kaggle-benchmarks

name	kaggle-benchmarks
version	0.5.0
description	Write benchmark tasks to evaluate LLMs using the kaggle_benchmarks Python library. Covers task decorators, structured outputs, assertions, tools, dataset evaluation, and multi-turn conversations.

Skill: Writing Kaggle Benchmarks Tasks

This skill file teaches you how to write high-quality benchmark tasks using the kaggle-benchmarks Python library (version 0.5.0+). Always verify patterns against the actual source code in src/kaggle_benchmarks/ when in doubt.

Quick Reference

import kaggle_benchmarks as kbench

Symbol	Purpose
kbench.task / kbench.benchmark	Decorator to define a benchmark task
kbench.llm	Default LLM actor (available when Kaggle is configured)
kbench.judge_llm	Judge LLM for evaluation
kbench.llms	Dict of all available models (e.g. kbench.llms["google/gemini-2.5-flash"])
kbench.assertions	Module with all assertion functions
kbench.chats	Conversation/chat context management
kbench.tools	Built-in tools (Python runner, etc.)
kbench.user / kbench.actors.user	Send user messages to conversation
kbench.system / kbench.actors.system	Send system-level messages
kbench.last_reasoning_traces()	Access reasoning traces from last prompt
kbench.content_types.images	Image input helpers
kbench.content_types.videos	Video input helpers
kbench.content_types.audios	Audio input helpers
kbench.client	Client for caching, storage

Minimal Examples

Simple assertion check

import kaggle_benchmarks as kbench

@kbench.task(name="geography_quiz")
def geography_quiz(llm):
    response = llm.prompt("What is the longest river in the world?")
    kbench.assertions.assert_contains_regex(
        r"(?i)nile", response,
        expectation="Should mention the Nile river."
    )

geography_quiz.run(kbench.llm)

Evaluating a list of questions

import kaggle_benchmarks as kbench
import pandas as pd

@kbench.task(name="math_qa", store_task=False)
def math_qa(llm, question, expected) -> bool:
    answer = llm.prompt(question + "\nAnswer with just the number.", schema=int)
    kbench.assertions.assert_equal(expected, answer)
    return answer == expected

# %%
df = pd.DataFrame([
    {"question": "What is 15% of 200?", "expected": 30},
    {"question": "What is 7 × 8?", "expected": 56},
])

@kbench.task(name="math_benchmark")
def math_benchmark(llm) -> float:
    results = math_qa.evaluate(llm=[llm], evaluation_data=df, n_jobs=2)
    scores = results.as_dataframe()
    return float(scores.result.mean())

math_benchmark.run(kbench.llm)

Key Rules

• The first parameter of every task function must be the LLM actor.
• If your task returns a value, you MUST add a return type annotation (-> float, -> bool, -> dict, etc.).
• Use kbench.assertions.* instead of Python assert — library assertions are recorded and tracked.
• Always check assess_response_with_judge for None before using the result.
• Do NOT wrap .run() or .evaluate() calls inside if __name__ == "__main__":. Benchmark files are notebook-style scripts — all code runs at the top level.
• Use # %% cell markers to create logical sections in benchmark files.
• Prefer # !pip install ... (commented) over !pip install ... so the file works everywhere.
• Use store_task=False for sub-tasks called inside other tasks.

Common Mistakes to Avoid

Mistake	Correct Approach
Missing return type annotation on scoring task	Add -> float, -> bool, -> dict, etc.
Using Python assert instead of kbench.assertions.*	Use library assertions — they're recorded and tracked
Not checking assess_response_with_judge for None	Always check: if assessment is None:
Using kbench.llm locally without Kaggle configured	Run kaggle benchmarks init to configure, or set env vars
Forgetting schema= when needing structured output	Pass schema=MyDataclass to llm.prompt()
Wrapping .run() / .evaluate() in if __name__ == "__main__":	Place them at module top level — benchmark files are scripts, not importable modules
Using user.send() with image URLs	user.send() passes URLs as-is; prefer llm.prompt(image=) for auto-conversion
Not isolating judge conversations	Use with kbench.chats.new("judge"):
Multiple tasks sharing conversation history	Each .run() creates its own conversation
Using store_task=True for sub-tasks	Set store_task=False for helper tasks called inside other tasks
Using !pip install without commenting	Use # !pip install -q pkg — uncommented magics break local execution
Forgetting last_reasoning_traces() can be None	Always check: traces = kbench.last_reasoning_traces(); if traces: ...

