Refactored type definitions (#1119)

* Updated types generation script * Refactored api method definitions * Updated test - Removed old test code - Added tsd dev dependency - Rewritten test with tsd * Removed unused dependencies * Fixed definition * Updated test * Updated docs * Improved events type definitions * Updated test * Minor fixes in the type definitons * More type test * Improved Transport type definitions * Updated test * Addressed comments * Code generation * Use RequestBody, Response and Context everywhere, also default Context to unknown * Updated test * body -> hasBody * Fixed conflicts * Updated code generation * Improved request body type definition * Updated code generation * Use BodyType for both request and reponses generics - Use extends for defining the RequestBody generic to force the user following the same shape. - BodyType and NDBodyType now accepts a generics to allow injecting more specific types in the future * API generation * Updated test * Updated docs * Use BodyType also in ReponseError * Removed useless client generics * Renamed generics and types - prefixed all generics with a T - BodyType => RequestBody - NDBodyType => RequestNDBody - Added ResponseBody * Updated test * Updated docs * Test ResponseBody as well * Simplify overloads * API generation * Updated test * Updated error types
2020-03-23 11:38:18 +01:00
parent a80f510a9a
commit 6c82a4967e
23 changed files with 3838 additions and 955 deletions
--- a/api/requestParams.d.ts
+++ b/api/requestParams.d.ts
@ -2,6 +2,8 @@
 // Elasticsearch B.V licenses this file to you under the Apache 2.0 License.
 // See the LICENSE file in the project root for more information

+import { RequestBody, RequestNDBody } from '../lib/Transport'
+
 export interface Generic {
  method?: string;
  ignore?: number | number[];
@ -12,7 +14,7 @@ export interface Generic {
  source?: string;
 }

-export interface Bulk<T = any> extends Generic {
+export interface Bulk<T = RequestNDBody> extends Generic {
  index?: string;
  type?: string;
  _source_exclude?: string | string[];
@ -249,12 +251,12 @@ export interface CatThreadPool extends Generic {
  v?: boolean;
 }

-export interface ClearScroll<T = any> extends Generic {
+export interface ClearScroll<T = RequestBody> extends Generic {
  scroll_id?: string | string[];
  body?: T;
 }

-export interface ClusterAllocationExplain<T = any> extends Generic {
+export interface ClusterAllocationExplain<T = RequestBody> extends Generic {
  include_yes_decisions?: boolean;
  include_disk_info?: boolean;
  body?: T;
@ -299,7 +301,7 @@ export interface ClusterPendingTasks extends Generic {
  master_timeout?: string;
 }

-export interface ClusterPutComponentTemplate<T = any> extends Generic {
+export interface ClusterPutComponentTemplate<T = RequestBody> extends Generic {
  name: string;
  create?: boolean;
  timeout?: string;
@ -307,7 +309,7 @@ export interface ClusterPutComponentTemplate<T = any> extends Generic {
  body: T;
 }

-export interface ClusterPutSettings<T = any> extends Generic {
+export interface ClusterPutSettings<T = RequestBody> extends Generic {
  flat_settings?: boolean;
  master_timeout?: string;
  timeout?: string;
@ -317,7 +319,7 @@ export interface ClusterPutSettings<T = any> extends Generic {
 export interface ClusterRemoteInfo extends Generic {
 }

-export interface ClusterReroute<T = any> extends Generic {
+export interface ClusterReroute<T = RequestBody> extends Generic {
  dry_run?: boolean;
  explain?: boolean;
  retry_failed?: boolean;
@ -346,7 +348,7 @@ export interface ClusterStats extends Generic {
  timeout?: string;
 }

-export interface Count<T = any> extends Generic {
+export interface Count<T = RequestBody> extends Generic {
  index?: string | string[];
  ignore_unavailable?: boolean;
  ignore_throttled?: boolean;
@ -365,7 +367,7 @@ export interface Count<T = any> extends Generic {
  body?: T;
 }

-export interface Create<T = any> extends Generic {
+export interface Create<T = RequestBody> extends Generic {
  id: string;
  index: string;
  type?: string;
@ -393,7 +395,7 @@ export interface Delete extends Generic {
  version_type?: 'internal' | 'external' | 'external_gte';
 }

-export interface DeleteByQuery<T = any> extends Generic {
+export interface DeleteByQuery<T = RequestBody> extends Generic {
  index: string | string[];
  _source_exclude?: string | string[];
  _source_include?: string | string[];
@ -477,7 +479,7 @@ export interface ExistsSource extends Generic {
  version_type?: 'internal' | 'external' | 'external_gte';
 }

-export interface Explain<T = any> extends Generic {
+export interface Explain<T = RequestBody> extends Generic {
  id: string;
  index: string;
  _source_exclude?: string | string[];
@ -550,7 +552,7 @@ export interface GetSource extends Generic {
  version_type?: 'internal' | 'external' | 'external_gte';
 }

-export interface Index<T = any> extends Generic {
+export interface Index<T = RequestBody> extends Generic {
  id?: string;
  index: string;
  wait_for_active_shards?: string;
@ -566,7 +568,7 @@ export interface Index<T = any> extends Generic {
  body: T;
 }

-export interface IndicesAnalyze<T = any> extends Generic {
+export interface IndicesAnalyze<T = RequestBody> extends Generic {
  index?: string;
  body?: T;
 }
@ -582,7 +584,7 @@ export interface IndicesClearCache extends Generic {
  request?: boolean;
 }

-export interface IndicesClone<T = any> extends Generic {
+export interface IndicesClone<T = RequestBody> extends Generic {
  index: string;
  target: string;
  timeout?: string;
@ -601,7 +603,7 @@ export interface IndicesClose extends Generic {
  wait_for_active_shards?: string;
 }

-export interface IndicesCreate<T = any> extends Generic {
+export interface IndicesCreate<T = RequestBody> extends Generic {
  index: string;
  wait_for_active_shards?: string;
  timeout?: string;
@ -609,7 +611,7 @@ export interface IndicesCreate<T = any> extends Generic {
  body?: T;
 }

-export interface IndicesCreateDataStream<T = any> extends Generic {
+export interface IndicesCreateDataStream<T = RequestBody> extends Generic {
  name: string;
  body: T;
 }
@ -773,7 +775,7 @@ export interface IndicesOpen extends Generic {
  wait_for_active_shards?: string;
 }

-export interface IndicesPutAlias<T = any> extends Generic {
+export interface IndicesPutAlias<T = RequestBody> extends Generic {
  index: string | string[];
  name: string;
  timeout?: string;
@ -781,7 +783,7 @@ export interface IndicesPutAlias<T = any> extends Generic {
  body?: T;
 }

-export interface IndicesPutMapping<T = any> extends Generic {
+export interface IndicesPutMapping<T = RequestBody> extends Generic {
  index: string | string[];
  timeout?: string;
  master_timeout?: string;
@ -791,7 +793,7 @@ export interface IndicesPutMapping<T = any> extends Generic {
  body: T;
 }

-export interface IndicesPutSettings<T = any> extends Generic {
+export interface IndicesPutSettings<T = RequestBody> extends Generic {
  index?: string | string[];
  master_timeout?: string;
  timeout?: string;
@ -803,7 +805,7 @@ export interface IndicesPutSettings<T = any> extends Generic {
  body: T;
 }

-export interface IndicesPutTemplate<T = any> extends Generic {
+export interface IndicesPutTemplate<T = RequestBody> extends Generic {
  name: string;
  order?: number;
  create?: boolean;
@ -824,7 +826,7 @@ export interface IndicesRefresh extends Generic {
  expand_wildcards?: 'open' | 'closed' | 'hidden' | 'none' | 'all';
 }

-export interface IndicesRollover<T = any> extends Generic {
+export interface IndicesRollover<T = RequestBody> extends Generic {
  alias: string;
  new_index?: string;
  timeout?: string;
@ -850,7 +852,7 @@ export interface IndicesShardStores extends Generic {
  expand_wildcards?: 'open' | 'closed' | 'hidden' | 'none' | 'all';
 }

-export interface IndicesShrink<T = any> extends Generic {
+export interface IndicesShrink<T = RequestBody> extends Generic {
  index: string;
  target: string;
  timeout?: string;
@ -859,7 +861,7 @@ export interface IndicesShrink<T = any> extends Generic {
  body?: T;
 }

-export interface IndicesSplit<T = any> extends Generic {
+export interface IndicesSplit<T = RequestBody> extends Generic {
  index: string;
  target: string;
  timeout?: string;
@ -883,7 +885,7 @@ export interface IndicesStats extends Generic {
  forbid_closed_indices?: boolean;
 }

-export interface IndicesUpdateAliases<T = any> extends Generic {
+export interface IndicesUpdateAliases<T = RequestBody> extends Generic {
  timeout?: string;
  master_timeout?: string;
  body: T;
@ -898,7 +900,7 @@ export interface IndicesUpgrade extends Generic {
  only_ancient_segments?: boolean;
 }

-export interface IndicesValidateQuery<T = any> extends Generic {
+export interface IndicesValidateQuery<T = RequestBody> extends Generic {
  index?: string | string[];
  type?: string | string[];
  explain?: boolean;
@ -933,20 +935,20 @@ export interface IngestGetPipeline extends Generic {
 export interface IngestProcessorGrok extends Generic {
 }

-export interface IngestPutPipeline<T = any> extends Generic {
+export interface IngestPutPipeline<T = RequestBody> extends Generic {
  id: string;
  master_timeout?: string;
  timeout?: string;
  body: T;
 }

-export interface IngestSimulate<T = any> extends Generic {
+export interface IngestSimulate<T = RequestBody> extends Generic {
  id?: string;
  verbose?: boolean;
  body: T;
 }

-export interface Mget<T = any> extends Generic {
+export interface Mget<T = RequestBody> extends Generic {
  index?: string;
  _source_exclude?: string | string[];
  _source_include?: string | string[];
@ -961,7 +963,7 @@ export interface Mget<T = any> extends Generic {
  body: T;
 }

-export interface Msearch<T = any> extends Generic {
+export interface Msearch<T = RequestNDBody> extends Generic {
  index?: string | string[];
  search_type?: 'query_then_fetch' | 'query_and_fetch' | 'dfs_query_then_fetch' | 'dfs_query_and_fetch';
  max_concurrent_searches?: number;
@ -973,7 +975,7 @@ export interface Msearch<T = any> extends Generic {
  body: T;
 }

-export interface MsearchTemplate<T = any> extends Generic {
+export interface MsearchTemplate<T = RequestNDBody> extends Generic {
  index?: string | string[];
  search_type?: 'query_then_fetch' | 'query_and_fetch' | 'dfs_query_then_fetch' | 'dfs_query_and_fetch';
  typed_keys?: boolean;
@ -983,7 +985,7 @@ export interface MsearchTemplate<T = any> extends Generic {
  body: T;
 }

-export interface Mtermvectors<T = any> extends Generic {
+export interface Mtermvectors<T = RequestBody> extends Generic {
  index?: string;
  ids?: string | string[];
  term_statistics?: boolean;
@ -1045,7 +1047,7 @@ export interface NodesUsage extends Generic {
 export interface Ping extends Generic {
 }

-export interface PutScript<T = any> extends Generic {
+export interface PutScript<T = RequestBody> extends Generic {
  id: string;
  context?: string;
  timeout?: string;
@ -1053,7 +1055,7 @@ export interface PutScript<T = any> extends Generic {
  body: T;
 }

-export interface RankEval<T = any> extends Generic {
+export interface RankEval<T = RequestBody> extends Generic {
  index?: string | string[];
  ignore_unavailable?: boolean;
  allow_no_indices?: boolean;
@ -1062,7 +1064,7 @@ export interface RankEval<T = any> extends Generic {
  body: T;
 }

