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LocalStack

2026.6.2 25 recorded runs

84.0%
correct, across 865 of 873 operations · 8 unsupported
Tier 1 93.0%
Tier 2 87.8%
Tier 3 67.3%

Fully supports

Operation areas this target implements completely - every test passes, nothing skipped. Areas it only partly implements, or gets wrong, are in “Where it falls short” below.

  • batchGetItem tier 1
  • createTable tier 1
  • deleteItem tier 1
  • deleteTable tier 1
  • describeTable tier 1
  • getItem tier 1
  • listTables tier 1
  • scan tier 1
  • updateTable tier 1
  • kinesis tier 2
  • streams tier 2
  • updateTable tier 2
  • legacy-api tier 3

Conformance over time

LocalStack conformance history, 2026-03-23 to 2026-07-13 75% 88% 100% 93.0% 23 Mar 93.0% 24 Mar 93.5% 24 Apr 92.3% 25 Apr 89.0% 27 Apr 89.0% 23 May 88.3% 24 May 87.9% 25 May 88.0% 26 May 88.3% 29 May 88.3% 9 Jun 88.3% 16 Jun 88.3% 18 Jun 88.3% 19 Jun 88.4% 21 Jun 86.4% 22 Jun 86.5% 23 Jun 85.8% 24 Jun 83.7% 27 Jun 83.7% 29 Jun 83.3% 30 Jun 84.0% 1 Jul 84.0% 2 Jul 84.0% 6 Jul 84.0% 13 Jul

Where it falls short

Operation groups with gaps in the latest run, biggest first. Unsupported means the target doesn't implement that feature at all, often by design. Open one for the exact tests, or see the conformance suite.

