diff --git a/go.mod b/go.mod
index 758159d..d0c2554 100644
--- a/go.mod
+++ b/go.mod
@@ -13,7 +13,8 @@ require (
 	github.com/mailru/easyjson v0.7.7
 	github.com/mattn/go-sqlite3 v1.14.18
 	github.com/nbd-wtf/go-nostr v0.28.5
-	github.com/stretchr/testify v1.8.4
+	github.com/opensearch-project/opensearch-go/v4 v4.0.0
+	github.com/stretchr/testify v1.9.0
 	github.com/urfave/cli/v3 v3.0.0-alpha7
 	go.etcd.io/bbolt v1.3.9
 	golang.org/x/exp v0.0.0-20231006140011-7918f672742d
diff --git a/go.sum b/go.sum
index ef2b903..2deebe6 100644
--- a/go.sum
+++ b/go.sum
@@ -116,6 +116,8 @@ github.com/mattn/go-sqlite3 v1.14.18 h1:JL0eqdCOq6DJVNPSvArO/bIV9/P7fbGrV00LZHc+
 github.com/mattn/go-sqlite3 v1.14.18/go.mod h1:2eHXhiwb8IkHr+BDWZGa96P6+rkvnG63S2DGjv9HUNg=
 github.com/nbd-wtf/go-nostr v0.28.5 h1:5vBAFKGVJ6Rhq2Jrtj+v+j8bUVLdsao5SFdBIQ7PJR4=
 github.com/nbd-wtf/go-nostr v0.28.5/go.mod h1:aFcp8NO3erHg+glzBfh4wpaMrV1/ahcUPAgITdptxwA=
+github.com/opensearch-project/opensearch-go/v4 v4.0.0 h1:Nrh30HhaknKcaPcIzlqA6Jf0CBgWP5XUaSp0HMsRBlA=
+github.com/opensearch-project/opensearch-go/v4 v4.0.0/go.mod h1:amlBgHgAX9AwwW50eOuzYa5n/8aD18LoWO8eDLoe8KQ=
 github.com/pkg/errors v0.9.1 h1:FEBLx1zS214owpjy7qsBeixbURkuhQAwrK5UwLGTwt4=
 github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
@@ -130,8 +132,8 @@ github.com/stretchr/testify v1.4.0/go.mod h1:j7eGeouHqKxXV5pUuKE4zz7dFj8WfuZ+81P
 github.com/stretchr/testify v1.7.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
 github.com/stretchr/testify v1.8.0/go.mod h1:yNjHg4UonilssWZ8iaSj1OCr/vHnekPRkoO+kdMU+MU=
 github.com/stretchr/testify v1.8.1/go.mod h1:w2LPCIKwWwSfY2zedu0+kehJoqGctiVI29o6fzry7u4=
-github.com/stretchr/testify v1.8.4 h1:CcVxjf3Q8PM0mHUKJCdn+eZZtm5yQwehR5yeSVQQcUk=
-github.com/stretchr/testify v1.8.4/go.mod h1:sz/lmYIOXD/1dqDmKjjqLyZ2RngseejIcXlSw2iwfAo=
+github.com/stretchr/testify v1.9.0 h1:HtqpIVDClZ4nwg75+f6Lvsy/wHu+3BoSGCbBAcpTsTg=
+github.com/stretchr/testify v1.9.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
 github.com/tidwall/gjson v1.17.0 h1:/Jocvlh98kcTfpN2+JzGQWQcqrPQwDrVEMApx/M5ZwM=
 github.com/tidwall/gjson v1.17.0/go.mod h1:/wbyibRr2FHMks5tjHJ5F8dMZh3AcwJEMf5vlfC0lxk=
 github.com/tidwall/match v1.1.1 h1:+Ho715JplO36QYgwN9PGYNhgZvoUSc9X2c80KVTi+GA=
@@ -139,8 +141,12 @@ github.com/tidwall/match v1.1.1/go.mod h1:eRSPERbgtNPcGhD8UCthc6PmLEQXEWd3PRB5JT
 github.com/tidwall/pretty v1.2.0/go.mod h1:ITEVvHYasfjBbM0u2Pg8T2nJnzm8xPwvNhhsoaGGjNU=
 github.com/tidwall/pretty v1.2.1 h1:qjsOFOWWQl+N3RsoF5/ssm1pHmJJwhjlSbZ51I6wMl4=
 github.com/tidwall/pretty v1.2.1/go.mod h1:ITEVvHYasfjBbM0u2Pg8T2nJnzm8xPwvNhhsoaGGjNU=
+github.com/tidwall/sjson v1.2.5 h1:kLy8mja+1c9jlljvWTlSazM7cKDRfJuR/bOJhcY5NcY=
+github.com/tidwall/sjson v1.2.5/go.mod h1:Fvgq9kS/6ociJEDnK0Fk1cpYF4FIW6ZF7LAe+6jwd28=
