diff --git a/informix/2.4/informix_transactions-1.1.0.mkp b/informix/2.4/informix_transactions-1.1.0.mkp
new file mode 100755
index 0000000..895c1d4
Binary files /dev/null and b/informix/2.4/informix_transactions-1.1.0.mkp differ
diff --git a/informix/2.4/local/lib/python3/cmk_addons/plugins/informix_transactions/agent_based/informix_transactions.py b/informix/2.4/local/lib/python3/cmk_addons/plugins/informix_transactions/agent_based/informix_transactions.py
new file mode 100644
index 0000000..48fc05e
--- /dev/null
+++ b/informix/2.4/local/lib/python3/cmk_addons/plugins/informix_transactions/agent_based/informix_transactions.py
@@ -0,0 +1,220 @@
+# Copyright 2026 Spearhead Systems SRL
+# Copyright (C) 2019 tribe29 GmbH
+#
+# Expected example input (and expect arbitrary blank lines):
+#
+# <<<informix_transactions>>>
+# [[[1/2]]]
+# a40dbb0  6        U---C-L  6        1:3263                500      372    74.40
+#
+# a6d8028   A---- a695028     0      -         -          COMMIT  -        0
+# a6d8348   A---- a695878     0      -         -          COMMIT  -        0
+# a6d8668   A---- a6960c8     0      -         -          COMMIT  -        0
+# a6d8988   A---- a696918     0      -         -          COMMIT  -        0
+# a6d8fc8   A---- a698208     0      -         -          COMMIT  -        0
+# a6d92e8   A---- a6979b8     0      -         -          COMMIT  -        0
+# a6d9608   A---- a698a58     0      -         -          COMMIT  -        0
+# a6d9928   A---- a6992a8     1      -         -          DIRTY   -        0
+# a6d9c48   A---- a6992a8     0      -         -          NOTRANS -        0
+# a6d9f68   A---- a69a348     0      -         -          COMMIT  -        0
+# a6da288   A---- a69ab98     0      -         -          COMMIT  -        0
+# a6da5a8   A---- a69b3e8     0      -         -          COMMIT  -        0
+# a6da8c8   A---- a69bc38     0      -         -          COMMIT  -        0
+# a6dabe8   A---- a69c488     0      -         -          COMMIT  -        0
+# a6daf08   A---- a699af8     0      -         -          COMMIT  -        0
+# a6db228   A---- a6992a8     0      -         -          COMMIT  -        0
+# a6db548   A---- a69ccd8     1      -         -          DIRTY   -        0
+# a6db868   A---- a69d528     1      -         -          DIRTY   -        0
+# a6dbb88   A---- a69ccd8     0      -         -          COMMIT  -        0
+# a6dbea8   A---- a69dd78     0      -         -          COMMIT  -        0
+# a6dc1c8   A---- a69e5c8     0      -         -          COMMIT  -        0
+# a6dc4e8   A-B-- a69ee18   502    33:0x25018  34:0x486fc COMMIT  0
+
+
+import json
+from cmk.agent_based.v2 import (
+    Result,
+    Service,
+    Metric,
+    State,
+    CheckPlugin,
+    AgentSection,
+)
+
+
+# This is what the columns from the onstat -x output represent:
+#
+# line[0]= first line represents current log ID
+# line[1]= <ignore>
+# line[2]= sessionID
+# line[3]= number of locks kept by sessionID
+# line[4]= begin log position
+# line[5]= current log position
+def parse_informix_transactions(string_table):
+    instance = string_table[0][0][3:-3]
+    curr_log = ""
+    sessions = []
+
+    for line in string_table[1:]:
+        if len(line) <= 5:
+            continue
+
+        if "C" in line[2]:
+            curr_log = int(line[3])
+            continue
+
+        if ":" in line[4]:
+            line[4] = int(line[4].split(":")[0])
+        else:
+            line[4] = None
+
+        if ":" in line[5]:
+            line[5] = int(line[5].split(":")[0])
+        else:
+            line[5] = None
+
+        sessions.append({
+            "id":        line[2],
+            "locks":     int(line[3]),
+            "log_start": line[4],
+            "log_end":   line[5],
+        })
+
+    return {
+        instance: {
+            "curr_log": curr_log,
+            "sessions": sessions,
+        }
+    }
+
+
+def discover_informix_transactions(section):
+    for instance in section:
+        yield Service(item=instance)
+
+
+def check_informix_locks(item, params, section):
+    data = section.get(item)
+    if not data:
+        return
+
+    levels    = params.get("levels")
+    infotext  = ""
+    state     = State.OK
+    max_locks = 0
+