---

§1. Import Styles

There are two main import styles. Prefer Style A for clarity.

Style A: Module import (Preferred)

import kaggle_benchmarks as kbench

@kbench.task(name="my_task")
def my_task(llm):
    response = llm.prompt("Question?")
    kbench.assertions.assert_true(True)

Style B: Direct imports

from kaggle_benchmarks import assertions, chats, llm, task, system, user

@task("my_task")
def my_task(llm):
    response = llm.prompt("Question?")
    assertions.assert_true(True)

Style B is shorter but risks name collisions (e.g., llm is both a module-level variable and a task parameter).

File Structure: Cell Markers

Benchmark files are Python scripts (.py), but use # %% cell markers to create logical sections. This makes them runnable as both standalone Python files and as interactive notebooks (via Jupyter/VS Code cell execution).

# %%
import kaggle_benchmarks as kbench

# %%
@kbench.task()
def my_task(llm):
    response = llm.prompt("Hello!")
    kbench.assertions.assert_not_empty(response)

my_task.run(kbench.llm)

# %%
@kbench.task()
def another_task(llm) -> float:
    ...

IPython magics (!pip install, %time, etc.): These work on Kaggle notebooks but NOT when running as standalone Python files. If you need a magic command (e.g., to install a dependency), comment it out so the file remains runnable locally:

# %%
# !pip install -q pronouncing syllables   # Uncomment on Kaggle
import pronouncing

Rule: Prefer # !pip install ... (commented) over !pip install ... so the file works everywhere. Only use uncommented magics when the file is exclusively for Kaggle notebook execution.

IMPORTANT — No if __name__ guards. Think of benchmark .py files as notebooks, not modules. They are never imported — they are always executed directly.

# ❌ WRONG — do not do this
if __name__ == "__main__":
    my_task.run(kbench.llm)

# ✅ CORRECT — top-level, in its own cell
# %%
my_task.run(kbench.llm)

---

§2. Defining Tasks

@kbench.task() Parameters

@kbench.task(
    name="optional_name",         # Defaults to function name, title-cased
    description="What it does",   # Defaults to docstring
    version=1,                    # Task version
    store_task=True,              # Set False for sub-tasks
    store_run=True,               # Set False to skip storing results
)
def my_task(llm):
    ...

@kbench.benchmark() is an exact alias for @kbench.task().

Task First Parameter

The first parameter must be the LLM actor. It receives the model to test.

@kbench.task()
def my_task(llm):           # ✅ Correct
    ...

@kbench.task()
def my_task(llm, judge_llm): # ✅ Also fine — second LLM for judging
    ...

Task Additional Parameters

Extra parameters are passed via .run() kwargs:

@kbench.task()
def check_knowledge(llm, question, expected_answer):
    response = llm.prompt(question)
    kbench.assertions.assert_contains_regex(
        rf"(?i){expected_answer}", response
    )

check_knowledge.run(kbench.llm, question="Capital of Japan?", expected_answer="Tokyo")

Return Types

If your task returns a value, you MUST add a return type annotation.

Annotation	Result Type	Meaning
(none) or -> None	PassFail	Pass if no exceptions, based on assertions
-> bool	Boolean	True = pass, False = fail
-> float	Score	Numerical score
-> int	Numerical	Integer value
-> dict	Dictionary	Arbitrary dict result
-> tuple[int, int]	PassCount	Count (e.g., (8, 10))
-> tuple[float, float]	MetricWithCI	Value ± confidence interval

Note: -> None is equivalent to omitting the annotation — both produce PassFail.

# Score task
@kbench.task()
def accuracy(llm) -> float:
    return 0.85

# Count task
@kbench.task()
def count_correct(llm) -> tuple[int, int]:
    return (8, 10)  # 8 out of 10 passed

# Dict task (for rich results)
@kbench.task()
def detailed_result(llm) -> dict:
    return {"accuracy": 0.9, "latency": 1.2, "is_correct": True}

---

§3. Running Tasks

Running a Task

# Single run — returns a Run object
run = my_task.run(kbench.llm)

# With extra parameters
run = my_task.run(kbench.llm, question="What is Python?")

# Multiple models
run1 = my_task.run(kbench.llm)         # Default model
run2 = my_task.run(kbench.judge_llm)   # Judge model

Available models (loaded from Kaggle environment):

• kbench.llm — default model
• kbench.judge_llm — judge model
• kbench.llms — list of ALL available models (useful for multi-model comparison)

