of AI brokers. LLMs are now not simply instruments. They’ve develop into energetic individuals in our lives, boosting productiveness and remodeling the way in which we reside and work.
- OpenAI lately launched Operator, an AI agent that may autonomously carry out varied duties, from shopping the online to filling out varieties and scheduling appointments.
- Anthropic launched MCP (Model Context Protocol), a brand new commonplace for the way AI assistants work together with the skin world. With over 5 thousand energetic MCP servers already, adoption is rising quickly.
- AI brokers are additionally altering the panorama of software program engineering. Instruments like GitHub Copilot’s agentic mode, Claude Code, OpenAI Codex, and others aren’t solely improving developer productivity and code quality but additionally democratising the sphere, making software program improvement accessible to individuals and not using a technical background.
We’ve beforehand checked out completely different AI Agent frameworks, reminiscent of LangGraph or CrewAI. On this article, I wish to focus on a brand new one I’ve been exploring lately — HuggingFace smolagents. It’s an fascinating framework because it implements the idea of code brokers.
On this article, we’ll discover a number of subjects:
- What code brokers are (teaser: it’s not associated to vibe coding).
- Tips on how to use the HuggingFace smolagents framework in observe.
- Whether or not it’s safe to offer LLMs a lot company.
- The true distinction in efficiency between code brokers and conventional tool-calling brokers.
AI Brokers recap
Let’s begin with a fast refresher: what precisely are AI brokers? HuggingFace provides a transparent and concise definition of what they imply by brokers.
AI Brokers are applications the place LLM outputs management the workflow.
So, we want an agentic circulation after we need a system to purpose and act primarily based on observations. Really, company shouldn’t be a binary variable (sure or no), however a spectrum.
- At one finish, we are able to have methods with out company in any respect, for instance, a easy course of the place an LLM defines the sentiment of a textual content, interprets it or summarises it.
- The subsequent degree is routing, the place an LLM can classify an incoming query and resolve which path to take — for instance, calling a software if a buyer is asking concerning the standing of their present order, and transferring the dialog to a human CS agent in any other case.
- Extra superior methods can exhibit greater levels of company. These would possibly embrace the power to execute different LLMs (multi-agent setup) and even create new instruments on the fly.
Code brokers fall into this extra superior class. They’re multi-step brokers that execute software calls within the type of code, in distinction to the extra conventional strategy utilizing a JSON format with the software title and arguments.
A number of current papers have proven that utilizing code in agentic flows results in higher outcomes:
It is sensible when you consider it. We’ve been growing programming languages for many years to resolve complicated issues. So, it’s pure that these languages are higher suited to LLM’s duties than easy JSON configs. An extra profit is that LLMs are already fairly good at writing code in widespread programming languages, due to the huge quantity of accessible knowledge for coaching.
This strategy comes with a number of different advantages as nicely:
- By producing code, an LLM shouldn’t be restricted to a predefined set of instruments and may create its personal features.
- It could possibly mix a number of instruments inside a single motion utilizing situations and loops, which helps scale back the variety of steps required to finish a process.
- It additionally permits the mannequin to work with a greater variety of outputs, reminiscent of producing charts, pictures, or different complicated objects.
These advantages aren’t simply theoretical; we are able to observe them in observe. In “Executable Code Actions Elicit Better LLM Agents”, the authors present that code brokers outperform conventional strategies, reaching the next success fee and finishing a process in fewer steps, which in flip reduces prices.

Code brokers look promising, which impressed me to do that strategy in observe.
HuggingFace smolagents framework
First attempt
Fortunately, we don’t must construct code brokers from scratch, as HuggingFace has launched a helpful library known as smolagents that implements this strategy.
Let’s begin by putting in the library.
pip set up smolagents[litellm]
# I've used litellm, since I am planning to make use of it with OpenAI mannequin
Subsequent, let’s construct a fundamental instance. To initialise the agent, we want simply two parameters: mannequin and instruments.