-export interface Reindex<T = any> extends Generic {
+export interface Reindex<T = RequestBody> extends Generic {
  refresh?: boolean;
  timeout?: string;
  wait_for_active_shards?: string;
@ -1079,23 +1081,23 @@ export interface ReindexRethrottle extends Generic {
  requests_per_second: number;
 }

-export interface RenderSearchTemplate<T = any> extends Generic {
+export interface RenderSearchTemplate<T = RequestBody> extends Generic {
  id?: string;
  body?: T;
 }

-export interface ScriptsPainlessExecute<T = any> extends Generic {
+export interface ScriptsPainlessExecute<T = RequestBody> extends Generic {
  body?: T;
 }

-export interface Scroll<T = any> extends Generic {
+export interface Scroll<T = RequestBody> extends Generic {
  scroll_id?: string;
  scroll?: string;
  rest_total_hits_as_int?: boolean;
  body?: T;
 }

-export interface Search<T = any> extends Generic {
+export interface Search<T = RequestBody> extends Generic {
  index?: string | string[];
  _source_exclude?: string | string[];
  _source_include?: string | string[];
@ -1154,7 +1156,7 @@ export interface SearchShards extends Generic {
  expand_wildcards?: 'open' | 'closed' | 'hidden' | 'none' | 'all';
 }

-export interface SearchTemplate<T = any> extends Generic {
+export interface SearchTemplate<T = RequestBody> extends Generic {
  index?: string | string[];
  ignore_unavailable?: boolean;
  ignore_throttled?: boolean;
@ -1172,14 +1174,14 @@ export interface SearchTemplate<T = any> extends Generic {
  body: T;
 }

-export interface SnapshotCleanupRepository<T = any> extends Generic {
+export interface SnapshotCleanupRepository<T = RequestBody> extends Generic {
  repository: string;
  master_timeout?: string;
  timeout?: string;
  body?: T;
 }

-export interface SnapshotCreate<T = any> extends Generic {
+export interface SnapshotCreate<T = RequestBody> extends Generic {
  repository: string;
  snapshot: string;
  master_timeout?: string;
@ -1187,7 +1189,7 @@ export interface SnapshotCreate<T = any> extends Generic {
  body?: T;
 }

-export interface SnapshotCreateRepository<T = any> extends Generic {
+export interface SnapshotCreateRepository<T = RequestBody> extends Generic {
  repository: string;
  master_timeout?: string;
  timeout?: string;
@ -1221,7 +1223,7 @@ export interface SnapshotGetRepository extends Generic {
  local?: boolean;
 }

-export interface SnapshotRestore<T = any> extends Generic {
+export interface SnapshotRestore<T = RequestBody> extends Generic {
  repository: string;
  snapshot: string;
  master_timeout?: string;
@ -1265,7 +1267,7 @@ export interface TasksList extends Generic {
  timeout?: string;
 }

-export interface Termvectors<T = any> extends Generic {
+export interface Termvectors<T = RequestBody> extends Generic {
  index: string;
  id?: string;
  term_statistics?: boolean;
@ -1282,7 +1284,7 @@ export interface Termvectors<T = any> extends Generic {
  body?: T;
 }

-export interface Update<T = any> extends Generic {
+export interface Update<T = RequestBody> extends Generic {
  id: string;
  index: string;
  type?: string;
@ -1302,7 +1304,7 @@ export interface Update<T = any> extends Generic {
  body: T;
 }

-export interface UpdateByQuery<T = any> extends Generic {
+export interface UpdateByQuery<T = RequestBody> extends Generic {
  index: string | string[];
  _source_exclude?: string | string[];
  _source_include?: string | string[];
@ -1359,7 +1361,7 @@ export interface AsyncSearchGet extends Generic {
  typed_keys?: boolean;
 }

-export interface AsyncSearchSubmit<T = any> extends Generic {
+export interface AsyncSearchSubmit<T = RequestBody> extends Generic {
  index?: string | string[];
  _source_exclude?: string | string[];
  _source_include?: string | string[];
@ -1463,7 +1465,7 @@ export interface CcrDeleteAutoFollowPattern extends Generic {
  name: string;
 }

-export interface CcrFollow<T = any> extends Generic {
+export interface CcrFollow<T = RequestBody> extends Generic {
  index: string;
  wait_for_active_shards?: string;
  body: T;
@ -1477,7 +1479,7 @@ export interface CcrFollowStats extends Generic {
  index: string | string[];
 }

-export interface CcrForgetFollower<T = any> extends Generic {
+export interface CcrForgetFollower<T = RequestBody> extends Generic {
  index: string;
  body: T;
 }
@ -1494,7 +1496,7 @@ export interface CcrPauseFollow extends Generic {
  index: string;
 }

-export interface CcrPutAutoFollowPattern<T = any> extends Generic {
+export interface CcrPutAutoFollowPattern<T = RequestBody> extends Generic {
  name: string;
  body: T;
 }
@ -1503,7 +1505,7 @@ export interface CcrResumeAutoFollowPattern extends Generic {
  name: string;
 }

-export interface CcrResumeFollow<T = any> extends Generic {
+export interface CcrResumeFollow<T = RequestBody> extends Generic {
  index: string;
  body?: T;
 }
@ -1534,11 +1536,11 @@ export interface DataFrameTransformDeprecatedGetTransformStats extends Generic {
  allow_no_match?: boolean;
 }

-export interface DataFrameTransformDeprecatedPreviewTransform<T = any> extends Generic {
+export interface DataFrameTransformDeprecatedPreviewTransform<T = RequestBody> extends Generic {
  body: T;
 }

-export interface DataFrameTransformDeprecatedPutTransform<T = any> extends Generic {
+export interface DataFrameTransformDeprecatedPutTransform<T = RequestBody> extends Generic {
  transform_id: string;
  defer_validation?: boolean;
  body: T;
@ -1556,7 +1558,7 @@ export interface DataFrameTransformDeprecatedStopTransform extends Generic {
  allow_no_match?: boolean;
 }

-export interface DataFrameTransformDeprecatedUpdateTransform<T = any> extends Generic {
+export interface DataFrameTransformDeprecatedUpdateTransform<T = RequestBody> extends Generic {
  transform_id: string;
  defer_validation?: boolean;
  body: T;
@ -1575,7 +1577,7 @@ export interface EnrichGetPolicy extends Generic {
  name?: string | string[];
 }

-export interface EnrichPutPolicy<T = any> extends Generic {
+export interface EnrichPutPolicy<T = RequestBody> extends Generic {
  name: string;
  body: T;
 }
@ -1583,12 +1585,12 @@ export interface EnrichPutPolicy<T = any> extends Generic {
 export interface EnrichStats extends Generic {
 }

-export interface EqlSearch<T = any> extends Generic {
+export interface EqlSearch<T = RequestBody> extends Generic {
  index: string;
  body: T;
 }

-export interface GraphExplore<T = any> extends Generic {
+export interface GraphExplore<T = RequestBody> extends Generic {
  index: string | string[];
  routing?: string;
  timeout?: string;
@ -1612,12 +1614,12 @@ export interface IlmGetLifecycle extends Generic {
 export interface IlmGetStatus extends Generic {
 }

-export interface IlmMoveToStep<T = any> extends Generic {
+export interface IlmMoveToStep<T = RequestBody> extends Generic {
  index: string;
  body?: T;
 }

-export interface IlmPutLifecycle<T = any> extends Generic {
+export interface IlmPutLifecycle<T = RequestBody> extends Generic {
  policy: string;
  body?: T;
 }
@ -1677,7 +1679,7 @@ export interface LicenseGetBasicStatus extends Generic {
 export interface LicenseGetTrialStatus extends Generic {
 }

-export interface LicensePost<T = any> extends Generic {
+export interface LicensePost<T = RequestBody> extends Generic {
  acknowledge?: boolean;
  body?: T;
 }
@ -1695,7 +1697,7 @@ export interface MigrationDeprecations extends Generic {
  index?: string;
 }

-export interface MlCloseJob<T = any> extends Generic {
+export interface MlCloseJob<T = RequestBody> extends Generic {
  job_id: string;
  allow_no_jobs?: boolean;
  force?: boolean;
@ -1756,20 +1758,20 @@ export interface MlDeleteTrainedModel extends Generic {
  model_id: string;
 }

-export interface MlEstimateModelMemory<T = any> extends Generic {
+export interface MlEstimateModelMemory<T = RequestBody> extends Generic {
  body: T;
 }

-export interface MlEvaluateDataFrame<T = any> extends Generic {
+export interface MlEvaluateDataFrame<T = RequestBody> extends Generic {
  body: T;
 }

-export interface MlExplainDataFrameAnalytics<T = any> extends Generic {
+export interface MlExplainDataFrameAnalytics<T = RequestBody> extends Generic {
  id?: string;
  body?: T;
 }

-export interface MlFindFileStructure<T = any> extends Generic {
+export interface MlFindFileStructure<T = RequestNDBody> extends Generic {
  lines_to_sample?: number;
  line_merge_size_limit?: number;
  timeout?: string;
@ -1787,7 +1789,7 @@ export interface MlFindFileStructure<T = any> extends Generic {
  body: T;
 }

-export interface MlFlushJob<T = any> extends Generic {
+export interface MlFlushJob<T = RequestBody> extends Generic {
  job_id: string;
  calc_interim?: boolean;
  start?: string;
@ -1803,7 +1805,7 @@ export interface MlForecast extends Generic {
  expires_in?: string;
 }

-export interface MlGetBuckets<T = any> extends Generic {
+export interface MlGetBuckets<T = RequestBody> extends Generic {
  job_id: string;
  timestamp?: string;
  expand?: boolean;
@ -1827,14 +1829,14 @@ export interface MlGetCalendarEvents extends Generic {
  size?: number;
 }

-export interface MlGetCalendars<T = any> extends Generic {
+export interface MlGetCalendars<T = RequestBody> extends Generic {
  calendar_id?: string;
  from?: number;
  size?: number;
  body?: T;
 }

-export interface MlGetCategories<T = any> extends Generic {
+export interface MlGetCategories<T = RequestBody> extends Generic {
  job_id: string;
  category_id?: number;
  from?: number;
@ -1872,7 +1874,7 @@ export interface MlGetFilters extends Generic {
  size?: number;
 }

-export interface MlGetInfluencers<T = any> extends Generic {
+export interface MlGetInfluencers<T = RequestBody> extends Generic {
  job_id: string;
  exclude_interim?: boolean;
  from?: number;
@ -1895,7 +1897,7 @@ export interface MlGetJobs extends Generic {
  allow_no_jobs?: boolean;
 }

-export interface MlGetModelSnapshots<T = any> extends Generic {
+export interface MlGetModelSnapshots<T = RequestBody> extends Generic {
  job_id: string;
  snapshot_id?: string;
  from?: number;
@ -1907,7 +1909,7 @@ export interface MlGetModelSnapshots<T = any> extends Generic {
  body?: T;
 }

-export interface MlGetOverallBuckets<T = any> extends Generic {
+export interface MlGetOverallBuckets<T = RequestBody> extends Generic {
  job_id: string;
  top_n?: number;
  bucket_span?: string;
@ -1919,7 +1921,7 @@ export interface MlGetOverallBuckets<T = any> extends Generic {
  body?: T;
 }

-export interface MlGetRecords<T = any> extends Generic {
+export interface MlGetRecords<T = RequestBody> extends Generic {
  job_id: string;
  exclude_interim?: boolean;
  from?: number;
@ -1956,12 +1958,12 @@ export interface MlOpenJob extends Generic {
  job_id: string;
 }

-export interface MlPostCalendarEvents<T = any> extends Generic {
+export interface MlPostCalendarEvents<T = RequestBody> extends Generic {
  calendar_id: string;
  body: T;
 }

