# `Lightning.Adaptors.NPM`
[🔗](https://github.com/OpenFn/lightning/blob/main/lib/lightning/adaptors/npm.ex#L1)

Production implementation of `Lightning.Adaptors.Strategy` that talks
to the public NPM registry and the OpenFn adaptors monorepo on GitHub.

  * `c:Lightning.Adaptors.Strategy.list_adaptors/0` merges the
    `@openfn` org's package listing with the search API's version
    lookup. See `Lightning.Adaptors.NPM.Registry` for why this is two
    calls, not one. A listing with no `@openfn/language-*` names is an
    error, not an empty catalogue.
  * `c:Lightning.Adaptors.Strategy.fetch_adaptor/1` fetches the
    packument and the latest version's schema from jsDelivr. Icon
    fields are not stamped here. The Scheduler joins them on after a
    bulk `c:Lightning.Adaptors.Strategy.fetch_icons/1` pass.
  * `c:Lightning.Adaptors.Strategy.fetch_icon/2` is a single raw GET
    against `raw.githubusercontent.com`, used when the Store misses an
    icon on disk.
  * `c:Lightning.Adaptors.Strategy.fetch_icons/1` fans out one GET per
    `(name, shape)` and sends `:prior_etags` as `If-None-Match`.

## HTTP

The HTTP work lives in three sub-modules, each with its own Tesla
client and base URL: `Lightning.Adaptors.NPM.Registry`,
`Lightning.Adaptors.NPM.Schema` and `Lightning.Adaptors.NPM.GitHub`.

Every request is single-shot and bounded by `http_timeout`. There is no
retry, backoff or circuit breaker. A transient failure (5xx, timeout,
nxdomain) of the primary request (the packument for `fetch_adaptor/1`,
the org listing for `list_adaptors/0` and `fetch_icons/1`) surfaces as
`{:error, term()}` unchanged, and a failed schema fetch inside
`fetch_adaptor/1` as
`{:error, {:schema_fetch_failed, reason}}`. Icon fetches inside
`fetch_icons/1` are best-effort instead: a miss degrades to an absent
icon shape rather than failing the batch.

## Configuration

The sub-modules read `:registry_url`, `:jsdelivr_url`, `:github_url`,
`:github_ref` and `:http_timeout` from
`Lightning.Adaptors.Config.strategy_opts(Lightning.Adaptors.NPM)`. All
three share this module's config key rather than having their own, and
each key has a default so the module works with no Application env set.

---

*Consult [api-reference.md](api-reference.md) for complete listing*