Pinecone 404: index not found usually means wrong project, not a typo

404 on an index: check the project before the spelling

The error

404 Not Found: The requested resource does not exist. The docs define it plainly: verify the resource name and that it has not been deleted.

The usual causes, in order

1. Wrong project. The API key belongs to project A; the index lives in project B. Keys are per-project. This is the most common cause and the one agents check last.
2. Name mismatch. Index names are lowercase alphanumeric plus dashes, no dots. My-Index, my.index, and my-index are three different strings and only the last can exist.
3. Actually deleted. Someone deleted it, or deletion protection blocked a recreate you expected to succeed. pc.list_indexes() shows what is really there.
4. Wrong control plane region for pods. Pod environments are region-specific strings; a pod index created in one environment is not visible from another.

Fix

1. Run pc.list_indexes() with the same client and key. If the index is absent, the key or project is wrong, not the code.
2. Compare the name character by character against the console. Copy it; do not retype it.
3. If it was deleted, recreate it (with the spec) and re-ingest. There is no undelete.

Pinecone's error-handling guide defines 404 as the requested resource not existing and advises verifying the name and deletion state. The manage-api-keys guide documents per-project keys. Verified against live docs 2026-09-26.