Initial commit

.gradle/buildOutputCleanup/cache.properties

@@ -0,0 +1,2 @@
+#Fri Oct 10 12:56:24 EAT 2025
+gradle.version=8.14.3

.idea/.gitignore

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+# Default ignored files
+/shelf/
+/workspace.xml
+# Environment-dependent path to Maven home directory
+/mavenHomeManager.xml

.idea/.name

@@ -0,0 +1 @@
+payment

.idea/compiler.xml

@@ -0,0 +1,18 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="CompilerConfiguration">
+    <annotationProcessing>
+      <profile name="Gradle Imported" enabled="true">
+        <outputRelativeToContentRoot value="true" />
+        <processorPath useClasspath="false">
+          <entry name="$USER_HOME$/.gradle/caches/modules-2/files-2.1/org.projectlombok/lombok/1.18.32/17d46b3e205515e1e8efd3ee4d57ce8018914163/lombok-1.18.32.jar" />
+        </processorPath>
+        <module name="payment.main" />
+      </profile>
+    </annotationProcessing>
+    <bytecodeTargetLevel target="17" />
+  </component>
+  <component name="JavacSettings">
+    <option name="ADDITIONAL_OPTIONS_STRING" value="-parameters" />
+  </component>
+</project>

.idea/gradle.xml

@@ -0,0 +1,15 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="GradleSettings">
+    <option name="linkedExternalProjectsSettings">
+      <GradleProjectSettings>
+        <option name="externalProjectPath" value="$PROJECT_DIR$" />
+        <option name="modules">
+          <set>
+            <option value="$PROJECT_DIR$" />
+          </set>
+        </option>
+      </GradleProjectSettings>
+    </option>
+  </component>
+</project>

.idea/misc.xml

@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="ExternalStorageConfigurationManager" enabled="true" />
+  <component name="ProjectRootManager" version="2" languageLevel="JDK_17" project-jdk-name="ms-17" project-jdk-type="JavaSDK" />
+</project>

.idea/modules.xml

@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="ProjectModuleManager">
+    <modules>
+      <module fileurl="file://$PROJECT_DIR$/.idea/modules/payment.main.iml" filepath="$PROJECT_DIR$/.idea/modules/payment.main.iml" />
+    </modules>
+  </component>
+</project>

.idea/modules/payment.main.iml

@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<module version="4">
+  <component name="AdditionalModuleElements">
+    <content url="file://$MODULE_DIR$/../../build/generated/sources/annotationProcessor/java/main">
+      <sourceFolder url="file://$MODULE_DIR$/../../build/generated/sources/annotationProcessor/java/main" isTestSource="false" generated="true" />
+    </content>
+  </component>
+</module>

.idea/vcs.xml

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="VcsDirectoryMappings">
+    <mapping directory="" vcs="Git" />
+  </component>
+</project>

HELP.md

@@ -0,0 +1,14 @@
+# Getting Started
+
+### Reference Documentation
+For further reference, please consider the following sections:
+
+* [Official Gradle documentation](https://docs.gradle.org)
+* [Spring Boot Gradle Plugin Reference Guide](https://docs.spring.io/spring-boot/3.5.6/gradle-plugin)
+* [Create an OCI image](https://docs.spring.io/spring-boot/3.5.6/gradle-plugin/packaging-oci-image.html)
+
+### Additional Links
+These additional references should also help you:
+
+* [Gradle Build Scans – insights for your project's build](https://scans.gradle.com#gradle)
+

