DynamoDB feature coverage

Served by default on 127.0.0.1:8000; opt out with --no-dynamodb; per-tenant signed access keys. Anything not listed as supported should be assumed unsupported.

The Nimbus DynamoDB endpoint implements the full operation set below, grouped into tiers T0–T7. Requests are dispatched on the standard X-Amz-Target header (DynamoDB_20120810.* and DynamoDBStreams_20120810.*); an unrecognized target is rejected with an explicit error.

Status values:

• Implemented — supported end to end.
• Implemented, with divergence — supported, with a recorded behavioral difference from AWS DynamoDB. Each DDB-DIV-* code is documented on the divergences page.

T0 — Control plane

Operation	Request surface	Response surface	Errors	Status
CreateTable	TableName, KeySchema, AttributeDefinitions, BillingMode, StreamSpecification, LocalSecondaryIndexes, GlobalSecondaryIndexes	TableDescription with TableStatus, TableArn, TableId	ResourceInUseException, ValidationException	Implemented, with divergence (DDB-DIV-004: tables are ACTIVE immediately; DDB-DIV-003: the _ddb_ name prefix is reserved)
DescribeTable	TableName	Table	ResourceNotFoundException	Implemented
ListTables	ExclusiveStartTableName, Limit	TableNames, LastEvaluatedTableName; paginated	—	Implemented
UpdateTable	TableName, BillingMode, StreamSpecification, GSI updates, deletion protection	TableDescription	ResourceNotFoundException, ValidationException	Implemented
DeleteTable	TableName	TableDescription (DELETING)	ResourceNotFoundException	Implemented
DescribeEndpoints	—	Endpoints	—	Implemented
DescribeLimits	—	account and table capacity maxima	—	Implemented

T1 — Single-item

Operation	Request surface	Response surface	Errors	Status
PutItem	TableName, Item, ConditionExpression, ExpressionAttributeNames/Values, ReturnValues	Attributes	ConditionalCheckFailedException, ResourceNotFoundException, ValidationException	Implemented, with divergence (DDB-DIV-005: storage format; DDB-DIV-001: smaller composite key-size limit)
GetItem	TableName, Key, ProjectionExpression, ConsistentRead	Item	ResourceNotFoundException, ValidationException	Implemented
UpdateItem	TableName, Key, UpdateExpression, ConditionExpression, ReturnValues	Attributes	ConditionalCheckFailedException, ResourceNotFoundException, ValidationException	Implemented
DeleteItem	TableName, Key, ConditionExpression, ReturnValues	Attributes	ConditionalCheckFailedException, ResourceNotFoundException, ValidationException	Implemented

Conditional writes are checked and committed in one storage transaction, so a condition cannot be raced between its check and its commit.

T2 — Query and scan

Operation	Request surface	Response surface	Errors	Status
Query	TableName, KeyConditionExpression, FilterExpression, ProjectionExpression, IndexName, Limit, ExclusiveStartKey, ScanIndexForward, Select	Items, Count, ScannedCount, LastEvaluatedKey; paginated	ResourceNotFoundException, ValidationException	Implemented, with divergence (DDB-DIV-002: sort-key encoding)
Scan	TableName, FilterExpression, ProjectionExpression, IndexName, Limit, ExclusiveStartKey, Segment, TotalSegments, Select	Items, Count, ScannedCount, LastEvaluatedKey; paginated, parallel scan supported	ResourceNotFoundException, ValidationException	Implemented

T3 — Batch and transactions

Operation	Request surface	Response surface	Errors	Status
BatchGetItem	RequestItems with Keys, ProjectionExpression, ConsistentRead	Responses, UnprocessedKeys	ResourceNotFoundException, ValidationException	Implemented
BatchWriteItem	RequestItems with PutRequest/DeleteRequest	UnprocessedItems	ResourceNotFoundException, ValidationException	Implemented
TransactGetItems	TransactItems (Get)	Responses (snapshot read)	ResourceNotFoundException, ValidationException, TransactionCanceledException	Implemented
TransactWriteItems	TransactItems (Put/Update/Delete/ConditionCheck), ClientRequestToken	empty on success; CancellationReasons on cancellation	TransactionCanceledException, ValidationException	Implemented

TransactWriteItems is atomic: either every item commits or none does, and a cancellation reports per-item CancellationReasons.

T4 — Secondary indexes

Capability	Coverage	Errors	Status
Local secondary indexes	Declared at CreateTable, with projections	ValidationException	Implemented
Global secondary indexes	Created, updated, and deleted through UpdateTable (GlobalSecondaryIndexUpdates)	ValidationException, ResourceInUseException	Implemented
Query with IndexName	LSI and GSI queries honoring the projected attribute set	ResourceNotFoundException, ValidationException	Implemented, with divergence (DDB-DIV-010: ConsistentRead on a GSI is served, not rejected)

Index entries are maintained in the same storage transaction as the base write, so index reads are never stale.

T5 — Streams

Operation	Request surface	Response surface	Errors	Status
StreamSpecification on CreateTable/UpdateTable	StreamEnabled, StreamViewType	LatestStreamArn, LatestStreamLabel	ValidationException	Implemented
DescribeStream	StreamArn, Limit, ExclusiveStartShardId	StreamDescription	ResourceNotFoundException	Implemented, with divergence (DDB-DIV-006: single shard)
GetShardIterator	StreamArn, ShardId, ShardIteratorType, SequenceNumber	ShardIterator	ResourceNotFoundException, ValidationException	Implemented
GetRecords	ShardIterator, Limit	Records, NextShardIterator	expired-iterator and validation errors	Implemented, with divergence (DDB-DIV-007: read-triggered retention)
ListStreams	TableName, Limit, ExclusiveStartStreamArn	Streams, LastEvaluatedStreamArn; paginated	ResourceNotFoundException	Implemented

Batch and transactional writes emit stream records like single-item writes; a transaction’s records are part of its atomic commit. TTL deletions emit REMOVE records.

T6 — TTL and tagging

Operation	Request surface	Response surface	Errors	Status
UpdateTimeToLive	TableName, TimeToLiveSpecification	TimeToLiveSpecification	ResourceNotFoundException, ValidationException	Implemented, with divergence (DDB-DIV-009: no modification cooldown)
DescribeTimeToLive	TableName	TimeToLiveDescription	ResourceNotFoundException	Implemented
TagResource	ResourceArn, Tags	empty	ResourceNotFoundException, ValidationException	Implemented
UntagResource	ResourceArn, TagKeys	empty	ResourceNotFoundException, ValidationException	Implemented
ListTagsOfResource	ResourceArn, NextToken	Tags; single page	ResourceNotFoundException, ValidationException	Implemented

Expired items are reclaimed by a background TTL sweeper (default cadence 60 seconds, configurable or disablable on the endpoint configuration).

T7 — Authentication

Capability	Behavior	Errors	Status
Access-key → tenant resolution	Each access key ID is bound to exactly one tenant; unknown keys fail closed	UnrecognizedClientException, MissingAuthenticationToken, IncompleteSignature	Implemented
Strict SigV4 verification (default)	Full canonical-request verification with constant-time comparison and a ±15-minute timestamp window	InvalidSignatureException, UnrecognizedClientException	Implemented
Persisted access-key management	Keys can be stored, rotated, deleted, and listed in a server-side store; listings never include the secret	ResourceNotFoundException	Implemented

Not modeled

No provisioned-capacity model and the other recorded behavioral differences are listed on the divergences page.