Temporary notes and ideas.
{
"project": {
"id": 1,
"name": "Build your own HTTP Server",
"runner_image": "local|go|rust|c",
"tasks": [
{
"id": 1,
"name": "Bind to a Port",
"description": "Create a TCP server that listens for incoming connections on port 4221.",
"scores": "5:10:50|10:20:35|20:30:20",
"status": "challenge_awaits",
"abandoned_deduction": 5,
"hints": [
{
"id": 1,
"text": "Use the standard library's net package to create a TCP listener.",
"unlock_criteria": "5:3:A",
"points_deduction": 5
}
],
"validators": [
"can_compile:bool(true)",
"tcp_listening:int(4221)"
]
},
{
"id": 2,
"name": "Respond with 200 OK",
"description": "Send a basic HTTP/1.1 200 OK response back to the client.",
"scores": "5:10:50|10:20:35|20:30:20",
"status": "challenge_awaits",
"abandoned_deduction": 5,
"hints": [
{
"id": 1,
"text": "HTTP responses need \\r\\n line endings, not just \\n.",
"unlock_criteria": "5:3:A",
"points_deduction": 5
},
{
"id": 2,
"text": "Don't forget the blank line after headers (double \\r\\n).",
"unlock_criteria": "10:6:A",
"points_deduction": 10
}
],
"validators": [
"http_response_status:int(200)"
]
},
{
"id": 3,
"name": "Extract the URL Path",
"description": "Parse the HTTP request line to extract the URL path. Return 200 for / and 404 for other paths.",
"scores": "8:15:75|15:25:50|25:40:30",
"status": "challenge_awaits",
"abandoned_deduction": 8,
"hints": [
{
"id": 1,
"text": "The request line format is: METHOD PATH HTTP/VERSION",
"unlock_criteria": "5:3:A",
"points_deduction": 8
},
{
"id": 2,
"text": "Split the first line by spaces to extract the path.",
"unlock_criteria": "10:6:A",
"points_deduction": 10
}
],
"validators": [
"http_get:string(/),int(200)",
"http_get:string(/unknown),int(404)",
"http_get:string(/foo/bar),int(404)"
]
},
{
"id": 4,
"name": "Respond with Content",
"description": "Implement /echo/{str} endpoint that returns {str} with Content-Type and Content-Length headers.",
"scores": "10:20:100|20:35:70|35:50:40",
"status": "challenge_awaits",
"abandoned_deduction": 10,
"hints": [
{
"id": 1,
"text": "Content-Length must match the exact byte length of the body.",
"unlock_criteria": "8:5:A",
"points_deduction": 10
},
{
"id": 2,
"text": "Extract the string after /echo/ from the path.",
"unlock_criteria": "12:8:A",
"points_deduction": 15
}
],
"validators": [
"http_get:string(/echo/hello),int(200),string(hello)",
"http_get:string(/echo/abc),int(200),string(abc)",
"http_header_present:string(Content-Type),bool(true)",
"http_header_present:string(Content-Length),bool(true)"
]
},
{
"id": 5,
"name": "Parse Request Headers",
"description": "Read HTTP headers and implement /user-agent endpoint returning the User-Agent header value.",
"scores": "10:20:100|20:35:70|35:50:40",
"status": "challenge_awaits",
"abandoned_deduction": 10,
"hints": [
{
"id": 1,
"text": "Headers are formatted as 'Name: value' and are case-insensitive.",
"unlock_criteria": "8:5:A",
"points_deduction": 10
},
{
"id": 2,
"text": "Read lines until you hit an empty line (end of headers).",
"unlock_criteria": "15:10:T",
"points_deduction": 15
}
],
"validators": [
"http_get_with_header:string(/user-agent),string(User-Agent),string(test-agent),int(200),string(test-agent)",
"http_get_with_header:string(/user-agent),string(user-agent),string(curl/7.64.1),int(200),string(curl/7.64.1)"
]
},
{
"id": 6,
"name": "Handle Concurrent Connections",
"description": "Modify your server to handle multiple simultaneous connections using threads or async I/O.",
"scores": "15:30:125|30:50:85|50:70:50",
"status": "challenge_awaits",
"abandoned_deduction": 15,
"hints": [
{
"id": 1,
"text": "Spawn a new thread/goroutine for each accepted connection.",
"unlock_criteria": "10:5:A",
"points_deduction": 15
},
{
"id": 2,
"text": "Make sure the main loop continues accepting while handlers run.",
"unlock_criteria": "20:10:T",
"points_deduction": 20
}
],
"validators": [
"concurrent_requests:int(3),string(/echo/test),int(200)"
]
},
{
"id": 7,
"name": "Serve Files from a Directory",
"description": "Serve static files from a --directory flag. Return file contents or 404 if not found.",
"scores": "15:30:125|30:50:85|50:70:50",