-export interface MlPostData<T = any> extends Generic {
+export interface MlPostData<T = RequestBody> extends Generic {
  job_id: string;
  reset_start?: string;
  reset_end?: string;
@ -1972,7 +1974,7 @@ export interface MlPreviewDatafeed extends Generic {
  datafeed_id: string;
 }

-export interface MlPutCalendar<T = any> extends Generic {
+export interface MlPutCalendar<T = RequestBody> extends Generic {
  calendar_id: string;
  body?: T;
 }
@ -1982,12 +1984,12 @@ export interface MlPutCalendarJob extends Generic {
  job_id: string;
 }

-export interface MlPutDataFrameAnalytics<T = any> extends Generic {
+export interface MlPutDataFrameAnalytics<T = RequestBody> extends Generic {
  id: string;
  body: T;
 }

-export interface MlPutDatafeed<T = any> extends Generic {
+export interface MlPutDatafeed<T = RequestBody> extends Generic {
  datafeed_id: string;
  ignore_unavailable?: boolean;
  allow_no_indices?: boolean;
@ -1996,22 +1998,22 @@ export interface MlPutDatafeed<T = any> extends Generic {
  body: T;
 }

-export interface MlPutFilter<T = any> extends Generic {
+export interface MlPutFilter<T = RequestBody> extends Generic {
  filter_id: string;
  body: T;
 }

-export interface MlPutJob<T = any> extends Generic {
+export interface MlPutJob<T = RequestBody> extends Generic {
  job_id: string;
  body: T;
 }

-export interface MlPutTrainedModel<T = any> extends Generic {
+export interface MlPutTrainedModel<T = RequestBody> extends Generic {
  model_id: string;
  body: T;
 }

-export interface MlRevertModelSnapshot<T = any> extends Generic {
+export interface MlRevertModelSnapshot<T = RequestBody> extends Generic {
  job_id: string;
  snapshot_id: string;
  delete_intervening_results?: boolean;
@ -2023,13 +2025,13 @@ export interface MlSetUpgradeMode extends Generic {
  timeout?: string;
 }

-export interface MlStartDataFrameAnalytics<T = any> extends Generic {
+export interface MlStartDataFrameAnalytics<T = RequestBody> extends Generic {
  id: string;
  timeout?: string;
  body?: T;
 }

-export interface MlStartDatafeed<T = any> extends Generic {
+export interface MlStartDatafeed<T = RequestBody> extends Generic {
  datafeed_id: string;
  start?: string;
  end?: string;
@ -2037,7 +2039,7 @@ export interface MlStartDatafeed<T = any> extends Generic {
  body?: T;
 }

-export interface MlStopDataFrameAnalytics<T = any> extends Generic {
+export interface MlStopDataFrameAnalytics<T = RequestBody> extends Generic {
  id: string;
  allow_no_match?: boolean;
  force?: boolean;
@ -2052,7 +2054,7 @@ export interface MlStopDatafeed extends Generic {
  timeout?: string;
 }

-export interface MlUpdateDatafeed<T = any> extends Generic {
+export interface MlUpdateDatafeed<T = RequestBody> extends Generic {
  datafeed_id: string;
  ignore_unavailable?: boolean;
  allow_no_indices?: boolean;
@ -2061,31 +2063,31 @@ export interface MlUpdateDatafeed<T = any> extends Generic {
  body: T;
 }

-export interface MlUpdateFilter<T = any> extends Generic {
+export interface MlUpdateFilter<T = RequestBody> extends Generic {
  filter_id: string;
  body: T;
 }

-export interface MlUpdateJob<T = any> extends Generic {
+export interface MlUpdateJob<T = RequestBody> extends Generic {
  job_id: string;
  body: T;
 }

-export interface MlUpdateModelSnapshot<T = any> extends Generic {
+export interface MlUpdateModelSnapshot<T = RequestBody> extends Generic {
  job_id: string;
  snapshot_id: string;
  body: T;
 }

-export interface MlValidate<T = any> extends Generic {
+export interface MlValidate<T = RequestBody> extends Generic {
  body: T;
 }

-export interface MlValidateDetector<T = any> extends Generic {
+export interface MlValidateDetector<T = RequestBody> extends Generic {
  body: T;
 }

-export interface MonitoringBulk<T = any> extends Generic {
+export interface MonitoringBulk<T = RequestNDBody> extends Generic {
  type?: string;
  system_id?: string;
  system_api_version?: string;
@ -2109,12 +2111,12 @@ export interface RollupGetRollupIndexCaps extends Generic {
  index: string;
 }

-export interface RollupPutJob<T = any> extends Generic {
+export interface RollupPutJob<T = RequestBody> extends Generic {
  id: string;
  body: T;
 }

-export interface RollupRollupSearch<T = any> extends Generic {
+export interface RollupRollupSearch<T = RequestBody> extends Generic {
  index: string | string[];
  type?: string;
  typed_keys?: boolean;
@ -2135,7 +2137,7 @@ export interface RollupStopJob extends Generic {
 export interface SecurityAuthenticate extends Generic {
 }

-export interface SecurityChangePassword<T = any> extends Generic {
+export interface SecurityChangePassword<T = RequestBody> extends Generic {
  username?: string;
  refresh?: 'true' | 'false' | 'wait_for';
  body: T;
@ -2150,7 +2152,7 @@ export interface SecurityClearCachedRoles extends Generic {
  name: string | string[];
 }

-export interface SecurityCreateApiKey<T = any> extends Generic {
+export interface SecurityCreateApiKey<T = RequestBody> extends Generic {
  refresh?: 'true' | 'false' | 'wait_for';
  body: T;
 }
@ -2210,7 +2212,7 @@ export interface SecurityGetRoleMapping extends Generic {
  name?: string;
 }

-export interface SecurityGetToken<T = any> extends Generic {
+export interface SecurityGetToken<T = RequestBody> extends Generic {
  body: T;
 }

@ -2221,37 +2223,37 @@ export interface SecurityGetUser extends Generic {
 export interface SecurityGetUserPrivileges extends Generic {
 }

-export interface SecurityHasPrivileges<T = any> extends Generic {
+export interface SecurityHasPrivileges<T = RequestBody> extends Generic {
  user?: string;
  body: T;
 }

-export interface SecurityInvalidateApiKey<T = any> extends Generic {
+export interface SecurityInvalidateApiKey<T = RequestBody> extends Generic {
  body: T;
 }

-export interface SecurityInvalidateToken<T = any> extends Generic {
+export interface SecurityInvalidateToken<T = RequestBody> extends Generic {
  body: T;
 }

-export interface SecurityPutPrivileges<T = any> extends Generic {
+export interface SecurityPutPrivileges<T = RequestBody> extends Generic {
  refresh?: 'true' | 'false' | 'wait_for';
  body: T;
 }

-export interface SecurityPutRole<T = any> extends Generic {
+export interface SecurityPutRole<T = RequestBody> extends Generic {
  name: string;
  refresh?: 'true' | 'false' | 'wait_for';
  body: T;
 }

-export interface SecurityPutRoleMapping<T = any> extends Generic {
+export interface SecurityPutRoleMapping<T = RequestBody> extends Generic {
  name: string;
  refresh?: 'true' | 'false' | 'wait_for';
  body: T;
 }

-export interface SecurityPutUser<T = any> extends Generic {
+export interface SecurityPutUser<T = RequestBody> extends Generic {
  username: string;
  refresh?: 'true' | 'false' | 'wait_for';
  body: T;
@ -2278,7 +2280,7 @@ export interface SlmGetStats extends Generic {
 export interface SlmGetStatus extends Generic {
 }

-export interface SlmPutLifecycle<T = any> extends Generic {
+export interface SlmPutLifecycle<T = RequestBody> extends Generic {
  policy_id: string;
  body?: T;
 }
@ -2289,16 +2291,16 @@ export interface SlmStart extends Generic {
 export interface SlmStop extends Generic {
 }

-export interface SqlClearCursor<T = any> extends Generic {
+export interface SqlClearCursor<T = RequestBody> extends Generic {
  body: T;
 }

-export interface SqlQuery<T = any> extends Generic {
+export interface SqlQuery<T = RequestBody> extends Generic {
  format?: string;
  body: T;
 }

-export interface SqlTranslate<T = any> extends Generic {
+export interface SqlTranslate<T = RequestBody> extends Generic {
  body: T;
 }

@ -2337,11 +2339,11 @@ export interface TransformGetTransformStats extends Generic {
  allow_no_match?: boolean;
 }

-export interface TransformPreviewTransform<T = any> extends Generic {
+export interface TransformPreviewTransform<T = RequestBody> extends Generic {
  body: T;
 }

-export interface TransformPutTransform<T = any> extends Generic {
+export interface TransformPutTransform<T = RequestBody> extends Generic {
  transform_id: string;
  defer_validation?: boolean;
  body: T;
@ -2361,7 +2363,7 @@ export interface TransformStopTransform extends Generic {
  wait_for_checkpoint?: boolean;
 }

-export interface TransformUpdateTransform<T = any> extends Generic {
+export interface TransformUpdateTransform<T = RequestBody> extends Generic {
  transform_id: string;
  defer_validation?: boolean;
  body: T;
@ -2384,7 +2386,7 @@ export interface WatcherDeleteWatch extends Generic {
  id: string;
 }

-export interface WatcherExecuteWatch<T = any> extends Generic {
+export interface WatcherExecuteWatch<T = RequestBody> extends Generic {
  id?: string;
  debug?: boolean;
  body?: T;
@ -2394,7 +2396,7 @@ export interface WatcherGetWatch extends Generic {
  id: string;
 }

-export interface WatcherPutWatch<T = any> extends Generic {
+export interface WatcherPutWatch<T = RequestBody> extends Generic {
  id: string;
  active?: boolean;
  version?: number;
--- a/docs/typescript.asciidoc
+++ b/docs/typescript.asciidoc
@ -13,7 +13,14 @@ request for instance, you can access them via `RequestParams.Search`.
 Every API that supports a body, accepts a 
 https://www.typescriptlang.org/docs/handbook/generics.html[generics] which 
 represents the type of the request body, if you don't configure anything, it 
-will default to `any`.
+will default to `RequestBody`. +
+`RequestBody`, along with `RequestNDBody` and `ResponseBody` are defined inside the client, and it looks like this:
+[source,ts]
+----
+type RequestBody<T = Record<string, any>> = T | string | Buffer | ReadableStream
+type RequestNDBody<T = Record<string, any>[]> = T | string[] | Buffer | ReadableStream
+type ResponseBody<T = Record<string, any>> = T | string | boolean | ReadableStream
+----

 For example:

@ -49,7 +56,7 @@ const searchParams: RequestParams.Search = {

 You can find the type definiton of a response in `ApiResponse`, which accepts a 
 generics as well if you want to specify the body type, otherwise it defaults to 
-`any`.
+`BodyType`.

