Does Harness generate API tests like Keploy?

No. Harness Test Intelligence optimizes the execution of existing tests but does not create new ones. Keploy's core value is auto-generating tests from production traffic. They solve different problems: Keploy creates tests, Harness runs them smarter.

Can I use Keploy with Harness CI/CD?

Yes. Keploy integrates with any CI/CD system including Harness. You can generate tests with Keploy and run them within Harness pipelines, potentially using Test Intelligence to optimize which Keploy-generated tests to run per commit.

Which tool reduces testing costs more?

Keploy reduces the cost of creating tests by eliminating manual test writing. Harness reduces the cost of running tests by selecting only relevant ones. If you spend more on writing tests, choose Keploy. If you spend more on CI compute, choose Harness.

Is Harness open source?

Harness open-sourced Gitness, a lightweight CI/CD platform. The full Harness platform including Test Intelligence is commercial. Keploy's core is fully open-source under Apache 2.0 with optional enterprise features.

Can Test Intelligence work with Keploy-generated tests?

In principle, yes. Test Intelligence analyzes code-to-test mappings to select affected tests. If Keploy-generated tests are in a supported format, Harness can apply intelligent selection. The integration depends on how test artifacts are structured.

Try Keploy with Claude

Keploy

Harness

What Harness Can’t Test, Keploy Cancatch what breaks

CI/CD Platform with Test Intelligence and Chaos Engineering

Keploy auto-generates API tests from real production traffic using eBPF, while Harness is a comprehensive CI/CD platform with Test Intelligence that optimizes test execution by selecting only tests affected by code changes. Keploy creates tests automatically; Harness optimizes existing test suites to run faster in CI/CD pipelines.

Try Keploy Free Read the Docs

18.4K+

GitHub Stars

1.2M+

Installs

Zero

Code Changes

Apache 2.0

Open Source License

eBPF · zero code changes

How Keploy turns real traffic into a test suite

One pipeline, running the moment your app receives a request. No SDKs, no sidecars, no test scripts — just kernel-level capture that becomes deterministic regression coverage.

01
Real API traffic
Live requests + responses from your running app
02
eBPF capture
Kernel-level recording — zero code changes
03
Normalize
Time-freeze + field noise removed automatically
04
Generate tests
Deterministic test cases from actual behavior
05
Generate mocks
Every downstream dependency stubbed for you
06
Replay in CI
Runs locally, in CI, or in-cluster on Kubernetes
07
Regression detection
Diffs flagged before they reach production

See how the capture-replay engine works under the hood.

Star on GitHub Read the docs

Trusted by engineering teams at scale

Globality

IdeyaLabs

Globality

IdeyaLabs

Globality

IdeyaLabs

Globality

IdeyaLabs

Why teams switch from Harness

Keploy eliminates manual test authoring by generating tests automatically from real traffic — no scripts, no stubs, no infrastructure setup.

Your bottleneck is creating tests, not running them faster

You need auto-generated API tests from real production traffic

You want dependency mocks generated automatically

The numbers behind the switch

Industry data on how much manual testing costs teams — and what Keploy delivers from the first recording session.

The cost of manual testing

Engineering time on toil

Writing tests, configuring mocks, debugging flakiness — not building features that ship.

Tests break on next refactor

A routine rename or interface change silently invalidates more than half your suite.

What Keploy delivers

Coverage from first recording

Keploy generates tests from every request your API actually handles — no guessing.

Production paths covered

Traffic capture reaches edge cases, error paths, and concurrent requests no dev would write.

Pain stats sourced from developer productivity surveys. Coverage stats from Keploy production recording sessions across 50+ engineering teams.

Every number here comes from teams running Keploy in CI.

Explore Keploy Read the docs

Zero code. Real tests. Automatically.

Keploy's eBPF agent intercepts every API call at the kernel level and turns live traffic into test cases with dependency mocks — no SDK, no sidecars, no annotations.

your-service — running on :3000live

Incoming API Requests

GET/users/list

POST/orders/create

PUT/users/42

DELETE/sessions/7

GET/products

+42 more…

eBPF Kernel Intercept Layer

intercepts all syscalls · no code changes · zero runtime overhead

HTTP/1.1HTTP/2gRPCWebSocketTCP/IP

Keploy Agentrecording · analyzing · generating

Test Cases

testcase-1.yaml

testcase-2.yaml

testcase-3.yaml

…+42 generated

Mock Files

mock-postgres.yaml

mock-redis.yaml

mock-s3.yaml

all deps covered

Every API call your app makes gets captured, replayed as a test, and its dependencies auto-mocked — continuously, from real traffic.