  • error-messages Tier 3 63 failing
    View these tests in the suite →
    • BatchGetItem - exact error messages empty RequestItems: full required-parameter error
    • BatchGetItem - exact error messages > 100 keys across all tables: interpolated full error
    • BatchGetItem - exact error messages non-existent table: full ResourceNotFoundException message
    • BatchWriteItem - exact error messages empty RequestItems: full required-parameter error
    • BatchWriteItem - exact error messages > 25 requests: anchored regex on the constraint phrase
    • BatchWriteItem - exact error messages non-existent table: full ResourceNotFoundException message
    • BatchWriteItem - exact error messages wrong-typed table key: full schema-mismatch message
    • BatchWriteItem - exact error messages non-scalar table key: full schema-mismatch message
    • BatchWriteItem - exact error messages wrong-typed index key: full type-mismatch message
    • BatchWriteItem - exact error messages non-scalar index key: full type-mismatch message
    • BatchWriteItem - exact error messages empty-string index key: full secondary-index-key message
    • CreateTable - exact error messages missing TableName: full required-parameter error
    • CreateTable - exact error messages short table name (2 chars): minimum length 3 error
    • CreateTable - exact error messages duplicate attribute in KeySchema
    • CreateTable - exact error messages more than 2 KeySchema elements
    • CreateTable - exact error messages invalid KeyType
    • CreateTable - exact error messages invalid AttributeType
    • CreateTable - exact error messages LSI without range key on base table
    • CreateTable - exact error messages duplicate index names
    • CreateTable - exact error messages GSI INCLUDE projection without NonKeyAttributes: full missing-attributes message
    • CreateTable - exact error messages LSI INCLUDE projection without NonKeyAttributes: full missing-attributes message
    • CreateTable - exact error messages StreamSpecification StreamEnabled:false with a StreamViewType: full conflict message
    • DeleteItem - exact error messages non-existent table: full ResourceNotFoundException message
    • DeleteItem - exact error messages malformed Key (missing range key on composite table): full schema-mismatch error
    • GetItem - exact error messages non-existent table: full ResourceNotFoundException message
    • GetItem - exact error messages malformed Key (missing range key on composite table): full schema-mismatch error
    • PutItem - exact error messages missing table name: full validation error string
    • PutItem - exact error messages empty table name: minimum length 1 error
    • PutItem - exact error messages table name too long (256 chars): maximum length 255 error
    • PutItem - exact error messages table name with invalid chars: regex pattern error
    • PutItem - exact error messages NULL attr with false is accepted and normalises to NULL true
    • Query - exact error messages missing hash key in KeyConditionExpression
    • Query - exact error messages non-key attribute in KeyConditionExpression
    • Query - exact error messages invalid Select value
    • Query - exact error messages Limit of 0
    • Query - exact error messages malformed ExclusiveStartKey: short invalid-starting-key error
    • Query - exact error messages Select SPECIFIC_ATTRIBUTES without ProjectionExpression: full required-projection message
    • Scan - exact error messages Segment without TotalSegments: full required-parameter error
    • Scan - exact error messages Segment >= TotalSegments: full out-of-range error
    • Scan - exact error messages TotalSegments without Segment: full required-parameter error
    • Scan - exact error messages Limit of 0: full minimum-value error
    • Scan - exact error messages non-existent table: full ResourceNotFoundException message
    • Scan - exact error messages malformed ExclusiveStartKey: long schema-mismatch error
    • TransactGetItems - exact error messages empty TransactItems: full minimum-length error
    • TransactGetItems - exact error messages > 100 gets: anchored regex on the constraint phrase
    • TransactGetItems - exact error messages non-existent table: full ResourceNotFoundException message
    • TransactGetItems - exact error messages missing key attribute: action-level ValidationError surfaces as TransactionCanceledException
    • TransactWriteItems - exact error messages empty TransactItems: full minimum-length error
    • TransactWriteItems - exact error messages > 100 actions: anchored regex on the constraint phrase
    • TransactWriteItems - exact error messages non-existent table: full ResourceNotFoundException message
    • TransactWriteItems - exact error messages Put wrong-typed table key: cancelled with full ValidationError reason
    • TransactWriteItems - exact error messages Put non-scalar table key: cancelled with full ValidationError reason
    • TransactWriteItems - exact error messages Put wrong-typed index key: cancelled with full ValidationError reason
    • TransactWriteItems - exact error messages Put non-scalar index key: cancelled with full ValidationError reason
    • TransactWriteItems - exact error messages Update wrong-typed index key: cancelled with full ValidationError reason
    • TransactWriteItems - exact error messages Update non-scalar index key: cancelled with full ValidationError reason
    • TransactWriteItems - exact error messages Put empty-string index key: top-level ValidationException
    • TransactWriteItems - exact error messages Update wrong-typed Key: cancelled with schema-mismatch reason
    • TransactWriteItems - exact error messages Update non-scalar Key: cancelled with schema-mismatch reason
    • TransactWriteItems - exact error messages Delete wrong-typed Key: cancelled with schema-mismatch reason
    • TransactWriteItems - exact error messages Delete non-scalar Key: cancelled with schema-mismatch reason
    • TransactWriteItems - exact error messages ConditionCheck wrong-typed Key: cancelled with schema-mismatch reason
    • TransactWriteItems - exact error messages ConditionCheck non-scalar Key: cancelled with schema-mismatch reason
  • putItem Tier 1 25 failing
    View these tests in the suite →
    • ReturnItemCollectionMetrics PutItem with SIZE returns ItemCollectionMetrics
    • ReturnItemCollectionMetrics DeleteItem with SIZE returns ItemCollectionMetrics
    • ReturnItemCollectionMetrics UpdateItem with SIZE returns ItemCollectionMetrics
    • PutItem - number format rejects "+e2"
    • PutItem - number format rejects "e2"
    • PutItem - number format rejects "+1+2"
    • PutItem - number format rejects "1+2"
    • PutItem - number format rejects "+1.2.3"
    • PutItem - number format rejects "1.2.3"
    • PutItem - number format rejects "++5"
    • PutItem - number format rejects "+-5"
    • PutItem - number format rejects "-+5"
    • PutItem - number format rejects "+"