+    if levels and levels[0] == "fixed":
+        warn, crit = levels[1]
+    else:
+        warn, crit = None, None
+
+    for session in data["sessions"]:
+        id        = session["id"]
+        locks     = session["locks"]
+        log_start = session["log_start"]
+
+        max_locks = max(max_locks, locks)
+
+        if log_start == "-":
+            continue
+
+        if crit and locks >= crit:
+            state = State.CRIT
+            infotext += f"Session with ID {id} has {locks} locks; "
+        elif warn and locks >= warn:
+            state = State.WARN
+            infotext += f"Session with ID {id} has {locks} locks; "
+
+    if state != State.OK:
+        infotext += f"(warn/crit at {warn}/{crit})"
+    else:
+        infotext = "There are no sessions with a high number of locks"
+
+    yield Metric(name="MaximumLocksInSession", value=max_locks)
+    yield Result(state=state, summary=infotext)
+
+
+def check_informix_activity(item, params, section):
+    data = section.get(item)
+    if not data:
+        return
+
+    state = State.OK
+    infotext = ""
+    curr_log = data["curr_log"]
+
+    for session in data["sessions"]:
+        id        = session["id"]
+        log_start = session["log_start"]
+
+        if log_start is None:
+            continue
+
+        if log_start < curr_log:
+            state = State.CRIT
+            infotext += f"Session {id} doesn't have activity in current log; "
+
+    if state == State.OK:
+        infotext = "There are no inactive sessions in current log"
+
+    yield Result(state=state, summary=infotext)
+
+
+def check_informix_long_transactions(item, params, section):
+    data = section.get(item)
+    if not data:
+        return
+
+    state = State.OK
+    infotext = ""
+
+    for session in data["sessions"]:
+        id        = session["id"]
+        log_start = session["log_start"]
+        log_end   = session["log_end"]
+
+        if log_start is None or log_end is None:
+            continue
+
+        if log_end - log_start > 2:
+            state = State.CRIT
+            infotext += f"Session {id} is using more than 3 logical logs; "
+
+    if state == State.OK:
+        infotext = "There are no long-running transactions"
+
+    yield Result(state=state, summary=infotext)
+
+
+agent_section_informix_transactions = AgentSection(
+    name           = "informix_transactions",
+    parse_function = parse_informix_transactions,
+)
+
+check_plugin_informix_session_locks = CheckPlugin(
+    name               = "informix_session_locks",
+    check_ruleset_name = "informix_session_locks",
+    service_name       = "Informix session locks %s",
+    sections           = ["informix_transactions"],
+    discovery_function = discover_informix_transactions,
+    check_function     = check_informix_locks,
+    check_default_parameters = {},
+)
+
+check_plugin_informix_session_activity = CheckPlugin(
+    name               = "informix_session_activity",
+    service_name       = "Informix session activity %s",
+    sections           = ["informix_transactions"],
+    discovery_function = discover_informix_transactions,
+    check_function     = check_informix_activity,
+    check_default_parameters = {},
+)
+
+check_plugin_informix_session_long_transactions = CheckPlugin(
+    name               = "informix_session_long_transactions",
+    service_name       = "Informix session long transactions %s",
+    sections           = ["informix_transactions"],
+    discovery_function = discover_informix_transactions,
+    check_function     = check_informix_long_transactions,
+    check_default_parameters = {},
+)
diff --git a/informix/2.4/local/lib/python3/cmk_addons/plugins/informix_transactions/rulesets/informix_transactions.py b/informix/2.4/local/lib/python3/cmk_addons/plugins/informix_transactions/rulesets/informix_transactions.py
new file mode 100644
index 0000000..eb94e76
--- /dev/null
+++ b/informix/2.4/local/lib/python3/cmk_addons/plugins/informix_transactions/rulesets/informix_transactions.py
@@ -0,0 +1,46 @@
+# Copyright 2026 Spearhead Systems SRL
+
+from cmk.rulesets.v1.form_specs import (
+    Dictionary,
+    DictElement,
+    Integer,
+    DefaultValue,
+    LevelDirection,
+    SimpleLevels,
+)
+from cmk.rulesets.v1.rule_specs import (