I plan to make use of OpenAI for the mannequin, which is accessible through LiteLLM. Nevertheless, the framework helps different choices as nicely. You need to use a neighborhood mannequin through Ollama or TransformersModel, or public fashions through Inference Providers or select different choices (you’ll find extra particulars in the documentation).
I didn’t specify any instruments, however used add_base_tools = True
, so my agent has a default set of tools, reminiscent of a Python interpreter or DuckDuckGo search. Let’s attempt it out with a easy query.
from smolagents import CodeAgent, LiteLLMModel
mannequin = LiteLLMModel(model_id="openai/gpt-4o-mini",
api_key=config['OPENAI_API_KEY'])
agent = CodeAgent(instruments=[], mannequin=mannequin, add_base_tools=True)
agent.run(
"""I've 5 completely different balls and I randomly choose 2.
What number of potential mixtures of the balls I can get?""",
)
Consequently, we see a very properly formatted execution circulation. It’s simply superb and means that you can perceive the method completely.

So, the agent discovered a solution in a single step and wrote Python code to calculate the variety of mixtures.
The output is kind of useful, however we are able to go even deeper and have a look at the entire data associated to execution (together with prompts), through agent.reminiscence.steps
. Let’s have a look at the system immediate utilized by the agent.
You might be an skilled assistant who can resolve any process utilizing code blobs.
You'll be given a process to resolve as greatest you may.
To take action, you've been given entry to an inventory of instruments: these instruments
are principally Python features which you'll be able to name with code.
To unravel the duty, you should plan ahead to proceed in a sequence of
steps, in a cycle of 'Thought:', 'Code:',
and 'Commentary:' sequences.
At every step, within the 'Thought:' sequence, you must first clarify
your reasoning in the direction of fixing the duty and the instruments that you really want
to make use of.
Then within the 'Code:' sequence, you must write the code in easy
Python. The code sequence should finish with '' sequence.
Throughout every intermediate step, you need to use 'print()' to avoid wasting
no matter essential data you'll then want.
These print outputs will then seem within the 'Commentary:' subject,
which shall be accessible as enter for the subsequent step.
In the long run you need to return a closing reply utilizing
the final_answer software.
Listed below are a number of examples utilizing notional instruments: <...>
It’s fairly clear that smolagents implements the ReAct strategy (launched within the paper by Yao et al. “ReAct: Synergizing Reasoning and Acting in Language Models”) and makes use of a few-shot prompting method.
The smolagents library handles all behind-the-scenes work concerned within the agent workflow: assembling the system immediate with all needed data for the LLM (i.e. accessible instruments), parsing the output and executing the generated code. It additionally gives complete logging and a retry mechanism to assist appropriate errors.
Moreover, the library affords reminiscence administration options. By default, all execution outcomes are saved to reminiscence, however you may customise this behaviour. For instance, you may take away some middleman outcomes from the reminiscence to cut back the variety of tokens or execute the agent step-by-step. Whereas we received’t dive deep into reminiscence administration right here, you’ll find helpful code examples in the documentation.
Safety
Now, it’s time to debate the drawbacks of the code brokers’ strategy. Giving an LLM extra company by permitting it to execute arbitrary code introduces greater dangers. Certainly, an LLM can run dangerous code both by mistake (since LLMs are nonetheless removed from excellent) or as a consequence of focused assaults like immediate injections or compromised fashions.
To mitigate these dangers, the native Python executor applied within the smolagents library has a bunch of security checks:
- By default, imports aren’t allowed until the bundle has been explicitly added to
additional_authorized_imports
checklist. - Furthermore, submodules are blocked by default, so you should authorise them particularly (i.e.
numpy.*
). It’s been carried out as a result of some packages can expose probably dangerous submodules, i.e.random._os
. - The full variety of executed operations is capped, stopping infinite loops and useful resource bloating.
- Any operation not explicitly outlined within the interpreter will increase an error.