 github.com/urfave/cli/v3 v3.0.0-alpha7 h1:dj+WjtBA2StTinGwue+o2oyFFvo8aQ/AGb5MYvUqk/8=
 github.com/urfave/cli/v3 v3.0.0-alpha7/go.mod h1:0kK/RUFHyh+yIKSfWxwheGndfnrvYSmYFVeKCh03ZUc=
+github.com/wI2L/jsondiff v0.5.1 h1:xS4zYUspH4U3IB0Lwo9+jv+MSRJSWMF87Y4BpDbFMHo=
+github.com/wI2L/jsondiff v0.5.1/go.mod h1:qqG6hnK0Lsrz2BpIVCxWiK9ItsBCpIZQiv0izJjOZ9s=
 github.com/xrash/smetrics v0.0.0-20201216005158-039620a65673 h1:bAn7/zixMGCfxrRTfdpNzjtPYqr8smhKouy9mxVdGPU=
 github.com/xrash/smetrics v0.0.0-20201216005158-039620a65673/go.mod h1:N3UwUGtsrSj3ccvlPHLoLsHnpR27oXr4ZE984MbSER8=
 github.com/yuin/goldmark v1.1.27/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=
diff --git a/opensearch/opensearch.go b/opensearch/opensearch.go
new file mode 100644
index 0000000..3986c1b
--- /dev/null
+++ b/opensearch/opensearch.go
@@ -0,0 +1,207 @@
+package opensearch
+
+import (
+	"bytes"
+	"context"
+	"crypto/tls"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"net/http"
+	"strings"
+	"time"
+
+	"github.com/fiatjaf/eventstore"
+	"github.com/nbd-wtf/go-nostr"
+	"github.com/opensearch-project/opensearch-go/v4"
+	"github.com/opensearch-project/opensearch-go/v4/opensearchapi"
+	"github.com/opensearch-project/opensearch-go/v4/opensearchutil"
+)
+
+var _ eventstore.Store = (*OpensearchStorage)(nil)
+
+type IndexedEvent struct {
+	Event         nostr.Event `json:"event"`
+	ContentSearch string      `json:"content_search"`
+}
+
+var indexMapping = `
+{
+	"settings": {
+		"number_of_shards": 1,
+		"number_of_replicas": 0
+	},
+	"mappings": {
+		"dynamic": false,
+		"properties": {
+			"event": {
+				"dynamic": false,
+				"properties": {
+					"id": {"type": "keyword"},
+					"pubkey": {"type": "keyword"},
+					"kind": {"type": "integer"},
+					"tags": {"type": "keyword"},
+					"created_at": {"type": "date"}
+				}
+			},
+			"content_search": {"type": "text"}
+		}
+	}
+}
+`
+
+type OpensearchStorage struct {
+	URL       string
+	IndexName string
+	Insecure  bool
+
+	client *opensearchapi.Client
+	bi     opensearchutil.BulkIndexer
+}
+
+func (oss *OpensearchStorage) Close() {}
+
+func (oss *OpensearchStorage) Init() error {
+	if oss.IndexName == "" {
+		oss.IndexName = "events"
+	}
+
+	cfg := opensearchapi.Config{}
+	if oss.URL != "" {
+		cfg.Client.Addresses = strings.Split(oss.URL, ",")
+	}
+	if oss.Insecure {
+		transport := http.DefaultTransport.(*http.Transport).Clone()
+		transport.TLSClientConfig = &tls.Config{InsecureSkipVerify: true}
+		cfg.Client.Transport = transport
+	}
+
+	client, err := opensearchapi.NewClient(cfg)
+	if err != nil {
+		return err
+	}
+
+	ctx := context.Background()
+	createIndexResponse, err := client.Indices.Create(
+		ctx,
+		opensearchapi.IndicesCreateReq{
+			Index: oss.IndexName,
+			Body:  strings.NewReader(indexMapping),