+    CheckParameters,
+    HostAndItemCondition,
+    Topic,
+    Title,
+    Help,
+)
+
+
+def _valuespec_informix_session_locks():
+    return Dictionary(
+        elements = {
+            "levels": DictElement(
+                parameter_form = SimpleLevels(
+                    title                = Title("Session locks"),
+                    help_text            = Help(
+                        "You can set a limit to the number of locks for a "
+                        "session in Informix Database application"
+                    ),
+                    level_direction      = LevelDirection.UPPER,
+                    form_spec_template   = Integer(title = Title("locks")),
+                    prefill_fixed_levels = DefaultValue(value=(40, 70))
+                )
+            ),
+        },
+    )
+
+rule_spec_informix_session_locks = CheckParameters(
+    title          = Title("Informix Session Locks"),
+    name           = "informix_session_locks",
+    topic          = Topic.APPLICATIONS,
+    parameter_form = _valuespec_informix_session_locks,
+    condition      = HostAndItemCondition(
+        item_title = Title("DBMS"),
+    ),
+)
diff --git a/informix/2.4/local/share/check_mk/agents/custom/informix_transactions/lib/plugins/informix_transactions b/informix/2.4/local/share/check_mk/agents/custom/informix_transactions/lib/plugins/informix_transactions
new file mode 100755
index 0000000..8cd421c
--- /dev/null
+++ b/informix/2.4/local/share/check_mk/agents/custom/informix_transactions/lib/plugins/informix_transactions
@@ -0,0 +1,184 @@
+#!/bin/bash
+# Copyright (C) 2019 Checkmk GmbH - License: GNU General Public License v2
+# This file is part of Checkmk (https://checkmk.com). It is subject to the terms and
+# conditions defined in the file COPYING, which is part of this source code package.
+
+# Reason for this no-op: shellcheck disable=... before the first command disables the error for the
+# entire script.
+:
+
+# Disable unused variable error (needed to keep track of version)
+# shellcheck disable=SC2034
+CMK_VERSION="2.4.0"
+
+# Informix
+# Make ENV-VARs avail for subshells
+set -a
+
+#   .--helper--------------------------------------------------------------.
+#   |                    _          _                                      |
+#   |                   | |__   ___| |_ __   ___ _ __                      |
+#   |                   | '_ \ / _ \ | '_ \ / _ \ '__|                     |
+#   |                   | | | |  __/ | |_) |  __/ |                        |
+#   |                   |_| |_|\___|_| .__/ \___|_|                        |
+#   |                                |_|                                   |
+#   '----------------------------------------------------------------------'
+
+# BEGIN COMMON PLUGIN CODE
+
+# check that no users other than root can change the file
+only_root_can_modify() {
+    permissions=$1
+    owner=$2
+    group=$3
+
+    group_write_perm=$(echo "$permissions" | cut -c 6)
+    other_write_perm=$(echo "$permissions" | cut -c 9)
+
+    if [ "$owner" != "root" ] || [ "$other_write_perm" != "-" ]; then
+        return 1
+    fi
+
+    [ "$group" = "root" ] || [ "$group_write_perm" = "-" ]
+}
+
+get_binary_owner() {
+    BINARY_PATH=$1
+    stat -c '%U' "${BINARY_PATH}"
+}
+
+get_binary_execution_mode() {
+    BINARY_PATH=$1
+    BINARY_USER=$2
+
+    # if the executable belongs to someone besides root, do not execute it as root
+    if needs_user_switch_before_executing "$BINARY_PATH"; then
+        echo "su ${BINARY_USER} -c"
+        return
+    fi
+    echo "bash -c"
+}
+
+needs_user_switch_before_executing() {
+    BINARY_PATH=$1
+
+    [ "$(whoami)" = "root" ] && ! only_root_can_modify "$(stat -c '%A' "$BINARY_PATH")" "$(stat -c '%U' "$BINARY_PATH")" "$(stat -c '%G' "$BINARY_PATH")"
+}
+
+# END COMMON PLUGIN CODE
+
+set_env() {
+    # set environment variables given in the form VARNAME1=value1;VARNAME2=value2;...
+    while IFS=';' read -ra parts; do
+        for part in "${parts[@]}"; do
+            var_name="${part%%=*}"
+            var_value="${part#*=}"
+            export "$var_name"="$var_value"
+        done
+    done <<<"$1"
+}
+
+
+#.
+#   .--sqls----------------------------------------------------------------.
