* feat(tools): surface tool failures instead of reporting them as success
A tool can finish without raising and still fail to do what it was asked.
Slack answers HTTP 200 with `{"ok": false, "error": "channel_not_found"}`;
an MCP server sets `isError`; a CrewAI AMP action returns
`API request failed: ...`. In every case the call "worked", so the error
text reached the agent as an ordinary result, the agent narrated the
problem in prose, and the run was recorded as a success.
Concretely: five failed `slackbot_send_message` calls each rendered as
"Tool Execution Completed", the task passed, and the crew passed -- with
the only evidence being a sentence in the final answer. Nothing
downstream could tell the difference, and an agent that keeps going on a
step that silently did nothing builds the rest of its work on it.
Give that outcome a type and a reaction:
- `ToolFailure` -- what a tool returns instead of an error string. The
agent still reads prose via `as_agent_message()`, so model behavior is
unchanged; the framework now knows the call failed.
- `ToolFailurePolicy` -- `ignore` (previous behavior), `warn` (default:
record + emit, keep going), `raise` (abort with
`ToolExecutionFailedError`). Resolved most-specific-first: tool, task,
agent, crew.
- `ToolFailureDetectedEvent` -- emitted before a `raise` aborts, so
subscribers always observe the failure. `ToolUsageFinishedEvent` also
carries a `failure` field so a trace UI can mark the call failed
without correlating two events.
- `tool_failures` on `TaskOutput`, `CrewOutput` and `LiteAgentOutput`,
plus `has_tool_failures`, so consumers never parse a string.
Detection is strictly declarative -- no string sniffing, so a tool that
legitimately returns text about an error is never misread as failing.
Failures come from a returned `ToolFailure`, a raised exception, MCP
`isError`, a spent `max_usage_count`, or an unknown tool.
Wired into all four tool-execution paths (the ReAct path and the three
native function-calling implementations). Sources updated to report
structurally: `MCPClient.call_tool_result()` preserves `isError` that
`call_tool()` dropped, and `CrewAIPlatformActionTool` returns a
`ToolFailure` for non-2xx and for caught exceptions.
Two latent bugs fixed along the way: `ToolUsage` assumed every agent has
a `fingerprint` (LiteAgent does not), and policy resolution now tolerates
malformed values rather than letting telemetry take down a tool call.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01ETacm2dMASfpMAYUiDu5YG
* fix(tools): address review round 1 on tool-failure signalling
Five real defects from Bugbot, none of them cosmetic.
Tool-scoped policy never applied (high). `resolve_tool_failure_policy`
read `tool_failure_policy` off the object handed to it, but every
execution path passes the `CrewStructuredTool` wrapper, which never
carried the attribute -- and `BaseTool` never declared it in the first
place. A tool-scoped `raise`/`ignore` was silently ignored while the
docs and a unit test claimed otherwise; the test passed only because it
called the resolver directly with an authored tool. Declared the field on
`BaseTool`, propagated it through `to_structured_tool()` and
`CrewStructuredTool`, and made resolution fall back through
`_original_tool` so either shape works.
A failed call still printed the green "Completed" panel, then the red
one. That is the terminal version of the exact bug this PR is about.
Suppressed the success panel when the call reported failure.
A raised tool printed twice: `ToolUsageErrorEvent` already renders a red
panel, and the new failure panel repeated it. The event is still emitted
-- policy and traces need it -- but the duplicate console output is gone.
Both decisions now live in named predicates on `ConsoleFormatter` rather
than inline in the listener closure, so they are directly testable.
Unknown tools were reported on the ReAct path but silently ignored on all
three native paths, so the same miss was loud or silent depending on
executor style. Native paths now record `UNKNOWN_TOOL` too. This also
surfaced a live `NameError`: ruff had pruned `ToolFailureReason` from
`agent_utils` as unused, so the new branch would have crashed at runtime.
`LiteAgentOutput` had `tool_failures` but not `has_tool_failures`, which
the PR promised on all three output types -- an `AttributeError` for any
caller sharing one check across result types.