Start recording traffic See setup docs

How they compare, dimension by dimension

A logical breakdown across the dimensions that matter. Click any row for real-world KPI impact across industries.

Key differences at a glance

Test Generation Method

Keploy

Auto-generates from real API traffic via eBPF

Harness

Test Intelligence selects relevant existing tests per change

Code Changes Required

Keploy

Zero code changes needed for test generation

Harness

Minimal; integrates with existing test frameworks

Mock/Stub Generation

Keploy

Auto-generates mocks for all external dependencies

Harness

No mock generation; runs existing tests as-is

CI/CD Integration

Keploy

Native CI/CD pipeline integration with CLI

Harness

Full CI/CD platform with native pipeline orchestration

Language Support

Keploy

Language-agnostic via eBPF traffic capture

Harness

Java, Python, .NET, Ruby for Test Intelligence

Open Source

Keploy

Apache 2.0 licensed with 20K+ GitHub stars

Harness

Open-source Gitness core; commercial Harness platform

Dimension

Keploy

Harness

Comparison

Click any dimension to see real-world KPI impact across industries.

Dive into how each capability actually works.

Read the docs Star on GitHub

Your tests miss more than you think

Manual tests cover paths developers remember to write — usually just the happy path. Keploy captures every pattern production traffic actually generates.

Manual with Harness

tested

not tested

Happy path

Auth error

Invalid input

Not found

DB timeout

Rate limit

Concurrent

Large payload

Edge case

Empty result

GET /users

POST /users

GET /orders

POST /orders

PUT /products

DELETE /sessions

GET /analytics

POST /payments

16%

Production path coverage

84% of real production scenarios go untested

16%

With Keploy

traffic-captured

tested

not tested

Happy path

Auth error

Invalid input

Not found

DB timeout

Rate limit

Concurrent

Large payload

Edge case

Empty result

GET /users

POST /users

GET /orders

POST /orders

PUT /products

DELETE /sessions

GET /analytics

POST /payments

95%

Production path coverage

Auto-captured from real traffic — no code changes needed

95%

Coverage grid shows 8 common endpoints × 10 production scenario types. Manual tests cover only what developers remember to write. Keploy captures every pattern your API actually serves in production.

Keploy is open source — read the code that captures this coverage.

Star on GitHub Explore Keploy

The infrastructure you're maintaining

Traditional testing stacks require a shadow infrastructure to exist alongside your real app. Keploy eliminates all of it — tests and mocks come from actual traffic, not from services you run and maintain.

With Harness

Your Appproduction code

Requires all of these ↓

Test Database

postgres-test-instance

Mock Server

WireMock / MSW

Redis Test Instance

separate container

S3 / Object Store

localstack / fake-s3

Test Config Files

env vars, secrets, fixtures

CI Test Runner

spins up all of the above

Infrastructure overhead6+ services

With Keploy

Your Appsame code, unchanged

Only this ↓

Your Real App

no changes needed

Keploy Agent

eBPF — zero overhead

Tests.yaml

Mocks.yaml

CI runpasses

Infrastructure overhead0 extra services

Services to provision

6+0

Config files to maintain

~120

CI spin-up overhead

3–5 min~10 sec

Eliminate test infrastructure See how it works

How they work differently

Architectural differences that affect workflow, cost, and velocity.

KeployeBPF-based

Keploy generates new tests from captured traffic, solving the test creation problem. It produces integration tests with auto-generated mocks that reflect real production behavior. The focus is on eliminating manual test writing for API regression coverage.

eBPF CaptureZero Code ChangesAuto MocksAI Noise DetectionCI/CD Native

Harnessits approach

Harness provides a full CI/CD platform with Test Intelligence that uses machine learning to identify which tests are affected by code changes and runs only those. It also includes chaos engineering, feature flags, and cloud cost management. The testing focus is on optimizing and accelerating existing test suites.

Collections / suitesCI integrationManaged / SaaS

When to use each tool

Specific scenarios where each tool delivers the most value.

