Stealth Check Web App
Budget: $30 – $250 USD
I am looking for a developer or small team to build a web application called Stealth Check, accessible over HTTPS, with behavior similar to ifconfig.io, but focused on connection fingerprint analysis, HTTP/TLS consistency validation, IP intelligence, and stealth / detection scoring.
The idea is that a user can access URLs such as:
https://mydomain.com/
https://mydomain.com/json
https://mydomain.com/ip
https://mydomain.com/headers
https://mydomain.com/tls
https://mydomain.com/score
and the application will display, in both HTML and JSON, a detailed report about the client connection.
PROJECT GOAL
This application should function as a Stealth Check tool, not just a “what is my IP” page.
Its purpose is to evaluate how natural or consistent a connection looks by analyzing browser, proxy, and automation signals across multiple layers, such as:
IP/network characteristics
User-Agent and Client Hints
HTTP headers and HTTP protocol behavior
TLS fingerprinting
consistency between HTTP, TLS, OS, browser, and device identity
a final stealth / bot-likeness score
The goal is to help determine whether a connection appears to come from a legitimate browser or from an automated / inconsistent environment.
CORE FEATURES
Main page similar to ifconfig.io
When a user accesses /, the application should display a clean, readable report of the current connection.
The page should show items such as:
client IP address
ASN
ISP / organization / hosting provider
country / city / approximate geolocation
User-Agent
detected HTTP version
received headers
TLS fingerprint information
JA3 / JA4 if technically possible
category scores
final stealth score
overall result such as PASS / WARNING / FAIL
Required endpoints
/
HTML report for the current visitor connection.
/json
Full report in JSON format.
/ip
Return only the client public IP.
/headers
Return or display the HTTP headers received from the client.
/tls
Return or display TLS-related information and fingerprint details, including as much as possible of the following:
TLS version
cipher suite
ALPN
SNI, if applicable
JA3
JA4
other available handshake data
/score
Return the final stealth score and a breakdown by category.
WHAT THE APPLICATION SHOULD VALIDATE
The application should validate, score, and display at least the following categories.
A. Network / IP
client IP address
ASN
ISP / organization
country / city / approximate geolocation
network type when possible:
residential
mobile
datacenter / hosting / cloud
proxy / VPN / relay, if detectable
B. User-Agent / Client Identity
raw User-Agent
browser parsing
operating system parsing
platform / device type parsing
consistency between User-Agent and other headers
C. HTTP Fingerprint
HTTP version used by the client:
HTTP/1.1
HTTP/2
HTTP/3 if supported
received headers
consistency of headers typically seen in real browsers
presence and consistency of headers such as:
Accept
Accept-Encoding
Accept-Language
Upgrade-Insecure-Requests
Sec-Fetch-*
Sec-CH-UA
Sec-CH-UA-Platform
Sec-CH-UA-Mobile
consistency between User-Agent and Client Hints
optionally, header structure / ordering if technically feasible
D. TLS Fingerprint
The application should capture as much of the client TLS fingerprint as possible. Ideally this includes:
TLS version
negotiated cipher suite
ALPN
TLS extensions where available
JA3
JA4
Important: the goal is to capture the real client fingerprint, not just the fingerprint of an intermediate reverse proxy. The developer should propose an architecture that makes this possible.
E. Cross-layer consistency checks
The application should validate consistency across:
User-Agent
Client Hints
HTTP fingerprint
TLS fingerprint
declared operating system
declared browser
expected behavior of real browsers
Example:
User-Agent says “Chrome on Windows”
Client Hints indicate Android
TLS fingerprint looks like a different stack
headers do not match a normal Chrome profile
These inconsistencies should affect the final score.
SCORING SYSTEM
The application should produce a score per category and a final score.
Example categories:
IP / ASN / network reputation
HTTP headers consistency
User-Agent / OS consistency
TLS / JA3 / JA4 consistency
browser-likeness
composite bot / stealth score
Example JSON output:
{
"ip": "1.2.3.4",
"asn": "AS12345",
"country": "US",
"user_agent": "...",
"http_version": "h2",
"tls": {
"version": "TLS1.3",
"ja3": "...",
"ja4": "..."
},
"checks": {
"headers": {"status": "pass", "score": 95},
"ua_os_consistency": {"status": "pass", "score": 100},
"tls_consistency": {"status": "warning", "score": 70},
"ip_reputation": {"status": "pass", "score": 90}
},
"final_score": 89,
"verdict": "likely legitimate"
}
INTERFACE
The web interface should be simple, fast, and functional, similar in spirit to tools like:
ifconfig.io
browserleaks
lightweight network diagnostic tools
I do not need a fancy UI. I prefer:
clean layout
easy readability
report organized in sections
clear presentation of checks and scores
TECHNICAL REQUIREMENTS
The freelancer may choose the stack, as long as the architecture is clearly explained.