Testing: 16 further tests, 45 total. Two console tests were passing
vacuously because `emit()` dispatches sync handlers on a thread pool, so
the assertions raced the handler; they now assert on the predicates
directly, and the native-path test drains the bus with `flush()` and
checks the synchronously-written record. Full suite still matches
baseline exactly at 377 pre-existing failures.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01ETacm2dMASfpMAYUiDu5YG
* chore: update tool specifications
* fix(tools): address review round 2 and fix CI type failure
CI caught a type error I should have: widening `agent` to accept a
`LiteAgent` (so a standalone LiteAgent resolves its own policy) left the
declared signatures behind. Widened `execute_tool_and_check_finality`,
its async twin, and `ToolCallHookContext` to `Agent | BaseAgent |
LiteAgent | None`, which is what those actually receive now.
Seven CodeRabbit findings, all verified against the code first:
`raise` was being downgraded by three enclosing handlers. With
`max_execution_time` set, `_execute_with_timeout` wrapped every exception
in `RuntimeError`, so `_check_execution_error` no longer recognized the
passthrough and sent the task through the retry loop instead of aborting.
`StepExecutor.execute` turned it into `StepResult(success=False)` and let
the plan continue. `LiteAgent.kickoff` ran it through
`handle_unknown_error` and printed "This is likely a bug - please report
it" for what is a deliberate, configured stop.
Failure records were dropped on two paths. `reset_tool_failures()` only
ran in `_prepare_task_execution`, so `Agent.kickoff()` / `kickoff_async()`
— which enter through `_prepare_kickoff` — accumulated records across
runs. And a guardrail retry calls `execute_task` again, which resets the
agent, so a tool that failed on a blocked attempt vanished from the final
output entirely: a run could report zero failures having demonstrably
failed one. Failures now accumulate across guardrail attempts.
Writing the tests for that surfaced a further miss of my own:
`Agent.kickoff()` builds its `LiteAgentOutput` in `agent/core.py` via
`AgentExecutor`, not through `LiteAgent`, so `tool_failures` was always
empty there regardless of the recording fix. Wired up, and the LiteAgent
path now reads from whichever agent the executor was handed
(`original_agent` under kickoff, `self` standalone) rather than assuming.
`last_tool_failures` returns a copy, so a caller cannot mutate the
agent's record or watch it shift mid-run.
Testing: 7 further tests, 52 total, covering the timeout wrapper, the
retry limit, kickoff reset, the kickoff output path, copy semantics and
guardrail accumulation. Full suite matches baseline exactly at 377
pre-existing failures; mypy clean on every changed file.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01ETacm2dMASfpMAYUiDu5YG
* fix(tools): make crew-scoped policy real and close the last raise leak
Two findings, and the first was a documented feature that never worked.
`resolve_tool_failure_policy` consulted a crew, and the docs advertised
crew as a scope, but `Crew` had no `tool_failure_policy` field at all --
and even with one it was unreachable, because `BaseAgent` defaulted the
policy to `WARN` rather than `None`, so resolution always stopped at the
agent. Crew-level configuration was silently ignored.
Fixed by making "inherit" the default everywhere instead of baking `warn`
into one layer: `Crew` gains the field, and `BaseAgent`/`LiteAgent`
default to `None` like `Task` and `BaseTool` already did. The resolver
owns the single fallback, so the chain is genuinely
tool > task > agent > crew > warn and the effective default with nothing
configured is still `warn`. Reading `agent.tool_failure_policy` now
returns `None` (meaning "inherit") rather than `WARN`.
The other: `StepExecutor` re-raised `ToolExecutionFailedError` from its
outer handler, but the nested handler around the native-to-text tooling
fallback still caught it and returned `StepResult(success=False)`. An
agent whose LLM lacked native tool calling would therefore not abort
under `raise`. That is the third distinct place this exception was being
downgraded; it now re-raises there too.
Testing: 8 further tests, 60 total, including the full precedence chain
walked one level at a time and crew-scoped `raise`/`ignore` driven
end-to-end through `kickoff()` rather than only through the resolver --
the gap that let the original crew bug pass review. Full suite matches
baseline exactly at 377 pre-existing failures; mypy clean on every
changed file.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01ETacm2dMASfpMAYUiDu5YG
* docs: trim comments and docstrings on tool-failure signalling
Prose only -- no behavior change. Cut the module docstring, the longer
class and method docstrings, the multi-line inline comments, and the
verbose Field descriptions down to what actually earns its place. Net 87
lines lighter.
Kept the "why" in every case where the reason is non-obvious (why the
event fires before a raise, why the policy reads through the tool wrapper,
why the bus needs draining in tests) and dropped the restatements of what
the code already says.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01ETacm2dMASfpMAYUiDu5YG
* fix(tools): make ignore truly silent, stop caching failures, close 4 gaps
Six findings from the latest review round, all verified against the code
before touching it.
