Staxly

LangSmith vs Paddle

LLM observability, testing & evaluation — by LangChain
vs. Merchant of Record for SaaS — global tax, billing, checkout in one

LangSmith websitePaddle website

Pricing tiers

LangSmith

Developer (Free)
Free forever. 5,000 traces/month. 14-day retention. 1 seat. Basic evaluations.
Free
Plus
$39/seat/month. 10k base traces included ($2.50 per 1k overage). Full evaluations, custom dashboards, email support.
$39/mo
Enterprise
Custom. Self-host option, SSO, custom retention, dedicated support.
Custom
LangSmith website

Paddle

Pay-as-you-go
5% + 50¢ per Checkout transaction. No monthly fee. All-inclusive (tax, fraud, support).
$0 base (usage-based)
Enterprise
Custom rates for high-volume. Dedicated success. Custom migration + implementation.
Custom
Invoicing (<$10 products)
Custom pricing for invoicing / products under $10.
Custom
Paddle website

Free-tier quotas head-to-head

Comparing developer on LangSmith vs payg on Paddle.

MetricLangSmithPaddle
No overlapping quota metrics for these tiers.

Features

LangSmith · 14 features

  • AlertsThreshold alerts on latency, cost, eval metrics.
  • Annotation QueuesHuman-review workflows for trace quality rating.
  • Custom DashboardsAggregate metrics dashboards per project/tag.
  • DatasetsCollect examples → use as eval sets or training data.
  • EvaluationsLLM-as-judge, embedding similarity, custom Python evaluators, offline batch eval
  • LangChain IntegrationAuto-trace any LangChain/LangGraph run with env var.
  • LangGraph IntegrationFirst-class trace + eval for LangGraph agents.
  • LLM TracingAutomatic trace every LLM call + tool call + chain step.
  • OpenTelemetry ExportExport traces as OTLP to Datadog/Honeycomb/etc.
  • PlaygroundTest prompts + models inline before deploying.
  • Prompt CanvasVisual prompt editor with live test + eval.
  • Prompt HubPublic + private prompt library with versioning.
  • Self-Hosted (Enterprise)Docker + k8s deployment in your infra.
  • Threads + SessionsGroup traces into conversational sessions.

Paddle · 12 features

  • Affiliates (Rewardful partnership)Affiliate tracking (via partner).
  • Customer PortalSelf-service subscription management.
  • Fraud ProtectionML + human review. Paddle absorbs chargebacks.
  • Global Tax ComplianceAutomatic VAT/GST/sales tax calc + remittance + filing.
  • One-time SalesPerpetual license sales, single purchases.
  • Paddle CheckoutHosted or overlay checkout. Localized + fraud-protected.
  • Paddle RetainRevenue recovery + cancel flows (acquired Retain).
  • ProfitWell AnalyticsIncluded subscription analytics (acquired ProfitWell).
  • Self-Serve InvoicesB2B invoicing with custom POs.
  • Smart DunningRetry logic + email sequences for failed payments.
  • SubscriptionsFull lifecycle: trials, changes, cancellations, recovery.
  • WebhooksStandard resource events with HMAC signing.

Developer interfaces

KindLangSmithPaddle
CLILangSmith CLI
SDKlangsmith-js, langsmith-pythonPaddle.js, @paddle/paddle-node-sdk, paddle-python
RESTLangSmith REST APIPaddle Billing API
MCPLangSmith MCP
OTHERLangSmith DashboardPaddle Checkout, Paddle Webhooks
Staxly is an independent catalog of developer platforms. Outbound links to LangSmith and Paddle are plain references to their official websites. Pricing is verified against vendor pages at publication time — reconfirm before buying.

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