# awslabs/llrt

LLRT (Low Latency Runtime) is an experimental, lightweight JavaScript runtime designed to address the growing demand for fast and efficient Serverless applications.

Repository: https://github.com/awslabs/llrt
Canonical: https://ross.abutalabs.com/products/llrt
Language: Rust
License: Apache-2.0
License Family: permissive
Last push: 2026-08-26T04:53:29+00:00

## Health v2 (maintenance only)
Score: 81/100 (v2, computed 2026-09-02T17:46:02.011165+00:00)
- activity 99, release rhythm 59, longevity 77
- inputs: {"age_days": 1078, "days_push": 7, "days_rel": 194, "gap_med": 45.0, "n_releases_24m": 11}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 8793, forks 391 (observed 2026-08-28T04:10:25.744831+00:00)

## What it is
LLRT (Low Latency Runtime) is a lightweight JavaScript runtime built in Rust on the QuickJS engine, designed for fast-starting serverless applications on AWS Lambda. It offers over 10x faster cold starts and up to 2x lower cost compared to Node.js, though it is not a drop-in Node.js replacement.

## Use cases
- run javascript on aws lambda with faster cold starts
- reduce serverless function costs
- deploy lightweight js lambda custom runtime
- bundle small lambda functions with quickjs
- evaluate alternatives to node.js for serverless

## When to choose
- your lambda workloads are latency-sensitive and cold-start dominated
- you can bundle dependencies and don't need full Node.js API compatibility
- you want lower memory and cost for simple serverless functions

## When to avoid
- you need full Node.js compatibility or native addons
- you require long-running processes outside AWS Lambda
- you need a production-guaranteed runtime - it is explicitly experimental

## Facets
- artifact type: cli-tool
- maturity: experimental
- function: interpreter, serverless, http-server, developer-tools
- domain: developer-tools, cloud-computing, programming-languages, performance
- platform: rust, serverless, cross-platform
- tags: javascript-runtime, quickjs, aws-lambda, cold-start, low-latency, edge-runtime, linux

## Member repositories
- awslabs/llrt (main) score 81

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:10:25.744831+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-29T17:25:12.451817+00:00, confidence not recorded.
  - readme: https://github.com/awslabs/llrt (fetched 2026-08-28T04:10:25.744831+00:00, sha db31b2565ea1)
- Data as of 2026-08-30T08:39:29.467469+00:00.