`ignore` was not silent. `ToolUsageFinishedEvent.failure` was set before
the policy ran, so traces still saw a failed call under a policy documented
as surfacing nothing. Worse, the console then showed *no* panel at all:
green was suppressed because `failure` was present, red was skipped because
`ignore` never emits `ToolFailureDetectedEvent`. New `reportable_failure()`
resolves the policy before the finished event and drops the flag under
`ignore`; wired into all four execution paths.
Failures were being cached. `CacheHandler.add` stored a `ToolFailure` like
any other result, so a transient error became permanent for the rest of the
run and every later hit re-reported a call that never re-ran. The cache now
refuses to store declared failures -- fixed at the single choke point rather
than at each of the four call sites.
A spent `max_usage_count` was invisible on the shared native path.
`BaseTool._claim_usage` returned a bare string that only the executors
recognising that exact message treated as a failure. It now returns a
`ToolFailure` with `USAGE_LIMIT`, so every path records it.
A guardrail returning a whole `TaskOutput` replaced the output without
carrying accumulated failures over, so earlier attempts vanished from
`CrewOutput.tool_failures`. New `merge_tool_failures()` combines and
deduplicates, and the retry-rebuild path uses it too.
A hook-blocked call inherited a cached failure and attributed it to a call
that never ran. Now cleared. Not reachable through the built-in cache once
failures stop being cached, so the test injects a custom cache handler that
does retain them -- verified to fail without the guard.
Also removed a `datetime` import left unused by the earlier console-test
rewrite.
Testing: 13 further tests, 73 total. Full suite matches baseline exactly at
377 pre-existing failures; the usage-limit suites that `_claim_usage`
touches pass unchanged; mypy clean on every changed file.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01ETacm2dMASfpMAYUiDu5YG
* fix(tools): let raise through the parallel native path, guard all handlers
Chasing down CodeRabbit's note about callers of
execute_single_native_tool_call turned up a fifth place this exception was
being downgraded: the experimental executor's parallel branch wrapped
future.result() in a broad except and folded the abort into a fake tool
result, so the remaining parallel calls carried on. The sequential path and
crew_agent_executor's parallel branch were already fine.
Five separate handlers have swallowed this during review, so added a guard
test asserting the passthrough at every site rather than trusting the next
one gets spotted.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01ETacm2dMASfpMAYUiDu5YG
* fix(tools): keep a failed tool out of the final answer, finish crew scope
Three more findings, all confirmed against the code.
A failed `result_as_answer` tool still became the task's output. The native
paths already excluded raised errors and hook blocks from short-circuiting,
but not declared failures -- so an error message silently became the answer,
which is the exact shape of bug this PR exists to prevent. Fixed on all
paths, and there were three independent override points, not one:
`ToolResult.result_as_answer` in tool_utils, the `execution_result`
finality checks in both executors, and `process_tool_results()`, which
reads `agent.tools_results` back separately. The first two fixes alone left
the behavior unchanged; only the third made the test pass.
`ToolUsage` never received a crew, so a crew-level `ignore` half-applied:
recording and `ToolFailureDetectedEvent` stayed quiet, but the flag was
still attached to `ToolUsageFinishedEvent`. It now takes and stores `crew`.
`CrewAgentExecutor.invoke`/`ainvoke` routed a deliberate stop through
`handle_unknown_error`, printing "An unknown error occurred" on verbose
runs. LiteAgent already special-cased this; both now do.
Testing: 5 further tests, 79 total, including that a *successful*
`result_as_answer` tool still short-circuits. Full suite matches baseline
exactly at 377 pre-existing failures; mypy clean on every changed file.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01ETacm2dMASfpMAYUiDu5YG
* fix(tools): report malformed tool args, correlate the failure event
Two findings from the latest round.
Malformed native tool arguments returned early with a plain error dict and
never reported a failure, so `ToolFailureReason.INVALID_INPUT` was declared
but unreferenced -- a bad tool call was absent from records, events and
`raise` aborts. `parse_tool_call_args` now carries an INVALID_INPUT failure
on the error dict and both executors report it before returning.
`ToolFailureDetectedEvent` never set `agent_id`, so a trace could not tie it
to a specific agent instance. Fixing that exposed the same gap running the
other way: `ToolUsage`'s own started/finished/error events never set
`agent_id` either, so on the ReAct path the paired finished event had
nothing to correlate against. Both now set it.