+		},
+	)
+	if err != nil {
+		var opensearchError *opensearch.StructError
+
+		// Load err into opensearch.Error to access the fields and tolerate if the index already exists
+		if errors.As(err, &opensearchError) {
+			if opensearchError.Err.Type != "resource_already_exists_exception" {
+				return err
+			}
+		} else {
+			return err
+		}
+	}
+	fmt.Printf("Created Index: %s\n  Shards Acknowledged: %t\n", createIndexResponse.Index, createIndexResponse.ShardsAcknowledged)
+
+	// bulk indexer
+	bi, err := opensearchutil.NewBulkIndexer(opensearchutil.BulkIndexerConfig{
+		Index:         oss.IndexName,
+		Client:        client,
+		NumWorkers:    2,
+		FlushInterval: 3 * time.Second,
+	})
+	if err != nil {
+		return fmt.Errorf("error creating the indexer: %s", err)
+	}
+
+	oss.client = client
+	oss.bi = bi
+
+	return nil
+}
+
+func (oss *OpensearchStorage) DeleteEvent(ctx context.Context, evt *nostr.Event) error {
+	done := make(chan error)
+	err := oss.bi.Add(
+		ctx,
+		opensearchutil.BulkIndexerItem{
+			Action:     "delete",
+			DocumentID: evt.ID,
+			OnSuccess: func(ctx context.Context, item opensearchutil.BulkIndexerItem, res opensearchapi.BulkRespItem) {
+				close(done)
+			},
+			OnFailure: func(ctx context.Context, item opensearchutil.BulkIndexerItem, res opensearchapi.BulkRespItem, err error) {
+				if err != nil {
+					done <- err
+				} else {
+					// ok if deleted item not found
+					if res.Status == 404 {
+						close(done)
+						return
+					}
+					txt, _ := json.Marshal(res)
+					err := fmt.Errorf("ERROR: %s", txt)
+					done <- err
+				}
+			},
+		},
+	)
+	if err != nil {
+		return err
+	}
+
+	err = <-done
+	return err
+}
+
+func (oss *OpensearchStorage) SaveEvent(ctx context.Context, evt *nostr.Event) error {
+	ie := &IndexedEvent{
+		Event: *evt,
+	}
+
+	// post processing: index for FTS
+	// some ideas:
+	// - index kind=0 fields a set of dedicated mapped fields
+	//   (or use a separate index for profiles with a dedicated mapping)
+	// - if it's valid JSON just index the "values" and not the keys
+	// - more content introspection: language detection
+	// - denormalization... attach profile + ranking signals to events
+	if evt.Kind != 4 {
+		ie.ContentSearch = evt.Content
+	}
+
+	data, err := json.Marshal(ie)
+	if err != nil {
+		return err
+	}
+
+	done := make(chan error)
+
+	// adapted from:
+	// https://github.com/elastic/go-elasticsearch/blob/main/_examples/bulk/indexer.go#L196
+	err = oss.bi.Add(
+		ctx,
+		opensearchutil.BulkIndexerItem{
+			Action:     "index",
+			DocumentID: evt.ID,
+			Body:       bytes.NewReader(data),
+			OnSuccess: func(ctx context.Context, item opensearchutil.BulkIndexerItem, res opensearchapi.BulkRespItem) {
+				close(done)
+			},
