diff --git a/async_postgres/pg_connection.nim b/async_postgres/pg_connection.nim
index 3029edf..1e5617a 100644
--- a/async_postgres/pg_connection.nim
+++ b/async_postgres/pg_connection.nim
@@ -168,6 +168,7 @@ type
     stmtCounter: int
     stmtCacheCapacity: int ## 0=disabled, default 256
     hstoreOid: int32 ## Dynamic OID for hstore extension type; 0 if not available
+    hstoreArrayOid: int32 ## Dynamic OID for hstore[] array; 0 if not available
     tracer: PgTracer ## Inherited from ConnConfig on connect
 
   QueryResult* = object
@@ -337,6 +338,27 @@ func hstoreOid*(conn: PgConnection): int32 {.inline.} =
   ## Dynamic OID for hstore extension type; 0 if not available.
   conn.hstoreOid
 
+func hstoreArrayOid*(conn: PgConnection): int32 {.inline.} =
+  ## Dynamic OID for hstore[] array type; 0 if not available.
+  conn.hstoreArrayOid
+
+proc toPgBinaryParam*(conn: PgConnection, v: PgHstore): PgParam {.inline.} =
+  ## Convenience overload: encode hstore in binary using ``conn.hstoreOid``.
+  ## Raises ``PgTypeError`` if the hstore extension OID has not been discovered
+  ## (e.g. extension not installed on the server).
+  if conn.hstoreOid == 0:
+    raise newException(PgTypeError, "hstore OID not available on this connection")
+  toPgBinaryParam(v, conn.hstoreOid)
+
+proc toPgBinaryParam*(conn: PgConnection, v: seq[PgHstore]): PgParam {.inline.} =
+  ## Convenience overload: encode hstore[] in binary using ``conn.hstoreOid``
+  ## and ``conn.hstoreArrayOid``. Raises ``PgTypeError`` if either OID has not
+  ## been discovered.
+  if conn.hstoreOid == 0 or conn.hstoreArrayOid == 0:
+    raise
+      newException(PgTypeError, "hstore/hstore[] OIDs not available on this connection")
+  toPgBinaryParam(v, conn.hstoreOid, conn.hstoreArrayOid)
+
 func notifyCallback*(conn: PgConnection): NotifyCallback {.inline.} =
   ## The callback invoked when a NOTIFY message arrives.
   conn.notifyCallback
@@ -679,10 +701,12 @@ proc addStmtCache*(conn: PgConnection, sql: string, cached: CachedStmt) =
     return # caller should have evicted; skip if still full
   var entry = cached
   if entry.resultFormats.len == 0 and entry.fields.len > 0:
+    var extraOids: seq[int32]
     if conn.hstoreOid != 0:
-      entry.resultFormats = buildResultFormats(entry.fields, [conn.hstoreOid])
-    else:
-      entry.resultFormats = buildResultFormats(entry.fields)
+      extraOids.add(conn.hstoreOid)
+    if conn.hstoreArrayOid != 0:
+      extraOids.add(conn.hstoreArrayOid)
+    entry.resultFormats = buildResultFormats(entry.fields, extraOids)
     entry.colFmts = newSeq[int16](entry.fields.len)
     entry.colOids = newSeq[int32](entry.fields.len)
     for i in 0 ..< entry.fields.len:
@@ -1277,7 +1301,7 @@ proc connectToHost(
     # Discover extension type OIDs (hstore, etc.)
     conn.state = csBusy
     await conn.sendMsg(
-      encodeQuery("SELECT oid FROM pg_type WHERE typname = 'hstore' LIMIT 1")
+      encodeQuery("SELECT oid, typarray FROM pg_type WHERE typname = 'hstore' LIMIT 1")
     )
     block discoverLoop:
       while true:
@@ -1292,6 +1316,11 @@ proc connectToHost(
                 conn.hstoreOid = int32(parseInt(bytesToString(msg.columns[0].get)))
               except ValueError:
                 discard
+            if msg.columns.len > 1 and msg.columns[1].isSome:
+              try:
+                conn.hstoreArrayOid = int32(parseInt(bytesToString(msg.columns[1].get)))
+              except ValueError:
+                discard
           of bmkCommandComplete, bmkEmptyQueryResponse:
             discard
           of bmkReadyForQuery:
@@ -1697,6 +1726,7 @@ proc reconnectInPlace(conn: PgConnection) {.async.} =
   conn.state = csReady
   conn.createdAt = newConn.createdAt
   conn.hstoreOid = newConn.hstoreOid
+  conn.hstoreArrayOid = newConn.hstoreArrayOid
   for ch in conn.listenChannels:
     discard await conn.simpleQuery("LISTEN " & quoteIdentifier(ch))
 
diff --git a/async_postgres/pg_types.nim b/async_postgres/pg_types.nim
index a38b7b5..82c508d 100644
--- a/async_postgres/pg_types.nim
+++ b/async_postgres/pg_types.nim
@@ -1568,19 +1568,7 @@ genArrayEncoder(PgMoney, OidMoneyArray, OidMoney)
 