Let’s check whether or not these security measures really work.
from smolagents.local_python_executor import LocalPythonExecutor
custom_executor = LocalPythonExecutor(["numpy.*", "random"])
# operate to have fairly formatted exceptions
def run_capture_exception(command: str):
attempt:
custom_executor(harmful_command)
besides Exception as e:
print("ERROR:n", e)
# Unauthorised imports are blocked
harmful_command="import os; exit_code = os.system('')"
run_capture_exception(harmful_command)
# ERROR: Code execution failed at line 'import os' as a consequence of:
# InterpreterError: Import of os shouldn't be allowed. Approved imports
# are: ['datetime', 'itertools', 're', 'math', 'statistics', 'time', 'queue',
# 'numpy.*', 'random', 'collections', 'unicodedata', 'stat']
# Submodules are additionally blocked until said particularly
harmful_command="from random import _os; exit_code = _os.system('')"
run_capture_exception(harmful_command)
# ERROR: Code execution failed at line 'exit_code = _os.system('')'
# as a consequence of: InterpreterError: Forbidden entry to module: os
# The cap on the variety of iterations breaks inifinity loops
harmful_command = '''
whereas True:
cross
'''
run_capture_exception(harmful_command)
# ERROR: Code execution failed at line 'whereas True: cross' as a consequence of:
# InterpreterError: Most variety of 1000000 iterations in Whereas loop
# exceeded
# Undefined operations do not work
harmful_command="!echo "
custom_executor(harmful_command)
# ERROR: Code parsing failed on line 1 as a consequence of: SyntaxError
It appears now we have some security nets with code brokers. Nevertheless, regardless of these safeguards, dangers persist once you’re executing code regionally. For instance, an LLM can recursively create threads in your pc or create too many recordsdata, resulting in useful resource bloating. A potential resolution is to execute code in a sandboxed setting, reminiscent of utilizing Docker or options like E2B. I’m keen to be adventurous and run my code regionally, however if you happen to favor a extra risk-averse strategy, you may observe the sandbox set-up steerage in the documentation.
Code agent vs conventional Instrument-Calling agent
It’s claimed that the code brokers carry out higher in comparison with the standard JSON-based strategy. Let’s put this to the check.
I’ll use the duty of metrics change evaluation that I described in my earlier article, “Making sense of KPI changes”. We are going to begin with an easy case: analysing a easy metric (income) break up by one dimension (nation).
raw_df = pd.read_csv('absolute_metrics_example.csv', sep = 't')
df = raw_df.groupby('nation')[['revenue_before', 'revenue_after_scenario_2']].sum()
.sort_values('revenue_before', ascending = False).rename(
columns = {'revenue_after_scenario_2': 'after',
'revenue_before': 'earlier than'})

The smolagents library helps two lessons, which we are able to use to match two approaches:
- CodeAgent — an agent that acts by producing and executing code,
- ToolCallingAgent — a standard JSON-based agent.
Our brokers will want some instruments, so let’s implement them. There are multiple options to create tools in smolagents: we are able to re-use LangChain instruments, obtain them from HuggingFace Hub or just create Python features. We are going to take essentially the most easy strategy by writing a few Python features and annotating them with @software
.
I’ll create two instruments: one to estimate the relative distinction between metrics, and one other to calculate the sum of an inventory. Since LLM shall be utilizing these instruments, offering detailed descriptions is essential.
@software
def calculate_metric_increase(earlier than: float, after: float) -> float:
"""
Calculate the share change of the metric between earlier than and after
Args:
earlier than: worth earlier than
after: worth after
"""
return (earlier than - after) * 100/ earlier than
@software
def calculate_sum(values: checklist) -> float:
"""
Calculate the sum of checklist
Args:
values: checklist of numbers
"""
return sum(values)
Teaser: I’ll later realise that I ought to have supplied extra instruments to the agent, however I genuinely neglected them.