Run Object Properties

The Run object returned by .run() has useful attributes:

run = my_task.run(kbench.llm)

run.passed              # bool — True if result + all assertions passed
run.result              # The returned value (type depends on task return annotation)
run.assertion_results   # list[AssertionResult] — all recorded assertions
run.status              # Status enum (PENDING, DONE, FAILED)
run.chat                # The conversation log

This is especially useful in sub-task composition:

runs = [subtask.run(llm, q=q) for q in questions]
accuracy = sum(r.passed for r in runs) / len(runs)

Batch Evaluation: .evaluate()

import pandas as pd

results = my_task.evaluate(
    llm=[kbench.llm],                    # List of models
    evaluation_data=df,                   # DataFrame of test cases
    n_jobs=3,                             # Parallel workers (default: 1)
    timeout=120,                          # Per-job timeout in seconds
    max_attempts=3,                       # Retry count
    retry_delay=15,                       # Seconds between retries
    stop_condition=lambda runs: len(runs) == df.shape[0],  # Early stop
    remove_run_files=True,                # Clean up after
)

# Access results
results.as_dataframe()

Note: Any extra keyword arguments (beyond llm, evaluation_data, etc.) are forwarded to the task function. For example, if your task has a critic parameter, pass critic=[critic_llm] to .evaluate().

Multi-Model Comparison

models = [
    kbench.llms["google/gemini-2.5-flash"],
    kbench.llms["meta/llama-3.1-70b"],
]

# When using stop_condition with multiple models, account for all combinations:
n_total = len(models) * df.shape[0]
results = my_task.evaluate(
    llm=models,
    evaluation_data=df,
    n_jobs=3,
    stop_condition=lambda runs: len(runs) == n_total,
)

Sub-Tasks Pattern

For nested evaluation (task calling sub-task):

@kbench.task(name="single_qa", store_task=False)  # store_task=False for sub-tasks
def single_qa(llm, question, answer) -> dict:
    response = llm.prompt(question)
    return {"is_correct": answer.lower() in response.lower()}

@kbench.task(name="full_eval")
def full_eval(llm, df) -> tuple[float, float]:
    with kbench.client.enable_cache():
        runs = single_qa.evaluate(
            llm=[llm], evaluation_data=df,
            n_jobs=2, timeout=120, max_attempts=1,
            remove_run_files=True,
        )
    eval_df = runs.as_dataframe()
    accuracy = float(eval_df.result.str.get("is_correct").mean())
    std = float(eval_df.result.str.get("is_correct").std())
    return accuracy, std

---

§4. LLM Interaction

llm.prompt() — Primary method

Parameter	Type	Default	Description
text	str	—	The prompt text (required, first positional arg)
schema	Type	str	Structured output type (returns parsed object, not string)
image	Image	None	Image content
video	Video	None	Video content
audio	Audio	None	Audio content
tools	list[Callable]	None	Callable Python functions as tools
reasoning	str	None	Reasoning effort: "none", "low", "medium", "high"
seed	int	0	Random seed for reproducibility
temperature	float	0	Temperature (0 = deterministic, higher = more creative)

Accessing Reasoning Traces

When using reasoning= parameter, access the model's thinking process:

response = llm.prompt("Solve: 15 × 17", reasoning="medium")
traces = kbench.last_reasoning_traces()  # str | None — the model's "thinking"
kbench.assertions.assert_not_empty(response)

last_reasoning_traces() returns None if the model didn't produce traces (e.g., reasoning was not enabled or the model doesn't support it).

# Simple text → returns str
response = llm.prompt("What is 2+2?")

# Multi-turn: history maintained automatically within a task
llm.prompt("My name is Alice.")
response = llm.prompt("What is my name?")  # Remembers "Alice"

Structured Output: Four Schema Styles

Style 1: Dataclass (Preferred for complex types)

from dataclasses import dataclass

@dataclass
class Sentiment:
    label: str
    score: float

result = llm.prompt("Analyze: 'I love this!'", schema=Sentiment)
print(result.label, result.score)  # "positive", 0.95

Style 2: Inline dict schema (Quick & simple)

result = llm.prompt(
    "9.9 - 9.11 = ?",
    schema={"answer": bool, "explanation": str},
)
print(result.answer, result.explanation)