 [source,ts]
 ----
@ -137,19 +144,43 @@ interface Source {
  foo: string
 }

-async function run (): Promise<void> {
-  // Define the search parameters
-  const searchParams: RequestParams.Search<SearchBody> = {
+async function run () {
+  // All of the examples below are valid code, by default,
+  // the request body will be `RequestBody` and response will be `ResponseBody`.
+  const response = await client.search({
    index: 'test',
    body: {
      query: {
        match: { foo: 'bar' }
      }
    }
-  }
+  })
+  // body here is `ResponseBody`
+  console.log(response.body)

-  // Craft the final type definition
-  const response: ApiResponse<SearchResponse<Source>> = await client.search(searchParams)
+  // The first generic is the request body
+  const response = await client.search<SearchBody>({
+    index: 'test',
+    // Here the body must follow the `SearchBody` interface
+    body: {
+      query: {
+        match: { foo: 'bar' }
+      }
+    }
+  })
+  // body here is `ResponseBody`
+  console.log(response.body)
+
+  const response = await client.search<SearchBody, SearchResponse<Source>>({
+    index: 'test',
+    // Here the body must follow the `SearchBody` interface
+    body: {
+      query: {
+        match: { foo: 'bar' }
+      }
+    }
+  })
+  // Now you can have full type definition of the response
  console.log(response.body)
 }

--- a/index.d.ts
+++ b/index.d.ts
--- a/lib/Connection.d.ts
+++ b/lib/Connection.d.ts
@ -5,10 +5,11 @@
 /// <reference types="node" />

 import { URL } from 'url';
-import { inspect, InspectOptions } from 'util';
+import { inspect, InspectOptions } from 'util'
+import { Readable as ReadableStream } from 'stream';
 import { ApiKeyAuth, BasicAuth } from './pool'
-import * as http from 'http';
-import { ConnectionOptions as TlsConnectionOptions } from 'tls';
+import * as http from 'http'
+import { ConnectionOptions as TlsConnectionOptions } from 'tls'

 export declare type agentFn = () => any;

@ -16,24 +17,31 @@ interface ConnectionOptions {
  url: URL;
  ssl?: TlsConnectionOptions;
  id?: string;
-  headers?: any;
+  headers?: Record<string, any>;
  agent?: AgentOptions | agentFn;
  status?: string;
-  roles?: any;
+  roles?: ConnectionRoles;
  auth?: BasicAuth | ApiKeyAuth;
 }

+interface ConnectionRoles {
+  master?: boolean
+  data?: boolean
+  ingest?: boolean
+  ml?: boolean
+}
+
 interface RequestOptions extends http.ClientRequestArgs {
  asStream?: boolean;
-  body?: any;
+  body?: string | Buffer | ReadableStream;
  querystring?: string;
 }

 export interface AgentOptions {
-  keepAlive: boolean;
-  keepAliveMsecs: number;
-  maxSockets: number;
-  maxFreeSockets: number;
+  keepAlive?: boolean;
+  keepAliveMsecs?: number;
+  maxSockets?: number;
+  maxFreeSockets?: number;
 }

 export default class Connection {
@ -47,27 +55,26 @@ export default class Connection {
    INGEST: string;
    ML: string;
  };
-  url: URL;
-  ssl: TlsConnectionOptions | null;
-  id: string;
-  headers: any;
-  deadCount: number;
-  resurrectTimeout: number;
-  statuses: any;
-  roles: any;
-  makeRequest: any;
-  _openRequests: number;
-  _status: string;
-  _agent: http.Agent;
-  constructor(opts?: ConnectionOptions);
-  request(params: RequestOptions, callback: (err: Error | null, response: http.IncomingMessage | null) => void): http.ClientRequest;
-  close(): Connection;
-  setRole(role: string, enabled: boolean): Connection;
-  status: string;
-  buildRequestObject(params: any): http.ClientRequestArgs;
+  url: URL
+  ssl: TlsConnectionOptions | null
+  id: string
+  headers: Record<string, any>
+  status: string
+  roles: ConnectionRoles
+  deadCount: number
+  resurrectTimeout: number
+  makeRequest: any
+  _openRequests: number
+  _status: string
+  _agent: http.Agent
+  constructor(opts?: ConnectionOptions)
+  request(params: RequestOptions, callback: (err: Error | null, response: http.IncomingMessage | null) => void): http.ClientRequest
+  close(): Connection
+  setRole(role: string, enabled: boolean): Connection
+  buildRequestObject(params: any): http.ClientRequestArgs
  // @ts-ignore
-  [inspect.custom](object: any, options: InspectOptions): string;
-  toJSON(): any;
+  [inspect.custom](object: any, options: InspectOptions): string
+  toJSON(): any
 }

 export {};
--- a/lib/Transport.d.ts
+++ b/lib/Transport.d.ts
@ -2,9 +2,16 @@
 // Elasticsearch B.V licenses this file to you under the Apache 2.0 License.
 // See the LICENSE file in the project root for more information

+import { Readable as ReadableStream } from 'stream';
 import { ConnectionPool, CloudConnectionPool } from './pool';
 import Connection from './Connection';
 import Serializer from './Serializer';
+import * as errors from './errors';
+
+export type ApiError = errors.ConfigurationError | errors.ConnectionError |
+                       errors.DeserializationError | errors.SerializationError |
+                       errors.NoLivingConnectionsError | errors.ResponseError |
+                       errors.TimeoutError

 export interface nodeSelectorFn {
  (connections: Connection[]): Connection;
@ -18,36 +25,33 @@ export interface generateRequestIdFn {
  (params: TransportRequestParams, options: TransportRequestOptions): any;
 }

-declare type noopFn = (...args: any[]) => void;
-declare type emitFn = (event: string | symbol, ...args: any[]) => boolean;
-
 interface TransportOptions {
-  emit: emitFn & noopFn;
+  emit: (event: string | symbol, ...args: any[]) => boolean;
  connectionPool: ConnectionPool | CloudConnectionPool;
  serializer: Serializer;
  maxRetries: number;
  requestTimeout: number | string;
-  suggestCompression: boolean;
+  suggestCompression?: boolean;
  compression?: 'gzip';
-  sniffInterval: number;
-  sniffOnConnectionFault: boolean;
+  sniffInterval?: number;
+  sniffOnConnectionFault?: boolean;
  sniffEndpoint: string;
-  sniffOnStart: boolean;
+  sniffOnStart?: boolean;
  nodeFilter?: nodeFilterFn;
  nodeSelector?: string | nodeSelectorFn;
-  headers?: anyObject;
+  headers?: Record<string, any>;
  generateRequestId?: generateRequestIdFn;
-  name: string;
+  name?: string;
  opaqueIdPrefix?: string;
 }

-export interface RequestEvent<T = any, C = any> {
-  body: T;
+export interface RequestEvent<TResponse = ResponseBody, TContext = unknown> {
+  body: TResponse;
  statusCode: number | null;
-  headers: anyObject | null;
+  headers: Record<string, any> | null;
  warnings: string[] | null;
  meta: {
-    context: C;
+    context: TContext;
    name: string;
    request: {
      params: TransportRequestParams;
@ -66,18 +70,18 @@ export interface RequestEvent<T = any, C = any> {

 // ApiResponse and RequestEvent are the same thing
 // we are doing this for have more clear names
-export interface ApiResponse<T = any, C = any> extends RequestEvent<T, C> {}
+export interface ApiResponse<TResponse = ResponseBody, TContext = unknown> extends RequestEvent<TResponse, TContext> {}

-declare type anyObject = {
-  [key: string]: any;
-};
+export type RequestBody<T = Record<string, any>> = T | string | Buffer | ReadableStream
+export type RequestNDBody<T = Record<string, any>[]> = T | string[] | Buffer | ReadableStream
+export type ResponseBody<T = Record<string, any>> = T | string | boolean | ReadableStream

 export interface TransportRequestParams {
  method: string;
  path: string;
-  body?: anyObject;
-  bulkBody?: anyObject;
-  querystring?: anyObject;
+  body?: RequestBody;
+  bulkBody?: RequestNDBody;
+  querystring?: Record<string, any>;
 }

 export interface TransportRequestOptions {
@ -85,12 +89,12 @@ export interface TransportRequestOptions {
  requestTimeout?: number | string;
  maxRetries?: number;
  asStream?: boolean;
-  headers?: anyObject;
-  querystring?: anyObject;
-  compression?: string;
+  headers?: Record<string, any>;
+  querystring?: Record<string, any>;
+  compression?: 'gzip';
  id?: any;
  context?: any;
-  warnings?: [string];
+  warnings?: string[];
  opaqueId?: string;
 }

@ -114,7 +118,7 @@ export default class Transport {
    SNIFF_ON_CONNECTION_FAULT: string;
    DEFAULT: string;
  };
-  emit: emitFn & noopFn;
+  emit: (event: string | symbol, ...args: any[]) => boolean;
  connectionPool: ConnectionPool | CloudConnectionPool;
  serializer: Serializer;
  maxRetries: number;
@ -130,9 +134,7 @@ export default class Transport {
  _isSniffing: boolean;
  constructor(opts: TransportOptions);
  request(params: TransportRequestParams, options?: TransportRequestOptions): Promise<ApiResponse>;
-  request(params: TransportRequestParams, options?: TransportRequestOptions, callback?: (err: Error | null, result: ApiResponse) => void): TransportRequestCallback;
+  request(params: TransportRequestParams, options?: TransportRequestOptions, callback?: (err: ApiError, result: ApiResponse) => void): TransportRequestCallback;
  getConnection(opts: TransportGetConnectionOptions): Connection | null;
  sniff(opts?: TransportSniffOptions, callback?: (...args: any[]) => void): void;
 }
-
-export {};
--- a/lib/errors.d.ts
+++ b/lib/errors.d.ts
@ -2,7 +2,7 @@
 // Elasticsearch B.V licenses this file to you under the Apache 2.0 License.
 // See the LICENSE file in the project root for more information

-import { ApiResponse } from './Transport'
+import { ApiResponse, ResponseBody } from './Transport'

 export declare class ElasticsearchClientError extends Error {
  name: string;
@ -33,8 +33,8 @@ export declare class NoLivingConnectionsError extends ElasticsearchClientError {
 export declare class SerializationError extends ElasticsearchClientError {
  name: string;
  message: string;
-  data: object;
-  constructor(message: string, data: object);
+  data: any;
+  constructor(message: string, data: any);
 }

 export declare class DeserializationError extends ElasticsearchClientError {
@ -54,8 +54,8 @@ export declare class ResponseError extends ElasticsearchClientError {
  name: string;
  message: string;
  meta: ApiResponse;
-  body: any;
+  body: ResponseBody;
  statusCode: number;
-  headers: any;
+  headers: Record<string, any>;
  constructor(meta: ApiResponse);
 }
--- a/lib/pool/index.d.ts
+++ b/lib/pool/index.d.ts
@ -4,6 +4,7 @@

 /// <reference types="node" />

+import { URL } from 'url'
 import { SecureContextOptions } from 'tls';
 import Connection, { AgentOptions } from '../Connection';
 import { nodeFilterFn, nodeSelectorFn } from '../Transport';
@ -13,14 +14,12 @@ interface BaseConnectionPoolOptions {
  agent?: AgentOptions;
  auth?: BasicAuth | ApiKeyAuth;
  emit: (event: string | symbol, ...args: any[]) => boolean;
-  pingTimeout?: number;
  Connection: typeof Connection;
-  resurrectStrategy?: string;
 }

 interface ConnectionPoolOptions extends BaseConnectionPoolOptions {
  pingTimeout?: number;
-  resurrectStrategy?: string;
+  resurrectStrategy?: 'ping' | 'optimistic' | 'none';
  sniffEnabled?: boolean;
 }

