Staxly

Knock vs Langfuse

Notifications-as-a-service: in-app feeds, email, push, SMS, chat via one API
vs. Open-source LLM engineering platform — observability, prompts, evals

Knock websiteLangfuse website

Pricing tiers

Knock

Developer
Free forever. 10K messages, 500 guide users, 500 AI credits/month.
$0 base (usage-based)
Starter
$250/mo. 50K messages, 2.5K guide users, 2K AI credits. Remove branding.
$250/mo
Enterprise
Custom pricing. White-label, i18n, data warehouse, Datadog, SCIM, SAML, HIPAA/BAA.
Custom
Knock website

Langfuse

Hobby (Cloud Free)
Free. 50k units/month included. 30 days data access. 2 users. Community support.
Free
Self-Hosted (OSS)
MIT-licensed. Docker Compose or Kubernetes deployment. Unlimited.
$0 base (usage-based)
Core
$29/month. 100k units included ($8 per 100k overage). 90 days retention. Unlimited users. In-app support.
$29/mo
Pro
$199/month. 100k units included + same overage. 3 YEARS retention. Unlimited annotation queues. High rate limits.
$199/mo
Teams Add-on
+$300/month. Adds Enterprise SSO + fine-grained RBAC + dedicated Slack support to Pro.
$300/mo
Enterprise
$2,499/month. Everything + custom rate limits, uptime SLA, dedicated support engineer. Yearly options.
$2499/mo
Langfuse website

Free-tier quotas head-to-head

Comparing starter on Knock vs hobby on Langfuse.

MetricKnockLangfuse
guide users2500 users
guide users overage$0.05/user USD/user
messages monthly50000 messages/mo
messages overage$0.005/message USD/message

Features

Knock · 13 features

  • AI AgentsAutonomous notification drafting & workflow generation.
  • Batch + DigestGroup notifications into digests on schedule or window.
  • ChatSlack, Microsoft Teams, Discord.
  • EmailSend via SendGrid/Postmark/Resend/Mailgun/AWS SES as relays.
  • GuidesIn-product messaging, announcements, modals, banners.
  • i18n / LocalizationTranslate templates by user locale.
  • In-App FeedNotification inbox with React/Vue/iOS/Android drop-in components.
  • Multi-tenancyPer-tenant branding, preferences, quiet hours.
  • Outbound WebhooksSubscribe to delivery events.
  • PreferencesUser + tenant preference center with granular controls.
  • PushiOS (APNs), Android (FCM), Expo, Web Push.
  • SMSTwilio, MessageBird, Telnyx, Vonage as providers.
  • WorkflowsVisual notification orchestration (branch, batch, delay, throttle).

Langfuse · 16 features

  • Annotation QueuesHuman reviewers rate traces. Unlimited on Pro+.
  • DashboardsAggregate metrics, cost, quality across projects.
  • DatasetsCurate test sets from production traces. Run experiments.
  • EU Cloud RegionGDPR-compliant hosting in EU.
  • EvaluationsLLM-as-judge, manual scores, custom model-graded evaluators.
  • LLM Cost TrackingAutomatic cost calculation per provider/model.
  • OpenTelemetry NativeOTel SDK → Langfuse endpoint works out of box.
  • PlaygroundTest prompts + models + variables live.
  • Prompt ManagementVersion, tag, label prompts. Reference from code by label.
  • Public APIFull REST API for ingest, query, prompt management.
  • Python @observe decoratorOne-line decorator to trace any function.
  • Self-HostingDocker Compose + k8s Helm chart.
  • SessionsGroup related traces (conversations, agent runs).
  • TracingCapture every LLM call, tool call, nested span with inputs/outputs/cost.
  • Users TrackingSegment traces by user ID, track per-user cost.
  • WebhooksSubscribe to trace completion events.

Developer interfaces

KindKnockLangfuse
CLIKnock CLI
SDKknockapi (Python), knockapi (Ruby), knock-elixir, knock-go, knock-java, @knocklabs/node, @knocklabs/reactlangfuse-js, langfuse-python
RESTKnock REST APILangfuse REST API
MCPKnock MCP ServerLangfuse MCP Server
OTHEROutbound WebhooksLangfuse Dashboard, OpenTelemetry endpoint
Staxly is an independent catalog of developer platforms. Some links to Knock and Langfuse may be affiliate links — Staxly may earn a commission if you sign up through them, at no extra cost to you. Pricing is verified against vendor pages at publication time — reconfirm before buying.

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