Health

Liveness Check

Liveness probe — process + asyncio loop responsiveness check only.

Returns 200 + {"status": "alive", ...} if the FastAPI worker is reachable and the event loop is not wedged. Does NOT touch the database. Does NOT touch Redis.

Intended as the Traefik routing probe so that a sick database (pool drain, replica lag, query storm) does NOT cause Traefik to de-register the backend. When the DB is sick:

• /v1/health/live → 200 → Traefik keeps routing • /v1/health/ready → 503 → docker marks unhealthy, monitoring alerts fire, operator intervenes

The cached / static / Redis-only paths can still serve while the DB recovers, instead of the whole service 404’ing at the edge — which is exactly what bit prod in the 2026-05-17 outage (memory prod_outage_2026_05_17_entitlements_pool_drain).

The await asyncio.sleep(0) is intentional: it yields control back to the event loop for a single tick, so if a sync handler is pegging the loop the probe will still time out (correctly surfacing the wedge). Without it a wedged loop could in theory complete this coroutine synchronously between handlers.

GET

health

live

Liveness Check

curl --request GET \
  --url https://api.polysimulator.com/v1/health/live

import requests

url = "https://api.polysimulator.com/v1/health/live"

response = requests.get(url)

print(response.text)

const options = {method: 'GET'};

fetch('https://api.polysimulator.com/v1/health/live', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

<?php

$curl = curl_init();

curl_setopt_array($curl, [
  CURLOPT_URL => "https://api.polysimulator.com/v1/health/live",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "GET",
]);

$response = curl_exec($curl);
$err = curl_error($curl);

curl_close($curl);

if ($err) {
  echo "cURL Error #:" . $err;
} else {
  echo $response;
}

package main

import (
	"fmt"
	"net/http"
	"io"
)

func main() {

	url := "https://api.polysimulator.com/v1/health/live"

	req, _ := http.NewRequest("GET", url, nil)

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(string(body))

}

HttpResponse<String> response = Unirest.get("https://api.polysimulator.com/v1/health/live")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://api.polysimulator.com/v1/health/live")

http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true

request = Net::HTTP::Get.new(url)

response = http.request(request)
puts response.read_body

{
  "status": "<string>",
  "timestamp": "<string>",
  "version": "1.0.0"
}

{
  "error": "<string>",
  "message": "<string>",
  "details": {},
  "request_id": "<string>"
}

{
  "error": "<string>",
  "message": "<string>",
  "details": {},
  "request_id": "<string>"
}

Response

Successful Response

Response for /v1/health/live.

Deliberately distinct from HealthResponse so monitoring tools can pin on status == "alive" (intent-revealing) without having to also accept the existing "ok" value used by /v1/health. No nested checks — the probe never touches DB or Redis.

status

string

required

timestamp

string

required

version

string

default:1.0.0

Readiness CheckReadiness probe — checks that database and Redis are reachable. Returns 200 with status "ok" if all dependencies are healthy. When ``HEALTH_READY_TOLERANCE_ENABLED`` is set (opt-in; default OFF), a single transient failure (e.g. a slow DB-ping during the bulk-poller burst) returns 200 with status "tolerating" — the endpoint only flips to **503** with status "degraded" after ``HEALTH_READY_FAIL_THRESHOLD`` consecutive failed probes (see the tolerance block above for the WHY). With the flag OFF (the default) the endpoint is strict fail-fast: any failed probe returns 503 immediately, exactly as it did pre-#1850.

Liveness Check

curl --request GET \
  --url https://api.polysimulator.com/v1/health/live

import requests

url = "https://api.polysimulator.com/v1/health/live"

response = requests.get(url)

print(response.text)

const options = {method: 'GET'};

fetch('https://api.polysimulator.com/v1/health/live', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

<?php

$curl = curl_init();

curl_setopt_array($curl, [
  CURLOPT_URL => "https://api.polysimulator.com/v1/health/live",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "GET",
]);

$response = curl_exec($curl);
$err = curl_error($curl);

curl_close($curl);

if ($err) {
  echo "cURL Error #:" . $err;
} else {
  echo $response;
}

package main

import (
	"fmt"
	"net/http"
	"io"
)

func main() {

	url := "https://api.polysimulator.com/v1/health/live"

	req, _ := http.NewRequest("GET", url, nil)

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(string(body))

}

HttpResponse<String> response = Unirest.get("https://api.polysimulator.com/v1/health/live")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://api.polysimulator.com/v1/health/live")

http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true

request = Net::HTTP::Get.new(url)

response = http.request(request)
puts response.read_body

{
  "status": "<string>",
  "timestamp": "<string>",
  "version": "1.0.0"
}

{
  "error": "<string>",
  "message": "<string>",
  "details": {},
  "request_id": "<string>"
}

{
  "error": "<string>",
  "message": "<string>",
  "details": {},
  "request_id": "<string>"
}

Overview

Endpoints

Liveness Check

Response