 # Numeric / binary / JSON array encoders
 
-proc toPgParam*(v: seq[PgNumeric]): PgParam =
-  if v.len == 0:
-    return PgParam(
-      oid: OidNumericArray, format: 1, value: some(encodeBinaryArrayEmpty(OidNumeric))
-    )
-  var elements = newSeq[seq[byte]](v.len)
-  for i, x in v:
-    elements[i] = encodeNumericBinary(x)
-  PgParam(
-    oid: OidNumericArray,
-    format: 1,
-    value: some(encodeBinaryArray(OidNumeric, elements)),
-  )
+genArrayEncoder(PgNumeric, OidNumericArray, OidNumeric)
 
 proc toPgByteaArrayParam*(v: seq[seq[byte]]): PgParam =
   if v.len == 0:
@@ -1789,6 +1777,40 @@ proc toPgBinaryParam*(v: PgHstore, oid: int32): PgParam =
   ## (available as ``conn.hstoreOid`` after connection).
   PgParam(oid: oid, format: 1, value: some(encodeHstoreBinary(v)))
 
+proc toPgParam*(v: seq[PgHstore]): PgParam =
+  ## Send hstore[] in text format using ``OidTextArray``. Requires an explicit
+  ## ``::hstore[]`` cast in the SQL statement (e.g. ``SELECT $1::hstore[]``),
+  ## since the parameter is typed as text[]. No connection-specific OID is
+  ## needed; prefer ``toPgBinaryParam`` when a ``PgConnection`` with the
+  ## discovered hstore OIDs is available (faster, no cast required).
+  if v.len == 0:
+    return PgParam(oid: OidTextArray, format: 0, value: some(toBytes("{}")))
+  var s = "{"
+  for i, h in v:
+    if i > 0:
+      s.add(',')
+    s.add('"')
+    for c in encodeHstoreText(h):
+      if c == '"' or c == '\\':
+        s.add('\\')
+      s.add(c)
+    s.add('"')
+  s.add('}')
+  PgParam(oid: OidTextArray, format: 0, value: some(toBytes(s)))
+
+proc toPgBinaryParam*(v: seq[PgHstore], elemOid: int32, arrayOid: int32): PgParam =
+  ## Encode hstore[] in binary format. Requires both the dynamic hstore OID
+  ## and hstore[] OID (available as ``conn.hstoreOid`` and
+  ## ``conn.hstoreArrayOid`` after connection). See also the ``PgConnection``
+  ## overload in ``pg_connection`` which reads these OIDs automatically.
+  if v.len == 0:
+    return
+      PgParam(oid: arrayOid, format: 1, value: some(encodeBinaryArrayEmpty(elemOid)))
+  var elements = newSeq[seq[byte]](v.len)
+  for i, x in v:
+    elements[i] = encodeHstoreBinary(x)
+  PgParam(oid: arrayOid, format: 1, value: some(encodeBinaryArray(elemOid, elements)))
+
 proc toPgBinaryParam*[T](v: Option[T]): PgParam =
   if v.isSome:
     result = toPgBinaryParam(v.get)
@@ -4099,6 +4121,28 @@ genStringArrayDecoder(getXmlArray, PgXml, "xml")
 genStringArrayDecoder(getTsVectorArray, PgTsVector, "tsvector")
 genStringArrayDecoder(getTsQueryArray, PgTsQuery, "tsquery")
 
+proc getHstoreArray*(row: Row, col: int): seq[PgHstore] =
+  ## Get a column value as ``seq[PgHstore]``. Handles both text and binary format.
+  if row.isBinaryCol(col):
+    let (off, clen) = cellInfo(row, col)
+    if clen == -1:
+      raise newException(PgTypeError, "Column " & $col & " is NULL")
+    let decoded = decodeBinaryArray(row.data.buf.toOpenArray(off, off + clen - 1))
+    result = newSeq[PgHstore](decoded.elements.len)
+    for i, e in decoded.elements:
+      if e.len == -1:
+        raise newException(PgTypeError, "NULL element in hstore array")
+      result[i] = decodeHstoreBinary(
+        row.data.buf.toOpenArray(off + e.off, off + e.off + e.len - 1)
+      )
+    return
+  let s = row.getStr(col)
+  let elems = parseTextArray(s)
+  for e in elems:
+    if e.isNone:
+      raise newException(PgTypeError, "NULL element in hstore array")
+    result.add(parseHstoreText(e.get))
+
 # Array Opt accessors (text format)
 
