hyperledger/fabric · error

not a chaincode parameters type: %s

Error message

not a chaincode parameters type: %s

What it means

fetchApprovedChaincodeDefinition validates that the state metadata datatype equals ChaincodeParametersType before deserializing. The stored metadata has a different datatype string, meaning the namespace entry is not chaincode parameters (e.g., it belongs to a token/tokenfilter or other namespace type or is corrupted).

Source

Thrown at core/chaincode/lifecycle/lifecycle.go:623

		}

		// Fetch the approved chaincode definition
		definition, err := ef.fetchApprovedChaincodeDefinition(ccname, sequence, metadata, orgState)
		if err != nil {
			return nil, errors.WithMessagef(err, "could not fetch approved chaincode definition (name: '%s', sequence: '%d') on channel '%s'", ccname, sequence, chname)
		}

		definitions[privateName] = definition
	}

	return definitions, nil
}

func (ef *ExternalFunctions) fetchApprovedChaincodeDefinition(ccname string, sequence int64, metadata *lb.StateMetadata, orgState ReadableState) (*ApprovedChaincodeDefinition, error) {
	privateName := fmt.Sprintf("%s#%d", ccname, sequence)
	// Verify that metadata type is chaincode parameters type
	if metadata.Datatype != ChaincodeParametersType {
		return nil, errors.Errorf("not a chaincode parameters type: %s", metadata.Datatype)
	}

	// Get chaincode parameters for the requested sequence
	ccParameters := &ChaincodeParameters{}
	if err := ef.Resources.Serializer.Deserialize(NamespacesName, privateName, metadata, ccParameters, orgState); err != nil {
		return nil, errors.WithMessagef(err, "could not deserialize chaincode parameters for %s", privateName)
	}

	// Get package ID for the requested sequence
	metadata, ok, err := ef.Resources.Serializer.DeserializeMetadata(ChaincodeSourcesName, privateName, orgState)
	if err != nil {
		return nil, errors.WithMessagef(err, "could not deserialize chaincode-source metadata for %s", privateName)
	}
	if !ok {
		return nil, errors.Errorf("could not fetch chaincode-source metadata for %s", privateName)
	}
	if metadata.Datatype != ChaincodeLocalPackageType {
		return nil, errors.Errorf("not a chaincode local package type: %s", metadata.Datatype)

View on GitHub (pinned to 2736b63f8f)

Solutions

1. Verify the chaincode name is correct and does not collide with another namespace in the channel state
2. Check the metadata datatype written by the approving peer; re-approve to rewrite correct metadata if corrupted
3. Ensure peer and lifecycle library versions match the ledger format in use

Example fix

// before
metadata.Datatype == "TOKENS" -> error
// after
ensure approveformyorg ran so metadata.Datatype == ChaincodeParametersType before querying

// Check metadata datatype before requesting the definition
md, ok, err := serializer.DeserializeMetadata(lifecycle.NamespacesName, privateName, orgState)
if err != nil || !ok || md.Datatype != lifecycle.ChaincodeParametersType {
    return fmt.Errorf("namespace %s is not a chaincode parameters entry (datatype=%v)", privateName, md)
}

func isChaincodeParametersMetadata(md *lb.StateMetadata) bool {
    return md != nil && md.Datatype == lifecycle.ChaincodeParametersType
}

def, err := ef.QueryApprovedChaincodeDefinition(ch, ccname, org, seq)
if err != nil && strings.Contains(err.Error(), "not a chaincode parameters type") {
    // namespace collision or corrupt metadata; re-approve or fix the name
}

When it happens

Trigger: QueryApprovedChaincodeDefinition(s) resolving to a namespace whose stored StateMetadata.Datatype is not CHAINCODE_PARAMETERS — typically a name collision or querying a non-chaincode namespace as a chaincode.

Common situations: Passing a namespace name that collides with another lifecycle-managed namespace; manually edited/corrupted state DB; version-mismatched code reading newer ledger datatypes.

Understand the failure class

Background: Schema validation failed / invalid input schema: payload rejected because its shape doesn't match the expected schema — this error's family across 28 libraries.

Related errors

• query iterator not found
• application config does not exist for channel '%s'
• unknown chaincode '%s' for channel '%s'
• could not find chaincode with package id '%s'
• requested sequence is 0, but first definable sequence number

AI-assisted analysis of hyperledger/fabric@2736b63f8f (2026-09-04). Data as JSON: /api/errors/00c3bfebb6312356. Report an issue: GitHub.