Lokalise Observability
Overview
Monitor Lokalise translation pipeline health: API response times, rate limit consumption, translation completion rates, webhook delivery reliability, file upload/download status, and per-word cost tracking. Built around the @lokalise/node-api SDK with Prometheus-compatible metrics and alerting rules.
Prerequisites
@lokalise/node-apiSDK installed- Metrics backend (Prometheus, Datadog, CloudWatch, or OpenTelemetry collector)
- Lokalise API token with read access
- Optional: webhook endpoint for real-time event monitoring
Instructions
Step 1: Instrument API Calls with Metrics
Wrap every SDK call to emit duration, success/failure counts, and rate limit status.
import { LokaliseApi } from "@lokalise/node-api";
interface MetricLabels {
operation: string;
status: "ok" | "error";
code?: string;
}
// Implement this to emit to your metrics backend
declare function emitHistogram(name: string, value: number, labels: MetricLabels): void;
declare function emitCounter(name: string, value: number, labels: MetricLabels): void;
const lok = new LokaliseApi({ apiKey: process.env.LOKALISE_API_TOKEN! });
async function trackedApiCall<T>(
operation: string,
fn: () => Promise<T>
): Promise<T> {
const start = performance.now();
try {
const result = await fn();
const durationMs = performance.now() - start;
emitHistogram("lokalise_api_duration_ms", durationMs, {
operation,
status: "ok",
});
emitCounter("lokalise_api_requests_total", 1, {
operation,
status: "ok",
});
return result;
} catch (err: unknown) {
const code = (err as { code?: number })?.code?.toString() ?? "unknown";
const durationMs = performance.now() - start;
emitHistogram("lokalise_api_duration_ms", durationMs, {
operation,
status: "error",
code,
});
emitCounter("lokalise_api_requests_total", 1, {
operation,
status: "error",
code,
});
throw err;
}
}
// Usage — wrap every SDK call
const keys = await trackedApiCall("keys.list", () =>
lok.keys().list({ project_id: projectId, limit: 500 })
);
const bundle = await trackedApiCall("files.download", () =>
lok.files().download(projectId, {
format: "json",
filter_langs: ["en"],
original_filenames: false,
})
);
Step 2: Monitor Translation Completion
Poll project statistics and emit per-locale progress as gauge metrics.
declare function emitGauge(name: string, value: number, labels: Record<string, string>): void;
async function collectTranslationMetrics(projectId: string): Promise<void> {
const project = await trackedApiCall("projects.get", () =>
lok.projects().get(projectId)
);
// Overall progress
emitGauge("lokalise_translation_progress_pct", project.statistics?.progress_total ?? 0, {
project: projectId,
locale: "all",
});
emitGauge("lokalise_keys_total", project.statistics?.keys_total ?? 0, {
project: projectId,
});
// Per-language progress
const languages = await trackedApiCall("languages.list", () =>
lok.languages().list({ project_id: projectId, limit: 100 })
);
for (const lang of languages.items) {
emitGauge("lokalise_translation_progress_pct", lang.statistics?.progress ?? 0, {
project: projectId,
locale: lang.lang_iso,
});
emitGauge("lokalise_words_to_do", lang.statistics?.words_to_do ?? 0, {
project: projectId,
locale: lang.lang_iso,
});
}
}
// Run on a schedule (every 5 minutes)
// setInterval(() => collectTranslationMetrics(projectId), 5 * 60_000);
Step 3: Track Rate Limit Consumption
set -euo pipefail
# Quick rate limit check — call from a monitoring cron job
HEADERS=$(curl -sI "https://api.lokalise.com/api2/projects?limit=1" \
-H "X-Api-Token: ${LOKALISE_API_TOKEN}" 2>/dev/null)
LIMIT=$(echo "$HEADERS" | grep -i "x-ratelimit-limit" | awk '{print $2}' | tr -d '\r')
REMAINING=$(echo "$HEADERS" | grep -i "x-ratelimit-remaining" | awk '{print $2}' | tr -d '\r')
RESET=$(echo "$HEADERS" | grep -i "x-ratelimit-reset" | awk '{print $2}' | tr -d '\r')
echo "Rate limit: ${REMAINING}/${LIMIT} remaining (resets at ${RESET})"
# Emit as metrics for Prometheus/Datadog
# lokalise_rate_limit_remaining ${REMAINING}
# lokalise_rate_limit_max ${LIMIT}
Step 4: Monitor Webhook Delivery
Track webhook processing success and latency in your webhook handler.
