Errors and results

What a failed run tells you

Every failed run carries a structured error, not just a line of text. It says what kind of failure it was, its type (ZeroDivisionError, RangeError, timeout…), the message, and — for an error your code raised — the frames: file, line and function for each step of the stack, each marked as your code or not. The same record is what the Runs page, an API caller and a flow step see.

1def average(orders):2    return sum(o["total"] for o in orders) / len(orders)3 4def main(day: str = "2026-10-15"):5    orders = load_orders(day)6    return {"average": average(orders)}

Read an error and jump to it

Run this script with its default (an empty list). Python divides by zero; the TypeScript version throws its own RangeError.

def average(values: list[float]) -> float:
    return sum(values) / len(values)


def main(values: list[float] = []):
    return {"average": average(values)}

1. 1
   Read the headline

   The block opens with the type over the message: ZeroDivisionError — division by zero. A platform failure shows its code instead, such as timeout; the log’s last line says it in words (The script exceeded its timeout).

2. 2
   Follow your frames

   Below it, each of your frames reads line 2 in average, with that line of code beside it — the deepest call last. Click one: the editor puts the cursor on that line and centres it. Frames from the runtime, the SDK or installed packages fold into Show 3 internal frames; a very deep stack keeps its first and last frames and folds the middle.

3. 3
   Check the logs

   The Logs tab still has everything the script printed before it failed, with a search box and a level filter (All levels, Info, Warning, Error, System).

Fix with AI

At the foot of an exception’s block, Fix with AI opens the editor’s AI chat tab with the message Fix the error this run raised. already typed and a chip ZeroDivisionError · code and inputs attached. Nothing is sent until you press Send — add a sentence of your own if you know what the fix should be, or remove the attachment with its ×. The assistant answers with a proposed change you review as code before it touches your draft; see The editor’s AI chat.

The button is offered for errors your code raised. A platform failure (a timeout, a lost worker) has nothing in the code to fix, so it has none; a package that would not install offers Declare package or Change version instead, which open the Dependencies panel with the package filled in. Copy error copies the whole error as text.

def average(values: list[float]) -> float | None:
    if not values:
        return None
    return sum(values) / len(values)


def main(values: list[float] = []):
    return {"average": average(values)}

Results as a table

A successful run shows what main returned as formatted JSON. When the result is a list of records — an array of objects with up to 50 different keys between them — it opens as a table instead: one column per key, a Search rows box that matches any cell, a row count (2 of 3 rows while searching), headers that sort on click (ascending, descending, back to the original order) and a CSV button that downloads the rows. The icons beside it switch between table and JSON, copy the JSON, download it as a .json file, or expand the result to fill the screen.

def main(limit: int = 3):
    products = [
        {"sku": "A-100", "name": "Stapler", "sold": 42, "price": 12.5},
        {"sku": "B-220", "name": "Pen", "sold": 130, "price": 2.0},
        {"sku": "C-310", "name": "Backpack", "sold": 17, "price": 89.9},
        {"sku": "D-404", "name": "Ruler", "sold": 64, "price": 3.4},
    ]
    products.sort(key=lambda p: p["sold"], reverse=True)
    return products[:limit]

What each language reports

• Python — the exception’s class and message, frames from the traceback; a syntax error points at its line and column. sys.exit() fails as SystemExit.
• TypeScript and JavaScript — the error’s name and message and frames from its stack. Throw an Error (not a bare string) to keep the frames.
• C and C++ — a non-zero exit code or a crash fails the run with the last line the program wrote to stderr and the exit code or signal (terminated by signal 11 (SIGSEGV)); there are no frames. A compile error stops the run before it starts, with gcc’s message in the error text.

Platform codes you may meet

Limits

• A stack keeps at most 60 frames (the first 20 and the last 40); the traceback text keeps its last 64 KB.
• Clickable frames and Fix with AI are in the editor. On the Runs page the same error is shown read-only.
• Search, sort and CSV work on a top-level list of records; a single object can be switched to a key/value table but opens as JSON.