Style 3: Primitive type

count = llm.prompt("How many letters in 'hello'?", schema=int)  # returns int
is_yes = llm.prompt("Is the sky blue?", schema=bool)             # returns bool
text = llm.prompt("Summarize briefly.", schema=str)               # returns str

Style 4: Pydantic model (with Field descriptions)

import pydantic

class Review(pydantic.BaseModel):
    sentiment: str = pydantic.Field(description="positive, negative, or neutral")
    score: float = pydantic.Field(description="confidence score 0-1")
    key_phrases: list[str] = pydantic.Field(description="notable phrases from the text")

result = llm.prompt("Analyze: 'Great movie!'", schema=Review)
# result.sentiment, result.score, result.key_phrases are all typed

Tip: Field(description=...) helps the LLM understand what each field expects, improving extraction accuracy for complex schemas.

When to use which:

• Dict schema: Quick prototyping, simple key-value results
• Dataclass: Complex types with enums, nested types, or frozen immutability
• Pydantic: When you need validation rules or Field(description=...) hints
• Primitive: When you need a single value (bool, int, str)

Multimodal Inputs

Images — Two approaches:

from kaggle_benchmarks.content_types import images

# Approach A: via prompt() — PREFERRED (auto-converts URL to Base64)
img = images.from_url("https://example.com/photo.jpg")
response = llm.prompt("Describe this image", image=img)

# Approach B: via user.send() — for multi-turn / stacking multiple images
kbench.user.send(images.from_url("https://example.com/photo.jpg"))
kbench.user.send(images.from_path("local/chart.png"))
response = llm.prompt("Compare these images")

Prefer Approach A — llm.prompt(image=) auto-converts URLs to Base64 for maximum compatibility. Use Approach B when you need to stack multiple images or build complex conversation history. Note: user.send() passes URLs as-is — the model must natively support URL inputs.

Image factories:

img = images.from_url("https://example.com/photo.jpg")   # From URL
img = images.from_path("local/photo.png")                 # From local file
img = images.from_base64(b64_str, format="png")           # From Base64
img = images.from_array(numpy_array)                      # From NumPy array (requires Pillow)
b64 = images.image_url_to_base64("https://...")            # Download + convert helper

Videos (limited to specific models — Gemini 2.5+):

from kaggle_benchmarks.content_types import videos
video = videos.from_url("https://www.youtube.com/watch?v=...")
response = llm.prompt("What happens in this video?", video=video)

Audio (limited to specific models — Gemini 2.0+):

from kaggle_benchmarks.content_types import audios

# Three factory methods:
audio = audios.from_path("speech.mp3")                               # From local file
audio = audios.from_base64(b64_string, format="mp3")                  # From Base64
audio = audios.from_url("https://example.com/speech.mp3")             # From URL

response = llm.prompt("Transcribe this audio.", audio=audio)

System Messages

Two approaches:

# Approach A: via kbench.system.send() inside a task — PREFERRED for in-task system prompts
@kbench.task()
def code_analysis(llm):
    kbench.system.send("You are an expert Python programmer.")
    response = llm.prompt("Check this code for bugs...")

# Approach B: via chats.new(system_instructions=) — for new isolated conversations
with kbench.chats.new("pirate_chat", system_instructions="You are a pirate."):
    response = llm.prompt("Tell me about treasure.")

Streaming

llm.stream_responses = True  # Enable streaming before prompting
response = llm.prompt("Write a long story...")

Temperature Control

# Default: temperature=0 (deterministic, reproducible output)
response = llm.prompt("What is 2+2?")

# Higher temperature = more creative/varied responses
response = llm.prompt("Write a creative story about a cat.", temperature=0.7)

# Use temperature=0 (default) for factual/deterministic tasks
# Use temperature=0.5-1.0 for creative/generative tasks

Reasoning Control

response = llm.prompt("Solve: 127 * 53?", reasoning="high")
# Valid: "none", "low", "medium", "high"

traces = kbench.last_reasoning_traces()  # Access model's reasoning

---

§5. Assertions

All assertions are under kbench.assertions. They do NOT raise exceptions by default — they record pass/fail results and execution continues.

Built-in Assertions

# Equality & Truth
kbench.assertions.assert_equal(expected, actual, expectation="...")
kbench.assertions.assert_true(expr, expectation="...")
kbench.assertions.assert_false(expr, expectation="...")

# Membership
kbench.assertions.assert_in(member, container, expectation="...")
kbench.assertions.assert_not_in(member, container, expectation="...")