    • PutItem - number format rejects "-"
    • PutItem - number format rejects "1e"
    • PutItem - number format rejects "1e+"
    • PutItem - number format rejects "."
    • PutItem - number format rejects "1.2e3.4"
    • PutItem - number format rejects "0x5"
    • PutItem - number format rejects "NaN"
    • PutItem - number format rejects "Infinity"
    • PutItem - number format rejects "1_000"
    • PutItem - number format rejects " 5"
    • PutItem - number format rejects "5 "
    • PutItem - number format rejects "1 5"
  • validation-ordering Tier 3 25 failing
    View these tests in the suite →
    • Batch operations - validation ordering BatchWriteItem rejects empty RequestItems
    • Batch operations - validation ordering BatchGetItem rejects empty RequestItems
    • CreateTable - validation ordering empty TableName reports only tableName constraint
    • CreateTable - validation ordering invalid table name pattern reports only tableName
    • CreateTable - validation ordering reports invalid BillingMode and invalid KeySchema element together
    • CreateTable - validation ordering rejects a duplicate attribute in KeySchema
    • CreateTable - validation ordering rejects more than two KeySchema elements
    • CreateTable - validation ordering rejects an invalid BillingMode on its own
    • DeleteItem - validation ordering empty TableName reports only tableName constraint
    • DeleteItem - validation ordering reports invalid ReturnValues and invalid ReturnConsumedCapacity together
    • DeleteItem - validation ordering invalid table name pattern reports only tableName
    • Non-existent index - error surface Query on a non-existent index reports ValidationException
    • PutItem - validation ordering empty TableName reports tableName constraint (stops early)
    • PutItem - validation ordering empty TableName with invalid ReturnValues reports only tableName
    • PutItem - validation ordering reports invalid ReturnConsumedCapacity, ReturnItemCollectionMetrics, and ReturnValues together
    • PutItem - validation ordering reports invalid table name pattern
    • Query - validation ordering reports invalid TableName pattern
    • Query - validation ordering reports invalid ReturnConsumedCapacity
    • Scan - validation ordering rejects Segment without TotalSegments
    • Scan - validation ordering rejects Segment >= TotalSegments
    • Scan - validation ordering rejects TotalSegments without Segment
    • Scan - validation ordering rejects a negative Segment
    • UpdateItem - validation ordering empty TableName reports only tableName constraint
    • UpdateItem - validation ordering rejects invalid ReturnValues (UpdateItem reports the first enum error)
    • UpdateItem - validation ordering invalid table name pattern reports only tableName
  • transactions Tier 2 11 failing
    View these tests in the suite →
    • TransactGetItems - ConsumedCapacity INDEXES breakdown includes the table read capacity units
    • TransactGetItems - projection matching nothing omits Item when the projection matches no attribute on a present item
    • TransactWriteItems - validation Put with a non-scalar table key cancels with a ValidationError reason
    • TransactWriteItems - validation Put with a non-scalar index key cancels with a ValidationError reason
    • TransactWriteItems - validation Update setting a non-scalar index key cancels with a ValidationError reason
    • TransactWriteItems - validation Update with a non-scalar Key cancels with a ValidationError reason
    • TransactWriteItems - validation Delete with a non-scalar Key cancels with a ValidationError reason
    • TransactWriteItems - validation ConditionCheck with a non-scalar Key cancels with a ValidationError reason
    • TransactWriteItems - ConsumedCapacity charges 2 write capacity units per item
    • TransactWriteItems - ConsumedCapacity: conditional, check, replay, cancel a standalone ConditionCheck action costs 2 write capacity units
    • TransactWriteItems - ConsumedCapacity: conditional, check, replay, cancel reports write capacity on the first call and read capacity on a same-token replay
  • batchWriteItem Tier 1 3 failing
    View these tests in the suite →
    • BatchWriteItem - validation rejects a wrong-typed table key value
    • BatchWriteItem - validation rejects a non-scalar table key value
    • BatchWriteItem - validation rejects a non-scalar index key value
  • backups Tier 2 3 skipped
    View these tests in the suite →
    • On-demand backups - lifecycle and restore CreateBackup → DescribeBackup → ListBackups → DeleteBackup
    • On-demand backups - lifecycle and restore RestoreTableFromBackup initiates a restore into a new table
    • On-demand backups - lifecycle and restore DescribeBackup on a deleted backup throws BackupNotFoundException
  • partiql Tier 2 3 failing
    View these tests in the suite →
    • ExecuteStatement - PartiQL rejects INSERT on an existing item (INSERT is not upsert)
    • ExecuteStatement - PartiQL returns a populated ConsumedCapacity block when requested
    • ExecuteTransaction - PartiQL idempotent replay under the same ClientRequestToken does not double-apply
  • query Tier 1 2 failing
    View these tests in the suite →
    • Query - Limit + FilterExpression interaction rejects ExclusiveStartKey that does not match the table schema
    • Query - KeyConditionExpression semantics rejects a nested path on a key attribute
  • export Tier 2 unsupported
    View these tests in the suite →
    • Export and import - S3 ExportTableToPointInTime initiates an export and reports it
    • Export and import - S3 ImportTable ingests S3 data into a new table
  • resourcePolicy Tier 2 unsupported
    View these tests in the suite →
    • Resource policies - Put/Get/Delete GetResourcePolicy on a table with no policy throws PolicyNotFoundException
    • Resource policies - Put/Get/Delete Put then Get round-trips the policy, and Delete removes it
  • tags Tier 2 2 failing
    View these tests in the suite →
    • Tags - validation rejects TagResource with an invalid ARN format
    • Tags - validation rejects ListTagsOfResource with a non-existent ARN
  • updateItem Tier 1 1 failing
    View these tests in the suite →
    • UpdateItem - ReturnValues granularity UPDATED_NEW on a nested SET returns only the changed fragment
  • account Tier 2 1 skipped
    View these tests in the suite →
    • Account reads - DescribeLimits, DescribeEndpoints DescribeEndpoints returns at least one endpoint with an address
  • contributorInsights Tier 2 1 failing
    View these tests in the suite →
    • Contributor insights - enable/describe/list enabling transitions the status and lists the table
  • ttl Tier 2 1 failing
    View these tests in the suite →
    • TTL - validation rejects empty attribute name
  • limits Tier 3 1 failing
    View these tests in the suite →
    • Nesting depth - 32-level document limit rejects a 32-level ExpressionAttributeValue with ValidationException