Keploy is the better fit when…

Your bottleneck is creating tests, not running them faster
You need auto-generated API tests from real production traffic
You want dependency mocks generated automatically
You need a focused tool for API test generation, not a full CI/CD platform
You prefer open-source, single-purpose testing tools

Harness is the better fit when…

You have a large existing test suite that takes too long to run in CI
You need a comprehensive CI/CD platform with integrated testing
Test Intelligence for smart test selection would significantly speed up your pipeline
You want CI/CD, feature flags, chaos engineering, and testing in one platform
Your organization is standardizing on a single DevOps platform

Compare the full workflow for your own stack.

Explore Keploy Read the docs

The workflow you're escaping

Same starting point, same finish line. One path is short because Keploy does the tedious middle for you — the other is where teams lose days every sprint.

Without Keploy (Harness / manual)

Every dependency is your problem, and every code change ripples back through the test suite you hand-built.

Write API

Write tests

Maintain mocks

Fix flaky tests

Chase non-determinism

Re-write on every change

Deploy

Steps to production7

With Keploy

Record once from real traffic, replay anywhere. Tests and mocks are generated and stay in sync automatically.

Write API

Record traffic

Replay

Deploy

Steps to production4

4 vs 7

Fewer steps between writing code and shipping it

Teams that switch from Harness to Keploy delete the entire maintenance middle — test authoring, mock upkeep, and flake chasing.

Cut the maintenance middle out of your test suite.

Read the docs Star on GitHub

The test maintenance trap

With Harness, every feature commit generates a hidden tax — a follow-up "fix tests" commit. The commit history tells the whole story.

With Harness

— your git log

git log --oneline

a1b2c3feat: add user auth endpoint

3 failing3 days ago

d4e5f6fix: update auth mocks & fixtures

passing3 days ago

g7h8i9feat: payment integration API

7 failing5 days ago

j1k2l3fix: mock timestamps & snapshots

passing5 days ago

m4n5o6feat: analytics dashboard endpoint

5 failing1 week ago

p7q8r9fix: update API response schemas

passing1 week ago

r1s2t3feat: notification service

4 failing2 weeks ago

u4v5w6fix: mock mailer & queue stubs

passing2 weeks ago

↑ Pattern detected: every feature commit breaks tests — 4 of 8 commits are just fixing tests

Commits wasted on test maintenance4/8

With Keploy

— your git log

git log --onelinekeploy active

a1b2c3feat: add user auth endpoint

passing+5 tests3 days ago

g7h8i9feat: payment integration API

passing+12 tests5 days ago

m4n5o6feat: analytics dashboard endpoint

passing+8 tests1 week ago

r1s2t3feat: notification service

passing+6 tests2 weeks ago

↑ Pattern: every feature commit auto-generates tests — 4/4 commits ship features

Feature commits that go straight to CI green4/4

"Fix tests" commits

4 per sprint0

Days spent on mocks

2–3 dayszero

Tests auto-generated

031+

Deterministic replays, no flaky tests — see how.

Star on GitHub Read the docs

Switch from Harness in minutes

Choose the path that fits your workflow. Both are up and running the same day.

Integration Testing

via eBPF + CLI · no code changes

Install, record real API traffic, then replay it as regression tests — zero code changes, zero framework dependencies.

~/terminal

1# 1. Install

2curl --silent -O https://keploy.io/install.sh && source install.sh

4# 2. Record your traffic

5keploy record -c "your-start-command"

7# 3. Replay as tests

8keploy test -c "your-start-command" --delay 10

API Testing

via Web UI · no install needed

Paste your cURLs, drop in an OpenAPI spec or Postman collection, and click Generate. Keploy builds your test suite in seconds.

1Go to app.keploy.io

2Paste your cURLs

3Add your schema — OpenAPI, Postman collection, or raw cURLs

4Click Generate — done

Open app.keploy.io

Most teams are generating tests within minutes

No code changes. No framework migration. No staging dependencies.

Get started free Read the docs

18.4K+

GitHub Stars

1.2M+

Installs

Code Changes Required

Apache 2.0

Open Source License

Real-world scenarios

How Keploy handles the challenges your team actually faces.

Reducing CI Pipeline Time from 45 Minutes to 10 Minutes

With Keploy

Keploy generates fast API tests but does not optimize your existing test suite execution time. If you already have thousands of slow tests, Keploy adds more tests; it does not make existing ones run faster.