 optAccessor(getIntArray, getIntArrayOpt, seq[int32])
@@ -4134,6 +4178,7 @@ optAccessor(getCircleArray, getCircleArrayOpt, seq[PgCircle])
 optAccessor(getXmlArray, getXmlArrayOpt, seq[PgXml])
 optAccessor(getTsVectorArray, getTsVectorArrayOpt, seq[PgTsVector])
 optAccessor(getTsQueryArray, getTsQueryArrayOpt, seq[PgTsQuery])
+optAccessor(getHstoreArray, getHstoreArrayOpt, seq[PgHstore])
 
 # Coerce a binary PgParam to match the server-inferred type from a prepared
 # statement.  This handles the common case where e.g. int32.toPgParam is
@@ -6293,6 +6338,9 @@ proc get*(row: Row, col: int, T: typedesc[seq[PgTsVector]]): seq[PgTsVector] =
 proc get*(row: Row, col: int, T: typedesc[seq[PgTsQuery]]): seq[PgTsQuery] =
   row.getTsQueryArray(col)
 
+proc get*(row: Row, col: int, T: typedesc[seq[PgHstore]]): seq[PgHstore] =
+  row.getHstoreArray(col)
+
 # Range types (DateTime-based ranges excluded — see note above)
 
 proc get*(row: Row, col: int, T: typedesc[PgRange[int32]]): PgRange[int32] =
@@ -6464,6 +6512,7 @@ nameAccessor(getCircleArray, seq[PgCircle])
 nameAccessor(getXmlArray, seq[PgXml])
 nameAccessor(getTsVectorArray, seq[PgTsVector])
 nameAccessor(getTsQueryArray, seq[PgTsQuery])
+nameAccessor(getHstoreArray, seq[PgHstore])
 nameAccessor(getTimestampArrayOpt, Option[seq[DateTime]])
 nameAccessor(getTimestampTzArrayOpt, Option[seq[DateTime]])
 nameAccessor(getDateArrayOpt, Option[seq[DateTime]])
@@ -6489,6 +6538,7 @@ nameAccessor(getCircleArrayOpt, Option[seq[PgCircle]])
 nameAccessor(getXmlArrayOpt, Option[seq[PgXml]])
 nameAccessor(getTsVectorArrayOpt, Option[seq[PgTsVector]])
 nameAccessor(getTsQueryArrayOpt, Option[seq[PgTsQuery]])
+nameAccessor(getHstoreArrayOpt, Option[seq[PgHstore]])
 nameAccessor(getInt4Range, PgRange[int32])
 nameAccessor(getInt8Range, PgRange[int64])
 nameAccessor(getNumRange, PgRange[PgNumeric])
diff --git a/tests/test_e2e.nim b/tests/test_e2e.nim
index 275b099..c6c3fb8 100644
--- a/tests/test_e2e.nim
+++ b/tests/test_e2e.nim
@@ -8050,6 +8050,60 @@ suite "E2E: Numeric / binary / JSON array types":
 
     waitFor t()
 