@ -65,6 +64,8 @@ interface ResurrectEvent {

 declare class BaseConnectionPool {
  connections: Connection[];
+  size: number;
+  emit: (event: string | symbol, ...args: any[]) => boolean;
  _ssl: SecureContextOptions | null;
  _agent: AgentOptions | null;
  auth: BasicAuth | ApiKeyAuth;
@ -137,7 +138,7 @@ declare class BaseConnectionPool {
   * @param {string} url
   * @returns {object} host
   */
-  urlToHost(url: string): any;
+  urlToHost(url: string): { url: URL };
 }

 declare class ConnectionPool extends BaseConnectionPool {
@ -167,7 +168,7 @@ declare class ConnectionPool extends BaseConnectionPool {
 declare class CloudConnectionPool extends BaseConnectionPool {
  cloudConnection: Connection | null
  constructor(opts?: BaseConnectionPoolOptions);
-  getConnection(): Connection;
+  getConnection(): Connection | null;
 }

 declare function defaultNodeFilter(node: Connection): boolean;
--- a/package.json
+++ b/package.json
@ -20,7 +20,7 @@
    "test:unit": "tap test/unit/*.test.js -t 300 --no-coverage",
    "test:behavior": "tap test/behavior/*.test.js -t 300 --no-coverage",
    "test:integration": "node test/integration/index.js",
-    "test:types": "tsc --project ./test/types/tsconfig.json",
+    "test:types": "tsd",
    "test:coverage": "nyc tap test/unit/*.test.js test/behavior/*.test.js -t 300 && nyc report --reporter=text-lcov > coverage.lcov",
    "lint": "standard",
    "lint:fix": "standard --fix",
@ -58,7 +58,7 @@
    "standard": "^13.0.2",
    "stoppable": "^1.1.0",
    "tap": "^14.4.1",
-    "typescript": "^3.4.5",
+    "tsd": "^0.11.0",
    "workq": "^2.1.0"
  },
  "dependencies": {
@ -80,5 +80,8 @@
  },
  "engines": {
    "node": ">=8"
+  },
+  "tsd": {
+    "directory": "test/types"
  }
 }
--- a/scripts/generate.js
+++ b/scripts/generate.js
@ -58,7 +58,7 @@ function start (opts) {
      { encoding: 'utf8' }
    )

-    const { fn: factory, types } = genFactory(apiOutputFolder)
+    const { fn: factory, types } = genFactory(apiOutputFolder, [apiFolder, xPackFolder])
    writeFileSync(
      mainOutputFile,
      factory,
--- a/scripts/utils/generateApis.js
+++ b/scripts/utils/generateApis.js
@ -543,3 +543,4 @@ function intersect (first, ...rest) {
 }

 module.exports = generate
+module.exports.ndjsonApi = ndjsonApi
--- a/scripts/utils/generateMain.js
+++ b/scripts/utils/generateMain.js
@ -7,10 +7,20 @@
 'use strict'

 const { readdirSync } = require('fs')
+const { join } = require('path')
 const dedent = require('dedent')
 const deepmerge = require('deepmerge')
+const { ndjsonApi } = require('./generateApis')

-function genFactory (folder) {
+const ndjsonApiKey = ndjsonApi
+  .map(api => {
+    return api
+      .replace(/\.([a-z])/g, k => k[1].toUpperCase())
+      .replace(/_([a-z])/g, k => k[1].toUpperCase())
+  })
+  .map(toPascalCase)
+
+function genFactory (folder, paths) {
  // get all the API files
  const apiFiles = readdirSync(folder)
  const types = apiFiles
@ -25,15 +35,18 @@ function genFactory (folder) {
        .split('.')
        .reverse()
        .reduce((acc, val) => {
-          const obj = {
-            [val]: acc === null
-              ? `ApiMethod<RequestParams.${name[0].toUpperCase() + name.slice(1)}>`
-              : acc
+          const body = hasBody(paths, file.slice(0, -3))
+          const methods = acc === null ? buildMethodDefinition(val, name, body) : null
+          const obj = {}
+          if (methods) {
+            for (const m of methods) {
+              obj[m.key] = m.val
            }
+          } else {
+            obj[val] = acc
            if (isSnakeCased(val)) {
-            obj[camelify(val)] = acc === null
-              ? `ApiMethod<RequestParams.${name[0].toUpperCase() + name.slice(1)}>`
-              : acc
+              obj[camelify(val)] = acc
+            }
          }
          return obj
        }, null)
@ -83,7 +96,7 @@ function genFactory (folder) {
    .join('\n')
    // remove useless quotes and commas
    .replace(/"/g, '')
-    .replace(/,/g, '')
+    .replace(/,$/gm, '')

  const fn = dedent`
  // Licensed to Elasticsearch B.V under one or more agreements.
@ -160,4 +173,64 @@ function isSnakeCased (str) {
  return !!~str.indexOf('_')
 }

+function toPascalCase (str) {
+  return str[0].toUpperCase() + str.slice(1)
+}
+
+function buildMethodDefinition (api, name, hasBody) {
+  const Name = toPascalCase(name)
+  const bodyType = ndjsonApiKey.includes(Name) ? 'RequestNDBody' : 'RequestBody'
+
+  if (hasBody) {
+    let methods = [
+      { key: `${api}<TRequestBody extends ${bodyType}, TResponse = ResponseBody, TContext = unknown>(params?: RequestParams.${Name}<TRequestBody>, options?: TransportRequestOptions)`, val: `Promise<ApiResponse<TResponse, TContext>>` },
+      { key: `${api}<TRequestBody extends ${bodyType}, TResponse = ResponseBody, TContext = unknown>(callback: callbackFn<TResponse, TContext>)`, val: `TransportRequestCallback` },
+      { key: `${api}<TRequestBody extends ${bodyType}, TResponse = ResponseBody, TContext = unknown>(params: RequestParams.${Name}<TRequestBody>, callback: callbackFn<TResponse, TContext>)`, val: `TransportRequestCallback` },
+      { key: `${api}<TRequestBody extends ${bodyType}, TResponse = ResponseBody, TContext = unknown>(params: RequestParams.${Name}<TRequestBody>, options: TransportRequestOptions, callback: callbackFn<TResponse, TContext>)`, val: `TransportRequestCallback` }
+    ]
+    if (isSnakeCased(api)) {
+      methods = methods.concat([
+        { key: `${camelify(api)}<TRequestBody extends ${bodyType}, TResponse = ResponseBody, TContext = unknown>(params?: RequestParams.${Name}<TRequestBody>, options?: TransportRequestOptions)`, val: `Promise<ApiResponse<TResponse, TContext>>` },
+        { key: `${camelify(api)}<TRequestBody extends ${bodyType}, TResponse = ResponseBody, TContext = unknown>(callback: callbackFn<TResponse, TContext>)`, val: `TransportRequestCallback` },
+        { key: `${camelify(api)}<TRequestBody extends ${bodyType}, TResponse = ResponseBody, TContext = unknown>(params: RequestParams.${Name}<TRequestBody>, callback: callbackFn<TResponse, TContext>)`, val: `TransportRequestCallback` },
+        { key: `${camelify(api)}<TRequestBody extends ${bodyType}, TResponse = ResponseBody, TContext = unknown>(params: RequestParams.${Name}<TRequestBody>, options: TransportRequestOptions, callback: callbackFn<TResponse, TContext>)`, val: `TransportRequestCallback` }
+      ])
+    }
+    return methods
+  } else {
+    let methods = [
+      { key: `${api}<TResponse = ResponseBody, TContext = unknown>(params?: RequestParams.${Name}, options?: TransportRequestOptions)`, val: `Promise<ApiResponse<TResponse, TContext>>` },
+      { key: `${api}<TResponse = ResponseBody, TContext = unknown>(callback: callbackFn<TResponse, TContext>)`, val: `TransportRequestCallback` },
+      { key: `${api}<TResponse = ResponseBody, TContext = unknown>(params: RequestParams.${Name}, callback: callbackFn<TResponse, TContext>)`, val: `TransportRequestCallback` },
+      { key: `${api}<TResponse = ResponseBody, TContext = unknown>(params: RequestParams.${Name}, options: TransportRequestOptions, callback: callbackFn<TResponse, TContext>)`, val: `TransportRequestCallback` }
+    ]
+    if (isSnakeCased(api)) {
+      methods = methods.concat([
+        { key: `${camelify(api)}<TResponse = ResponseBody, TContext = unknown>(params?: RequestParams.${Name}, options?: TransportRequestOptions)`, val: `Promise<ApiResponse<TResponse, TContext>>` },
+        { key: `${camelify(api)}<TResponse = ResponseBody, TContext = unknown>(callback: callbackFn<TResponse, TContext>)`, val: `TransportRequestCallback` },
+        { key: `${camelify(api)}<TResponse = ResponseBody, TContext = unknown>(params: RequestParams.${Name}, callback: callbackFn<TResponse, TContext>)`, val: `TransportRequestCallback` },
+        { key: `${camelify(api)}<TResponse = ResponseBody, TContext = unknown>(params: RequestParams.${Name}, options: TransportRequestOptions, callback: callbackFn<TResponse, TContext>)`, val: `TransportRequestCallback` }
+      ])
+    }
+    return methods
+  }
+}
+
+function hasBody (paths, file) {
+  const spec = readSpec()
+  return !!spec[file].body
+
+  function readSpec () {
+    try {
+      return require(join(paths[0], file))
+    } catch (err) {}
+
+    try {
+      return require(join(paths[1], file))
+    } catch (err) {}
+
+    throw new Error(`Cannot read spec file ${file}`)
+  }
+}
+
 module.exports = genFactory
--- a/scripts/utils/generateRequestTypes.js
+++ b/scripts/utils/generateRequestTypes.js
@ -6,6 +6,15 @@

 const semver = require('semver')
 const deprecatedParameters = require('./patch.json')
+const { ndjsonApi } = require('./generateApis')
+
+const ndjsonApiKey = ndjsonApi
+  .map(api => {
+    return api
+      .replace(/\.([a-z])/g, k => k[1].toUpperCase())
+      .replace(/_([a-z])/g, k => k[1].toUpperCase())
+  })
+  .map(toPascalCase)

 function generate (version, api) {
  const release = semver.valid(version) ? semver.major(version) : version
@ -13,6 +22,8 @@ function generate (version, api) {
 // Elasticsearch B.V licenses this file to you under the Apache 2.0 License.
 // See the LICENSE file in the project root for more information

+import { RequestBody, RequestNDBody } from '../lib/Transport'
+
 export interface Generic {
  method?: string;
  ignore?: number | number[];
@ -83,8 +94,10 @@ export interface Generic {
      return `${e.key}${optional}: ${getType(e.value.type, e.value.options)};`
    }

+    const bodyGeneric = ndjsonApiKey.includes(toPascalCase(name)) ? 'RequestNDBody' : 'RequestBody'
+
    const code = `
-export interface ${name[0].toUpperCase() + name.slice(1)}${body ? '<T = any>' : ''} extends Generic {
+export interface ${toPascalCase(name)}${body ? `<T = ${bodyGeneric}>` : ''} extends Generic {
  ${partsArr.map(genLine).join('\n  ')}
  ${paramsArr.map(genLine).join('\n  ')}
  ${body ? `body${body.required ? '' : '?'}: T;` : ''}
@ -122,4 +135,8 @@ function intersect (first, ...rest) {
  }, first)
 }

