LangSmith reprices usage into LCU/LSU units; base traces double to 0.005 LSU
LangSmith replaced its per-1k trace dollar rates with normalized LCU/LSU units. Base traces now cost 0.005 LSU each — double the old $2.50/1k — and extended retention drops to 180 days.
Base traces $2.50 / 1,000 (14-day retention); extended traces $5.00 / 1,000 (400-day retention), upgrade +$2.50 / 1,000. Deployment billed per deployment run ($0.005) plus uptime ($0.0036/min production, $0.0007/min development). Fleet billed per run (50 runs/mo on Developer; 500 included on Plus, then $0.05/run). Sandboxes billed in dollars per vCPU-hr / GiB-hr.
All usage metered in two normalized units — LCU (LangChain Compute Unit, $1.50) and LSU (LangChain Storage Unit, $1.00). Base trace 0.005 LSU; extended-retention upgrade 0.0025 LSU with retention cut to 180 days. Deployment charged on resources consumed (runtime compute 0.045 LCU/vCPU-hr, runtime memory 0.006 LCU/GiB-hr, database compute 0.177 LSU/vCPU-hr, database memory 0.025 LSU/GiB-hr) with 1 free Serverless (Small) deployment on Plus. Fleet metered in LCU (5 LCU/mo free on Developer, 25 LCU/mo on Plus) with model costs now included. Sandboxes re-denominated into LCU/LSU at the same effective dollar rates. Seats unchanged: $0 Developer, $39/seat Plus.
LangChain rebuilt the LangSmith pricing page around two normalized meters — LangChain Compute Units for work and compute, LangChain Storage Units for traces and storage — and stopped publishing dollar-per-1,000-trace rates entirely. The per-trace rate is now disclosed only in a hover tooltip on the feature table: 0.005 LSU per base trace, 0.0025 LSU per extended-trace upgrade.
The re-denomination is not cost-neutral everywhere. Sandbox rates convert back to exactly their previous dollar values (0.0384 LCU x $1.50 = $0.0576 per vCPU-hr, the old published rate), which confirms the conversion factors — and by the same arithmetic base traces moved from $2.50 to $5.00 per 1,000, a 100% increase. The extended-retention upgrade held at its prior effective rate, so an all-in extended trace rose from $5.00 to $7.50 per 1,000. Extended retention itself was shortened from 400 days to 180 on the pricing page, while the billing docs still say 400 — a live inconsistency.
Deployment and Fleet also moved off per-run pricing onto resource metering. The LangSmith billing docs note that the new model “replaces the previous per-run and uptime pricing”, with existing customers grandfathered until October 1, 2026, and scale-to-zero available only on the new pricing. The page also gained a LangSmith Usage Calculator that estimates a monthly bill across Observability & Evals, Engine, Deployments, Sandboxes and Fleet.
LangSmith replaced its published dollar-per-1k trace rates and Deployment/Fleet per-run pricing with two normalized meters: LangChain Compute Units (LCU, $1.50) and LangChain Storage Units (LSU, $1.00). Base traces are now 0.005 LSU each (double the prior $2.50/1k), the extended-retention upgrade is 0.0025 LSU, and extended retention shortened from 400 days to 180. Deployment and Sandboxes moved to resource metering; Fleet moved from per-run to LCU and now includes model costs. Seats unchanged at $0 / $39. Existing deployment customers grandfathered until 2026-10-01.