# Emptiness
kbench.assertions.assert_empty(container, expectation="...")
kbench.assertions.assert_not_empty(container, expectation="...")

# Regex
kbench.assertions.assert_contains_regex(pattern, text, expectation="...", flags=re.NOFLAG)
kbench.assertions.assert_not_contains_regex(pattern, text, expectation="...", flags=re.NOFLAG)

# Exception safety
kbench.assertions.assert_raises_no_exceptions(callable_obj, expectation="...", *args, **kwargs)

# Unconditional failure
kbench.assertions.assert_fail(expectation="...")

Choosing the Right Assertion

Goal	Preferred Assertion
Check exact value	assert_equal(expected, actual)
Check keyword in response	assert_contains_regex(r"(?i)keyword", response) — use (?i) for case-insensitive
Check absence of keyword	assert_not_contains_regex(r"(?i)badword", response)
Check membership	assert_in("item", collection)
Validate boolean condition	assert_true(condition) / assert_false(condition)
Signal unconditional failure	assert_fail("reason") — useful as fallback (e.g., judge returns None)
Validate no errors	assert_raises_no_exceptions(fn)
Subjective/open-ended evaluation	assess_response_with_judge(criteria, response, judge)

Assertions vs Python assert

# ❌ Python assert — stops execution, not tracked
assert "Paris" in response

# ✅ Library assertion — recorded, execution continues
kbench.assertions.assert_in("Paris", response, expectation="Should mention Paris")

# Note: Python assert IS caught by the task runner (doesn't crash),
# but it won't be recorded with proper tracking.

LLM-as-Judge (for subjective evaluation)

Default schema (AssessReport):

assessment = kbench.assertions.assess_response_with_judge(
    criteria=[
        "The poem has exactly 3 lines.",
        "The syllable structure is 5-7-5.",
    ],
    response_text=response,
    judge_llm=kbench.judge_llm,
)

# ALWAYS check for None — returns None on failure
if assessment is None:
    kbench.assertions.assert_fail("Judge failed to respond.")
else:
    for result in assessment.results:
        kbench.assertions.assert_true(
            result.passed,
            expectation=f"'{result.criterion}': {result.reason}"
        )

Custom schema:

@dataclasses.dataclass
class StoryCritique:
    overall_rating: int
    feedback: str
    passed_checks: list[str]

assessment = kbench.assertions.assess_response_with_judge(
    criteria=[...],
    response_text=story,
    judge_llm=kbench.judge_llm,
    prompt_fn=custom_prompt_fn,       # Custom prompt generator
    output_schema=StoryCritique,       # Custom output type
)

Custom Assertions

from kaggle_benchmarks.assertions import assertion_handler, AssertionResult

@assertion_handler()
def assert_word_count(text: str, min_w: int, max_w: int, expectation: str) -> AssertionResult:
    count = len(text.split())
    return AssertionResult(
        passed=(min_w <= count <= max_w),
        expectation=expectation,
    )

# Use like built-in assertions:
assert_word_count(response, 10, 100, "Response should be 10-100 words")

Rules:

• Return type must be annotated as -> AssertionResult
• Use @assertion_handler(raises_assertion_error=True) to raise on failure
• Normalize inputs inside your custom assertion (e.g., .lower(), .strip()) to make checks robust

---

§6. Conversation Management

Default: Automatic History

Within a task, llm.prompt() calls share history:

@kbench.task()
def multi_turn(llm):
    llm.prompt("My favorite color is blue.")
    response = llm.prompt("What's my favorite color?")
    kbench.assertions.assert_contains_regex(r"(?i)blue", response)

chats.new() — Isolated Conversation

Creates a clean conversation (no shared history):

with kbench.chats.new("evaluation") as chat:
    judge_llm.prompt("Rate this response...")  # Clean slate

Parameters:

kbench.chats.new(
    name="chat_name",                    # Display name
    system_instructions="You are ...",   # Optional system prompt
    orphan=False,                        # If True, don't nest in parent chat history
)

chats.fork() — Copy Current History

Creates a new conversation starting with the current chat's history (the original chat is unaffected):

# Build up some context
llm.prompt("My name is Alice and I'm a data scientist.")
llm.prompt("I work on NLP projects.")

# Branch the conversation — fork has full history, original continues separately
with kbench.chats.fork("hypothesis") as branch:
    # This prompt sees "Alice" + "NLP" context
    response = llm.prompt("Given my background, suggest a research topic.")
    # Anything said here does NOT affect the original conversation

# Back in original — still only has the two original messages
response = llm.prompt("What's my name?")  # Still remembers "Alice"

contexts.enter() — Multi-Agent

For complex multi-agent scenarios:

from kaggle_benchmarks import chats, contexts

agent_a_chat = chats.Chat(name="Agent A")
agent_b_chat = chats.Chat(name="Agent B")

with contexts.enter(chat=agent_a_chat):
    response_a = llm_a.prompt("Agent A's prompt...")

with contexts.enter(chat=agent_b_chat):
    response_b = llm_b.prompt("Agent B's prompt...")