+			OnFailure: func(ctx context.Context, item opensearchutil.BulkIndexerItem, res opensearchapi.BulkRespItem, err error) {
+				if err != nil {
+					done <- err
+				} else {
+					err := fmt.Errorf("ERROR: %s: %s", res.Error.Type, res.Error.Reason)
+					done <- err
+				}
+			},
+		},
+	)
+	if err != nil {
+		return err
+	}
+
+	err = <-done
+	return err
+}
diff --git a/opensearch/query.go b/opensearch/query.go
new file mode 100644
index 0000000..bcc1eaf
--- /dev/null
+++ b/opensearch/query.go
@@ -0,0 +1,231 @@
+package opensearch
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"fmt"
+	"reflect"
+
+	"github.com/aquasecurity/esquery"
+	"github.com/nbd-wtf/go-nostr"
+	"github.com/opensearch-project/opensearch-go/v4/opensearchapi"
+	"github.com/opensearch-project/opensearch-go/v4/opensearchutil"
+)
+
+func buildDsl(filter nostr.Filter) ([]byte, error) {
+	dsl := esquery.Bool()
+
+	prefixFilter := func(fieldName string, values []string) {
+		if len(values) == 0 {
+			return
+		}
+		prefixQ := esquery.Bool()
+		for _, v := range values {
+			if len(v) < 64 {
+				prefixQ.Should(esquery.Prefix(fieldName, v))
+			} else {
+				prefixQ.Should(esquery.Term(fieldName, v))
+			}
+		}
+		dsl.Must(prefixQ)
+	}
+
+	// ids
+	prefixFilter("event.id", filter.IDs)
+
+	// authors
+	prefixFilter("event.pubkey", filter.Authors)
+
+	// kinds
+	if len(filter.Kinds) > 0 {
+		dsl.Must(esquery.Terms("event.kind", toInterfaceSlice(filter.Kinds)...))
+	}
+
+	// tags
+	if len(filter.Tags) > 0 {
+		tagQ := esquery.Bool()
+		for char, terms := range filter.Tags {
+			vs := toInterfaceSlice(append(terms, char))
+			tagQ.Should(esquery.Terms("event.tags", vs...))
+		}
+		dsl.Must(tagQ)
+	}
+
+	// since
+	if filter.Since != nil {
+		dsl.Must(esquery.Range("event.created_at").Gte(filter.Since))
+	}
+
+	// until
+	if filter.Until != nil {
+		dsl.Must(esquery.Range("event.created_at").Lte(filter.Until))
+	}
+
+	// search
+	if filter.Search != "" {
+		dsl.Must(esquery.Match("content_search", filter.Search))
+	}
+
+	return json.Marshal(esquery.Query(dsl))
+}
+
+func (oss *OpensearchStorage) getByID(filter nostr.Filter) ([]*nostr.Event, error) {
+	ctx := context.Background()
+	mgetResponse, err := oss.client.MGet(
+		ctx,
+		opensearchapi.MGetReq{
+			Body:  opensearchutil.NewJSONReader(filter),
+			Index: oss.IndexName,
+		},
+	)
+	if err != nil {
+		return nil, err
+	}
+
+	events := make([]*nostr.Event, 0, len(mgetResponse.Docs))
+	for _, e := range mgetResponse.Docs {
+		if e.Found {
+			if b, err := e.Source.MarshalJSON(); err == nil {
+				var payload struct {
+					Event nostr.Event `json:"event"`
+				}
+				if err = json.Unmarshal(b, &payload); err == nil {
+					events = append(events, &payload.Event)
+				}
+			}
+		}
+	}
+
+	return events, nil
+}
+