import express from "express";
const webhookMetrics = {
received: 0,
processed: 0,
failed: 0,
totalLatencyMs: 0,
};
app.post("/webhooks/lokalise", async (req: express.Request, res: express.Response) => {
webhookMetrics.received++;
const start = performance.now();
// Respond immediately — Lokalise times out after 8 seconds
res.status(200).json({ received: true });
try {
await processWebhookEvent(req.body);
webhookMetrics.processed++;
} catch (error) {
webhookMetrics.failed++;
console.error("Webhook processing failed:", error);
}
const latencyMs = performance.now() - start;
webhookMetrics.totalLatencyMs += latencyMs;
emitCounter("lokalise_webhook_received_total", 1, {
event: req.body.event,
status: webhookMetrics.failed > 0 ? "error" : "ok",
});
emitHistogram("lokalise_webhook_processing_ms", latencyMs, {
event: req.body.event,
status: "ok",
});
});
// Health endpoint exposing webhook metrics
app.get("/metrics/webhooks", (_req, res) => {
res.json({
received: webhookMetrics.received,
processed: webhookMetrics.processed,
failed: webhookMetrics.failed,
avgLatencyMs: webhookMetrics.received > 0
? Math.round(webhookMetrics.totalLatencyMs / webhookMetrics.received)
: 0,
});
});
Step 5: Register Webhooks for Key Events
set -euo pipefail
# Subscribe to events that matter for pipeline monitoring
curl -s -X POST "https://api.lokalise.com/api2/projects/${LOKALISE_PROJECT_ID}/webhooks" \
-H "X-Api-Token: ${LOKALISE_API_TOKEN}" \
-H "Content-Type: application/json" \
-d '{
"url": "https://hooks.company.com/lokalise",
"events": [
"project.imported",
"project.exported",
"project.key.added",
"project.key.modified",
"project.translation.updated",
"project.translation.proofread",
"project.task.closed",
"project.contributor.added"
]
}' | jq '{webhook_id: .webhook.webhook_id, events: .webhook.events}'
Step 6: Prometheus Alerting Rules
groups:
- name: lokalise
rules:
- alert: LokaliseApiRateLimited
expr: rate(lokalise_api_requests_total{status="error", code="429"}[5m]) > 0
for: 2m
annotations:
summary: "Lokalise API rate limit hit — requests being throttled"
runbook: "Check for runaway loops. Lokalise limit is 6 req/sec per token."
- alert: LokaliseApiErrors
expr: rate(lokalise_api_requests_total{status="error", code=~"5.."}[10m]) > 0.1
for: 5m
annotations:
summary: "Lokalise API returning 5xx errors"
runbook: "Check https://status.lokalise.com. Enable fallback translations."
- alert: TranslationProgressStalled
expr: lokalise_translation_progress_pct < 80 and changes(lokalise_translation_progress_pct[24h]) == 0
for: 24h
annotations:
summary: "Translation progress stalled at {{ $value }}% for 24+ hours"
- alert: WebhookDeliveryFailing
expr: rate(lokalise_webhook_received_total{status="error"}[1h]) > 3
annotations:
summary: "Lokalise webhook deliveries failing ({{ $value }} errors/hour)"
- alert: LokaliseApiLatencyHigh
expr: histogram_quantile(0.95, rate(lokalise_api_duration_ms_bucket[5m])) > 5000
for: 10m
annotations:
summary: "Lokalise API P95 latency above 5 seconds"
Step 7: Translation Pipeline Dashboard Spec
Key panels for Grafana/Datadog:
| Panel | Metric | Type |
|-------|--------|------|
| API Request Rate | rate(lokalise_api_requests_total[5m]) | Time series |
| API Latency P50/P95 | histogram_quantile(0.5/0.95, ...) | Time series |
| Rate Limit Remaining | lokalise_rate_limit_remaining | Gauge |
| Translation Progress | lokalise_translation_progress_pct by locale | Bar chart |
| Words Remaining | lokalise_words_to_do by locale | Bar chart |
| Webhook Success Rate | rate(lokalise_webhook_received_total{status="ok"}[5m]) | Time series |
| Error Rate by Code | rate(lokalise_api_requests_total{status="error"}[5m]) by code | Stacked area |
Output
trackedApiCall()wrapper emitting duration and error metrics for every Lokalise API operation- Translation progress gauge metrics broken down by project and locale
- Rate limit consumption monitoring via response headers
- Webhook delivery tracking with latency and error counters
- Prometheus alerting rules for rate limiting, API errors, stalled progress, and webhook failures
- Dashboard specification with 7 panels covering the full translation pipeline
Error Handling
| Issue | Cause | Solution |
|-------|-------|----------|
| 429 Too Many Requests | Exceeded 6 req/sec rate limit | Add request throttling with p-queue |
| Webhook not firing | Wrong event type registered | Verify event names match API reference |
| Progress metric stuck at 0 | Language not added to project | Add target locale in Lokalise project settings |
| Stale metrics | Polling interval too long | Reduce collection interval to 5 minutes |
| High cardinality | Too many label values | Limit operation labels to top-level SDK methods |
Resources
- Lokalise Webhooks API
- Lokalise Webhook Events
- Lokalise API Rate Limits
- Lokalise Project Statistics
- Prometheus Alerting Rules
- p-queue — rate-limited request queue
Next Steps
For setting up real-time automation based on webhook events, see lokalise-webhooks-events. For incident response procedures when alerts fire, see lokalise-incident-runbook.