Set explicitly rather than via `from_agent`, which would also overwrite
`agent_role` and lose the `_original_role` preference those events already
apply -- a behavior change that has nothing to do with correlation.
Testing: 5 further tests, 84 total, asserting the ids match between the
failure event and its paired finished event. One existing test pinned the
exact key set of the parse-error dict and was updated for the new key. Full
suite matches baseline at 377 pre-existing failures; the one apparent
addition was the known `test_trace_enable_disable` order-flake, confirmed by
re-running rather than assumed.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01ETacm2dMASfpMAYUiDu5YG
* fix(tools): scope failure accumulation per execution, drop deprecated executor
Two review requests from @lorenzejay.
Accumulation no longer lives as mutable state on the shared agent. A
ContextVar collector is opened around each execution -- task, kickoff, and
each guardrail retry -- and the output reads that collector directly instead
of copying the agent's list. ContextVars are copied per asyncio task and per
thread, so concurrent executions cannot see each other's records, and
nesting is safe for retries. `last_tool_failures` prefers the active
collector and falls back to the last completed execution, so the accessor is
correct during a run too. The per-execution reset that caused the erasure is
gone.
Reproducing this took some digging and the finding is worth recording: crew
tasks *cannot* hit it, because `AgentExecutor` refuses concurrent reuse of
one instance and raises. `agent.kickoff()` has no such guard, and there the
bug reproduces exactly as reported -- two concurrent kickoffs each returned
two records. The regression test forces the overlap with a barrier so it is
deterministic rather than timing-dependent, and I verified it reports [2, 2]
against the old behavior and [1, 1] now.
Removed the tool-failure integration from `CrewAgentExecutor` entirely; that
file is back to its state on main. Note the shared ReAct helper it calls
still records failures, since that is common code rather than new behavior in
the deprecated file -- so a `raise` policy will be swallowed by that
executor's generic handler. Flagged on the PR rather than papered over.
Testing: 89 total. Two tests I wrote for this were vacuous on the first
attempt -- they passed against the simulated pre-fix code -- so each
concurrency test was checked against the old behavior before being kept.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01ETacm2dMASfpMAYUiDu5YG
* fix(tools): report malformed calls everywhere, drop the unused block reason
Four findings.
`execute_single_native_tool_call` swallowed a JSON decode error into an empty
args dict and ran the tool with no input at all -- worse than not reporting
it. It now routes through `parse_tool_call_args` like the executors do, so
the StepExecutor/planning path reports INVALID_INPUT and returns instead of
executing. That also removes a duplicated inline parse.
The ReAct path returned a `ToolUsageError` message as an ordinary result
without reporting it, so a malformed call there was invisible while the
equivalent native failure was recorded. Now reported as INVALID_INPUT too.
`Agent.kickoff` opened a collector but no longer reset the agent-level list,
so `last_tool_failures` grew across kickoffs. Reset restored, matching task
execution.
`ToolFailureReason.BLOCKED_BY_HOOK` was declared and never produced. Rather
than start reporting hook blocks as failures, the member is removed: a block
is a deliberate decision by the hook author, and treating it as a failure
would make `raise` abort on an intentional veto. Added a guard test that every
remaining reason is actually produced somewhere, so a dead member cannot
reappear -- the same smell that flagged INVALID_INPUT last round.
Also switched the deprecation guard test to a single import style.
Testing: 6 further tests, 95 total, including that the tool does not run when
its args fail to parse. Full suite matches baseline at 377 pre-existing
failures; mypy clean.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01ETacm2dMASfpMAYUiDu5YG
* fix(tools): merge failures across kickoff guardrail retries, cancel siblings
Kickoff guardrail retries discarded the blocked attempt's failures. Each
retry calls `_execute_and_build_output`, which opens a fresh collector and
builds a new output, so a run could report zero failures having demonstrably
failed one -- the same bug already fixed on the task guardrail path, which
merges. Now merged there too. Verified the test fails without the fix.
Under `raise`, one parallel native tool aborting left its siblings running:
the pool waited for them and pending ones still started. It now shuts the
pool down with `cancel_futures=True` so a not-yet-started sibling never runs.
Threads already in flight cannot be interrupted in Python, so a concurrent
tool may still complete before the abort surfaces; that is noted at the call
site rather than left implied.