"status": "challenge_awaits",
"abandoned_deduction": 15,
"hints": [
{
"id": 1,
"text": "Use Content-Type: application/octet-stream for file responses.",
"unlock_criteria": "10:5:A",
"points_deduction": 12
},
{
"id": 2,
"text": "Watch out for path traversal attacks (../) - sanitize the path!",
"unlock_criteria": "20:12:T",
"points_deduction": 20
}
],
"validators": [
"http_get_file:string(/files/test.txt),int(200)",
"http_get_file:string(/files/nonexistent.txt),int(404)",
"http_get_file:string(/files/../etc/passwd),int(404)"
]
},
{
"id": 8,
"name": "Handle POST Requests",
"description": "Support POST requests to /files/{filename} to upload and save files.",
"scores": "20:35:150|35:55:100|55:80:60",
"status": "challenge_awaits",
"abandoned_deduction": 18,
"hints": [
{
"id": 1,
"text": "Read exactly Content-Length bytes from the request body.",
"unlock_criteria": "12:6:A",
"points_deduction": 15
},
{
"id": 2,
"text": "Return 201 Created status code on successful file creation.",
"unlock_criteria": "20:12:T",
"points_deduction": 20
}
],
"validators": [
"http_post_file:string(/files/upload.txt),string(hello world),int(201)",
"file_contents_match:string(upload.txt),string(hello world),bool(true)"
]
},
{
"id": 9,
"name": "Support HTTP Compression",
"description": "Add gzip compression support when client sends Accept-Encoding: gzip header.",
"scores": "25:45:175|45:70:120|70:100:70",
"status": "challenge_awaits",
"abandoned_deduction": 20,
"hints": [
{
"id": 1,
"text": "Check if 'gzip' is in the Accept-Encoding header (may have multiple values).",
"unlock_criteria": "15:8:A",
"points_deduction": 18
},
{
"id": 2,
"text": "Use your language's gzip library. Don't forget Content-Encoding header.",
"unlock_criteria": "25:15:T",
"points_deduction": 25
},
{
"id": 3,
"text": "Content-Length must be the compressed size, not original size.",
"unlock_criteria": "35:20:T",
"points_deduction": 30
}
],
"validators": [
"http_get_compressed:string(/echo/hello),string(gzip),int(200),string(hello)",
"http_header_value:string(Content-Encoding),string(gzip),bool(true)",
"http_get:string(/echo/hello),int(200),string(hello)"
]
}
]
}
}Format: "local|go|rust|c"
local= no runtime needed- Uses
|delimiter (not comma) to reserve commas for future tuple syntax (e.g., multi-service: web server + database)
Format: "attempts:minutes:points|..."
- Example:
"10:12:15|15:20:7"means:- Bucket 1: 10 attempts OR 12 minutes → 15 points
- Bucket 2: 15 attempts OR 20 minutes → 7 points
- Bucket selection: whichever threshold is hit first (
min(attempts, time))
Format: "time:attempts:priority"
- Example:
"10:30:T"means unlock after 10 minutes OR 30 attempts, prioritize time (T) - Priority:
T= time-based,A= attempt-based
Enum: challenge_awaits | challenged | challenge_completed | challenge_failed | challenge_abandoned
| Status | Description |
|---|---|
challenge_awaits |
User has not started this task yet |
challenged |
User has started and is actively working |
challenge_completed |
User successfully finished the task |
challenge_failed |
User explicitly gave up or hit max attempts |
challenge_abandoned |
No activity for N time (set by backend job) |
State transitions:
challenge_awaits → challenged (user starts task)
challenged → challenge_completed (user passes all validators)
challenged → challenge_failed (user gives up or max attempts)
challenged → challenge_abandoned (no activity, backend job checks updated_at)
challenge_abandoned → challenged (user returns and resumes)
Points deducted when user resumes an abandoned task.
Backend job runs every ~10 mins, checks updated_at column to determine if task should be marked abandoned.
Format: "validator_name:param1,param2,...,paramN"
Type annotations:
bool(true)/bool(false)- boolean valuestring(value)- string valueint(123)- integer value
Examples:
"can_compile:bool(true)"
"tcp_listening:int(4221)"
"http_get:string(/echo/hello),int(200),string(hello)"
"http_header_present:string(Content-Type),bool(true)"
Notes:
- Beginner projects: 1 validator per task
- Advanced projects: multiple validators per task (harder to earn points)
- Hints and points are based on "Task" level, not individual validations