build.gradle

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+plugins {
+	id 'java'
+	id 'org.springframework.boot' version '3.5.6'
+	id 'io.spring.dependency-management' version '1.1.7'
+}
+
+group = 'com.test'
+version = '0.0.1-SNAPSHOT'
+description = 'Demo project for Spring Boot'
+
+java {
+	toolchain {
+		languageVersion = JavaLanguageVersion.of(17)
+	}
+}
+
+repositories {
+	mavenCentral()
+}
+
+
+dependencies {
+	implementation("org.springframework.boot:spring-boot-starter-webflux")
+	implementation("org.springframework.boot:spring-boot-starter-data-jpa")
+	implementation("org.springframework.boot:spring-boot-starter-data-r2dbc")/*
+	implementation("io.r2dbc:r2dbc-postgresql")*/
+
+	implementation("org.springframework.boot:spring-boot-starter-data-redis-reactive")
+	implementation("io.lettuce:lettuce-core:6.2.2.RELEASE")
+
+	implementation 'com.h2database:h2'
+
+	implementation("io.github.resilience4j:resilience4j-reactor:2.0.2")
+	implementation("io.github.resilience4j:resilience4j-ratelimiter:2.0.2")
+	implementation("io.github.resilience4j:resilience4j-circuitbreaker:2.0.2")
+	implementation("io.github.resilience4j:resilience4j-retry:2.0.2")
+	implementation("io.github.resilience4j:resilience4j-spring-boot3:2.0.2")
+
+	implementation("org.springframework.boot:spring-boot-starter")
+
+	implementation 'org.projectlombok:lombok:1.18.32' // Use the latest stable version
+	annotationProcessor 'org.projectlombok:lombok:1.18.32' // For annotation processing
+
+	testImplementation("org.springframework.boot:spring-boot-starter-test")
+}
+
+
+tasks.named('test') {
+	useJUnitPlatform()
+}

build/resources/main/application.yml

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+#spring:
+ # redis:
+  #  host: localhost
+   # port: 6379
+
+resilience4j:
+  ratelimiter:
+    instances:
+      mpesaLimiter:
+        limit-for-period: 10
+        limit-refresh-period: 1s
+        timeout-duration: 0s
+
+  retry:
+    instances:
+      mpesaRetry:
+        max-attempts: 3
+        wait-duration: 2s
+        retry-exceptions:
+          - org.springframework.web.reactive.function.client.WebClientRequestException
+          - java.io.IOException
+        ignore-exceptions:
+          - com.test.payment.exceptions.MpesaPermanentException
+
+  circuitbreaker:
+    instances:
+      mpesaCircuitBreaker:
+        sliding-window-size: 10
+        permitted-number-of-calls-in-half-open-state: 3
+        failure-rate-threshold: 50
+        wait-duration-in-open-state: 10s
+
+spring:
+  datasource:
+    url: jdbc:h2:mem:testdb;DB_CLOSE_DELAY=-1;DB_CLOSE_ON_EXIT=FALSE
+    driverClassName: org.h2.Driver
+    username: sa
+    password: password
+    platform: h2
+

gradle/wrapper/gradle-wrapper.properties

@@ -0,0 +1,7 @@
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.14.3-bin.zip
+networkTimeout=10000
+validateDistributionUrl=true
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists

gradlew

@@ -0,0 +1,251 @@
+#!/bin/sh
+
+#
+# Copyright © 2015-2021 the original authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+# SPDX-License-Identifier: Apache-2.0
+#
+
+##############################################################################
+#
+#   Gradle start up script for POSIX generated by Gradle.
+#
+#   Important for running:
+#
+#   (1) You need a POSIX-compliant shell to run this script. If your /bin/sh is
+#       noncompliant, but you have some other compliant shell such as ksh or
+#       bash, then to run this script, type that shell name before the whole
+#       command line, like:
+#
+#           ksh Gradle
+#
+#       Busybox and similar reduced shells will NOT work, because this script
+#       requires all of these POSIX shell features:
+#         * functions;
+#         * expansions «$var», «${var}», «${var:-default}», «${var+SET}»,
+#           «${var#prefix}», «${var%suffix}», and «$( cmd )»;
+#         * compound commands having a testable exit status, especially «case»;
+#         * various built-in commands including «command», «set», and «ulimit».
+#
+#   Important for patching:
+#
+#   (2) This script targets any POSIX shell, so it avoids extensions provided
+#       by Bash, Ksh, etc; in particular arrays are avoided.
+#
+#       The "traditional" practice of packing multiple parameters into a
+#       space-separated string is a well documented source of bugs and security
+#       problems, so this is (mostly) avoided, by progressively accumulating
+#       options in "$@", and eventually passing that to Java.
+#
+#       Where the inherited environment variables (DEFAULT_JVM_OPTS, JAVA_OPTS,
+#       and GRADLE_OPTS) rely on word-splitting, this is performed explicitly;
+#       see the in-line comments for details.
+#
+#       There are tweaks for specific operating systems such as AIX, CygWin,
+#       Darwin, MinGW, and NonStop.
+#
+#   (3) This script is generated from the Groovy template
+#       https://github.com/gradle/gradle/blob/HEAD/platforms/jvm/plugins-application/src/main/resources/org/gradle/api/internal/plugins/unixStartScript.txt
+#       within the Gradle project.
+#
+#       You can find Gradle at https://github.com/gradle/gradle/.
+#
+##############################################################################
+
+# Attempt to set APP_HOME
+
+# Resolve links: $0 may be a link
+app_path=$0
+
+# Need this for daisy-chained symlinks.
+while
+    APP_HOME=${app_path%"${app_path##*/}"}  # leaves a trailing /; empty if no leading path
+    [ -h "$app_path" ]
+do
+    ls=$( ls -ld "$app_path" )
+    link=${ls#*' -> '}
+    case $link in             #(
+      /*)   app_path=$link ;; #(
+      *)    app_path=$APP_HOME$link ;;
+    esac
+done
+
+# This is normally unused
+# shellcheck disable=SC2034
+APP_BASE_NAME=${0##*/}
+# Discard cd standard output in case $CDPATH is set (https://github.com/gradle/gradle/issues/25036)
+APP_HOME=$( cd -P "${APP_HOME:-./}" > /dev/null && printf '%s\n' "$PWD" ) || exit
+
+# Use the maximum available, or set MAX_FD != -1 to use that value.
+MAX_FD=maximum
+
+warn () {
+    echo "$*"
+} >&2
+
+die () {
+    echo
+    echo "$*"
+    echo
+    exit 1
+} >&2
+
+# OS specific support (must be 'true' or 'false').
+cygwin=false
+msys=false
+darwin=false
+nonstop=false
+case "$( uname )" in                #(
+  CYGWIN* )         cygwin=true  ;; #(
+  Darwin* )         darwin=true  ;; #(
+  MSYS* | MINGW* )  msys=true    ;; #(
+  NONSTOP* )        nonstop=true ;;
+esac
+
+CLASSPATH="\\\"\\\""
+
+
+# Determine the Java command to use to start the JVM.
+if [ -n "$JAVA_HOME" ] ; then
+    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
+        # IBM's JDK on AIX uses strange locations for the executables
+        JAVACMD=$JAVA_HOME/jre/sh/java
+    else
+        JAVACMD=$JAVA_HOME/bin/java
+    fi
+    if [ ! -x "$JAVACMD" ] ; then
+        die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+    fi
+else
+    JAVACMD=java
+    if ! command -v java >/dev/null 2>&1
+    then
