# metacall/core

MetaCall: The ultimate polyglot programming experience.

Repository: https://github.com/metacall/core
Canonical: https://ross.abutalabs.com/products/metacall-core
Homepage: https://metacall.io
Language: C
License: Apache-2.0
License Family: permissive
Topics: metacall, function-mesh, programming-language, inter-language, ffi, polyglot, polyglot-programming, c, cpp, golang, javascript, node, nodejs, python, docker, faas, gsoc, ruby
Last push: 2026-08-20T01:23:31+00:00

## Health v2 (maintenance only)
Score: 97/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 98, release rhythm 94, longevity 100
- inputs: {"age_days": 2807, "days_push": 14, "days_rel": 41, "gap_med": 5, "n_releases_24m": 26}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1813, forks 258 (observed 2026-08-28T04:05:39.725614+00:00)

## What it is
MetaCall is an extensible, embeddable polyglot runtime that lets you call functions, methods, or procedures across multiple programming languages (Python, JavaScript, TypeScript, Ruby, C#, Java, Go, Rust, C/C++, WASM, and more) within a single application. It is the core engine behind MetaCall Hub, a deployment platform that turns functions into auto-generated APIs.

## Use cases
- call a python function from javascript
- mix multiple programming languages in one application
- embed a scripting language interpreter into a c++ application
- build polyglot microservices without rewriting code
- expose functions from any language as http apis
- run nodejs and python code together in one process

## When to choose
- you need seamless cross-language function calls without network overhead
- you want to embed interpreters for several languages in a single host application
- you are building a polyglot codebase and want to reuse existing modules across languages
- you need a runtime for mixed-language serverless or FaaS deployments

## When to avoid
- you only work in a single language and standard tooling suffices
- you need strict process isolation or security sandboxing between languages
- your project depends on languages not yet supported by MetaCall's loaders
- you need battle-tested production FFI with a very large community

## Facets
- artifact type: library
- maturity: active
- function: interpreter, rpc, sdk, plugin-system, cli, developer-tools
- domain: programming-languages, developer-tools, cross-platform, backend, apis
- platform: windows, python, cpp, c, rust, go, cli, cross-platform
- tags: polyglot-runtime, ffi, inter-language-calls, function-mesh, faas, language-interop, embeddable-runtime, linux, macos, docker, nodejs

## Member repositories
- metacall/core (main) score 97

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:05:39.725614+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 2026-08-30T03:21:10.498963+00:00, confidence not recorded.
  - readme: https://github.com/metacall/core (fetched 2026-08-28T04:05:39.725614+00:00, sha c87c2673add8)
  - homepage: https://metacall.io (fetched 2026-08-29T10:59:51.689850+00:00, sha 06888743ae19)
  - site_page: https://metacall.io/pricing (fetched 2026-08-29T10:59:51.698975+00:00, sha f6558552fff8)
  - site_page: https://metacall.io/faq (fetched 2026-08-29T10:59:51.700894+00:00, sha 803146bacd7a)
  - site_page: https://core.metacall.io (fetched 2026-08-29T10:59:51.702537+00:00, sha 0df5a34a8425)
- Data as of 2026-08-30T08:39:29.467469+00:00.