Perplexity runs its Teammates agents on Firecracker microVMs and Git

An agent you leave running overnight has to pick up on the same files you left it with. The New Stack reports on how Perplexity built that part of Teammates, the agent product it launched on 5 November. Amanda Caswell interviewed Nate Kupp, Perplexity's VP of Infrastructure, for the piece on 8 November.

The stack. Perplexity built the agents on SPACE, its own sandbox runtime. The New Stack reports that SPACE uses Firecracker microVMs and Btrfs snapshots. That lets Perplexity pause, resume or fork an agent session without losing its state. Each session runs in its own sandbox with its own browser. Project files live in Git-backed repositories. State carries across sessions through Git. A separate store, Perplexity's Brain system, holds the agent's memory between runs.

The two numbers Perplexity states

Perplexity says fewer than 2 percent of agent submissions are rejected because they are based on outdated repository state. Median submission latency is under 1.7 seconds. The p99 stays below eight seconds. Those are Perplexity's own figures as reported by The New Stack.

Kupp told The New Stack that stateful systems are hard to build. He raised the hand-off problem out loud. When one agent passes a task to another, the session has to travel with it. That means the files, the sandbox and the tool permissions.

One honest gap

The New Stack flags a gap the piece could not close. "It's unclear how it prevents agents from accessing resources beyond their permissions when tasks are handed off," Caswell writes. The launch post and the interview do not spell out the permission check at the point of hand-off. A buyer should ask.

Perplexity open-sourced SPACE on 16 October under Apache 2.0. A team that wants the sandbox model can read the code. The Git-backing of project state is a design choice a reader can copy without running Perplexity.

What a buyer can read from the stack

Three design calls carry out of this piece. First, a long-running agent needs a sandbox it can stop and start. A plain container loses state on exit. Firecracker and Btrfs give Perplexity that stop-and-start. Second, the agent's files belong in Git, not in the sandbox's own disk. A fork or a crash then costs no work. Third, memory is a separate store from files. The Brain system holds what the agent has learned, so a new session can read it.

A team building its own agent platform now has one named production stack to study. Perplexity's numbers are its own. Verify the latency and the stale-rejection rate against your own load before copying the design.

Source

The New Stack, Perplexity's AI agents keep working after you close the tab, by Amanda Caswell. Perplexity's launch post: Teammates are agents for complex, ongoing work.