+#   |                                     _                                |
+#   |                           ___  __ _| |___                            |
+#   |                          / __|/ _` | / __|                           |
+#   |                          \__ \ (_| | \__ \                           |
+#   |                          |___/\__, |_|___/                           |
+#   |                                  |_|                                 |
+#   '----------------------------------------------------------------------'
+
+informix_transactions() {
+    echo "<<<informix_transactions>>>"
+    echo "[[[$INFORMIXSERVER/$SERVERNUM]]]"
+    $EXECUTION_MODE "\"$INFORMIXDIR\"/bin/onstat -l" | grep C | tail -n 1
+    $EXECUTION_MODE "\"$INFORMIXDIR\"/bin/onstat -x" | egrep -v 'IBM|maximum|Transactions|est.|userthread|logpos' | sed 's/:[^:]*$//'
+}
+
+
+#.
+#   .--config--------------------------------------------------------------.
+#   |                                      __ _                            |
+#   |                      ___ ___  _ __  / _(_) __ _                      |
+#   |                     / __/ _ \| '_ \| |_| |/ _` |                     |
+#   |                    | (_| (_) | | | |  _| | (_| |                     |
+#   |                     \___\___/|_| |_|_| |_|\__, |                     |
+#   |                                           |___/                      |
+#   '----------------------------------------------------------------------'
+
+# Config opts:
+# - oninit-path; Default is empty, which means autodetection:
+#       ONINIT_PATH=<path to oninit-binary>
+# - Excluding sections ("status sessions locks tabextents dbspaces logusage"):
+#       EXCLUDES="SECTION SECTION ..."
+#       EXCLUDES=ALL
+
+# shellcheck source=agents/cfg_examples/informix.cfg
+. "$MK_CONFDIR/informix.cfg" 2>/dev/null
+
+if [ -z "$ONINIT_PATH" ] || [ ! -x "$ONINIT_PATH" ]; then
+    ONINIT=$(UNIX95=true ps ax | grep oninit | grep -v grep | head -1 | awk '{print $1 " " $5}')
+    if [ -z "$ONINIT" ]; then
+        exit 0
+    fi
+
+    ONINIT_PATH=${ONINIT#* }
+    ONINIT_PID=${ONINIT% *}
+    case "$ONINIT_PATH" in
+        /*) ;;
+
+        *) # BUG not platform independent!
+            ONINIT_PATH=$(readlink "/proc/$ONINIT_PID/exe")
+            ;;
+    esac
+
+    # If not set in config or not found we end up here
+    if [ -z "$ONINIT_PATH" ] || [ ! -f "$ONINIT_PATH" ]; then
+        exit 1
+    fi
+fi
+
+#.
+#   .--main----------------------------------------------------------------.
+#   |                                       _                              |
+#   |                       _ __ ___   __ _(_)_ __                         |
+#   |                      | '_ ` _ \ / _` | | '_ \                        |
+#   |                      | | | | | | (_| | | | | |                       |
+#   |                      |_| |_| |_|\__,_|_|_| |_|                       |
+#   |                                                                      |
+#   '----------------------------------------------------------------------'
+
+INFORMIXDIR=${ONINIT_PATH%/bin*}
+
+if [ ! -f "$INFORMIXDIR/bin/onstat" ]; then
+    exit 1
+fi
+
+EXECUTION_MODE="$(get_binary_execution_mode "$INFORMIXDIR/bin/onstat" "$(get_binary_owner "$INFORMIXDIR/bin/onstat")")"
+
+for IDSENV in $(
+    $EXECUTION_MODE "$INFORMIXDIR/bin/onstat -g dis" |
+        grep -E '^Server[         ]*:|^Server Number[     ]*:|^INFORMIX|^SQLHOSTS|^ONCONFIG' |
+        sed -e 's/Server Number/SERVERNUM/' \
+            -e 's/Server/INFORMIXSERVER/' \
+            -e 's/SQLHOSTS/INFORMIXSQLHOSTS/' \
+            -e 's/[     ]*:[    ]*/=/' |
+        tr '\n' ';' |
+        sed -e 's/;$/\n/' -e 's/;\(INFORMIXSERVER=[^;]*;\)/\n\1/g'
+
+); do
+    (
+        set_env "$IDSENV"
+
+        # try to set them via 'onstat -g env' otherwise
+        # DB HAS TO BE RUNNING
+        if [ -z "$INFORMIXSQLHOSTS" ] || [ -z "$ONCONFIG" ]; then
+            $EXECUTION_MODE "$INFORMIXDIR/bin/onstat -g env" | grep -E -e '^INFORMIXSQLHOSTS' \
+                -e '^ONCONFIG' |
+                sed -e 's/[         ][      ]*/=/'
+        fi
+
+        informix_transactions
+    )
+done