CodeAgent
Let’s begin with a CodeAgent. I’ve initialised the agent with the instruments we outlined earlier and authorised the utilization of some Python packages that could be useful.
agent = CodeAgent(
mannequin=mannequin,
instruments=[calculate_metric_increase, calculate_sum],
max_steps=10,
additional_authorized_imports=["pandas", "numpy", "matplotlib.*",
"plotly.*"],
verbosity_level=1
)
process = """
Here's a dataframe exhibiting income by phase, evaluating values
earlier than and after.
Might you please assist me perceive the modifications? Particularly:
1. Estimate how the full income and the income for every phase
have modified, each in absolute phrases and as a share.
2. Calculate the contribution of every phase to the full
change in income.
Please spherical all floating-point numbers within the output
to 2 decimal locations.
"""
agent.run(
process,
additional_args={"knowledge": df},
)
General, the code agent accomplished the duty in simply two steps, utilizing solely 5,451 enter and 669 output tokens. The consequence additionally appears to be like fairly believable.
{'total_before': 1731985.21, 'total_after':
1599065.55, 'total_change': -132919.66, 'segment_changes':
{'absolute_change': {'different': 4233.09, 'UK': -4376.25, 'France':
-132847.57, 'Germany': -690.99, 'Italy': 979.15, 'Spain':
-217.09}, 'percentage_change': {'different': 0.67, 'UK': -0.91,
'France': -55.19, 'Germany': -0.43, 'Italy': 0.81, 'Spain':
-0.23}, 'contribution_to_change': {'different': -3.18, 'UK': 3.29,
'France': 99.95, 'Germany': 0.52, 'Italy': -0.74, 'Spain': 0.16}}}
Let’s check out the execution circulation. The LLM obtained the next immediate.
╭─────────────────────────── New run ────────────────────────────╮
│ │
│ Here's a pandas dataframe exhibiting income by phase, │
│ evaluating values earlier than and after. │
│ Might you please assist me perceive the modifications? │
│ Particularly: │
│ 1. Estimate how the full income and the income for every │
│ phase have modified, each in absolute phrases and as a │
│ share. │
│ 2. Calculate the contribution of every phase to the full │
│ change in income. │
│ │
│ Please spherical all floating-point numbers within the output to 2 │
│ decimal locations. │
│ │
│ You've been supplied with these further arguments, that │
│ you may entry utilizing the keys as variables in your python │
│ code: │
│ {'df': earlier than after │
│ nation │
│ different 632767.39 637000.48 │
│ UK 481409.27 477033.02 │
│ France 240704.63 107857.06 │
│ Germany 160469.75 159778.76 │
│ Italy 120352.31 121331.46 │
│ Spain 96281.86 96064.77}. │
│ │
╰─ LiteLLMModel - openai/gpt-4o-mini ────────────────────────────╯
In step one, the LLM generated a dataframe and carried out all calculations. Apparently, it selected to jot down all of the code independently fairly than utilizing the supplied instruments.
Much more surprisingly, the LLM recreated the dataframe primarily based on the enter knowledge as a substitute of referencing it immediately. This strategy shouldn’t be preferrred (particularly when working with large datasets), as it might result in errors and better token utilization. This behaviour might probably be improved by utilizing a extra specific system immediate. Right here’s the code the agent executed in step one.
import pandas as pd
# Creating the DataFrame from the supplied knowledge
knowledge = {
'earlier than': [632767.39, 481409.27, 240704.63, 160469.75,
120352.31, 96281.86],
'after': [637000.48, 477033.02, 107857.06, 159778.76,
121331.46, 96064.77]
}
index = ['other', 'UK', 'France', 'Germany', 'Italy', 'Spain']
df = pd.DataFrame(knowledge, index=index)
# Calculating complete income earlier than and after
total_before = df['before'].sum()
total_after = df['after'].sum()
# Calculating absolute and share change for every phase
df['absolute_change'] = df['after'] - df['before']
df['percentage_change'] = (df['absolute_change'] /
df['before']) * 100
# Calculating complete income change
total_change = total_after - total_before
# Calculating contribution of every phase to the full change
df['contribution_to_change'] = (df['absolute_change'] /
total_change) * 100
# Rounding outcomes
df = df.spherical(2)
# Printing the calculated outcomes
print("Whole income earlier than:", total_before)
print("Whole income after:", total_after)
print("Whole change in income:", total_change)
print(df)
Within the second step, the LLM merely constructed the ultimate reply by referring to the variables calculated on the earlier step (which is basically neat).
