generated: '2026-07-21'
method: searched
source: https://docs.urbit.org/build-on-urbit/environment.md
description: >-
  Urbit's test/sandbox story is the "fake ship": a local development ship
  booted with an Urbit ID you don't own, running entirely off-network with
  fake keys. Fake ships never touch the live network; multiple fake ships on
  one machine network with each other. Disposable comets (free live-net IDs)
  and local-only comets (-L) are the intermediate tier. Published values are
  captured verbatim from docs.urbit.org and the urbit.org running-urbit-os
  agent skill.
modes:
  - mode: fake ship
    live: false
    command: "./urbit -F zod"
    identity: any valid Urbit ID you don't own (canonical example ~zod; ~bus for a second ship)
    isolation: >-
      Fake ships run on their own network using fake keys and do not
      communicate with live-net ships in any way. Fake ships on the same
      machine automatically talk to one another (test with |hi ~bus).
    docs: https://docs.urbit.org/build-on-urbit/environment#creating-a-fake-ship
  - mode: local-only comet
    live: false
    command: "./urbit -t -L -B <pill> -p <ames-port> --http-port <http-port> -c <pier>"
    notes: -L keeps networking local; documented in the urbit.org MCP-bootstrap agent reference for disposable ships.
    docs: https://urbit.org/.agents/skills/running-urbit-os/references/mcp-bootstrap.md
  - mode: comet
    live: true
    cost: free
    notes: >-
      Disposable live-net identity; can do almost everything a planet can but
      some groups refuse comets to prevent spam. Automated comet onboarding
      for agents is documented in the running-urbit-os skill.
    docs: https://docs.urbit.org/get-on-urbit
fixtures:
  - name: backup pier
    pattern: >-
      Boot a fresh fake ship once (./urbit -F zod -c zod.new), mount desks,
      shut down, keep zod.new as a golden copy; recreate a clean test ship in
      seconds with rm -r zod && cp -r zod.new zod && ./urbit zod.
    docs: https://docs.urbit.org/build-on-urbit/environment#faster-fake-ship-booting
test_identities:
  - "~zod (canonical fake galaxy for development)"
  - "~bus (second fake ship for network testing)"
notes:
  - No hosted sandbox environment exists; the sandbox is always a local ship.
  - The dev web login code for a fake ship is obtained the same way as live (+code in the dojo).