# uber-go/multierr

Combine one or more Go errors together

Repository: https://github.com/uber-go/multierr
Canonical: https://ross.abutalabs.com/products/multierr
Homepage: https://go.uber.org/multierr
Language: Go
License: MIT
License Family: permissive
Topics: golang, go, errors
Last push: 2024-04-29T19:14:36+00:00

## Health v2 (maintenance only)
Score: 23/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 0, release rhythm 8, longevity 100
- inputs: {"age_days": 3458, "days_push": 856, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1198, forks 50 (observed 2026-08-28T04:03:57.714463+00:00)

## What it is
multierr is a lightweight Go library for combining one or more errors into a single error value. It is idiomatic, performant, and interoperates seamlessly with the standard library's errors.Is and errors.As APIs.

## Use cases
- combine multiple errors from a loop into one
- append errors safely from defer statements
- aggregate errors from parallel goroutines
- return all validation errors at once instead of only the first
- work with multiple errors using errors.Is and errors.As

## When to choose
- you need to collect and report multiple errors together in Go
- you want a dependency-free, stable error-combining library
- you need compatibility with Go 1.20+ errors.Is/errors.As semantics

## When to avoid
- you are on Go 1.20+ and only need basic multi-error wrapping via the standard errors.Join
- you need rich error formatting or stack traces, which other libraries provide

## Facets
- artifact type: library
- maturity: stable
- function: error-handling
- domain: developer-tools, backend
- platform: go
- tags: errors, error-aggregation, multi-error

## Member repositories
- uber-go/multierr (main) score 23

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:03:57.714463+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 2026-08-30T06:21:11.833318+00:00, confidence not recorded.
  - readme: https://github.com/uber-go/multierr (fetched 2026-08-28T04:03:57.714463+00:00, sha 722b4d97ced4)
  - homepage: https://go.uber.org/multierr (fetched 2026-08-29T12:28:29.522743+00:00, sha 4aad7164c395)
- Data as of 2026-08-30T08:39:29.467469+00:00.