Choosing Conversation Strategy

Scenario	Method
Default multi-turn	Automatic — just call llm.prompt() repeatedly
Judge evaluation	chats.new("judge") — no history leakage
System instructions for a section	chats.new(system_instructions="...")
Continue with shared history	chats.fork("branch")
Multiple agents with separate histories	contexts.enter(chat=...)

---

§7. Tools

Python Code Execution — Two Approaches

Approach A: Extract + Run (Preferred for code generation tasks)

response = llm.prompt("Write Python to calculate factorial of 10.")
code = kbench.tools.python.extract_code(response)
result = kbench.tools.python.script_runner.run_code(code)
kbench.assertions.assert_contains_regex("3628800", result.stdout)
kbench.assertions.assert_empty(result.stderr.strip(), "No errors expected")

# For programs that read stdin:
result = kbench.tools.python.script_runner.run_code(code, input="test input\n")

Approach B: IPythonREPL (for expression evaluation)

repl = kbench.tools.python.IPythonREPL()
output = repl.invoke("2 + 2", is_visible_to_llm=False)
kbench.assertions.assert_equal(4, float(output.output))

Web/HTML Testing

with kbench.tools.web.Browser() as browser:
    html_code = kbench.tools.web.extract_html(response)
    snapshot = browser.take_snapshot(html_code, wait_before=5000, full_page=True)
    # snapshot.html — rendered HTML
    # snapshot.logs — console logs

Custom Function Tools

Define plain Python functions with type hints and docstrings. Pass them via tools=.

def run_simple_calculator(a: float, b: float, operator: str) -> float:
    """Calculates the result of an arithmetic operation. Supported operators: + - * /"""
    if operator == "+": return a + b
    if operator == "-": return a - b
    if operator == "*": return a * b
    if operator == "/": return a / b
    raise ValueError(f"Unknown operator: {operator}")

@kbench.task()
def calc_task(llm):
    response = llm.prompt("What is 50 plus 25?", tools=[run_simple_calculator])
    kbench.assertions.assert_contains_regex(r"75", response)

Multiple tools — LLM selects the right one:

def add_tool(a: float, b: float) -> float:
    """Adds two numbers."""
    return a + b

def multiply_tool(a: float, b: float) -> float:
    """Multiplies two numbers."""
    return a * b

@kbench.task()
def multi_tool_task(llm):
    response = llm.prompt(
        "What is 12 multiplied by 34?",
        tools=[add_tool, multiply_tool],
    )
    kbench.assertions.assert_contains_regex(r"408", response)

Tool error handling — tools can raise exceptions:

def flaky_tool() -> str:
    """This tool always fails with an error."""
    raise ValueError("Tool execution failed.")

@kbench.task()
def error_handling_task(llm):
    response = llm.prompt("Call the flaky_tool and report what happens.", tools=[flaky_tool])
    kbench.assertions.assert_contains_regex(r"(?i)error|failed", response)

Tool calling behavior: When you pass tools= to prompt(), the library automatically handles the tool invocation loop: it sends the tool schemas to the LLM, executes any requested tool calls, feeds results back, and repeats until the LLM returns a final text answer (up to max_tool_rounds=10 rounds by default). This works on both genai and openai API backends.

Verifying tool usage: Use kbench.assertions.assert_tool_was_invoked(fn) to assert that a specific tool was called during the task.

