ColdTally

ColdTally is an independent price-and-change tracker for agent infrastructure: the code-execution sandboxes and cloud browsers that AI agents run on.

Providers bill in different units (vCPU-seconds, active CPU, GiB-hours, session minutes), so ColdTally converts each one's published rates into the cost of one typical task. For sandboxes that is a 2 vCPU / 4 GiB sandbox running 5 minutes at 10% CPU; for browsers, one 3-minute session. Each cost states what it excludes, such as plan fees, free credits, egress, proxies and LLM tokens.

• Compares 12 providers: 6 sandboxes (Cloudflare Sandbox, Vercel Sandbox, E2B, Daytona, Blaxel, Modal) and 6 cloud browsers (Browser Use, KERNEL, Cloudflare Browser Run, Steel, Hyperbrowser, Browserbase).
• Every value has a source URL, a fetch date and a verified flag. Values it couldn't confirm are shown as unverified.
• Rankings are computed from cost alone. Vendors can't pay for placement.
• A calculator in the browser uses the same open-source cost model as the tables.
• A changelog with an RSS feed records each pricing, plan, limit and terms change, with its date and source. Startup times are measured daily and shown separately from cost.
• Agent-readable files (llms.txt, answer pages and a rankings JSON) let a coding agent quote the numbers with their dates.

It's for engineers choosing a sandbox or browser provider for an agent, and for teams already paying one who want to know when its prices change. ColdTally is free with no account. The weekly email is optional and uses double opt-in. Code is MIT and data is CC BY 4.0, in latent-signal/coldtally-data.