diff --git a/go.mod b/go.mod
index 1aeffc55..3318d491 100644
--- a/go.mod
+++ b/go.mod
@@ -12,6 +12,7 @@ require (
 	github.com/davecgh/go-spew v1.1.1
 	github.com/lightninglabs/neutrino/cache v1.1.0
 	github.com/lightningnetwork/lnd/queue v1.0.1
+	github.com/linden/indexeddb v0.0.0-20240218035359-81389d584a5e
 	github.com/linden/tempdb v0.0.0-20240218031655-83bc03e79f51
 	github.com/stretchr/testify v1.8.1
 )
diff --git a/go.sum b/go.sum
index 7cbb6007..a63e56d9 100644
--- a/go.sum
+++ b/go.sum
@@ -84,8 +84,8 @@ github.com/lightningnetwork/lnd/queue v1.0.1 h1:jzJKcTy3Nj5lQrooJ3aaw9Lau3I0IwvQ
 github.com/lightningnetwork/lnd/queue v1.0.1/go.mod h1:vaQwexir73flPW43Mrm7JOgJHmcEFBWWSl9HlyASoms=
 github.com/lightningnetwork/lnd/ticker v1.0.0 h1:S1b60TEGoTtCe2A0yeB+ecoj/kkS4qpwh6l+AkQEZwU=
 github.com/lightningnetwork/lnd/ticker v1.0.0/go.mod h1:iaLXJiVgI1sPANIF2qYYUJXjoksPNvGNYowB8aRbpX0=
-github.com/linden/tempdb v0.0.0-20231124230014-42fe18a60308 h1:3J67IzgcvBcl1UyzMuExSPmq7hejA1Vr1E7ixKqAUds=
-github.com/linden/tempdb v0.0.0-20231124230014-42fe18a60308/go.mod h1:xR9HUmc4girdp/lNzw1jOt53GaCSmctyB8t+Q6EkWp8=
+github.com/linden/indexeddb v0.0.0-20240218035359-81389d584a5e h1:6FTMUiW0wI+my/+7w4CEEYt5zvGmbAjugt2q/fCUyBM=
+github.com/linden/indexeddb v0.0.0-20240218035359-81389d584a5e/go.mod h1:2AP38q2ks+pRwMc2EhmCexlyri456KCewavN30MZQ8Y=
 github.com/linden/tempdb v0.0.0-20240218031655-83bc03e79f51 h1:RfZREkHD3XpItaIN2I1/tb2hCzE2TN5e14OkTH6Sv74=
 github.com/linden/tempdb v0.0.0-20240218031655-83bc03e79f51/go.mod h1:xR9HUmc4girdp/lNzw1jOt53GaCSmctyB8t+Q6EkWp8=
 github.com/nxadm/tail v1.4.4/go.mod h1:kenIhsEOeOJmVchQTgglprH7qJGnHDVpk1VPCcaMI8A=
diff --git a/headerfs/js.go b/headerfs/js.go
new file mode 100644
index 00000000..87ca34f2
--- /dev/null
+++ b/headerfs/js.go
@@ -0,0 +1,402 @@
+//go:build js && wasm
+
+package headerfs
+
+import (
+	"bytes"
+	"errors"
+	"fmt"
+	"strconv"
+	"strings"
+	"sync"
+	"syscall/js"
+
+	"github.com/btcsuite/btcd/chaincfg/chainhash"
+	"github.com/btcsuite/btcd/wire"
+	"github.com/btcsuite/btcwallet/walletdb"
+	"github.com/linden/indexeddb"
+)
+
+const headersStore = "headers"
+
+// headerStore combines a IndexedDB store of headers within a flat file in addition
+// to a database which indexes that flat file. Together, these two abstractions
+// can be used in order to build an indexed header store for any type of
+// "header" as it deals only with raw bytes, and leaves it to a higher layer to
+// interpret those raw bytes accordingly.
+//
+// TODO(roasbeef): quickcheck coverage.
+type headerStore struct {
+	mtx sync.RWMutex // nolint:structcheck // false positive because used as embedded struct only
+
+	idb *indexeddb.DB
+
+	*headerIndex
+}
+
+// readHeader reads a full block header from the flat-file. The header read is
+// determined by the hight value.
+func (h *headerStore) readHeader(height uint32) (wire.BlockHeader, error) {
+	// Create a new read/write transaction, scoped to headers.
+	tx, err := h.idb.NewTransaction([]string{headersStore}, indexeddb.ReadWriteMode)
+	if err != nil {
+		return wire.BlockHeader{}, err
+	}
+
+	// Get the headers store.
+	hdrs := tx.Store(headersStore)
+
+	// Get the raw header.
+	val, err := hdrs.Get(height)
+
+	// check if the value was not found as that case is handled differently.
+	if errors.Is(err, indexeddb.ErrValueNotFound) {
+		return wire.BlockHeader{}, &ErrHeaderNotFound{err}
+	}
+
+	if err != nil {
+		return wire.BlockHeader{}, err
+	}
+
+	// Ensure the value is a string.