+function toPascalCase (str) {
+  return str[0].toUpperCase() + str.slice(1)
+}
+
 module.exports = generate
--- a/test/types/api-response-body.test-d.ts
+++ b/test/types/api-response-body.test-d.ts
@ -0,0 +1,128 @@
+// Licensed to Elasticsearch B.V under one or more agreements.
+// Elasticsearch B.V licenses this file to you under the Apache 2.0 License.
+// See the LICENSE file in the project root for more information
+
+import { expectType, expectError } from 'tsd'
+import { ResponseBody } from '../../lib/Transport'
+import { Client } from '../../'
+
+const client = new Client({
+  node: 'http://localhost:9200'
+})
+
+interface SearchBody {
+  query: {
+    match: { foo: string }
+  }
+}
+
+interface ShardsResponse {
+  total: number;
+  successful: number;
+  failed: number;
+  skipped: number;
+}
+
+interface Explanation {
+  value: number;
+  description: string;
+  details: Explanation[];
+}
+
+interface SearchResponse<T> {
+  took: number;
+  timed_out: boolean;
+  _scroll_id?: string;
+  _shards: ShardsResponse;
+  hits: {
+    total: number;
+    max_score: number;
+    hits: Array<{
+      _index: string;
+      _type: string;
+      _id: string;
+      _score: number;
+      _source: T;
+      _version?: number;
+      _explanation?: Explanation;
+      fields?: any;
+      highlight?: any;
+      inner_hits?: any;
+      matched_queries?: string[];
+      sort?: string[];
+    }>;
+  };
+  aggregations?: any;
+}
+
+interface Source {
+  foo: string
+}
+
+// Use a bad body
+expectError(
+  client.search({
+    index: 'hello',
+    body: 42
+  }).then(console.log)
+)
+
+// No generics
+{
+  const response = await client.search({
+    index: 'test',
+    body: {
+      query: {
+        match: { foo: 'bar' }
+      }
+    }
+  })
+
+  expectType<ResponseBody>(response.body)
+  expectType<unknown>(response.meta.context)
+}
+
+// Define only the request body
+{
+  const response = await client.search<SearchBody>({
+    index: 'test',
+    body: {
+      query: {
+        match: { foo: 'bar' }
+      }
+    }
+  })
+
+  expectType<ResponseBody>(response.body)
+  expectType<unknown>(response.meta.context)
+}
+
+// Define request body and response body
+{
+  const response = await client.search<SearchBody, SearchResponse<Source>>({
+    index: 'test',
+    body: {
+      query: {
+        match: { foo: 'bar' }
+      }
+    }
+  })
+
+  expectType<SearchResponse<Source>>(response.body)
+  expectType<unknown>(response.meta.context)
+}
+
+// Define request body, response body and the context
+{
+  const response = await client.search<SearchBody, SearchResponse<Source>, string>({
+    index: 'test',
+    body: {
+      query: {
+        match: { foo: 'bar' }
+      }
+    }
+  })
+
+  expectType<SearchResponse<Source>>(response.body)
+  expectType<string>(response.meta.context)
+}
--- a/test/types/api-response.test-d.ts
+++ b/test/types/api-response.test-d.ts
@ -0,0 +1,35 @@
+// Licensed to Elasticsearch B.V under one or more agreements.
+// Elasticsearch B.V licenses this file to you under the Apache 2.0 License.
+// See the LICENSE file in the project root for more information
+
+import { expectType } from 'tsd'
+import { ResponseBody } from '../../lib/Transport'
+import { Client } from '../../'
+
+const client = new Client({
+  node: 'http://localhost:9200'
+})
+
+// No generics
+{
+  const response = await client.cat.count({ index: 'test' })
+
+  expectType<ResponseBody>(response.body)
+  expectType<unknown>(response.meta.context)
+}
+
+// Define only the request body
+{
+  const response = await client.cat.count<string>({ index: 'test' })
+
+  expectType<string>(response.body)
+  expectType<unknown>(response.meta.context)
+}
+
+// Define request body and  the context
+{
+  const response = await client.cat.count<string, string>({ index: 'test' })
+
+  expectType<string>(response.body)
+  expectType<string>(response.meta.context)
+}
--- a/test/types/client-options.test-d.ts
+++ b/test/types/client-options.test-d.ts
@ -0,0 +1,618 @@
+// Licensed to Elasticsearch B.V under one or more agreements.
+// Elasticsearch B.V licenses this file to you under the Apache 2.0 License.
+// See the LICENSE file in the project root for more information
+
+import { URL } from 'url'
+import { expectType, expectError } from 'tsd'
+import { TransportGetConnectionOptions } from '../../lib/Transport'
+import {
+  Client,
+  Serializer,
+  Connection,
+  ConnectionPool,
+  Transport,
+  errors
+} from '../../'
+
+/**
+ * `node` option
+ */
+expectType<Client>(
+  new Client({
+    node: 'http://localhost:9200'
+  })
+)
+
+expectType<Client>(
+  new Client({
+    nodes: ['http://localhost:9200', 'http://localhost:9200']
+  })
+)
+
+expectType<Client>(
+  new Client({
+    node: {
+      url: new URL('http://localhost:9200'),
+      id: 'my-node'
+    }
+  })
+)
+
+expectType<Client>(
+  new Client({
+    nodes: [{
+      url: new URL('http://localhost:9200'),
+      id: 'my-node-1'
+    }, {
+      url: new URL('http://localhost:9201'),
+      id: 'my-node-2'
+    }]
+  })
+)
+
+expectError<errors.ConfigurationError>(
+  new Client({
+    node: 42
+  })
+)
+
+expectError<errors.ConfigurationError>(
+  new Client({
+    node: {
+      url: 'http://localhost:9200',
+      id: 'my-node'
+    }
+  })
+)
+
+/**
+ * `maxRetries` option
+ */
+expectType<Client>(
+  new Client({
+    node: 'http://localhost:9200',
+    maxRetries: 5
+  })
+)
+
+expectError<errors.ConfigurationError>(
+  new Client({
+    node: 'http://localhost:9200',
+    maxRetries: 'five'
+  })
+)
+
+/**
+ * `requestTimeout` option
+ */
+expectType<Client>(
+  new Client({
+    node: 'http://localhost:9200',
+    requestTimeout: 5
+  })
+)
+
+expectError<errors.ConfigurationError>(
+  new Client({
+    node: 'http://localhost:9200',
+    requestTimeout: 'five'
+  })
+)
+
+/**
+ * `pingTimeout` option
+ */
+expectType<Client>(
+  new Client({
+    node: 'http://localhost:9200',
+    pingTimeout: 5
+  })
+)
+
+expectError<errors.ConfigurationError>(
+  new Client({
+    node: 'http://localhost:9200',
+    pingTimeout: 'five'
+  })
+)
+
+/**
+ * `sniffInterval` option
+ */
+expectType<Client>(
+  new Client({
+    node: 'http://localhost:9200',
+    sniffInterval: 5
+  })
+)
+
+expectType<Client>(
+  new Client({
+    node: 'http://localhost:9200',
+    sniffInterval: false
+  })
+)
+
+expectError<errors.ConfigurationError>(
+  new Client({
+    node: 'http://localhost:9200',
+    sniffInterval: 'five'
+  })
+)
+
+/**
+ * `sniffOnStart` option
+ */
+expectType<Client>(
+  new Client({
+    node: 'http://localhost:9200',
+    sniffOnStart: true
+  })
+)
+
+expectError<errors.ConfigurationError>(
+  new Client({
+    node: 'http://localhost:9200',
+    sniffOnStart: 'no'
+  })
+)
+
+/**
+ * `sniffEndpoint` option
+ */
+expectType<Client>(
+  new Client({
+    node: 'http://localhost:9200',
+    sniffEndpoint: '/custom'
+  })
+)
+
+expectError<errors.ConfigurationError>(
+  new Client({
+    node: 'http://localhost:9200',
+    sniffEndpoint: false
+  })
+)
+
+/**
+ * `sniffOnConnectionFault` option
+ */
+expectType<Client>(
+  new Client({
+    node: 'http://localhost:9200',
+    sniffOnConnectionFault: true
+  })
+)
+
+expectError<errors.ConfigurationError>(
+  new Client({
+    node: 'http://localhost:9200',
+    sniffOnConnectionFault: 'yes'
+  })
+)
+
+/**
+ * `resurrectStrategy` option
+ */
+expectType<Client>(
+  new Client({
+    node: 'http://localhost:9200',
+    resurrectStrategy: 'ping'
+  })
+)
+
+expectType<Client>(
+  new Client({
+    node: 'http://localhost:9200',
+    resurrectStrategy: 'optimistic'
+  })
+)
+
+expectType<Client>(
+  new Client({
+    node: 'http://localhost:9200',
+    resurrectStrategy: 'none'
+  })
+)
+
+expectError<errors.ConfigurationError>(
+  new Client({
+    node: 'http://localhost:9200',
+    resurrectStrategy: 'custom'
+  })
+)
+
+/**
+ * `suggestCompression` option
+ */
+expectType<Client>(
+  new Client({
+    node: 'http://localhost:9200',
+    suggestCompression: true
+  })
+)
+
+expectError<errors.ConfigurationError>(
+  new Client({
+    node: 'http://localhost:9200',
+    suggestCompression: 'no'
+  })
+)
+
+/**
+ * `compression` option
+ */
+expectType<Client>(
+  new Client({
+    node: 'http://localhost:9200',
+    compression: 'gzip'
+  })
+)
+
+expectError<errors.ConfigurationError>(
+  new Client({
+    node: 'http://localhost:9200',
+    compression: 'deflate'
+  })
+)
+
+/**
+ * `headers` option
+ */
+expectType<Client>(
+  new Client({
+    node: 'http://localhost:9200',
+    headers: { foo: 'bar' }
+  })
+)
+
+expectError<errors.ConfigurationError>(
+  new Client({
+    node: 'http://localhost:9200',
+    headers: 'foo=bar'
+  })
+)
+
+/**
+ * `opaqueIdPrefix` option
+ */
+expectType<Client>(
+  new Client({
+    node: 'http://localhost:9200',
+    opaqueIdPrefix: 'foo-'
+  })
+)
+
+expectError<errors.ConfigurationError>(
+  new Client({
+    node: 'http://localhost:9200',
+    opaqueIdPrefix: 42
+  })
+)
+
+/**
+ * `name` option
+ */
+expectType<Client>(
+  new Client({
+    node: 'http://localhost:9200',
+    name: 'foo'
+  })
+)
+
+expectError<errors.ConfigurationError>(
+  new Client({
+    node: 'http://localhost:9200',
+    name: 42
+  })
+)
+
+/**
+ * `auth` option
+ */
+expectType<Client>(
+  new Client({
+    node: 'http://localhost:9200',
+    auth: {
+      username: 'username',
+      password: 'password'
+    }
+  })
+)
+
+expectType<Client>(
+  new Client({
+    node: 'http://localhost:9200',
+    auth: {
+      apiKey: 'abcd'
+    }
+  })
+)
+
+expectType<Client>(
+  new Client({
+    node: 'http://localhost:9200',
+    auth: {
+      apiKey: {
+        api_key: 'foo',
+        id: 'bar'
+      }
+    }
+  })
+)
+
+expectError<errors.ConfigurationError>(
+  new Client({
+    node: 'http://localhost:9200',
+    auth: 'password'
+  })
+)
+
+/**
+ * `cloud` option
+ */
+expectType<Client>(
+  new Client({
+    cloud: {
+      id: 'localhost:9200'
+    }
+  })
+)
+
+expectError<errors.ConfigurationError>(
+  new Client({
+    cloud: {
+      id: 42
+    }
+  })
+)
+
+/**
+ * `agent` option
+ */
+expectType<Client>(
+  new Client({
+    node: 'http://localhost:9200',
+    agent: {
+      keepAlive: true,
+      keepAliveMsecs: 42,
+      maxSockets: 42,
+      maxFreeSockets: 42
+    }
+  })
+)
+
+expectError<errors.ConfigurationError>(
+  new Client({
+    node: 'http://localhost:9200',
+    agent: {
+      keepAlive: 'yes',
+      keepAliveMsecs: true,
+      maxSockets: 'all',
+      maxFreeSockets: null
+    }
+  })
+)
+
+/**
+ * `ssl` option
+ */
+expectType<Client>(
+  new Client({
+    node: 'http://localhost:9200',
+    ssl: {
+      ca: 'cert',
+      rejectUnauthorized: true