+        die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+    fi
+fi
+
+# Increase the maximum file descriptors if we can.
+if ! "$cygwin" && ! "$darwin" && ! "$nonstop" ; then
+    case $MAX_FD in #(
+      max*)
+        # In POSIX sh, ulimit -H is undefined. That's why the result is checked to see if it worked.
+        # shellcheck disable=SC2039,SC3045
+        MAX_FD=$( ulimit -H -n ) ||
+            warn "Could not query maximum file descriptor limit"
+    esac
+    case $MAX_FD in  #(
+      '' | soft) :;; #(
+      *)
+        # In POSIX sh, ulimit -n is undefined. That's why the result is checked to see if it worked.
+        # shellcheck disable=SC2039,SC3045
+        ulimit -n "$MAX_FD" ||
+            warn "Could not set maximum file descriptor limit to $MAX_FD"
+    esac
+fi
+
+# Collect all arguments for the java command, stacking in reverse order:
+#   * args from the command line
+#   * the main class name
+#   * -classpath
+#   * -D...appname settings
+#   * --module-path (only if needed)
+#   * DEFAULT_JVM_OPTS, JAVA_OPTS, and GRADLE_OPTS environment variables.
+
+# For Cygwin or MSYS, switch paths to Windows format before running java
+if "$cygwin" || "$msys" ; then
+    APP_HOME=$( cygpath --path --mixed "$APP_HOME" )
+    CLASSPATH=$( cygpath --path --mixed "$CLASSPATH" )
+
+    JAVACMD=$( cygpath --unix "$JAVACMD" )
+
+    # Now convert the arguments - kludge to limit ourselves to /bin/sh
+    for arg do
+        if
+            case $arg in                                #(
+              -*)   false ;;                            # don't mess with options #(
+              /?*)  t=${arg#/} t=/${t%%/*}              # looks like a POSIX filepath
+                    [ -e "$t" ] ;;                      #(
+              *)    false ;;
+            esac
+        then
+            arg=$( cygpath --path --ignore --mixed "$arg" )
+        fi
+        # Roll the args list around exactly as many times as the number of
+        # args, so each arg winds up back in the position where it started, but
+        # possibly modified.
+        #
+        # NB: a `for` loop captures its iteration list before it begins, so
+        # changing the positional parameters here affects neither the number of
+        # iterations, nor the values presented in `arg`.
+        shift                   # remove old arg
+        set -- "$@" "$arg"      # push replacement arg
+    done
+fi
+
+
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
+
+# Collect all arguments for the java command:
+#   * DEFAULT_JVM_OPTS, JAVA_OPTS, and optsEnvironmentVar are not allowed to contain shell fragments,
+#     and any embedded shellness will be escaped.
+#   * For example: A user cannot expect ${Hostname} to be expanded, as it is an environment variable and will be
+#     treated as '${Hostname}' itself on the command line.
+
+set -- \
+        "-Dorg.gradle.appname=$APP_BASE_NAME" \
+        -classpath "$CLASSPATH" \
+        -jar "$APP_HOME/gradle/wrapper/gradle-wrapper.jar" \
+        "$@"
+
+# Stop when "xargs" is not available.
+if ! command -v xargs >/dev/null 2>&1
+then
+    die "xargs is not available"
+fi
+
+# Use "xargs" to parse quoted args.
+#
+# With -n1 it outputs one arg per line, with the quotes and backslashes removed.
+#
+# In Bash we could simply go:
+#
+#   readarray ARGS < <( xargs -n1 <<<"$var" ) &&
+#   set -- "${ARGS[@]}" "$@"
+#
+# but POSIX shell has neither arrays nor command substitution, so instead we
+# post-process each arg (as a line of input to sed) to backslash-escape any
+# character that might be a shell metacharacter, then use eval to reverse
+# that process (while maintaining the separation between arguments), and wrap
+# the whole thing up as a single "set" statement.
+#
+# This will of course break if any of these variables contains a newline or
+# an unmatched quote.
+#
+
+eval "set -- $(
+        printf '%s\n' "$DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS" |
+        xargs -n1 |
+        sed ' s~[^-[:alnum:]+,./:=@_]~\\&~g; ' |
+        tr '\n' ' '
+    )" '"$@"'
+
+exec "$JAVACMD" "$@"