Run history

Run Total Movement
84.0% 0.0pp unchanged
84.0% 0.0pp unchanged
84.0% 0.0pp unchanged

Suite on

Grew to 873 tests, up 49, all characterised against real DynamoDB in eu-west-2. New coverage in three areas:

  • ConsumedCapacity: the transactional read/write split on a same-token replay and on ExecuteTransaction, and a correction that single-item operations report the aggregate CapacityUnits and omit the split, which is transactional-only.
  • Empty-binary key values: rejected as a top-level ValidationException on every path, including secondary-index keys and inside transactions, mirroring the empty-string rejection.
  • Expression, limit and response-shape parity: KeyConditionExpression operand and nested-path rules, ExpressionAttributeNames/Values hygiene, projection validation and list-index fidelity, reversed-bounds BETWEEN, read-path key-length and segment caps, whitespace numbers, batch unprocessed fields and cross-table projection mixing, the bare no-op upsert, multi-subpath UPDATED_NEW, filter operand ordering, hash-only-GSI pagination, and CreateTable spec validation.
 		84.0% +0.7pp rose 0.7 percentage points

Suite on

Grew to 824 tests, up 7, in two parts: two sibling-parity gaps where one half of a rule was pinned and the other was not, and the capacity accounting of conditional and idempotent transactional writes. All characterised against real DynamoDB in eu-west-2.

The first covers the LSI side of the INCLUDE-projection-without-NonKeyAttributes rejection; the GSI side already had it. An LSI declared with ProjectionType INCLUDE and no NonKeyAttributes is rejected as a ValidationException in tier1 and pinned to the exact message in tier3, the same wording the GSI case returns.

The second pins the Query message for Select SPECIFIC_ATTRIBUTES with no ProjectionExpression, which Scan already had. Query and Scan enforce the same rule but word it differently: Query wraps the phrase in the "1 validation error detected:" envelope, Scan returns it bare.

The transaction cases settle what a conditional TransactWriteItems actually costs. A passing condition adds no read capacity: a conditional write bills the same 2 WCU per sub-1KB item as an unconditional one, and a standalone ConditionCheck costs 2 WCU, billed as write not read. Idempotent replay splits the accounting - the first call reports 2 write capacity units, a same-token replay within the window reports 2 read capacity units for re-reading the stored result. A failing condition cancels the transaction, and the response carries no ConsumedCapacity at all. Answers #27.

 		83.3% -0.4pp fell 0.4 percentage points
83.7% 0.0pp unchanged
83.7% -2.1pp fell 2.1 percentage points

Suite on

Grew to 762 tests, up 18, covering a malformed value in the lookup Key of a TransactWriteItems Update, Delete, or ConditionCheck - the path a Put item key does not take. Captured across four regions (eu-west-2, us-east-1, ap-southeast-2, eu-central-1), where every string was identical, so they pin exactly. An empty-string Key surfaces as a top-level ValidationException with the same message a Put item key gives; a wrong-typed or non-scalar Key cancels with a ValidationError reason carrying "The provided key element does not match the schema" - the key-only form, not the "Type mismatch for key" message the item-key path returns. The same run confirmed the BatchWriteItem table-key schema-mismatch message is region-invariant.

 		85.8% -0.7pp fell 0.7 percentage points

Suite on

Grew to 744 tests, up 8, pinning the Select / ProjectionExpression rules on Query and Scan. A ProjectionExpression is only valid with Select SPECIFIC_ATTRIBUTES, and ALL_PROJECTED_ATTRIBUTES is only valid with an IndexName; real DynamoDB rejects both with a ValidationException before reading anything. The cases span ALL_ATTRIBUTES, COUNT, and ALL_PROJECTED_ATTRIBUTES, including the request that breaks both rules at once, where AWS reports the ProjectionExpression one. They assert the contractual phrase, so they hold whether or not the engine carries the wrapper AWS adds on Query but not Scan.