+	if val.Type() != js.TypeString {
+		return wire.BlockHeader{}, fmt.Errorf("unexpected type: %s", val.Type())
+	}
+
+	var header wire.BlockHeader
+
+	// Unquote the value.
+	unquote, err := strconv.Unquote(val.String())
+	if err != nil {
+		return wire.BlockHeader{}, err
+	}
+
+	// Create a new reader from the raw header.
+	reader := strings.NewReader(unquote)
+
+	// Finally, decode the  bytes into a proper bitcoin header.
+	err = header.Deserialize(reader)
+
+	return header, err
+}
+
+func (h *headerStore) height() (uint32, bool, error) {
+	// Create a new read-only transaction. Scoped to headers.
+	tx, err := h.idb.NewTransaction([]string{headersStore}, indexeddb.ReadMode)
+	if err != nil {
+		return 0, false, err
+	}
+
+	// Get the headers store.
+	hdrs := tx.Store(headersStore)
+
+	// Count the amount of headers.
+	count, err := hdrs.Count()
+
+	// Fallback to the zero value if no value is found.
+	if errors.Is(err, indexeddb.ErrValueNotFound) || count == 0 {
+		return 0, true, nil
+	}
+
+	if err != nil {
+		return 0, false, err
+	}
+
+	// Subtract one as the block height does not include the genesis block.
+	return uint32(count - 1), false, nil
+}
+
+func (h *headerStore) singleTruncate() error {
+	// Get the current height.
+	height, genesis, err := h.height()
+	if err != nil {
+		return err
+	}
+
+	// Create a write transaction. Scoped to height.
+	tx, err := h.idb.NewTransaction([]string{headersStore}, indexeddb.ReadWriteMode)
+	if err != nil {
+		return err
+	}
+
+	// Get the height store.
+	hdrs := tx.Store(headersStore)
+
+	// Delete the genesis block.
+	if genesis {
+		return hdrs.Delete("genesis")
+	}
+
+	// Delete the header.
+	return hdrs.Delete(height + 1)
+}
+
+// Remove every key/value and set the height to 0.
+func (h *headerStore) Remove() error {
+	// Create a write transaction. Scoped to headers.
+	tx, err := h.idb.NewTransaction([]string{headersStore}, indexeddb.ReadWriteMode)
+	if err != nil {
+		return err
+	}
+
+	// Get the headers store.
+	hdrs := tx.Store(headersStore)
+
+	// Clear all the headers.
+	return hdrs.Clear()
+}
+
+// newHeaderStore creates a new headerStore given an already open database, a
+// target file path for the flat-file and a particular header type. The target
+// file will be created as necessary.
+func newHeaderStore(db walletdb.DB, filePath string, hType HeaderType) (*headerStore, error) {
+	var prefix string
+	switch hType {
+	case Block:
+		prefix = "blocks"
+	case RegularFilter:
+		prefix = "filters"
+	default:
+		return nil, fmt.Errorf("unrecognized filter type: %v", hType)
+	}
+
+	// Prefix with the file path to prevent collisions.
+	prefix = filePath + "-" + prefix
+
+	// Create the database.
+	idb, err := indexeddb.New(prefix, 1, func(up *indexeddb.Upgrade) error {
+		// Create the headers store.
+		up.CreateStore(headersStore)
+
+		return nil
+	})
+	if err != nil {
+		return nil, err
+	}
+
+	// With the file open, we'll then create the header index so we can
+	// have random access into the flat files.
+	index, err := newHeaderIndex(db, hType)
+	if err != nil {
+		return nil, err
+	}
+
+	return &headerStore{
+		idb:         idb,
+		headerIndex: index,
+	}, nil
+}
+
+// readHeaderRange will attempt to fetch a series of block headers within the
+// target height range.
+//
+// NOTE: The end height is _inclusive_ so we'll fetch all headers from the
+// startHeight up to the end height, including the final header.
+func (h *blockHeaderStore) readHeaderRange(startHeight uint32,
+	endHeight uint32) ([]wire.BlockHeader, error) {
+	var headers []wire.BlockHeader
+
+	// Add headers from start height to end height.
+	for height := startHeight; height <= endHeight; height++ {
+		// Read the header.
+		header, err := h.readHeader(height)
+		if err != nil {
+			return nil, err
+		}
+
+		// Append the header to the slice.
+		headers = append(headers, header)
+	}
+
+	return headers, nil
+}
+
+// WriteHeaders writes a set of headers to disk and updates the index in a
+// single atomic transaction.
+//
+// NOTE: Part of the BlockHeaderStore interface.
+func (h *blockHeaderStore) WriteHeaders(hdrs ...BlockHeader) error {
+	// Lock store for write.