gradlew.bat

@@ -0,0 +1,94 @@
+@rem
+@rem Copyright 2015 the original author or authors.
+@rem
+@rem Licensed under the Apache License, Version 2.0 (the "License");
+@rem you may not use this file except in compliance with the License.
+@rem You may obtain a copy of the License at
+@rem
+@rem      https://www.apache.org/licenses/LICENSE-2.0
+@rem
+@rem Unless required by applicable law or agreed to in writing, software
+@rem distributed under the License is distributed on an "AS IS" BASIS,
+@rem WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+@rem See the License for the specific language governing permissions and
+@rem limitations under the License.
+@rem
+@rem SPDX-License-Identifier: Apache-2.0
+@rem
+
+@if "%DEBUG%"=="" @echo off
+@rem ##########################################################################
+@rem
+@rem  Gradle startup script for Windows
+@rem
+@rem ##########################################################################
+
+@rem Set local scope for the variables with windows NT shell
+if "%OS%"=="Windows_NT" setlocal
+
+set DIRNAME=%~dp0
+if "%DIRNAME%"=="" set DIRNAME=.
+@rem This is normally unused
+set APP_BASE_NAME=%~n0
+set APP_HOME=%DIRNAME%
+
+@rem Resolve any "." and ".." in APP_HOME to make it shorter.
+for %%i in ("%APP_HOME%") do set APP_HOME=%%~fi
+
+@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+set DEFAULT_JVM_OPTS="-Xmx64m" "-Xms64m"
+
+@rem Find java.exe
+if defined JAVA_HOME goto findJavaFromJavaHome
+
+set JAVA_EXE=java.exe
+%JAVA_EXE% -version >NUL 2>&1
+if %ERRORLEVEL% equ 0 goto execute
+
+echo. 1>&2
+echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH. 1>&2
+echo. 1>&2
+echo Please set the JAVA_HOME variable in your environment to match the 1>&2
+echo location of your Java installation. 1>&2
+
+goto fail
+
+:findJavaFromJavaHome
+set JAVA_HOME=%JAVA_HOME:"=%
+set JAVA_EXE=%JAVA_HOME%/bin/java.exe
+
+if exist "%JAVA_EXE%" goto execute
+
+echo. 1>&2
+echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME% 1>&2
+echo. 1>&2
+echo Please set the JAVA_HOME variable in your environment to match the 1>&2
+echo location of your Java installation. 1>&2
+
+goto fail
+
+:execute
+@rem Setup the command line
+
+set CLASSPATH=
+
+
+@rem Execute Gradle
+"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" -jar "%APP_HOME%\gradle\wrapper\gradle-wrapper.jar" %*
+
+:end
+@rem End local scope for the variables with windows NT shell
+if %ERRORLEVEL% equ 0 goto mainEnd
+
+:fail
+rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of
+rem the _cmd.exe /c_ return code!
+set EXIT_CODE=%ERRORLEVEL%
+if %EXIT_CODE% equ 0 set EXIT_CODE=1
+if not ""=="%GRADLE_EXIT_CONSOLE%" exit %EXIT_CODE%
+exit /b %EXIT_CODE%
+
+:mainEnd
+if "%OS%"=="Windows_NT" endlocal
+
+:omega

settings.gradle

@@ -0,0 +1 @@
+rootProject.name = 'payment'

src/main/java/com/test/payment/PaymentApplication.java

@@ -0,0 +1,15 @@
+package com.test.payment;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.scheduling.annotation.EnableScheduling;
+
+@SpringBootApplication
+@EnableScheduling
+public class PaymentApplication {
+
+	public static void main(String[] args) {
+		SpringApplication.run(PaymentApplication.class, args);
+	}
+
+}

src/main/java/com/test/payment/configurations/RedisConfig.java

@@ -0,0 +1,22 @@
+package com.test.payment.configurations;
+
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.data.redis.connection.lettuce.LettuceConnectionFactory;
+import org.springframework.data.redis.core.RedisTemplate;
+
+@Configuration
+public class RedisConfig {
+
+    @Bean
+    public LettuceConnectionFactory redisConnectionFactory() {
+        return new LettuceConnectionFactory();
+    }
+
+    @Bean
+    public RedisTemplate<String, String> redisTemplate(LettuceConnectionFactory factory) {
+        RedisTemplate<String, String> template = new RedisTemplate<>();
+        template.setConnectionFactory(factory);
+        return template;
+    }
+}