final_answer({
"total_before": spherical(total_before, 2),
"total_after": spherical(total_after, 2),
"total_change": spherical(total_change, 2),
"segment_changes": df[['absolute_change',
'percentage_change', 'contribution_to_change']].to_dict()
})
It labored fairly nicely.
ToolCallingAgent
Now, it’s time to see how conventional tool-calling brokers can deal with this drawback. We initialised it in an identical method and ran the duty.
from smolagents import ToolCallingAgent
traditional_agent = ToolCallingAgent(
mannequin=mannequin,
instruments=[calculate_metric_increase, calculate_sum],
max_steps=30,
)
process = """
Here's a dataframe exhibiting income by phase, evaluating values
earlier than and after.
Might you please assist me perceive the modifications? Particularly:
1. Estimate how the full income and the income for every phase
have modified, each in absolute phrases and as a share.
2. Calculate the contribution of every phase to the full
change in income.
Please spherical all floating-point numbers within the output
to 2 decimal locations.
"""
traditional_agent.run(
process,
additional_args={"knowledge": df},
)
The outcomes are removed from preferrred: solely the relative modifications are appropriate, whereas the remainder of the numbers are pure hallucinations. I’ve to confess, the core challenge was the dearth of applicable instruments (particularly, instruments to calculate variations and to estimate shares). Nevertheless, the agent ought to have flagged lacking instruments fairly than producing random numbers.
Whole income change: -7319.66 (-7.67%). Income Modifications by Section:
- Different: +232.09 (-0.67%)
- UK: -4376.25 (0.91%)
- France: -132847.57 (55.19%)
- Germany: -690.99 (0.43%)
- Italy: +979.15 (-0.81%)
- Spain: -217.09 (0.23%)
Contribution to complete change:
- Different: 0.03%
- UK: -59.88%
- France: -181.77%
- Germany: -9.43%
- Italy: +13.38%
- Spain: -0.03%
When it comes to useful resource utilization, the tool-calling agent carried out considerably worse: 12 steps, with 29,201 enter and 1,695 output tokens. So, code brokers clearly provide price financial savings on the subject of agent execution.
Let’s dig a bit deeper to grasp what the agent really did. First, it took 4 iterations simply to determine the way to name calculate_sum
accurately and estimate the full income earlier than and after.
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Step 1 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
╭──────────────────────────────────────────────────────────────╮
│ Calling software: 'calculate_sum' with arguments: │
│ {'values': {'earlier than': [632767.39, 481409.27, 240704.63, │
│ 160469.75, 120352.31, 96281.86], │
│ 'after': [637000.48, 477033.02, 107857.06, 159778.76, │
│ 121331.46, 96064.77]}} │
╰──────────────────────────────────────────────────────────────╯
Invalid name to software 'calculate_sum' with arguments
{"values": {"earlier than": [632767.39, 481409.27, 240704.63,
160469.75, 120352.31, 96281.86],
"after": [637000.48, 477033.02, 107857.06, 159778.76,
121331.46, 96064.77]}}:
unsupported operand kind(s) for +: 'int' and 'str'
You must name this software with appropriate enter arguments.
