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Failure injection

The simulator injects failures; the agent or application owns the retry policy.

from python_sim import Simulation
from python_sim.errors import SimulationTimeoutError

sim = Simulation(seed=42)
sim.stripe.fail_next("timeout")

try:
    sim.stripe.list_payments(order_id="123")
except SimulationTimeoutError:
    payments = sim.stripe.list_payments(order_id="123")

Failures are deterministic and one-shot. Supported values include:

  • timeout → SimulationTimeoutError
  • service_unavailable → ServiceUnavailableError
  • permission_denied → PermissionDeniedError
  • 429 or rate_limited → RateLimitError
  • 500 or integer HTTP status codes → HttpError

Failures can be queued on a service with service.fail_next(...). A failed call emits service.call.failed before raising.