+    }
+  })
+)
+
+expectError<errors.ConfigurationError>(
+  new Client({
+    node: 'http://localhost:9200',
+    ssl: {
+      ca: 42,
+      rejectUnauthorized: 'yes'
+    }
+  })
+)
+
+/**
+ * `generateRequestId` option
+ */
+expectType<Client>(
+  new Client({
+    node: 'http://localhost:9200',
+    generateRequestId (params, options) {
+      return 'id'
+    }
+  })
+)
+
+expectError<errors.ConfigurationError>(
+  new Client({
+    node: 'http://localhost:9200',
+    generateRequestId: 'id'
+  })
+)
+
+/**
+ * `nodeSelector` option
+ */
+expectType<Client>(
+  new Client({
+    node: 'http://localhost:9200',
+    nodeSelector (connections) {
+      return connections[0]
+    }
+  })
+)
+
+expectType<Client>(
+  new Client({
+    node: 'http://localhost:9200',
+    nodeSelector: 'round-robin'
+  })
+)
+
+expectError<errors.ConfigurationError>(
+  new Client({
+    node: 'http://localhost:9200',
+    nodeSelector (connections) {
+      return 'id'
+    }
+  })
+)
+
+/**
+ * `nodeFilter` option
+ */
+expectType<Client>(
+  new Client({
+    node: 'http://localhost:9200',
+    nodeFilter (connection) {
+      return true
+    }
+  })
+)
+
+expectError<errors.ConfigurationError>(
+  new Client({
+    node: 'http://localhost:9200',
+    nodeFilter (connection) {
+      return 'id'
+    }
+  })
+)
+
+/**
+ * `Serializer` option
+ */
+{
+  class CustomSerializer extends Serializer {
+    deserialize (str: string) {
+      return super.deserialize(str)
+    }
+  }
+
+  expectType<Client>(
+    new Client({
+      node: 'http://localhost:9200',
+      Serializer: CustomSerializer
+    })
+  )
+}
+
+{
+  class CustomSerializer {
+    deserialize (str: string) {
+      return JSON.parse(str)
+    }
+  }
+
+  expectError<errors.ConfigurationError>(
+    new Client({
+      node: 'http://localhost:9200',
+      Serializer: CustomSerializer
+    })
+  )
+}
+
+/**
+ * `Connection` option
+ */
+{
+  class CustomConnection extends Connection {
+    close () {
+      return super.close()
+    }
+  }
+
+  expectType<Client>(
+    new Client({
+      node: 'http://localhost:9200',
+      Connection: CustomConnection
+    })
+  )
+}
+
+{
+  class CustomConnection {
+    close () {
+      return Promise.resolve()
+    }
+  }
+
+  expectError<errors.ConfigurationError>(
+    new Client({
+      node: 'http://localhost:9200',
+      Connection: CustomConnection
+    })
+  )
+}
+
+/**
+ * `ConnectionPool` option
+ */
+{
+  class CustomConnectionPool extends ConnectionPool {
+    empty () {
+      return super.empty()
+    }
+  }
+
+  expectType<Client>(
+    new Client({
+      node: 'http://localhost:9200',
+      ConnectionPool: CustomConnectionPool
+    })
+  )
+}
+
+{
+  class CustomConnectionPool {
+    empty () {
+      return this
+    }
+  }
+
+  expectError<errors.ConfigurationError>(
+    new Client({
+      node: 'http://localhost:9200',
+      ConnectionPool: CustomConnectionPool
+    })
+  )
+}
+
+/**
+ * `Transport` option
+ */
+{
+  class CustomTransport extends Transport {
+    getConnection (opts: TransportGetConnectionOptions) {
+      return super.getConnection(opts)
+    }
+  }
+
+  expectType<Client>(
+    new Client({
+      node: 'http://localhost:9200',
+      Transport: CustomTransport
+    })
+  )
+}
+
+{
+  class CustomTransport {
+    getConnection (opts: TransportGetConnectionOptions) {
+      return null
+    }
+  }
+
+  expectError<errors.ConfigurationError>(
+    new Client({
+      node: 'http://localhost:9200',
+      Transport: CustomTransport
+    })
+  )
+}
--- a/test/types/client.test-d.ts
+++ b/test/types/client.test-d.ts
@ -0,0 +1,114 @@
+// Licensed to Elasticsearch B.V under one or more agreements.
+// Elasticsearch B.V licenses this file to you under the Apache 2.0 License.
+// See the LICENSE file in the project root for more information
+
+import { expectType } from 'tsd'
+import { Client, ApiError, ApiResponse, RequestEvent, ResurrectEvent } from '../../'
+import { TransportRequestCallback } from '../..//lib/Transport';
+
+const client = new Client({
+  node: 'http://localhost:9200'
+})
+
+client.on('request', (err, meta) => {
+  expectType<ApiError>(err)
+  expectType<RequestEvent>(meta)
+})
+
+client.on('response', (err, meta) => {
+  expectType<ApiError>(err)
+  expectType<RequestEvent>(meta)
+})
+
+client.on('sniff', (err, meta) => {
+  expectType<ApiError>(err)
+  expectType<RequestEvent>(meta)
+})
+
+client.on('resurrect', (err, meta) => {
+  expectType<null>(err)
+  expectType<ResurrectEvent>(meta)
+})
+
+// Test all overloads
+
+// Callbacks style
+{
+  const result = client.info((err, result) => {
+    expectType<ApiError>(err)
+    expectType<ApiResponse>(result)
+  })
+  expectType<TransportRequestCallback>(result)
+}
+
+{
+  const result = client.info({ pretty: true }, (err, result) => {
+    expectType<ApiError>(err)
+    expectType<ApiResponse>(result)
+  })
+  expectType<TransportRequestCallback>(result)
+}
+
+{
+  const result = client.info({ pretty: true }, { ignore: [404] }, (err, result) => {
+    expectType<ApiError>(err)
+    expectType<ApiResponse>(result)
+  })
+  expectType<TransportRequestCallback>(result)
+}
+
+// Promise style
+{
+  const promise = client.info()
+  expectType<Promise<ApiResponse>>(promise)
+  promise
+    .then(result => expectType<ApiResponse>(result))
+    .catch((err: ApiError) => expectType<ApiError>(err))
+}
+
+{
+  const promise = client.info({ pretty: true })
+  expectType<Promise<ApiResponse>>(promise)
+  promise
+    .then(result => expectType<ApiResponse>(result))
+    .catch((err: ApiError) => expectType<ApiError>(err))
+}
+
+{
+  const promise = client.info({ pretty: true }, { ignore: [404] })
+  expectType<Promise<ApiResponse>>(promise)
+  promise
+    .then(result => expectType<ApiResponse>(result))
+    .catch((err: ApiError) => expectType<ApiError>(err))
+}
+
+// Promise style with async await
+{
+  const promise = client.info()
+  expectType<Promise<ApiResponse>>(promise)
+  try {
+    expectType<ApiResponse>(await promise)
+  } catch (err) {
+    expectType<any>(err)
+  }
+}
+
+{
+  const promise = client.info({ pretty: true })
+  expectType<Promise<ApiResponse>>(promise)
+  try {
+    expectType<ApiResponse>(await promise)
+  } catch (err) {
+    expectType<any>(err)
+  }
+}
+
+{
+  const promise = client.info({ pretty: true }, { ignore: [404] })
+  expectType<Promise<ApiResponse>>(promise)
+  try {
+    expectType<ApiResponse>(await promise)
+  } catch (err) {
+    expectType<any>(err)
+  }
+}
--- a/test/types/connection-pool.test-d.ts
+++ b/test/types/connection-pool.test-d.ts
@ -0,0 +1,95 @@
+// Licensed to Elasticsearch B.V under one or more agreements.
+// Elasticsearch B.V licenses this file to you under the Apache 2.0 License.
+// See the LICENSE file in the project root for more information
+
+import { expectType, expectAssignable } from 'tsd'
+import { URL } from 'url'
+import {
+  BaseConnectionPool,
+  ConnectionPool,
+  CloudConnectionPool,
+  Connection
+} from '../../'
+
+{
+  const pool = new BaseConnectionPool({
+    Connection: Connection,
+    ssl: { ca: 'stirng' },
+    emit: (event, ...args) => true,
+    agent: { keepAlive: true },
+    auth: { username: 'username', password: 'password' }
+  })
+
+  expectType<BaseConnectionPool>(pool)
+  expectType<Connection[]>(pool.connections)
+  expectType<number>(pool.size)
+
+  expectType<BaseConnectionPool>(pool.markAlive(new Connection()))
+  expectType<BaseConnectionPool>(pool.markDead(new Connection()))
+  expectType<Connection | null>(pool.getConnection({
+    filter (node) { return true },
+    selector (connections) { return connections[0] },
+    requestId: 'id',
+    name: 'name',
+    now: Date.now()
+  }))
+  expectType<Connection>(pool.addConnection({}))
+  expectType<BaseConnectionPool>(pool.removeConnection(new Connection()))
+  expectType<BaseConnectionPool>(pool.empty())
+  expectType<BaseConnectionPool>(pool.update([]))
+  expectType<any[]>(pool.nodesToHost([], 'https'))
+  expectType<{ url: URL }>(pool.urlToHost('url'))
+}
+
+{
+  const pool = new ConnectionPool({
+    Connection: Connection,
+    ssl: { ca: 'stirng' },
+    emit: (event, ...args) => true,
+    agent: { keepAlive: true },
+    auth: { username: 'username', password: 'password' },
+    pingTimeout: 1000,
+    resurrectStrategy: 'ping',
+    sniffEnabled: true
+  })
+
+  expectAssignable<ConnectionPool>(pool)
+  expectType<Connection[]>(pool.connections)
+  expectType<number>(pool.size)
+  expectType<string[]>(pool.dead)
+
+  expectAssignable<ConnectionPool>(pool.markAlive(new Connection()))
+  expectAssignable<ConnectionPool>(pool.markDead(new Connection()))
+  expectType<Connection | null>(pool.getConnection({
+    filter (node) { return true },
+    selector (connections) { return connections[0] },
+    requestId: 'id',
+    name: 'name',
+    now: Date.now()
+  }))
+  expectType<Connection>(pool.addConnection({}))
+  expectAssignable<ConnectionPool>(pool.removeConnection(new Connection()))
+  expectAssignable<ConnectionPool>(pool.empty())
+  expectAssignable<ConnectionPool>(pool.update([]))
+  expectType<any[]>(pool.nodesToHost([], 'https'))
+  expectType<{ url: URL }>(pool.urlToHost('url'))
+  expectType<void>(pool.resurrect({
+    now: Date.now(),
+    requestId: 'id',
+    name: 'name'
+  }))
+}
+
+{
+  const pool = new CloudConnectionPool({
+    Connection: Connection,
+    ssl: { ca: 'stirng' },
+    emit: (event, ...args) => true,
+    agent: { keepAlive: true },
+    auth: { username: 'username', password: 'password' }
+  })
+
+  expectAssignable<CloudConnectionPool>(pool)
+  expectType<Connection | null>(pool.cloudConnection)
+  expectType<Connection | null>(pool.getConnection())
+}
--- a/test/types/connection.test-d.ts
+++ b/test/types/connection.test-d.ts
@ -0,0 +1,26 @@
+// Licensed to Elasticsearch B.V under one or more agreements.
+// Elasticsearch B.V licenses this file to you under the Apache 2.0 License.
+// See the LICENSE file in the project root for more information
+
+import { expectType } from 'tsd'
+import { URL } from 'url'
+import { Connection } from '../../'
+
+const conn = new Connection({
+  url: new URL('http://localhost:9200'),
+  ssl: { ca: 'string' },
+  id: 'id',
+  headers: {},
+  agent: { keepAlive: false },
+  status: 'alive',
+  roles: { master: true },
+  auth: { username: 'username', password: 'password' }
+})
+
+expectType<Connection>(conn)
+expectType<URL>(conn.url)
+expectType<string>(conn.id)
+expectType<Record<string, any>>(conn.headers)
+expectType<number>(conn.deadCount)
+expectType<number>(conn.resurrectTimeout)
+expectType<string>(conn.status)
--- a/test/types/errors.test-d.ts