Anticipated inputs: {"values": {"kind": "object",
"description": "checklist of values"}}
Returns output kind: quantity
Instrument description: 'Calculate the sum of checklist'
[Step 1: Duration 4.06 sec | Input tokens: 1,190 | Output: 250]
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Step 2 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
╭──────────────────────────────────────────────────────────────╮
│ Calling software: 'calculate_sum' with arguments: │
│ {'values': {'earlier than': [632767.39, 481409.27, 240704.63, │
│ 160469.75, 120352.31, 96281.86], │
│ 'after': [637000.48, 477033.02, 107857.06, 159778.76, │
│ 121331.46, 96064.77]}} │
╰──────────────────────────────────────────────────────────────╯
Invalid name to software 'calculate_sum' with arguments
{"values": {"earlier than": [632767.39, 481409.27, 240704.63,
160469.75, 120352.31, 96281.86],
"after": [637000.48, 477033.02, 107857.06, 159778.76,
121331.46, 96064.77]}}:
unsupported operand kind(s) for +: 'int' and 'str'
You must name this software with appropriate enter arguments.
Anticipated inputs: {"values": {"kind": "object",
"description": "checklist of values"}}
Returns output kind: quantity
Instrument description: 'Calculate the sum of checklist'
[Step 2: Duration 8.60 sec | Input tokens: 2,815 | Output: 386]
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Step 3 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
╭──────────────────────────────────────────────────────────────╮
│ Calling software: 'calculate_sum' with arguments: │
│ {'values': [632767.39, 481409.27, 240704.63, 160469.75, │
│ 120352.31, 96281.86]} │
╰──────────────────────────────────────────────────────────────╯
Observations: 1731985.2100000002
[Step 3: Duration 1.23 sec | Input tokens: 4,871 | Output: 488]
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Step 4 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
╭──────────────────────────────────────────────────────────────╮
│ Calling software: 'calculate_sum' with arguments: │
│ {'values': [637000.48, 477033.02, 107857.06, 159778.76, │
│ 121331.46, 96064.77]} │
╰──────────────────────────────────────────────────────────────╯
Observations: 1599065.55
The subsequent seven steps have been spent calculating the relative metric modifications utilizing the calculate_metric_increase
software.
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Step 5 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
╭──────────────────────────────────────────────────────────────╮
│ Calling software: 'calculate_metric_increase' with │
│ arguments: {'earlier than': 1731985.21, 'after': 1599065.55} │
╰──────────────────────────────────────────────────────────────╯
Observations: 7.674410799385517
<-- related software requires all nation segments -->
In the long run, the agent put collectively a closing name.
So, if the LLM had had instruments to calculate absolutely the distinction and the share of the sum, it will have taken an extra 14 iterations and much more tokens. After all, we are able to forestall such inefficiencies by rigorously designing the instruments we offer:
- We might modify our features to work with lists of values as a substitute of single objects, which might considerably scale back the variety of steps.
- Moreover, we might create extra complicated features that calculate all needed metrics without delay (much like what the code agent did). This manner, LLM wouldn’t must carry out calculations step-by-step. Nevertheless, this strategy would possibly scale back the pliability of the system.
Despite the fact that the outcomes weren’t preferrred as a consequence of a poor selection of instruments, I nonetheless discover this instance fairly insightful. It’s clear that code brokers are extra highly effective, cost-efficient and versatile as they will invent their very own complete instruments and carry out a number of actions in a single step.
Yow will discover the entire code and execution logs on GitHub.
Abstract
We’ve realized so much concerning the code brokers. Now, it’s time to wrap issues up with a fast abstract.
Code brokers are LLM brokers that “suppose” and act utilizing Python code. As a substitute of calling instruments through JSON, they generate and execute precise code. It makes them extra versatile and cost-efficient as they will invent their very own complete instruments and carry out a number of actions in a single step.
HuggingFace has introduced this lifestyle of their framework, smolagents. Smolagents makes it straightforward to construct fairly complicated brokers with out a lot problem, whereas additionally offering security measures in the course of the code execution.
On this article, we’ve explored the fundamental performance of the smolagents library. However there’s much more to it. Within the subsequent article, we’ll dive into extra superior options (like multi-agent setup and planning steps) to construct the agent that may narrate KPI modifications. Keep tuned!
Thank you numerous for studying this text. I hope this text was insightful for you.
Reference
This text is impressed by the “Building Code Agents with Hugging Face smolagents” quick course by DeepLearning.AI.