Also satisfied CodeQL by materialising the enum in the guard test's loop.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01ETacm2dMASfpMAYUiDu5YG
---------
Co-authored-by: Claude Opus 5 (1M context) <noreply@anthropic.com>
Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>
Co-authored-by: Lorenze Jay <63378463+lorenzejay@users.noreply.github.com>
Homepage · Docs · Start Cloud Trial · Blog · Forum
Fast and Flexible Multi-Agent Automation Framework
CrewAI is a lean, lightning-fast Python framework built entirely from scratch—completely independent of LangChain or other agent frameworks. It empowers developers with both high-level simplicity and precise low-level control, ideal for creating autonomous AI agents tailored to any scenario.
- CrewAI Crews: Optimize for autonomy and collaborative intelligence.
- CrewAI Flows: Enable granular, event-driven control, single LLM calls for precise task orchestration and supports Crews natively
With over 100,000 developers certified through our community courses at learn.crewai.com, CrewAI is rapidly becoming the standard for enterprise-ready AI automation.
CrewAI AMP Suite
CrewAI AMP Suite is a comprehensive bundle tailored for organizations that require secure, scalable, and easy-to-manage agent-driven automation.
You can try one part of the suite the Crew Control Plane for free
Crew Control Plane Key Features:
- Tracing & Observability: Monitor and track your AI agents and workflows in real-time, including metrics, logs, and traces.
- Unified Control Plane: A centralized platform for managing, monitoring, and scaling your AI agents and workflows.
- Seamless Integrations: Easily connect with existing enterprise systems, data sources, and cloud infrastructure.
- Advanced Security: Built-in robust security and compliance measures ensuring safe deployment and management.
- Actionable Insights: Real-time analytics and reporting to optimize performance and decision-making.
- 24/7 Support: Dedicated enterprise support to ensure uninterrupted operation and quick resolution of issues.
- On-premise and Cloud Deployment Options: Deploy CrewAI AMP on-premise or in the cloud, depending on your security and compliance requirements.
CrewAI AMP is designed for enterprises seeking a powerful, reliable solution to transform complex business processes into efficient, intelligent automations.
Table of contents
- Why CrewAI?
- Getting Started
- Key Features
- Understanding Flows and Crews
- CrewAI vs LangGraph
- Examples
- Connecting Your Crew to a Model
- How CrewAI Compares
- Frequently Asked Questions (FAQ)
- Contribution
- Telemetry
- License
Why CrewAI?
CrewAI unlocks the true potential of multi-agent automation, delivering the best-in-class combination of speed, flexibility, and control with either Crews of AI Agents or Flows of Events:
- Standalone Framework: Built from scratch, independent of LangChain or any other agent framework.
- High Performance: Optimized for speed and minimal resource usage, enabling faster execution.
- Flexible Low Level Customization: Complete freedom to customize at both high and low levels - from overall workflows and system architecture to granular agent behaviors, internal prompts, and execution logic.
- Ideal for Every Use Case: Proven effective for both simple tasks and highly complex, real-world, enterprise-grade scenarios.
- Robust Community: Backed by a rapidly growing community of over 100,000 certified developers offering comprehensive support and resources.
CrewAI empowers developers and enterprises to confidently build intelligent automations, bridging the gap between simplicity, flexibility, and performance.
Getting Started
Setup and run your first CrewAI agents by following this tutorial.
Learning Resources
Learn CrewAI through our comprehensive courses:
- Multi AI Agent Systems with CrewAI - Master the fundamentals of multi-agent systems
- Practical Multi AI Agents and Advanced Use Cases - Deep dive into advanced implementations
Understanding Flows and Crews
CrewAI offers two powerful, complementary approaches that work seamlessly together to build sophisticated AI applications:
-
Crews: Teams of AI agents with true autonomy and agency, working together to accomplish complex tasks through role-based collaboration. Crews enable:
- Natural, autonomous decision-making between agents
- Dynamic task delegation and collaboration
- Specialized roles with defined goals and expertise
- Flexible problem-solving approaches
-
Flows: Production-ready, event-driven workflows that deliver precise control over complex automations. Flows provide:
- Fine-grained control over execution paths for real-world scenarios
- Secure, consistent state management between tasks
- Clean integration of AI agents with production Python code
- Conditional branching for complex business logic
The true power of CrewAI emerges when combining Crews and Flows. This synergy allows you to:
- Build complex, production-grade applications
- Balance autonomy with precise control
- Handle sophisticated real-world scenarios
- Maintain clean, maintainable code structure
Getting Started with Installation
To get started with CrewAI, follow these simple steps:
1. Installation
Ensure you have Python >=3.10 <3.14 installed on your system. CrewAI uses UV for dependency management and package handling, offering a seamless setup and execution experience.