src/main/java/com/test/payment/configurations/ResilienceConfig.java

@@ -0,0 +1,45 @@
+package com.test.payment.configurations;
+
+import com.test.payment.exceptions.MpesaPermanentException;
+import io.github.resilience4j.circuitbreaker.*;
+import io.github.resilience4j.ratelimiter.*;
+import io.github.resilience4j.retry.*;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.web.reactive.function.client.WebClientRequestException;
+
+import java.io.IOException;
+import java.time.Duration;
+
+@Configuration
+public class ResilienceConfig {
+
+    @Bean
+    public RateLimiter rateLimiter() {
+        return RateLimiter.of("mpesaLimiter", RateLimiterConfig.custom()
+                .limitForPeriod(10)
+                .limitRefreshPeriod(Duration.ofSeconds(1))
+                .timeoutDuration(Duration.ZERO)
+                .build());
+    }
+
+    @Bean
+    public Retry retry() {
+        return Retry.of("mpesaRetry", RetryConfig.custom()
+                .maxAttempts(3)
+                .waitDuration(Duration.ofSeconds(2))
+                .retryExceptions(WebClientRequestException.class, IOException.class)
+                .ignoreExceptions(MpesaPermanentException.class)
+                .build());
+    }
+
+    @Bean
+    public CircuitBreaker circuitBreaker() {
+        return CircuitBreaker.of("mpesaCircuitBreaker", CircuitBreakerConfig.custom()
+                .failureRateThreshold(50)
+                .waitDurationInOpenState(Duration.ofSeconds(10))
+                .permittedNumberOfCallsInHalfOpenState(3)
+                .slidingWindowSize(10)
+                .build());
+    }
+}

src/main/java/com/test/payment/configurations/WebClientConfig.java

@@ -0,0 +1,16 @@
+package com.test.payment.configurations;
+
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.web.reactive.function.client.WebClient;
+
+@Configuration
+public class WebClientConfig {
+
+    @Bean
+    public WebClient mpesaWebClient(WebClient.Builder builder) {
+        return builder
+                .baseUrl("https://sandbox.safaricom.co.ke")
+                .build();
+    }
+}

src/main/java/com/test/payment/controller/MpesaController.java

@@ -0,0 +1,28 @@
+package com.test.payment.controller;
+
+
+import com.test.payment.models.*;
+import com.test.payment.models.MpesaResponse;
+import com.test.payment.models.PaymentRequest;
+import com.test.payment.service.MpesaService;
+import lombok.RequiredArgsConstructor;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.*;
+import reactor.core.publisher.Mono;
+
+@RestController
+@RequestMapping("/api/mpesa")
+@RequiredArgsConstructor
+public class MpesaController {
+
+    private final MpesaService mpesaService;
+
+    @PostMapping("/pay")
+    public Mono<ResponseEntity<MpesaResponse>> pay(@RequestBody PaymentRequest request) {
+        return mpesaService.initiatePayment(request)
+                .map(ResponseEntity::ok)
+                .onErrorResume(ex -> Mono.just(ResponseEntity.badRequest()
+                        .body(new MpesaResponse("FAILED", ex.getMessage()))));
+    }
+}
+

src/main/java/com/test/payment/exceptions/MpesaPermanentException.java

@@ -0,0 +1,8 @@
+package com.test.payment.exceptions;
+
+
+public class MpesaPermanentException extends RuntimeException {
+    public MpesaPermanentException(String msg) {
+        super(msg);
+    }
+}

src/main/java/com/test/payment/exceptions/MpesaTransientException.java

@@ -0,0 +1,7 @@
+package com.test.payment.exceptions;
+
+public class MpesaTransientException extends RuntimeException {
+    public MpesaTransientException(String msg, Throwable cause) {
+        super(msg, cause);
+    }
+}