---

§8. Model Loading, Dataset Evaluation, and Publishing

Model Loading

Three approaches:

# 1. Default model (Preferred — lets Kaggle platform manage model selection)
kbench.llm          # Default model
kbench.judge_llm    # Judge model

# 2. Named model from available models
kbench.llms["google/gemini-2.5-flash"]
kbench.llms["meta/llama-3.1-70b"]

# 3. Direct ModelProxy (for explicit API control)
from kaggle_benchmarks.kaggle import model_proxy
llm = model_proxy.ModelProxy(model="google/gemini-2.5-flash", api="genai")
llm = model_proxy.ModelProxy(model="google/gemini-2.5-flash", api="openai")

When to use which:

• kbench.llm: Default choice — portable across Kaggle's "Add Models" feature
• kbench.llms["..."]: When you need a specific model (e.g., vision, judge)
• ModelProxy: When you need to specify the API backend (genai vs openai)

Dataset Evaluation

import pandas as pd

@kbench.task()
def qa_task(llm, question, answer) -> bool:
    response = llm.prompt(question)
    return answer.lower() in response.lower()

df = pd.DataFrame([
    {"question": "What is 2+2?", "answer": "4"},
    {"question": "Capital of France?", "answer": "Paris"},
])

# Task parameter names must match DataFrame column names
results = qa_task.evaluate(llm=[kbench.llm], evaluation_data=df)
print(results.as_dataframe())

Caching

with kbench.client.enable_cache():
    results = my_task.evaluate(llm=[kbench.llm], evaluation_data=df)

Publishing to Leaderboard

# Final cell of Kaggle notebook:
%choose my_main_task

Currently only one task per notebook for leaderboards.

Environment Variables

• MODEL_PROXY_URL — Model proxy endpoint
• MODEL_PROXY_API_KEY — API key
• KBENCH_EXECUTION_MODE — testing for test mode
• KBENCH_UI_MODE — panel, console, or none

Testing Your Tasks

Running with uv

source ~/ws/uv/bin/activate

uv pip install -e .
uv run python documentation/examples/simple_task.py
uv run --group test pytest tests/ -v

MockedChat for Unit Tests

from tests.mocks import MockedChat

mock = MockedChat(responses=["Paris", "42"])
response1 = mock.prompt("Capital of France?")  # Returns "Paris"
response2 = mock.prompt("What is 6*7?")         # Returns "42"

# Verify what was sent
assert mock.invocations[0].messages[0].content == "Capital of France?"

---

§9. Complete Example Patterns

Pattern A: Simple Q&A — Regex Check

The most basic pattern. Good for factual questions with known keywords.

import kaggle_benchmarks as kbench

@kbench.task(name="geography_quiz")
def geography_quiz(llm):
    response = llm.prompt("What is the longest river in the world?")
    kbench.assertions.assert_contains_regex(
        r"(?i)nile", response,
        expectation="Should mention the Nile river."
    )

geography_quiz.run(kbench.llm)

Pattern B: Structured Output + Validation

For tasks needing parsed, validated responses.

import kaggle_benchmarks as kbench
from dataclasses import dataclass

@dataclass
class Person:
    name: str
    age: int
    occupation: str

@kbench.task(name="extract_person")
def extract_person(llm, bio: str):
    person = llm.prompt(
        f"Extract the name, age, and occupation:\n\n{bio}",
        schema=Person
    )
    kbench.assertions.assert_equal("Marie Curie", person.name)
    kbench.assertions.assert_equal(66, person.age)
    kbench.assertions.assert_in("physicist", person.occupation.lower())

extract_person.run(kbench.llm, bio="Marie Curie was a physicist... born 1867, died 1934 at 66.")

Pattern C: Hallucination Detection (Structured + Negative Assert)

Combining structured output with negative assertions to catch model hallucinations.

@kbench.task("hallucination_check")
def check_hallucination(llm):
    response = llm.prompt(
        "When Richard Feynman mentioned gravity-light-contraction theory in his Nobel speech, did he think it was important?",
        schema={"answer": bool, "explanation": str},
    )
    kbench.assertions.assert_false(
        response.answer,
        expectation="Model should recognize fictitious theory.",
    )
    kbench.assertions.assert_contains_regex(
        r"(not|never|no|didn't)", response.explanation.lower(),
        expectation="Explanation should deny the theory exists.",
    )

Pattern D: Judge-Based Evaluation with Error Handling

For open-ended tasks where deterministic checks aren't possible.

@kbench.task(name="story_quality")
def story_quality(llm):
    story = llm.prompt("Write a one-paragraph story about a cat detective.")

    assessment = kbench.assertions.assess_response_with_judge(
        criteria=[
            "The story is exactly one paragraph.",
            "The main character is a cat.",
            "The cat is a detective.",
        ],
        response_text=story,
        judge_llm=kbench.judge_llm,
    )

    if assessment is None:
        kbench.assertions.assert_fail("Judge failed to respond.")
    else:
        for result in assessment.results:
            kbench.assertions.assert_true(
                result.passed,
                expectation=f"'{result.criterion}': {result.reason}"
            )

story_quality.run(kbench.llm)

Pattern E: Code Generation + Execution

Combines prompting, code extraction, and programmatic validation.