+func (oss *OpensearchStorage) QueryEvents(ctx context.Context, filter nostr.Filter) (chan *nostr.Event, error) {
+	ch := make(chan *nostr.Event)
+
+	// optimization: get by id
+	if isGetByID(filter) {
+		if evts, err := oss.getByID(filter); err == nil {
+			for _, evt := range evts {
+				ch <- evt
+			}
+			close(ch)
+		} else {
+			return nil, fmt.Errorf("error getting by id: %w", err)
+		}
+	}
+
+	dsl, err := buildDsl(filter)
+	if err != nil {
+		return nil, err
+	}
+
+	limit := 1000
+	if filter.Limit > 0 && filter.Limit < limit {
+		limit = filter.Limit
+	}
+
+	ctx = context.Background()
+	searchResponse, err := oss.client.Search(
+		ctx,
+		&opensearchapi.SearchReq{
+			Indices: []string{oss.IndexName},
+			Body:    bytes.NewReader(dsl),
+			Params: opensearchapi.SearchParams{
+				Size: opensearchapi.ToPointer(limit),
+				Sort: []string{"event.created_at:desc"},
+			},
+		},
+	)
+	if err != nil {
+		return nil, err
+	}
+
+	go func() {
+		for _, e := range searchResponse.Hits.Hits {
+			if b, err := e.Source.MarshalJSON(); err == nil {
+				var payload struct {
+					Event nostr.Event `json:"event"`
+				}
+				if err = json.Unmarshal(b, &payload); err == nil {
+					ch <- &payload.Event
+				}
+			}
+		}
+		close(ch)
+	}()
+
+	return ch, nil
+}
+
+func isGetByID(filter nostr.Filter) bool {
+	isGetById := len(filter.IDs) > 0 &&
+		len(filter.Authors) == 0 &&
+		len(filter.Kinds) == 0 &&
+		len(filter.Tags) == 0 &&
+		len(filter.Search) == 0 &&
+		filter.Since == nil &&
+		filter.Until == nil
+
+	if isGetById {
+		for _, id := range filter.IDs {
+			if len(id) != 64 {
+				return false
+			}
+		}
+	}
+	return isGetById
+}
+
+// from: https://stackoverflow.com/a/12754757
+func toInterfaceSlice(slice interface{}) []interface{} {
+	s := reflect.ValueOf(slice)
+	if s.Kind() != reflect.Slice {
+		panic("InterfaceSlice() given a non-slice type")
+	}
+
+	// Keep the distinction between nil and empty slice input
+	if s.IsNil() {
+		return nil
+	}
+
+	ret := make([]interface{}, s.Len())
+
+	for i := 0; i < s.Len(); i++ {
+		ret[i] = s.Index(i).Interface()
+	}
+
+	return ret
+}
+
+func (oss *OpensearchStorage) CountEvents(ctx context.Context, filter nostr.Filter) (int64, error) {
+	count := int64(0)
+
+	// optimization: get by id
+	if isGetByID(filter) {
+		if evts, err := oss.getByID(filter); err == nil {
+			count += int64(len(evts))
+		} else {
+			return 0, fmt.Errorf("error getting by id: %w", err)
+		}
+	}
+
+	dsl, err := buildDsl(filter)
+	if err != nil {
+		return 0, err
+	}
+
+	ctx = context.Background()
+	countRes, err := oss.client.Indices.Count(
+		ctx,
+		&opensearchapi.IndicesCountReq{
+			Indices: []string{oss.IndexName},
+			Body:    bytes.NewReader(dsl),
+		},
+	)
+	if err != nil {
+		return 0, err
+	}
+
+	return int64(countRes.Count) + count, nil
+}