`version not found: 0.0.99`

npm registry · GET /{package}/{version} · HTTP 404

Status: ✅ verified:server:prod · first seen 2026-10-31 · last confirmed 2026-10-31 · 1 confirmation from 1 vantage

GET /{package}/{version} for an existing package with an unknown version or dist-tag returns HTTP 404 whose body is a bare JSON string "version not found: <version>", not an object.

What to do

No client-side fix known (by design).

Example

What probe af:npm-registry:probe:version-not-found sends (prod) and what it checks in the answer.

Step 1 → HTTP 404:

GET https://registry.npmjs.org/left-pad/0.0.99

Step 2 → HTTP 404:

GET https://registry.npmjs.org/left-pad/agent-facts-no-such-tag

Response (only what the probe asserts; other fields omitted):

HTTP 404

$ = "version not found: agent-facts-no-such-tag"

Dimensions

env: prod · plan: any · region: any · account_state: anonymous

Evidence

Probe af:npm-registry:probe:version-not-found (declarative, source)

Observations: none from reporters yet.

Related errors

Not Found · GET /{package}/{version} · HTTP 404
Not Found · GET /-/package/{package}/dist-tags · HTTP 404
Not found · GET /{package} · HTTP 404

Machine access

Match signature (what check() matches): version not found: #.#.##

curl -s https://apifacts.dev/v0/check \
  -H 'content-type: application/json' \
  -d '{"target":{"method":"GET","url":"https://registry.npmjs.org/{package}/{version}"},"error":{"status":404,"body_excerpt":"version not found: #.#.##"}}'

YAML: facts/npm-registry/version-not-found-404.yaml

Data: CC BY 4.0 · apifacts registry · This page is generated; edit the YAML, not the page.