ipfs/kubo · error

dagStore: key was not a cid: %w

Error message

dagStore: key was not a cid: %w

What it means

`cidFromBinString` parses a dagStore key string as a CID using `cid.CidFromBytes`. If the bytes are not a valid CID, the parse error is wrapped with this `dagStore` prefix. The dagStore `Get` implementation uses it to translate storage keys back into CIDs, so a key that fails to parse means the key is malformed or was written by an incompatible component.

Source

Thrown at core/commands/dag/export.go:286

	return block.RawData(), nil
}

func (ds *dagStore) Has(ctx context.Context, key string) (bool, error) {
	_, err := ds.Get(ctx, key)
	if err != nil {
		if errors.Is(err, ipld.ErrNotFound{}) {
			return false, nil
		}
		return false, err
	}
	return true, nil
}

func cidFromBinString(key string) (cid.Cid, error) {
	l, k, err := cid.CidFromBytes([]byte(key))
	if err != nil {
		return cid.Undef, fmt.Errorf("dagStore: key was not a cid: %w", err)
	}
	if l != len(key) {
		return cid.Undef, fmt.Errorf("dagStore: key was not a cid: had %d bytes leftover", len(key)-l)
	}
	return k, nil
}

View on GitHub (pinned to 329838acdf)

Solutions

1. Identify the offending key from the wrapped error message and inspect it in the datastore.
2. Run `ipfs repo gc` and verify blockstore integrity; back up and repair the datastore if keys are corrupt.
3. Stop any custom code writing non-CID keys directly into the blockstore.
4. If caused by a version migration issue, upgrade/downgrade kubo consistently and re-verify with `ipfs repo verify` if available.

if _, err := cid.Decode(keyString); err != nil {
    return fmt.Errorf("dagStore key %q is not a valid cid: %w", keyString, err)
}

var cidErr *cid.ParseError
if errors.Is(err, cid.ErrCidTooShort()) || strings.Contains(err.Error(), "key was not a cid") {
    // inspect/repair the offending datastore key
}

When it happens

Trigger: Calling dagStore `Get` (indirectly, e.g. via `ipfs dag export --local-only`'s partial CAR exporter which treats the blockstore as a DAG store) with a blockstore key whose bytes are not a valid CID binary string.

Common situations: A corrupted or hand-modified blockstore directory; a datastore shared with an older/newer key encoding; custom tooling that inserted non-CID keys into the blockstore.

Related errors

• dagStore: key was not a cid: had %d bytes leftover
• CheckCIDSize: getting dag: %w
• checking if new root exists: %w
• new root %s does not exist locally; fetch it first with 'ipf
• pin check failed: %w

AI-assisted analysis of ipfs/kubo@329838acdf (2026-09-03). Data as JSON: /api/errors/56c88aee5a98790d. Report an issue: GitHub.