LangSmith
LangSmith is a proprietary hosted observability and evaluation platform that meters traces directly, at 0.005 LSU per base trace or $500 per 100k, with self-hosting on its Enterprise plan only.
Last verified
| Licence | proprietary (SaaS; self-hosted deployment of the same LangSmith product line is an Enterprise add-on gated by a vendor-issued licence key — no open-source licence for the product core is published by the vendor) Source, checked docs.langchain.comhttps://docs.langchain.com/langsmith/self-hostedChecked |
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| Self-host | partial: yes on the Enterprise plan only — managed cloud, bring-your-own-cloud (BYOC) and fully self-hosted (your VPC) options; Developer and Plus plans are cloud-only Source, checked www.langchain.comhttps://www.langchain.com/langsmith/observabilityChecked |
| OpenTelemetry | yes — LangSmith exposes an OTLP endpoint (https://api.smith.langchain.com/otel) and ingests traces from any OpenTelemetry-compatible application; trace data can also be exported to other OTel pipelines Source, checked docs.langchain.comhttps://docs.langchain.com/langsmith/trace-with-opentelemetryChecked |
| Free tier limits | Developer plan: $0/seat per month, 1 seat, up to 5k base traces/mo included then pay-as-you-go, community support; base traces carry 14-day retention. (Plus plan at $39/seat/mo includes 10k base traces/mo.) Source, checked www.langchain.comhttps://www.langchain.com/pricingChecked |
| Price per 100k traces | $500 USD per 100k base traces — the vendor's current pricing page meters traces at 0.005 LSU per base trace with 1 LSU = $1.00 (0.005 x 100,000 = $500), before the plan's included allowance is deducted (5k Developer / 10k Plus). Upgrading those traces to extended (400-day) retention adds 0.0025 LSU per trace = $250 per 100k, i.e. $750 per 100k for extended-retention traces. Note: the docs billing page (https://docs.langchain.com/langsmith/usage-and-billing, checked 2026-08-22) still states an older pre-LSU rate of .05¢ per base trace; the pricing page's LSU model is taken as current. Source, checked www.langchain.comhttps://www.langchain.com/pricingChecked |
| Data residency | Enterprise: Cloud = LangChain's Cloud (US or EU); Hybrid = LangChain's Cloud (US or EU) control plane with a self-hosted data plane; Self-Hosted = your VPC. Plus: LangChain's Cloud (US or EU). Developer: the pricing table's Data location cell reads N/A and the hosting-options row lists Cloud only. Source, checked www.langchain.comhttps://www.langchain.com/pricingChecked |
| Retention | Two trace tiers: base = 14 days, extended = 400 days (base traces can be upgraded to extended for an additional fee). Enterprise customers can customise the extended retention period per workspace. Datasets have indefinite retention. Source, checked www.langchain.comhttps://www.langchain.com/pricingChecked |
| SDK languages | Python, TypeScript/JavaScript, Go, Java (plus OpenTelemetry-based instrumentation for any OTel-compatible stack) Source, checked www.langchain.comhttps://www.langchain.com/langsmith/observabilityChecked |
| Last release | Cloud (listed product): the LangSmith changelog's newest entry is the week of "August 10-17, 2026"; the cloud changelog publishes dated weekly entries without version numbers. For the self-hosted deployment of the same product line, the newest Helm chart is langsmith-0.16.10, released 2026-08-20 (with a 0.17.0-rc.10 release-candidate line dated the same day). Source, checked docs.langchain.comhttps://docs.langchain.com/langsmith/changelogChecked |
Assessment
LangSmith is proprietary: the vendor publishes no open-source licence for the product core, and self-hosted LangSmith is an Enterprise add-on gated by a vendor-issued licence key. Enterprise offers managed cloud, bring-your-own-cloud and fully self-hosted deployment in the customer's VPC; Developer and Plus are cloud-only.
An OTLP endpoint ingests traces from any OpenTelemetry-compatible application, and trace data can also be exported to other OTel pipelines. Official SDKs are Python, TypeScript, Go and Java.
The meter here is the trace itself. The pricing page charges 0.005 LSU per base trace at $1.00 per LSU, which is $500 per 100k base traces before the plan allowance is deducted. Upgrading those traces to extended retention adds 0.0025 LSU each, another $250 per 100k. One caution: the docs billing page still carries an older pre-LSU rate of .05¢ per base trace, and the two models differ structurally; the pricing page is taken as current.
The Developer plan is $0 for one seat with 5k base traces a month then pay-as-you-go; Plus is $39 per seat a month with 10k. Base traces are retained 14 days and extended traces 400 days, customisable per workspace on Enterprise, with datasets kept indefinitely. Plus and Enterprise data sits in LangChain's US or EU cloud. The cloud changelog is dated, not versioned; the newest entry covers 10–17 August 2026.
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