+++ b/test/types/errors.test-d.ts
@ -0,0 +1,83 @@
+// Licensed to Elasticsearch B.V under one or more agreements.
+// Elasticsearch B.V licenses this file to you under the Apache 2.0 License.
+// See the LICENSE file in the project root for more information
+
+import { expectType } from 'tsd'
+import { errors, ApiResponse, Connection } from '../../'
+import { ResponseBody } from '../../lib/Transport'
+
+const response = {
+  body: {},
+  statusCode: 200,
+  headers: {},
+  warnings: null,
+  meta: {
+    context: {},
+    name: 'name',
+    request: {
+      params: { method: 'GET', path: '/' },
+      options: {},
+      id: 42
+    },
+    connection: new Connection(),
+    attempts: 0,
+    aborted: false,
+  }
+}
+
+{
+  const err = new errors.ElasticsearchClientError()
+  expectType<string>(err.name)
+  expectType<string>(err.message)
+}
+
+{
+  const err = new errors.TimeoutError('message', response)
+  expectType<string>(err.name)
+  expectType<string>(err.message)
+  expectType<ApiResponse>(err.meta)
+}
+
+{
+  const err = new errors.ConnectionError('message', response)
+  expectType<string>(err.name)
+  expectType<string>(err.message)
+  expectType<ApiResponse>(err.meta)
+}
+
+{
+  const err = new errors.NoLivingConnectionsError('message', response)
+  expectType<string>(err.name)
+  expectType<string>(err.message)
+  expectType<ApiResponse>(err.meta)
+}
+
+{
+  const err = new errors.SerializationError('message', {})
+  expectType<string>(err.name)
+  expectType<string>(err.message)
+  expectType<any>(err.data)
+}
+
+{
+  const err = new errors.DeserializationError('message', 'data')
+  expectType<string>(err.name)
+  expectType<string>(err.message)
+  expectType<string>(err.data)
+}
+
+{
+  const err = new errors.ConfigurationError('message')
+  expectType<string>(err.name)
+  expectType<string>(err.message)
+}
+
+{
+  const err = new errors.ResponseError(response)
+  expectType<string>(err.name)
+  expectType<string>(err.message)
+  expectType<ApiResponse>(err.meta)
+  expectType<ResponseBody>(err.body)
+  expectType<number>(err.statusCode)
+  expectType<Record<string, any>>(err.headers)
+}
--- a/test/types/index.ts
+++ b/test/types/index.ts
@ -1,166 +0,0 @@
-// Licensed to Elasticsearch B.V under one or more agreements.
-// Elasticsearch B.V licenses this file to you under the Apache 2.0 License.
-// See the LICENSE file in the project root for more information
-
-'use strict'
-
-import {
-  Client,
-  ApiResponse,
-  RequestParams,
-  RequestEvent,
-  ResurrectEvent,
-  events,
-  errors,
-  ClientExtendsCallbackOptions,
-  NodeOptions
-} from '../../index'
-
-import { TransportRequestParams, TransportRequestOptions } from '../../lib/Transport'
-import { URL } from 'url'
-
-const client = new Client({ node: 'http://localhost:9200' })
-
-const nodeOpts: NodeOptions = {
-  url: new URL('http://localhost:9200'),
-  id: 'winteriscoming',
-  headers: { 'foo': 'bar' },
-  roles: {
-    master: false,
-    data: true,
-    ingest: false,
-    ml: false
-  }
-}
-
-const client2 = new Client({ node: nodeOpts })
-
-const clientBasicAuth = new Client({
-  node: 'http://localhost:9200',
-  auth: { username: 'foo', password: 'bar' }
-})
-
-const clientApiKeyString = new Client({
-  node: 'http://localhost:9200',
-  auth: { apiKey: 'foobar' }
-})
-
-const clientApiKeyObject = new Client({
-  node: 'http://localhost:9200',
-  auth: {
-    apiKey: {
-      id: 'foo',
-      api_key: 'bar'
-    }
-  }
-})
-
-client.on(events.RESPONSE, (err: errors.ElasticsearchClientError | null, request: RequestEvent) => {
-  if (err) console.log(err)
-  const { body, statusCode } = request
-  const { params } = request.meta.request
-  console.log(params, body, statusCode)
-})
-client.on(events.RESURRECT, (err: errors.ElasticsearchClientError | null, meta: ResurrectEvent) => {})
-
-// Callbacks
-client.info((err: errors.ElasticsearchClientError | null, result: ApiResponse) => {})
-
-client.index({
-  index: 'test',
-  id: 'test',
-  body: { hello: 'world' }
-}, (err: errors.ElasticsearchClientError | null, result: ApiResponse) => {})
-
-// request options
-client.index({
-  index: 'test',
-  id: 'test',
-  body: { hello: 'world' }
-}, {
-  maxRetries: 2,
-  ignore: [404],
-  requestTimeout: 2000,
-  headers: { foo: 'bar' },
-  querystring: { baz: 'faz' },
-  compression: 'gzip',
-  asStream: false
-}, (err: errors.ElasticsearchClientError | null, result: ApiResponse) => {})
-
-// Promises
-client.info()
-  .then((result: ApiResponse) => {})
-  .catch((err: errors.ElasticsearchClientError) => {})
-
-client.index({
-  index: 'test',
-  id: 'test',
-  body: { hello: 'world' }
-})
-  .then((result: ApiResponse) => {})
-  .catch((err: errors.ElasticsearchClientError) => {})
-
-// request options
-client.index({
-  index: 'test',
-  id: 'test',
-  body: { hello: 'world' }
-}, {
-  maxRetries: 2,
-  ignore: [404],
-  requestTimeout: 2000
-})
-  .then((result: ApiResponse) => {})
-  .catch((err: errors.ElasticsearchClientError) => {})
-
-// --- Use generics ---
-// Define the search parameters
-interface SearchBody {
-  query: {
-    match: { foo: string }
-  }
-}
-const searchParams: RequestParams.Search<SearchBody> = {
-  index: 'test',
-  body: {
-    query: {
-      match: { foo: 'bar' }
-    }
-  }
-}
-
-// Define the interface of the search response
-interface SearchResponse<T> {
-  hits: {
-    hits: Array<{
-      _source: T;
-    }>
-  }
-}
-
-// Define the interface of the source object
-interface Source {
-  foo: string
-}
-
-client.search(searchParams)
-  .then((response: ApiResponse<SearchResponse<Source>>) => console.log(response))
-  .catch((err: errors.ElasticsearchClientError) => {})
-
-// extend client
-client.extend('namespace.method', (options: ClientExtendsCallbackOptions) => {
-  return function (params: any) {
-    const requestParams: TransportRequestParams = {
-      method: 'GET',
-      path: '/',
-      querystring: {}
-    }
-
-    const requestOptions: TransportRequestOptions = {
-      ignore: [404],
-      maxRetries: 5
-    }
-
-    return options.makeRequest(requestParams, requestOptions)
-  }
-})
--- a/test/types/serializer.test-d.ts
+++ b/test/types/serializer.test-d.ts
@ -0,0 +1,13 @@
+// Licensed to Elasticsearch B.V under one or more agreements.
+// Elasticsearch B.V licenses this file to you under the Apache 2.0 License.
+// See the LICENSE file in the project root for more information
+
+import { expectType } from 'tsd'
+import { Serializer } from '../../'
+
+const serializer = new Serializer()
+
+expectType<string>(serializer.serialize({}))
+expectType<any>(serializer.deserialize(''))
+expectType<string>(serializer.ndserialize([]))
+expectType<string>(serializer.qserialize({}))
--- a/test/types/transport.test-d.ts
+++ b/test/types/transport.test-d.ts
@ -0,0 +1,129 @@
+// Licensed to Elasticsearch B.V under one or more agreements.
+// Elasticsearch B.V licenses this file to you under the Apache 2.0 License.
+// See the LICENSE file in the project root for more information
+
+import { Readable as ReadableStream } from 'stream';
+import { expectType, expectAssignable, expectError } from 'tsd'
+import {
+  Transport,
+  Connection,
+  ConnectionPool,
+  Serializer
+} from '../..'
+import {
+  TransportRequestParams,
+  TransportRequestOptions,
+  TransportRequestCallback,
+  RequestEvent,
+  ApiError,
+  ApiResponse,
+  RequestBody,
+  RequestNDBody,
+  ResponseBody
+} from '../../lib/Transport'
+
+const params = {
+  method: 'POST',
+  path: '/search',
+  body: { foo: 'bar' },
+  querystring: { baz: 'faz' }
+}
+
+const options = {
+  ignore: [404],
+  requestTimeout: 5000,
+  maxRetries: 3,
+  asStream: false,
+  headers: {},
+  querystring: {},
+  id: 'id',
+  context: {},
+  warnings: ['warn'],
+  opaqueId: 'id'
+}
+
+const response = {
+  body: {},
+  statusCode: 200,
+  headers: {},
+  warnings: null,
+  meta: {
+    context: {},
+    name: 'name',
+    request: {
+      params,
+      options,
+      id: 'id'
+    },
+    connection: new Connection(),
+    attempts: 0,
+    aborted: false
+  }
+}
+
+expectAssignable<TransportRequestParams>(params)
+expectAssignable<TransportRequestParams>({ method: 'GET', path: '/' })
+expectAssignable<TransportRequestOptions>(options)
+expectAssignable<RequestEvent>(response)
+expectAssignable<ApiResponse>(response)
+
+// verify that RequestBody, RequestNDBody and ResponseBody works as expected
+interface TestBody { hello: string }
+expectAssignable<RequestBody>({ foo: 'bar' })
+expectAssignable<RequestBody<TestBody>>({ hello: 'world' })
+expectError<RequestBody<TestBody>>({ foo: 'bar' })
+expectAssignable<RequestBody>('string')
+expectAssignable<RequestBody<TestBody>>('string')
+expectAssignable<RequestBody>(Buffer.from('hello world'))
+expectAssignable<RequestBody>(new ReadableStream())
+
+expectAssignable<RequestNDBody>([{ foo: 'bar' }])
+expectAssignable<RequestNDBody<TestBody>[]>([{ hello: 'world' }])
+expectError<RequestNDBody>({ foo: 'bar' })
+expectError<RequestNDBody<TestBody>[]>([{ foo: 'bar' }])
+expectAssignable<RequestNDBody>(['string'])
+expectAssignable<RequestNDBody>(Buffer.from('hello world'))
+expectAssignable<RequestNDBody>(new ReadableStream())
+
+expectAssignable<ResponseBody>({ foo: 'bar' })
+expectAssignable<ResponseBody<TestBody>>({ hello: 'world' })
+expectError<ResponseBody<TestBody>>({ foo: 'bar' })
+expectAssignable<ResponseBody>('string')
+expectAssignable<ResponseBody<TestBody>>('string')
+expectAssignable<ResponseBody>(true)
+expectAssignable<ResponseBody>(new ReadableStream())
+
+const transport = new Transport({
+  emit: (event, ...args) => true,
+  serializer: new Serializer(),
+  connectionPool: new ConnectionPool(),
+  maxRetries: 5,
+  requestTimeout: 1000,
+  suggestCompression: true,
+  compression: 'gzip',
+  sniffInterval: 1000,
+  sniffOnConnectionFault: true,
+  sniffEndpoint: '/sniff',
+  sniffOnStart: false
+})
+
+expectType<Transport>(transport)
+
+expectType<TransportRequestCallback>(transport.request(params, options, (err, result) => {}))
+transport.request(params, options, (err, result) => {
+  expectType<ApiError>(err)
+  expectType<ApiResponse>(result)
+})
+
+const promise = transport.request(params, options)
+expectType<Promise<ApiResponse>>(promise)
+promise.then(result => expectType<ApiResponse>(result))
+expectType<ApiResponse>(await promise)
+
+expectError(
+  transport.request({
+    method: 'POST',
+    path: '/',
+    body: 42
+  })
+)
--- a/test/types/tsconfig.json
+++ b/test/types/tsconfig.json
@ -1,11 +0,0 @@
-{
-  "compilerOptions": {
-    "target": "es6",
-    "module": "commonjs",
-    "noEmit": true,
-    "strict": true
-  },
-  "files": [
-    "./index.ts"
-  ]
-}