src/main/java/com/test/payment/jobs/MpesaTransactionJob.java

@@ -0,0 +1,23 @@
+package com.test.payment.jobs;
+
+
+import com.test.payment.repository.MpesaRepository;
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.scheduling.annotation.Scheduled;
+import org.springframework.stereotype.Component;
+
+@Component
+@RequiredArgsConstructor
+@Slf4j
+public class MpesaTransactionJob {
+
+    private final MpesaRepository mpesaRepository;
+
+    @Scheduled(fixedDelay = 60000)
+    public void pullTransactions() {
+        mpesaRepository.findAllTransactions()
+                .doOnNext(tx -> log.info("Checking transaction: {}", tx))
+                .subscribe();
+    }
+}

src/main/java/com/test/payment/models/MpesaResponse.java

@@ -0,0 +1,13 @@
+package com.test.payment.models;
+
+import lombok.AllArgsConstructor;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+@Data
+@AllArgsConstructor
+@NoArgsConstructor
+public class MpesaResponse {
+    private String status;
+    private String message;
+}

src/main/java/com/test/payment/models/PaymentRequest.java

@@ -0,0 +1,12 @@
+package com.test.payment.models;
+
+
+import lombok.Data;
+
+@Data
+public class PaymentRequest {
+    private String phoneNumber;
+    private double amount;
+    private String accountReference;
+    private String transactionDesc;
+}

src/main/java/com/test/payment/models/Transaction.java

@@ -0,0 +1,21 @@
+package com.test.payment.models;
+
+import jakarta.persistence.Entity;
+import jakarta.persistence.Id;
+import lombok.AllArgsConstructor;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+@Data
+@AllArgsConstructor
+@NoArgsConstructor
+@Entity
+public class Transaction {
+
+    @Id
+    private String id;
+    private String phoneNumber;
+    private double amount;
+    private String status;
+}
+

src/main/java/com/test/payment/repository/MpesaRepository.java

@@ -0,0 +1,31 @@
+package com.test.payment.repository;
+
+
+import com.test.payment.models.Transaction;
+import org.springframework.data.redis.core.RedisTemplate;
+import org.springframework.stereotype.Repository;
+import reactor.core.publisher.Flux;
+import reactor.core.publisher.Mono;
+
+import java.util.List;
+
+@Repository
+public class MpesaRepository {
+
+    private final RedisTemplate<String, String> redisTemplate;
+
+    public MpesaRepository(RedisTemplate<String, String> redisTemplate) {
+        this.redisTemplate = redisTemplate;
+    }
+
+    public Mono<Void> saveTransaction(Transaction transaction) {
+        return Mono.fromRunnable(() ->
+                redisTemplate.opsForHash().put("mpesa:transactions", transaction.getId(), transaction.getStatus())
+        ).then();
+    }
+
+    public Flux<Transaction> findAllTransactions() {
+        List<Object> values = redisTemplate.opsForHash().values("mpesa:transactions");
+        return Flux.fromIterable(values).cast(Transaction.class);
+    }
+}