+	h.mtx.Lock()
+	defer h.mtx.Unlock()
+
+	height, genesis, err := h.height()
+	if err != nil {
+		return err
+	}
+
+	tx, err := h.idb.NewTransaction([]string{headersStore}, indexeddb.ReadWriteMode)
+	if err != nil {
+		return err
+	}
+
+	str := tx.Store(headersStore)
+
+	// Next, we'll write out all the passed headers in series.
+	for _, header := range hdrs {
+		buf := new(bytes.Buffer)
+
+		// Serialize the header.
+		if err := header.Serialize(buf); err != nil {
+			return err
+		}
+
+		var key any
+
+		if genesis {
+			key = height
+			genesis = false
+		} else {
+			// Add space for the genesis block.
+			key = height + 1
+		}
+
+		// Put the block header.
+		err = str.Put(
+			key,
+			// Quote the string so it is UTF-8 safe.
+			strconv.Quote(buf.String()),
+		)
+		if err != nil {
+			return err
+		}
+
+		height++
+
+	}
+
+	// Once those are written, we'll then collate all the headers into
+	// headerEntry instances so we can write them all into the index in a
+	// single atomic batch.
+	headerLocs := make([]headerEntry, len(hdrs))
+	for i, header := range hdrs {
+		headerLocs[i] = header.toIndexEntry()
+	}
+
+	return h.addHeaders(headerLocs)
+}
+
+// readHeader reads a single filter header at the specified height from the
+// flat files on disk.
+func (f *FilterHeaderStore) readHeader(height uint32) (*chainhash.Hash, error) {
+	// Create a new read-only transaction.
+	tx, err := f.idb.NewTransaction([]string{headersStore}, indexeddb.ReadMode)
+	if err != nil {
+		return nil, err
+	}
+
+	// Get the headers store.
+	hdrs := tx.Store(headersStore)
+
+	// Get the header.
+	val, err := hdrs.Get(height)
+
+	// check if the value was not found as that case is handled differently.
+	if errors.Is(err, indexeddb.ErrValueNotFound) {
+		return nil, &ErrHeaderNotFound{err}
+	}
+
+	if err != nil {
+		return nil, err
+	}
+
+	// Ensure the value is a string.
+	if val.Type() != js.TypeString {
+		return nil, fmt.Errorf("unexpected type: %s", val.Type())
+	}
+
+	// Unquote the value.
+	unquote, err := strconv.Unquote(val.String())
+	if err != nil {
+		return nil, err
+	}
+
+	// Cast the hash to a chainhash.
+	return (*chainhash.Hash)([]byte(unquote)), nil
+}
+
+// readHeaderRange will attempt to fetch a series of filter headers within the
+// target height range. This method batches a set of reads into a single system
+// call thereby increasing performance when reading a set of contiguous
+// headers.
+//
+// NOTE: The end height is _inclusive_ so we'll fetch all headers from the
+// startHeight up to the end height, including the final header.
+func (f *FilterHeaderStore) readHeaderRange(startHeight uint32,
+	endHeight uint32) ([]chainhash.Hash, error) {
+	var headers []chainhash.Hash
+
+	// Add headers from start height to end height.
+	for height := startHeight; height <= endHeight; height++ {
+		// Read the header.
+		header, err := f.readHeader(height)
+		if err != nil {
+			return nil, err
+		}
+
+		// Append the header to the slice.
+		headers = append(headers, *header)
+	}
+
+	return headers, nil
+}
+
+// WriteHeaders writes a batch of filter headers to persistent storage. The
+// headers themselves are appended to the flat file, and then the index updated
+// to reflect the new entires.
+func (f *FilterHeaderStore) WriteHeaders(hdrs ...FilterHeader) error {
+	// Lock store for write.
+	f.mtx.Lock()
+	defer f.mtx.Unlock()
+
+	// If there are 0 headers to be written, return immediately. This
+	// prevents the newTip assignment from panicking because of an index
+	// of -1.
+	if len(hdrs) == 0 {
+		return nil
+	}
+
+	height, genesis, err := f.height()
+	if err != nil {
+		return err
+	}
+
+	// Create a new transaction.
+	tx, err := f.idb.NewTransaction([]string{headersStore}, indexeddb.ReadWriteMode)
+	if err != nil {
+		return err
+	}
+
+	str := tx.Store(headersStore)
+
+	// Next, we'll write out all the passed headers in series into the
+	// buffer we just extracted from the pool.
+	for _, header := range hdrs {
+		var key any
+
+		if genesis {
+			key = height
+			genesis = false
+		} else {
+			// Add space for the genesis block.
+			key = height + 1
+		}
+
+		// Put the filter header.
+		err = str.Put(
+			key,
+			// Encode the filter hash.
+			strconv.Quote(string(header.FilterHash[:])),
+		)
+		if err != nil {
+			return err
+		}
+
+		height++
+	}
+
+	// As the block headers should already be written, we only need to
+	// update the tip pointer for this particular header type.
+	newTip := hdrs[len(hdrs)-1].toIndexEntry().hash
+	return f.truncateIndex(&newTip, false)
+}