Accepted approaches:
Go
Python + FastAPI
Python with another lightweight backend
Node.js, if there is a strong technical reason
hybrid architecture, for example:
web backend in Python
dedicated TLS / fingerprint collector in Go
or another specialized component for handshake capture
IMPORTANT NOTE
If the chosen stack cannot reliably capture the real client TLS fingerprint, the freelancer must propose a complementary solution.
This project should not be just a “what is my IP” API. The focus is a Stealth Check with multi-layer analysis.
EXPECTED DELIVERABLES
Full source code
Well-structured and maintainable.
Deployment instructions
Ideally including:
complete README
instructions to run locally
instructions to run in production
environment variables
dependencies
Working application
With the endpoints described above.
Scoring engine
With clear and documented logic.
Extensible structure
I want to be able to add new checks in the future.
NICE-TO-HAVE EXPERIENCE
It is a strong plus if the freelancer has experience with:
TLS fingerprinting / JA3 / JA4
HTTP/2 and HTTP/3
proxy detection / bot detection / browser fingerprinting
reverse proxy / edge / L7 infrastructure
OpenResty / HAProxy / Envoy / Go networking
scoring systems and consistency validation
WHAT I WOULD LIKE THE FREELANCER TO ANSWER IN THE PROPOSAL
Please include the following in your proposal:
What stack you would use and why
How you would capture the real client TLS fingerprint
Whether you can expose JA3 / JA4 or an equivalent fingerprint
How you would structure the scoring logic
Estimated timeline
Any previous experience with network, fingerprinting, HTTP/TLS, or detection-related projects
SHORT SUMMARY FOR THE LISTING
I need an HTTPS web application, similar in presentation to ifconfig.io, but focused on Stealth Check functionality. It should display and validate client connection information including IP, ASN, User-Agent, HTTP headers, TLS fingerprint, JA3/JA4 if possible, cross-layer consistency checks, and a final stealth/detection score, with both HTML and JSON output.
Se você quiser, eu posso fazer agora uma segunda versão:
mais curta e mais forte para atrair propostas melhores no Freelancer.com
mais técnica e mais “restritiva”, para filtrar freelancers que não dominam TLS fingerprinting de verdade
Se quiser, eu já te entrego as duas em inglês, também em texto simples.
The idea is that a user can access URLs such as:
https://mydomain.com/
https://mydomain.com/json
https://mydomain.com/ip
https://mydomain.com/headers
https://mydomain.com/tls
https://mydomain.com/score
and the application will display, in both HTML and JSON, a detailed report about the client connection.
PROJECT GOAL
This application should function as a Stealth Check tool, not just a “what is my IP” page.
Its purpose is to evaluate how natural or consistent a connection looks by analyzing browser, proxy, and automation signals across multiple layers, such as:
IP/network characteristics
User-Agent and Client Hints
HTTP headers and HTTP protocol behavior
TLS fingerprinting
consistency between HTTP, TLS, OS, browser, and device identity
a final stealth / bot-likeness score
The goal is to help determine whether a connection appears to come from a legitimate browser or from an automated / inconsistent environment.
CORE FEATURES
Main page similar to ifconfig.io
When a user accesses /, the application should display a clean, readable report of the current connection.
The page should show items such as:
client IP address
ASN
ISP / organization / hosting provider
country / city / approximate geolocation
User-Agent
detected HTTP version
received headers
TLS fingerprint information
JA3 / JA4 if technically possible
category scores
final stealth score
overall result such as PASS / WARNING / FAIL
Required endpoints
/
HTML report for the current visitor connection.
/json
Full report in JSON format.
/ip
Return only the client public IP.
/headers
Return or display the HTTP headers received from the client.
/tls
Return or display TLS-related information and fingerprint details, including as much as possible of the following:
TLS version
cipher suite
ALPN
SNI, if applicable
JA3
JA4
other available handshake data
/score
Return the final stealth score and a breakdown by category.
WHAT THE APPLICATION SHOULD VALIDATE
The application should validate, score, and display at least the following categories.