src/main/java/com/test/payment/service/MpesaService.java

@@ -0,0 +1,65 @@
+package com.test.payment.service;
+
+
+import com.test.payment.exceptions.MpesaPermanentException;
+import com.test.payment.exceptions.MpesaTransientException;
+import com.test.payment.models.*;
+import com.test.payment.repository.MpesaRepository;
+import io.github.resilience4j.circuitbreaker.*;
+import io.github.resilience4j.ratelimiter.*;
+import io.github.resilience4j.retry.*;
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.stereotype.Service;
+import org.springframework.web.reactive.function.client.WebClient;
+import reactor.core.publisher.Mono;
+
+import java.util.UUID;
+import java.util.function.Supplier;
+
+@Service
+@RequiredArgsConstructor
+@Slf4j
+public class MpesaService {
+
+    private final WebClient mpesaWebClient;
+    private final MpesaRepository mpesaRepository;
+    private final MpesaTokenService tokenService;
+    private final RateLimiter rateLimiter;
+    private final Retry retry;
+    private final CircuitBreaker circuitBreaker;
+
+    public Mono<MpesaResponse> initiatePayment(PaymentRequest request) {
+        Supplier<Mono<MpesaResponse>> decoratedSupplier =
+                CircuitBreaker.decorateSupplier(circuitBreaker,
+                        RateLimiter.decorateSupplier(rateLimiter,
+                                Retry.decorateSupplier(retry, () -> callMpesa(request))
+                        )
+                );
+
+        return Mono.defer(decoratedSupplier)
+                .flatMap(response -> {
+                    Transaction tx = new Transaction(UUID.randomUUID().toString(),
+                            request.getPhoneNumber(), request.getAmount(), response.getStatus());
+                    return mpesaRepository.saveTransaction(tx).thenReturn(response);
+                })
+                .doOnError(e -> log.error("M-Pesa API failed: {}", e.getMessage()));
+    }
+
+    private Mono<MpesaResponse> callMpesa(PaymentRequest request) {
+        return tokenService.getToken()
+                .flatMap(token ->
+                        mpesaWebClient.post()
+                                .uri("/mpesa/stkpush/v1/processrequest")
+                                .header("Authorization", "Bearer " + token)
+                                .bodyValue(request)
+                                .retrieve()
+                                .bodyToMono(MpesaResponse.class)
+                                .timeout(java.time.Duration.ofSeconds(20))
+                                .onErrorResume(ex -> {
+                                    log.error("Error calling M-Pesa: {}", ex.getMessage());
+                                    return Mono.error(new MpesaTransientException("Temporary M-Pesa issue", ex));
+                                })
+                );
+    }
+}

src/main/java/com/test/payment/service/MpesaTokenService.java

@@ -0,0 +1,27 @@
+package com.test.payment.service;
+
+
+import lombok.RequiredArgsConstructor;
+import org.springframework.data.redis.core.RedisTemplate;
+import org.springframework.stereotype.Service;
+import reactor.core.publisher.Mono;
+
+import java.time.Duration;
+
+@Service
+@RequiredArgsConstructor
+public class MpesaTokenService {
+
+    private final RedisTemplate<String, String> redisTemplate;
+
+    public Mono<String> getToken() {
+        String cachedToken = redisTemplate.opsForValue().get("mpesa:token");
+        if (cachedToken != null) {
+            return Mono.just(cachedToken);
+        }
+        // Simulate token fetch from M-Pesa auth endpoint
+        String newToken = "access_token_" + System.currentTimeMillis();
+        redisTemplate.opsForValue().set("mpesa:token", newToken, Duration.ofMinutes(50));
+        return Mono.just(newToken);
+    }
+}

src/main/resources/application.yml

@@ -0,0 +1,40 @@
+#spring:
+ # redis:
+  #  host: localhost
+   # port: 6379
+
+resilience4j:
+  ratelimiter:
+    instances:
+      mpesaLimiter:
+        limit-for-period: 10
+        limit-refresh-period: 1s
+        timeout-duration: 0s
+
+  retry:
+    instances:
+      mpesaRetry:
+        max-attempts: 3
+        wait-duration: 2s
+        retry-exceptions:
+          - org.springframework.web.reactive.function.client.WebClientRequestException
+          - java.io.IOException
+        ignore-exceptions:
+          - com.test.payment.exceptions.MpesaPermanentException
+
+  circuitbreaker:
+    instances:
+      mpesaCircuitBreaker:
+        sliding-window-size: 10
+        permitted-number-of-calls-in-half-open-state: 3
+        failure-rate-threshold: 50
+        wait-duration-in-open-state: 10s
+
+spring:
+  datasource:
+    url: jdbc:h2:mem:testdb;DB_CLOSE_DELAY=-1;DB_CLOSE_ON_EXIT=FALSE
+    driverClassName: org.h2.Driver
+    username: sa
+    password: password
+    platform: h2
+

src/test/java/com/test/payment/PaymentApplicationTests.java

@@ -0,0 +1,13 @@
+package com.test.payment;
+
+import org.junit.jupiter.api.Test;
+import org.springframework.boot.test.context.SpringBootTest;
+
+@SpringBootTest
+class PaymentApplicationTests {
+
+	@Test
+	void contextLoads() {
+	}
+
+}