min per task	Country, optionally city	€2.00 / GB €1.12 at 1 TB (−44%)
ARC Ultra Premium residential	Escalation For the handful of targets where ARC Fast leaves you with failures you cannot explain. It is the priciest of the three rotating pools, so route only those tasks through it.	Sticky	Country + city	€3.50 / GB €2.17 at 1 TB (−38%)
ARC Basic Rotating ISP	Plain fetches The HTTP calls around an agent run — fetching docs, checking links, reading an API — do not need a browser or a residential IP. The ISP pool is a fraction of the price.	Rotating	Country	€0.75 / GB €0.59 at 1 TB (−21%)

ARC Fast — default1 line

http://USERNAME_pool-arcfast_country-us_session-k3f9a1x2_sesstime-30:PASSWORD@proxy.arcproxies.io:8000

ARC Ultra — escalation1 line

http://USERNAME_pool-arcultra_country-de_city-berlin_session-k3f9a1x2_sesstime-30:PASSWORD@proxy.arcproxies.io:8000

ARC Basic — plain fetches1 line

http://USERNAME_pool-arc_country-us:PASSWORD@proxy.arcproxies.io:8000

Prices are list prices in EUR, excl. VAT. Volume discounts apply automatically at checkout — full ladder on the pricing page.

Code

One snippet per tool

Each one uses the tool's documented proxy option. Replace USERNAME and PASSWORD with the credentials from your dashboard; everything after USERNAME is targeting.

agent.py19 lines

from browser_use import Agent, Browser, ChatOpenAIfrom browser_use.browser.profile import ProxySettings# One sticky session per task: every request this agent makes for the next# 30 minutes leaves from the same residential IP in the US.browser = Browser(    proxy=ProxySettings(        server="http://proxy.arcproxies.io:8000",        username="USERNAME_pool-arcfast_country-us_session-k3f9a1x2_sesstime-30",        password="PASSWORD",    ))agent = Agent(    task="Find the shipping cost for a 2 kg parcel to Chicago on example.com",    llm=ChatOpenAI(model="gpt-4.1-mini"),    browser=browser,)result = await agent.run()

browser-use takes the proxy on the Browser it drives; the Agent inherits it. Give every concurrent agent its own _session- handle so their IPs never collide.

Before you ship

One _session- handle per concurrent task; reuse it to return to the same IP.
Generate endpoints once per run, not once per request — the API limit is per key.
Keep the password and the API key in environment variables, never in a prompt.
Block images, fonts and media in the browser where the task allows. It is the single biggest bandwidth saving.
Check the balance before a long run, not on every request.

Hand your coding agent api.arcproxy.cloud/api/v1/llms.txt — the whole API reference in one file, generated from the live catalog.

Works with anything that takes a proxy URL

browser-use
Playwright
Playwright MCP
Crawl4AI
Firecrawl (self-hosted)
Crawlee
Apify actors
n8n
LangChain loaders
Stagehand
Puppeteer

Illustration

What 2,000 browser-agent tasks a month costs

An illustration with round numbers — your pages, payloads and retry rate will differ. The arithmetic is the real price ladder.

Assumptions

Tasks per month: 2,000
Page loads per task: 12
Average page, images blocked: 1.5 MB
Retries and navigation overhead: +10%
Bandwidth per month: ≈ 40 GB

On ARC Fast

€70.40per month, excl. VAT

40 GB bought in one purchase at €1.76 / GB (−12% volume rung, applied automatically).

The same 40 GB on ARC Ultra: €124.60 at €3.12 / GB. Route only the jobs that need it through the pricier pool.

A browser task is heavy because every page pulls scripts, styles and — unless you block them — images and fonts. The per-task figure is the number to measure on your own runs before you size a purchase.

Bandwidth never expires, so a bigger single purchase is only ever cheaper per GB. See the ladder.

FAQ

Agent questions

Something not covered? Write to contact@arcproxies.io.

Get started

Give your agents residential IPs today.

Create an account, and code WELCOME15 takes 15% off your first bandwidth purchase, up to 25 GB. No subscription, no sales call, and the gigabytes never expire.

Create your account Questions first? contact@arcproxies.io

Multi-accounting

One stable exit per profile, held as long as the session needs, so the accounts you are entitled to run stay separate in an anti-detect browser.

QA & localisation

See your own site the way a user in Tokyo, São Paulo or Munich sees it — currency, language, consent banner, CDN edge and all — before they report it.

Threat intel

Investigate phishing kits, typosquats and malicious infrastructure from an IP that is not your company's, and see the payload the target audience is served.

Web scraping

A second provider that just works — Scrapy, requests, Crawlee or Playwright, self-serve, no sales call, bandwidth that never expires.