+  test "hstore array roundtrip (text cast)":
+    proc t() {.async.} =
+      let conn = await connect(plainConfig())
+      discard await conn.simpleQuery("CREATE EXTENSION IF NOT EXISTS hstore;")
+      var h1: PgHstore = initTable[string, Option[string]]()
+      h1["a"] = some("1")
+      var h2: PgHstore = initTable[string, Option[string]]()
+      h2["b"] = none(string)
+      let res = await conn.query("SELECT $1::hstore[]", @[toPgParam(@[h1, h2])])
+      doAssert res.rows.len == 1
+      let arr = res.rows[0].getHstoreArray(0)
+      doAssert arr.len == 2
+      doAssert arr[0] == h1
+      doAssert arr[1] == h2
+      await conn.close()
+
+    waitFor t()
+
+  test "hstore array roundtrip (binary)":
+    proc t() {.async.} =
+      let conn = await connect(plainConfig())
+      discard await conn.simpleQuery("CREATE EXTENSION IF NOT EXISTS hstore;")
+      doAssert conn.hstoreOid != 0
+      doAssert conn.hstoreArrayOid != 0
+      var h1: PgHstore = initTable[string, Option[string]]()
+      h1["x"] = some("y")
+      var h2: PgHstore = initTable[string, Option[string]]()
+      h2["nul"] = none(string)
+      let bin = toPgBinaryParam(@[h1, h2], conn.hstoreOid, conn.hstoreArrayOid)
+      let res = await conn.query("SELECT $1", @[bin])
+      doAssert res.rows.len == 1
+      let arr = res.rows[0].getHstoreArray(0)
+      doAssert arr.len == 2
+      doAssert arr[0] == h1
+      doAssert arr[1] == h2
+      await conn.close()
+
+    waitFor t()
+
+  test "hstore array roundtrip (binary, conn overload)":
+    proc t() {.async.} =
+      let conn = await connect(plainConfig())
+      discard await conn.simpleQuery("CREATE EXTENSION IF NOT EXISTS hstore;")
+      var h1: PgHstore = initTable[string, Option[string]]()
+      h1["k"] = some("v")
+      let res = await conn.query("SELECT $1", @[conn.toPgBinaryParam(@[h1])])
+      doAssert res.rows.len == 1
+      let arr = res.rows[0].getHstoreArray(0)
+      doAssert arr.len == 1
+      doAssert arr[0] == h1
+      await conn.close()
+
+    waitFor t()
+
   test "bytea array roundtrip":
     proc t() {.async.} =
       let conn = await connect(plainConfig())
diff --git a/tests/test_types.nim b/tests/test_types.nim
index 47cab97..70234a2 100644
--- a/tests/test_types.nim
+++ b/tests/test_types.nim
@@ -5011,6 +5011,73 @@ suite "hstore":
     let row = mkRow(@[none(seq[byte])], fields)
     check row.getHstoreOpt(0).isNone
 
+  test "toPgParam seq[PgHstore] text roundtrip":
+    var h1: PgHstore = initTable[string, Option[string]]()
+    h1["a"] = some("1")
+    var h2: PgHstore = initTable[string, Option[string]]()
+    h2["b"] = none(string)
+    let p = toPgParam(@[h1, h2])
+    check p.oid == OidTextArray
+    check p.format == 0
+    let fields = @[mkField(OidTextArray, 0'i16)]
+    let row = mkRow(@[p.value], fields)
+    let arr = row.getHstoreArray(0)
+    check arr.len == 2
+    check arr[0] == h1
+    check arr[1] == h2
+
+  test "toPgParam seq[PgHstore] empty":
+    let p = toPgParam(newSeq[PgHstore]())
+    check p.oid == OidTextArray
+    check p.format == 0
+    check toString(p.value.get) == "{}"
+
+  test "toPgBinaryParam seq[PgHstore] roundtrip":
+    var h1: PgHstore = initTable[string, Option[string]]()
+    h1["x"] = some("y")
+    var h2: PgHstore = initTable[string, Option[string]]()
+    h2["nul"] = none(string)
+    let p = toPgBinaryParam(@[h1, h2], 16385'i32, 16386'i32)
+    check p.oid == 16386'i32
+    check p.format == 1
+    let fields = @[mkField(16386'i32, 1'i16)]
+    let row = mkRow(@[p.value], fields)
+    let arr = row.getHstoreArray(0)
+    check arr.len == 2
+    check arr[0] == h1
+    check arr[1] == h2
+
+  test "toPgBinaryParam seq[PgHstore] empty":
+    let p = toPgBinaryParam(newSeq[PgHstore](), 16385'i32, 16386'i32)
+    check p.oid == 16386'i32
+    check p.format == 1
+    let fields = @[mkField(16386'i32, 1'i16)]
+    let row = mkRow(@[p.value], fields)
+    check row.getHstoreArray(0).len == 0
+
+  test "getHstoreArray text format":
+    let row: Row = @[some(toBytes("{\"\\\"a\\\"=>\\\"1\\\"\",\"\\\"b\\\"=>NULL\"}"))]
+    let arr = row.getHstoreArray(0)
+    check arr.len == 2
+    check arr[0]["a"] == some("1")
+    check arr[1]["b"] == none(string)
+
+  test "getHstoreArrayOpt some":
+    var h1: PgHstore = initTable[string, Option[string]]()
+    h1["k"] = some("v")
+    let p = toPgParam(@[h1])
+    let fields = @[mkField(OidTextArray, 0'i16)]
+    let row = mkRow(@[p.value], fields)
+    let r = row.getHstoreArrayOpt(0)
+    check r.isSome
+    check r.get.len == 1
+    check r.get[0] == h1
+
+  test "getHstoreArrayOpt none":
+    let fields = @[mkField(OidTextArray, 0'i16)]
+    let row = mkRow(@[none(seq[byte])], fields)
+    check row.getHstoreArrayOpt(0).isNone
+
 suite "PgBit":
   test "OID constants":
     check OidBit == 1560'i32