Frequently asked questions

Twin Browser is the browser execution layer for LLM agents — a token-efficient browser API that turns a plain-English goal into deterministic, replayable action. It compiles a task once, matches re-phrased requests to it with a semantic dispatch cache, and replays deterministically with zero LLM calls.

Most browser infrastructure re-runs the LLM on every execution, so cost climbs with usage. Twin moves the LLM to the planning stage: the first run compiles a reusable skill, and subsequent similar runs hit a semantic cache and replay deterministically. A cache hit is roughly 5x cheaper, so the marginal cost per run trends toward zero the more your agents run.

An exact-match cache only helps when the identical action repeats — it is keyed on a selector or a parameter hash, so a re-worded request is a cold start. Twin embeds the request and matches by meaning, so "schedule a call" finds the skill compiled for "book a demo." That is why Twin keeps saving where exact-match caches fall back to a full LLM run.

When a goal succeeds, Twin freezes the action path into a skill keyed to the page structure. On a cache hit it replays that skill deterministically — the same indexed clicks and inputs — with no model call. It is production-ready, not a debug-only recording.

The cross-tenant skill corpus reuses the structural action plan of a skill, not your data, credentials, or run inputs. Secrets stay in your per-tenant credential vault, the backend enforces default-deny row-level security, and every call is authenticated and audit-logged. The shared layer is the "how to operate this page" knowledge, which raises the cache-hit rate for everyone.

Pricing is usage-based credits, free to start, with an entry plan from $29/mo. LLM cost is metered per call and passed through at 1x — no markup — with a transparent rate card published at /api/v1/pricing. Pay-as-you-go auto top-up keeps long-running agents from stalling.

Because Twin is built so usage gets cheaper. As your cache-hit rate rises, more runs replay deterministically at near-zero LLM cost, so your blended cost-per-1k-runs falls. A flat per-seat price would hide that; usage credits let the savings flow straight to you.

Twin automates the web where you are authorized — first-party sites, operator-approved automation, internal RPA, accessibility, and authorized testing. The run target URL is the authorization signal, and auth, billing, and audit logging run on every call. Twin is not a CAPTCHA-bypass-for-hire or anti-bot evasion service.

A multi-tenant Supabase backend with default-deny row-level security, per-tenant API keys, a credential vault, and an audit log on every call. Tenants are isolated by default; access is granted explicitly, never assumed.

They are all good at running a browser, but their default loop re-runs the LLM (or caches only exact, single-workflow repeats), so cost stays flat or rises with usage. Twin adds a semantic dispatch cache that matches re-phrased requests and a cross-tenant skill corpus that compounds savings. See the side-by-side breakdowns on the compare pages.