Without Keploy

Harness Test Intelligence analyzes code changes and runs only the tests affected by each commit, reducing a 45-minute suite to 10 minutes. It uses ML to build a dependency graph between code and tests.

Building API Regression Coverage from Scratch

With Keploy

Keploy generates a comprehensive API regression suite by capturing production traffic. Within hours, you have hundreds of tests covering real usage patterns, edge cases, and error scenarios without writing a single test manually.

Without Keploy

Harness does not generate tests. If you have no existing tests, Test Intelligence has nothing to optimize. You would still need to write tests manually or use another tool like Keploy to create them.

Join the teams shipping with confidence on Keploy.

Explore Keploy Read the docs

What you write vs what Keploy writes

The same test coverage — one approach takes hours of setup and ongoing maintenance, the other takes five minutes and zero boilerplate.

Manual with Harness~35 lines you write & maintain

users.test.js

hand-written39 lines

1// users.test.js — written manually

2import request from 'supertest';

3import app from '../app';

4import { setupTestDB, teardownTestDB } from './helpers';

5import { mockRedis, mockS3, mockMailer } from './mocks';

7let db;

9beforeEach(async () => {

10 db = await setupTestDB();

11 await mockRedis.connect();

12 await mockS3.setup({ bucket: 'test-uploads' });

13 await mockMailer.start();

14 jest.useFakeTimers();

15 jest.setSystemTime(new Date('2024-01-15T10:00:00Z'));

16});

18afterEach(async () => {

19 await db.cleanup();

20 await mockRedis.disconnect();

21 await mockS3.teardown();

22 await mockMailer.stop();

23 jest.useRealTimers();

24});

26describe('GET /users/list', () => {

27 it('returns paginated users', async () => {

28 await db.seed('users', testData.users);

29 const res = await request(app)

30 .get('/users/list?page=1&limit=10')

31 .set('Authorization', `Bearer ${testToken}`);

32 expect(res.status).toBe(200);

33 expect(res.body.data.length).toBe(10);

34 expect(res.body.data[0]).toMatchObject({

35 id: expect.any(String),

36 createdAt: expect.any(String),

37 });

38 });

39});

Every new endpoint needs a new file. Every refactor breaks tests. Every non-deterministic value (timestamps, IDs) needs custom handling.

Auto-generated by Keploy~27 lines, zero effort

test-1.yaml

auto-generated27 lines

1# test-1.yaml — auto-generated by Keploy

2version: api.keploy.io/v1beta1

3kind: Http

4name: test-1

5spec:

6 metadata:

7 name: test-1

8 type: GET

9 req:

10 method: GET

11 url: /users/list?page=1&limit=10

12 header:

13 Authorization: Bearer <captured>

14 resp:

15 status_code: 200

16 body:

17 data:

18 - id: "usr_abc123"

19 email: "alice@example.com"

20 createdAt: "2024-01-15T10:00:00Z"

21 pagination:

22 page: 1

23 total: 47

24 noise:

25 - body.data.[].id

26 - body.data.[].createdAt

27 - header.X-Request-Id

Keploy captures the real request, response, and all dependency calls. Non-deterministic fields are auto-detected and excluded from assertions.

Lines of test code

per endpoint

~39+

~27

Setup time

initial run

3–4 hrs

5 min

Maintenance

Keploy self-updates

Every PR

Zero

Generate tests automatically See the docs

Frequently asked questions

Common questions about choosing between Keploy and Harness.

Still have questions? The docs and community can help.

Read the docs Star on GitHub

Looking for a Harness alternative?

Engineering teams evaluating Harness alternatives often compare it with Keploy for API testing and regression coverage. Keploy captures real production traffic via eBPF and auto-generates tests with dependency mocks — requiring zero code changes. The key differences come down to how tests are generated (traffic-based vs manual), how dependencies are mocked (automatic vs configured), and what infrastructure changes are needed (none vs SDK/sidecar/containers).

Harness alternativeHarness vs Keploybest alternative to Harnesscompare Harness and KeployHarness open source alternativeswitch from Harness

Ready to stop writing tests manually?

Keploy captures your real API traffic and turns it into a regression suite automatically. Zero code changes. Full coverage from day one.

Try Keploy Free Read the Docs