A. Network / IP
client IP address
ASN
ISP / organization
country / city / approximate geolocation
network type when possible:
residential
mobile
datacenter / hosting / cloud
proxy / VPN / relay, if detectable
B. User-Agent / Client Identity
raw User-Agent
browser parsing
operating system parsing
platform / device type parsing
consistency between User-Agent and other headers
C. HTTP Fingerprint
HTTP version used by the client:
HTTP/1.1
HTTP/2
HTTP/3 if supported
received headers
consistency of headers typically seen in real browsers
presence and consistency of headers such as:
Accept
Accept-Encoding
Accept-Language
Upgrade-Insecure-Requests
Sec-Fetch-*
Sec-CH-UA
Sec-CH-UA-Platform
Sec-CH-UA-Mobile
consistency between User-Agent and Client Hints
optionally, header structure / ordering if technically feasible
D. TLS Fingerprint
The application should capture as much of the client TLS fingerprint as possible. Ideally this includes:
TLS version
negotiated cipher suite
ALPN
TLS extensions where available
JA3
JA4
Important: the goal is to capture the real client fingerprint, not just the fingerprint of an intermediate reverse proxy. The developer should propose an architecture that makes this possible.
E. Cross-layer consistency checks
The application should validate consistency across:
User-Agent
Client Hints
HTTP fingerprint
TLS fingerprint
declared operating system
declared browser
expected behavior of real browsers
Example:
User-Agent says “Chrome on Windows”
Client Hints indicate Android
TLS fingerprint looks like a different stack
headers do not match a normal Chrome profile
These inconsistencies should affect the final score.
SCORING SYSTEM
The application should produce a score per category and a final score.
Example categories:
IP / ASN / network reputation
HTTP headers consistency
User-Agent / OS consistency
TLS / JA3 / JA4 consistency
browser-likeness
composite bot / stealth score
Example JSON output:
{
"ip": "1.2.3.4",
"asn": "AS12345",
"country": "US",
"user_agent": "...",
"http_version": "h2",
"tls": {
"version": "TLS1.3",
"ja3": "...",
"ja4": "..."
},
"checks": {
"headers": {"status": "pass", "score": 95},
"ua_os_consistency": {"status": "pass", "score": 100},
"tls_consistency": {"status": "warning", "score": 70},
"ip_reputation": {"status": "pass", "score": 90}
},
"final_score": 89,
"verdict": "likely legitimate"
}
INTERFACE
The web interface should be simple, fast, and functional, similar in spirit to tools like:
ifconfig.io
browserleaks
lightweight network diagnostic tools
I do not need a fancy UI. I prefer:
clean layout
easy readability
report organized in sections
clear presentation of checks and scores
TECHNICAL REQUIREMENTS
The freelancer may choose the stack, as long as the architecture is clearly explained.
Accepted approaches:
Go
Python + FastAPI
Python with another lightweight backend
Node.js, if there is a strong technical reason
hybrid architecture, for example:
web backend in Python
dedicated TLS / fingerprint collector in Go
or another specialized component for handshake capture
IMPORTANT NOTE
If the chosen stack cannot reliably capture the real client TLS fingerprint, the freelancer must propose a complementary solution.
This project should not be just a “what is my IP” API. The focus is a Stealth Check with multi-layer analysis.
EXPECTED DELIVERABLES
Full source code
Well-structured and maintainable.
Deployment instructions
Ideally including:
complete README
instructions to run locally
instructions to run in production
environment variables
dependencies
Working application
With the endpoints described above.
Scoring engine
With clear and documented logic.
Extensible structure
I want to be able to add new checks in the future.
NICE-TO-HAVE EXPERIENCE
It is a strong plus if the freelancer has experience with:
TLS fingerprinting / JA3 / JA4
HTTP/2 and HTTP/3
proxy detection / bot detection / browser fingerprinting
reverse proxy / edge / L7 infrastructure
OpenResty / HAProxy / Envoy / Go networking
scoring systems and consistency validation
WHAT I WOULD LIKE THE FREELANCER TO ANSWER IN THE PROPOSAL
Please include the following in your proposal:
What stack you would use and why
How you would capture the real client TLS fingerprint
Whether you can expose JA3 / JA4 or an equivalent fingerprint
How you would structure the scoring logic
Estimated timeline
Any previous experience with network, fingerprinting, HTTP/TLS, or detection-related projects
SHORT SUMMARY FOR THE LISTING
I need an HTTPS web application, similar in presentation to ifconfig.io, but focused on Stealth Check functionality. It should display and validate client connection information including IP, ASN, User-Agent, HTTP headers, TLS fingerprint, JA3/JA4 if possible, cross-layer consistency checks, and a final stealth/detection score, with both HTML and JSON output.
Se você quiser, eu posso fazer agora uma segunda versão:
mais curta e mais forte para atrair propostas melhores no Freelancer.com
mais técnica e mais “restritiva”, para filtrar freelancers que não dominam TLS fingerprinting de verdade
Se quiser, eu já te entrego as duas em inglês, também em texto simples.