Rate limiting on add_project — undocumented limits beyond 10 req/s?

[KrisbelGV]

I maintain Scratch Studio Adder, a tool that adds a Scratch project to multiple studios using scratchattach. Each studio takes 2 requests: connect_studio + add_project, spaced 200ms apart (5 req/s, half the documented limit). I'm still hitting 429 errors early in the run.

What I'm trying to understand:

• Are there stricter or separate rate limits for write endpoints like adding projects to studios, beyond the 10 req/s documented for the REST API?
• Have others observed per-minute, per-endpoint, or per-studio limits in practice?
• What spacing or approach has worked reliably for bulk operations like this?

The tool is open source and I want it to play nicely with Scratch's infrastructure. Any insight — even anecdotal — would help.

[TheCommCraft]

When I made a tool called the same thing, I was pretty much never rate limited. I will look into the code to see what timing I used. You do need to be careful, I believe Scratch temp bans you from adding to studios if they see that you are having a suspiciously high amount of activity regularly.

[TheCommCraft]

My code:

import scratchattach
from requests import get
import time, os, traceback, random, json

api = "https://api.scratch.mit.edu"
session = scratchattach.login(os.getenv("USERNAME"), os.getenv("PASSWORD"))
user = session.get_linked_user()
add_projects = user.projects()
random.shuffle(add_projects)

def search(term=None):
    url = f"{api}/search/studios?q={term}" if term else f"{api}/search/studios"
    res = get(url).json()
    for studio in res:
        if not studio["open_to_all"]:
            continue
        yield studio["id"]

def connect_all(term=None):
    for studio in search(term):
        try:
            studio = session.connect_studio(studio)
            yield studio
        except:
            print(f"Failed to connect to {studio}")

def add_all(term=None, *, projects=None):
    projects = projects or add_projects
    for studio in connect_all(term):
        if not studio:
            continue
        if any(i.lower() in studio.description.lower() for i in blacklist):
            continue
        for project in random.sample(projects, 3) if len(projects) > 3 else projects:
            try:
                project = project.id
            except: 
                pass
            try:
                studio.remove_project(project)
                time.sleep(1+3*(random.random()**2))
                studio.add_project(project)
                time.sleep(3+3*(random.random()**2))
            except json.decoder.JSONDecodeError:
                print(f"Ratelimited at {studio.id}")
                exit()
            except Exception:
                print(f"Failed to access {studio.id if studio else None}")
                traceback.print_exc()

blacklist = ["undertale", "minecraft"]

add_all("anything")
add_all("games")
add_all("cool games")
add_all("all projects")
add_all("everything")
add_all("best games")
add_all("good games")
add_all("whatever")
add_all("get this to")
add_all("10000 projects")
add_all("100000 projects")

[TheCommCraft]

(this code probably does not work anymore because it was written for an old version of scratchattach)

[KrisbelGV]

Mi código:

import scratchattach
from requests import get
import time, os, traceback, random, json

api = "https://api.scratch.mit.edu"
session = scratchattach.login(os.getenv("USERNAME"), os.getenv("PASSWORD"))
user = session.get_linked_user()
add_projects = user.projects()
random.shuffle(add_projects)

def search(term=None):
    url = f"{api}/search/studios?q={term}" if term else f"{api}/search/studios"
    res = get(url).json()
    for studio in res:
        if not studio["open_to_all"]:
            continue
        yield studio["id"]

def connect_all(term=None):
    for studio in search(term):
        try:
            studio = session.connect_studio(studio)
            yield studio
        except:
            print(f"Failed to connect to {studio}")

def add_all(term=None, *, projects=None):
    projects = projects or add_projects
    for studio in connect_all(term):
        if not studio:
            continue
        if any(i.lower() in studio.description.lower() for i in blacklist):
            continue
        for project in random.sample(projects, 3) if len(projects) > 3 else projects:
            try:
                project = project.id
            except: 
                pass
            try:
                studio.remove_project(project)
                time.sleep(1+3*(random.random()**2))
                studio.add_project(project)
                time.sleep(3+3*(random.random()**2))
            except json.decoder.JSONDecodeError:
                print(f"Ratelimited at {studio.id}")
                exit()
            except Exception:
                print(f"Failed to access {studio.id if studio else None}")
                traceback.print_exc()

blacklist = ["undertale", "minecraft"]

add_all("anything")
add_all("games")
add_all("cool games")
add_all("all projects")
add_all("everything")
add_all("best games")
add_all("good games")
add_all("whatever")
add_all("get this to")
add_all("10000 projects")
add_all("100000 projects")

Thank you so much! This is a great starting point for solving my problem.

[KrisbelGV]

I tried using your wait times as a reference. Here’s what I found:
The total execution time jumped from 3–5 minutes to nearly 30 minutes and the error occurred EXACTLY IN STUDY NUMBER 301. I wish I had saved my report to show it as evidence; in fact, it had happened before and I hadn’t noticed it. Maybe it’s just a coincidence, but personally, I’ll try to stay below that limit at all costs.
It’s worth noting that this isn’t the daily use I intend for it, but rather a test to fine-tune the script and ensure that both its users and the API are secure.