 		86.5% +0.1pp rose 0.1 percentage points

Suite on

Grew to 736 tests, up 30, covering what TransactWriteItems and BatchWriteItem do with an item whose key value is malformed - the wrong type, non-scalar, or an empty string - across both table and index keys. PutItem already covered this; the transactional and batch paths covered none of it.

Characterising it against real AWS turned up a split worth pinning. An empty-string key value is rejected by up-front input validation, so even inside a transaction it surfaces as a top-level ValidationException. A wrong-typed or non-scalar key value is caught while the transaction runs, so it comes back as a TransactionCanceledException carrying a ValidationError reason rather than a top-level error. BatchWriteItem has no cancellation path, so every variant there is a plain ValidationException. The tests pin both halves, which catches two opposite mistakes: an engine that wraps the empty-string case as a cancellation, and one that surfaces the type-mismatch case as a top-level error.

 		86.4% -2.0pp fell 2.0 percentage points

Suite on

Grew to 706 tests, up 7, tightening secondary-index behaviour in Tier 1. Query and Scan on a GSI or LSI now assert sparse membership: an item that omits the index key stays off the index but remains on the base table. And PutItem now rejects an item whose GSI or LSI key value is the wrong type, non-scalar, or an empty string while the base-table keys are valid, holding an index key to its declared scalar type the same way a table key is held.

 		88.4% +0.1pp rose 0.1 percentage points
88.3% 0.0pp unchanged
88.3% 0.0pp unchanged
88.3% 0.0pp unchanged

Suite on

Real DynamoDB in eu-west-2 reworded a chunk of its validation errors, and the Tier 3 error-message tests moved with it. They now assert the contract the error carries - its type, the field it objects to, and the constraint - rather than the exact prose, because AWS varies the wrapper, the echoed input value and the field casing from one region to the next. A four-region capture in June found eu-west-2 and eu-central-1 on the new wording and us-east-1 and ap-southeast-2 still on the old, so the line between contract and cosmetic is drawn from what is invariant across all four.

This moves some Tier 3 numbers. Targets that were only ever marked down for wording DynamoDB itself renders inconsistently now pass those checks, so their Tier 3 scores rise: the suite has stopped counting a cosmetic difference as a behavioural one. Genuine behavioural divergences are still pinned exactly, for example PutItem with a { NULL: false } attribute, which DynamoDB now accepts in eu-west-2 and normalises to { NULL: true }.

 		88.3% 0.0pp unchanged
88.3% +0.3pp rose 0.3 percentage points

Suite on

Grew to 684 tests with a control-plane and table-configuration sweep: the CreateTable/UpdateTable config parameters and the secondary control-plane operations (limits, backups and PITR, exports and imports, Kinesis, resource policies, contributor insights), each characterised against real AWS and probe-skipped where a target doesn't implement it.

The published percentage changed with it. It now measures correctness over implemented operations, Pass / (Pass + Fail), so skips no longer count against the score. A skip is honest scope; a fail is a bug.

 		88.0% +0.1pp rose 0.1 percentage points
87.9% -0.4pp fell 0.4 percentage points

Suite on

Grew to 625 tests, up 24 on the previous run: eleven more in Tier 1 and thirteen more in Tier 3, tightening coverage of core operations and the strict edge cases.

 		88.3% -0.7pp fell 0.7 percentage points

Suite on

ExtendDB joined the run as a target. The suite itself held steady at 601 tests.

 		89.0% 0.0pp unchanged

Suite on

Grew to 601 tests, up 29, and every new test landed in Tier 3: a broader strict surface spanning validation ordering, exact error messages, service limits, and the legacy request shapes. Floci and Ministack were added to the run as targets the same day.

 		89.0% -3.3pp fell 3.3 percentage points
92.3% -1.2pp fell 1.2 percentage points

Suite on

Grew to 572 tests, up 46 on the first run: thirty-six more in Tier 1 and ten more in Tier 2, deepening coverage of the core and complete-feature behaviour.

 		93.5% +0.6pp rose 0.6 percentage points
93.0% 0.0pp unchanged

Suite on

The suite was established with 526 tests across the three tiers (267 Tier 1, 93 Tier 2, 166 Tier 3), run against Dynalite, DynamoDB Local, Dynoxide, and LocalStack, with live AWS DynamoDB as the baseline.

 		93.0% first run