Outbound Throttling
Spectest can rate-limit the outbound HTTP requests made by a Node-based server under test (SUT) — calls your API makes to a payments provider, a third-party API, etc. This is separate from --rps, which limits how fast Spectest itself calls your API; outboundThrottle limits calls going the other direction, from your API out to the services it depends on.
Like HTTP recording, this works by injecting instrumentation into the SUT process at startup, so outbound throttling is incompatible with runningServer: 'reuse' — Spectest must be the one that spawns the server.
Configuration
outboundThrottle is config-file only; there is no CLI flag.
// spectest.config.js
export default {
startCmd: 'npm run start',
runningServer: 'kill',
outboundThrottle: [
{ match: 'https://api.stripe.com', rps: 5, name: 'stripe' },
{ match: /^https:\/\/.*\.internal\.example\.com/, rps: 20 },
],
};Each rule:
| Key | Description |
|---|---|
match | A string (canonical URL prefix match) or RegExp (tested against the canonical URL) |
rps | Requests per second allowed for outbound calls matching this rule |
name | Optional label used in throttling-related log output |
Rules are evaluated in order and the first match wins; outbound calls that match no rule are unthrottled.
Related: HTTP Recording for the other SUT-process instrumentation feature, and CLI for --server-startup-timeout / --server-health-check-interval, which control how long Spectest waits for the (now-instrumented) server to become ready.