Staxly

LangSmith vs PlanetScale

LLM observability, testing & evaluation — by LangChain
vs. Serverless MySQL (Vitess) and Postgres at scale

LangSmith websitePlanetScale 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

PlanetScale

Postgres EBS single-node — PS-5
Single-node EBS, 512 MiB RAM, arm64. Entry point for Postgres.
$5/mo
Postgres EBS HA — PS-5
3-node (primary + 2 replicas), 512 MiB, arm64.
$15/mo
Vitess (non-Metal) — PS-10
Vitess MySQL sharded cluster, 1 GiB RAM.
$39/mo
Postgres Metal — M-10
3-node Metal, 1 GiB RAM + 10 GiB local storage. Much higher IOPS.
$50/mo
Vitess Metal — M-160
Vitess Metal, 16 GiB RAM + 110 GiB storage.
$609/mo
Enterprise
Custom agreements, dedicated regions, 99.99% SLA.
Custom
PlanetScale website

Free-tier quotas head-to-head

Comparing developer on LangSmith vs pg-ebs-nonha-starter on PlanetScale.

MetricLangSmithPlanetScale
ha0 nodes
ram mib512 MiB

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.

PlanetScale · 12 features

  • BackupsAutomated daily backups with retention.
  • Database BranchingGit-like branches of your DB schema (not data). Create, diff, merge via deploy r
  • Deploy RequestsSchema changes in a feature branch get reviewed + auto-applied to main with zero
  • HIPAAHIPAA-compliant deployments (Enterprise).
  • Metal (NVMe)Dedicated NVMe local storage. 10x IOPS vs EBS, latency-critical workloads.
  • PgBouncer PoolerManaged PgBouncer for Postgres clusters. Optional dedicated pooler.
  • PlanetScale BoostQuery result cache with sub-ms reads.
  • Point-in-Time RecoveryRestore cluster to any point within retention window.
  • Postgres on PlanetScalePostgreSQL 15+ with the same branching + deploy-request flow. Launched 2024.
  • Query InsightsPer-query performance analytics, slow query tracking, explain plans.
  • Read-only RegionsRoute reads to the nearest region for lower latency.
  • Vitess (MySQL at scale)Horizontally-sharded MySQL (YouTube-scale) — original PlanetScale offering.

Developer interfaces

KindLangSmithPlanetScale
CLILangSmith CLIPlanetScale CLI (pscale)
SDKlangsmith-js, langsmith-python@planetscale/database
RESTLangSmith REST APIManagement API
MCPLangSmith MCPPlanetScale MCP
OTHERLangSmith DashboardMySQL Wire Protocol, Postgres Wire Protocol
Staxly is an independent catalog of developer platforms. Outbound links to LangSmith and PlanetScale are plain references to their official websites. Pricing is verified against vendor pages at publication time — reconfirm before buying.

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