@kbench.task(name="solve_with_python")
def solve_with_python(llm):
    response = llm.prompt(
        "What is the 15th Fibonacci number? Write Python to calculate and print it."
    )
    code = kbench.tools.python.extract_code(response)
    result = kbench.tools.python.script_runner.run_code(code)

    kbench.assertions.assert_empty(
        result.stderr.strip(), "Code should run without errors."
    )
    kbench.assertions.assert_equal(
        "610", result.stdout.strip(), "Should print 610."
    )

solve_with_python.run(kbench.llm)

Pattern F: Multi-Turn Game Loop

Interactive game with state tracking.

@kbench.task(name="twenty_questions")
def twenty_questions(llm, judge_llm, target: str):
    from dataclasses import dataclass

    @dataclass
    class Response:
        question: str = ""
        guess: str = ""

    rules = f"Let's play 20 questions! I'm thinking of an animal. Ask yes/no questions."
    response = llm.prompt(rules, schema=Response)

    for i in range(20):
        if response.guess:
            kbench.assertions.assert_in(target, response.guess.lower())
            return True

        with kbench.chats.new("Answering"):
            yes = judge_llm.prompt(
                f"I'm thinking of {target}. Question: {response.question}",
                schema=bool,
            )

        answer = "Yes" if yes else "No"
        response = llm.prompt(f"{answer}. Guess or ask another?", schema=Response)

    return False

twenty_questions.run(kbench.llm, kbench.judge_llm, target="dog")

Pattern G: Multi-Model Judging with Isolated Chats

Multiple judges scoring the same output, each in isolation.

from dataclasses import dataclass

@dataclass
class PoemScore:
    score: float

@kbench.task(name="judge_poem")
def judge_poem(llm, question: str) -> float:
    judge1 = kbench.llms["google/gemini-2.5-pro"]
    judge2 = kbench.llms["meta/llama-3.1-70b"]

    with kbench.chats.new("writing"):
        poem = llm.prompt(question)

    with kbench.chats.new("judge_1"):
        score1 = judge1.prompt(f"Rate this poem 0-10:\n{poem}", schema=PoemScore)

    with kbench.chats.new("judge_2"):
        score2 = judge2.prompt(f"Rate this poem 0-10:\n{poem}", schema=PoemScore)

    return (score1.score + score2.score) / 2

judge_poem.run(kbench.llm, question="Write a haiku about clouds.")

Pattern H: Dataset Evaluation with Parallel Execution

import pandas as pd

@kbench.task()
def riddle_solver(llm, riddle: str, answer_keyword: str) -> bool:
    response = llm.prompt(riddle)
    is_correct = answer_keyword.lower() in response.lower()
    kbench.assertions.assert_true(is_correct)
    return is_correct

df = pd.DataFrame({
    "riddle": ["I have cities but no houses. What am I?", "What has an eye but cannot see?"],
    "answer_keyword": ["map", "needle"],
})

runs = riddle_solver.evaluate(
    llm=[kbench.llm], evaluation_data=df, n_jobs=3
)
runs.as_dataframe()

Pattern I: Code Analysis with System Prompt + Tools

Combining system messages, structured output, and code execution.

from dataclasses import dataclass

@dataclass
class CodeAnalysis:
    has_bugs: bool
    fixed_code: str

@kbench.task("code_analysis")
def analyze_code(llm):
    buggy_code = """
fruits = ['apple', 'orange' 'banana', 'peach']
print(len(fruits))
"""
    kbench.system.send("You are an expert Python programmer.")
    response = llm.prompt(
        f"Does this code have bugs? Fix it.\n{buggy_code}",
        schema=CodeAnalysis,
    )
    kbench.assertions.assert_true(response.has_bugs, "Should detect the missing comma.")

    fixed = kbench.tools.python.extract_code(response.fixed_code)
    output = kbench.tools.python.script_runner.run_code(fixed)
    kbench.assertions.assert_equal("4", output.stdout.strip(), "Fixed code outputs 4.")

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Related Skills

• kaggle-cli — Covers using the kaggle CLI to manage datasets, notebooks, and submit benchmarks to Kaggle. Use that skill after writing your benchmark code with this one.