LangSmith vs Fastly
LLM observability, testing & evaluation — by LangChain
vs. Edge cloud platform — CDN + compute + security + observability
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
Fastly
Free Trial
Free allowances: 100 GB bandwidth, 1M CDN requests, 10M Edge Compute requests, 100M vCPU-ms, 500K DDoS requests.
Free
Pay-as-you-go
Usage-based rates with volume discounts. No minimum commitment.
$0 base (usage-based)
Basic Package
$1,500/month. 100M requests. Standard support.
$1500/mo
Starter Package
$6,000/month. 500M requests. Gold support.
$6000/mo
Advantage
Custom. 2B requests. Gold support.
Custom
Ultimate
Custom. 5B+ requests. Enterprise support.
Custom
Free-tier quotas head-to-head
Comparing developer on LangSmith vs free on Fastly.
| Metric | LangSmith | Fastly |
|---|---|---|
| No overlapping quota metrics for these tiers. | ||
Features
LangSmith · 14 features
- Alerts — Threshold alerts on latency, cost, eval metrics.
- Annotation Queues — Human-review workflows for trace quality rating.
- Custom Dashboards — Aggregate metrics dashboards per project/tag.
- Datasets — Collect examples → use as eval sets or training data.
- Evaluations — LLM-as-judge, embedding similarity, custom Python evaluators, offline batch eval…
- LangChain Integration — Auto-trace any LangChain/LangGraph run with env var.
- LangGraph Integration — First-class trace + eval for LangGraph agents.
- LLM Tracing — Automatic trace every LLM call + tool call + chain step.
- OpenTelemetry Export — Export traces as OTLP to Datadog/Honeycomb/etc.
- Playground — Test prompts + models inline before deploying.
- Prompt Canvas — Visual prompt editor with live test + eval.
- Prompt Hub — Public + private prompt library with versioning.
- Self-Hosted (Enterprise) — Docker + k8s deployment in your infra.
- Threads + Sessions — Group traces into conversational sessions.
Fastly · 16 features
- API Security — Schema validation + rate limiting.
- Bot Management — Behavioral bot detection + mitigation.
- CDN — Global Varnish-based CDN with VCL customization.
- Compute@Edge — Wasm-based serverless at 200+ POPs. Rust, JS, Go.
- DDoS Protection — Included on all plans.
- Fanout (WebSockets) — Persistent connection fan-out at edge.
- Image Optimization — On-the-fly resize/format/quality.
- Instant Purge — <150ms global cache invalidation.
- KV Store (Config) — Edge key-value store for config.
- Live Streaming — HLS + DASH live video delivery.
- Log Streaming — Real-time logs to S3, Datadog, Splunk, Azure, GCS, Kafka.
- Managed TLS — Automated cert issuance + renewal.
- Next-Gen WAF — Signal Sciences acquired — runtime app protection.
- Real-Time Analytics — Sub-second log streaming + metrics.
- Secret Store — Encrypted secrets at edge.
- Shield POP — Origin shield to reduce origin load.
Developer interfaces
| Kind | LangSmith | Fastly |
|---|---|---|
| CLI | LangSmith CLI | Fastly CLI |
| SDK | langsmith-js, langsmith-python | compute-go-starter, compute-js-starter, compute-rust-starter |
| REST | LangSmith REST API | Fastly API |
| MCP | LangSmith MCP | — |
| OTHER | LangSmith Dashboard | Compute@Edge (Wasm), VCL (Varnish) |
Staxly is an independent catalog of developer platforms. Some links to LangSmith and Fastly 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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