First, install CrewAI:
pip install crewai
If you want to install the 'crewai' package along with its optional features that include additional tools for agents, you can do so by using the following command:
pip install 'crewai[tools]'
The command above installs the basic package and also adds extra components which require more dependencies to function.
Troubleshooting Dependencies
If you encounter issues during installation or usage, here are some common solutions:
Common Issues
-
ModuleNotFoundError: No module named 'tiktoken'
- Install tiktoken explicitly:
pip install 'crewai[embeddings]' - If using embedchain or other tools:
pip install 'crewai[tools]'
- Install tiktoken explicitly:
-
Failed building wheel for tiktoken
- Ensure Rust compiler is installed (see installation steps above)
- For Windows: Verify Visual C++ Build Tools are installed
- Try upgrading pip:
pip install --upgrade pip - If issues persist, use a pre-built wheel:
pip install tiktoken --prefer-binary
2. Setting Up Your Crew with the YAML Configuration
To create a new CrewAI project, run the following CLI (Command Line Interface) command:
crewai create crew <project_name>
This command creates a new project folder with the following structure:
my_project/
├── .gitignore
├── pyproject.toml
├── README.md
├── .env
└── src/
└── my_project/
├── __init__.py
├── main.py
├── crew.py
├── tools/
│ ├── custom_tool.py
│ └── __init__.py
└── config/
├── agents.yaml
└── tasks.yaml
You can now start developing your crew by editing the files in the src/my_project folder. The main.py file is the entry point of the project, the crew.py file is where you define your crew, the agents.yaml file is where you define your agents, and the tasks.yaml file is where you define your tasks.
To customize your project, you can:
- Modify
src/my_project/config/agents.yamlto define your agents. - Modify
src/my_project/config/tasks.yamlto define your tasks. - Modify
src/my_project/crew.pyto add your own logic, tools, and specific arguments. - Modify
src/my_project/main.pyto add custom inputs for your agents and tasks. - Add your environment variables into the
.envfile.
Example of a simple crew with a sequential process:
Instantiate your crew:
crewai create crew latest-ai-development
Modify the files as needed to fit your use case:
agents.yaml
# src/my_project/config/agents.yaml
researcher:
role: >
{topic} Senior Data Researcher
goal: >
Uncover cutting-edge developments in {topic}
backstory: >
You're a seasoned researcher with a knack for uncovering the latest
developments in {topic}. Known for your ability to find the most relevant
information and present it in a clear and concise manner.
reporting_analyst:
role: >
{topic} Reporting Analyst
goal: >
Create detailed reports based on {topic} data analysis and research findings
backstory: >
You're a meticulous analyst with a keen eye for detail. You're known for
your ability to turn complex data into clear and concise reports, making
it easy for others to understand and act on the information you provide.
tasks.yaml
# src/my_project/config/tasks.yaml
research_task:
description: >
Conduct a thorough research about {topic}
Make sure you find any interesting and relevant information given
the current year is 2025.
expected_output: >
A list with 10 bullet points of the most relevant information about {topic}
agent: researcher
reporting_task:
description: >
Review the context you got and expand each topic into a full section for a report.
Make sure the report is detailed and contains any and all relevant information.
expected_output: >
A fully fledge reports with the mains topics, each with a full section of information.
Formatted as markdown without '```'
agent: reporting_analyst
output_file: report.md
crew.py
# src/my_project/crew.py
from crewai import Agent, Crew, Process, Task
from crewai.project import CrewBase, agent, crew, task
from crewai_tools import SerperDevTool
from crewai.agents.agent_builder.base_agent import BaseAgent
from typing import List
@CrewBase
class LatestAiDevelopmentCrew():
"""LatestAiDevelopment crew"""
agents: List[BaseAgent]
tasks: List[Task]
@agent
def researcher(self) -> Agent:
return Agent(
config=self.agents_config['researcher'],
verbose=True,
tools=[SerperDevTool()]
)
@agent
def reporting_analyst(self) -> Agent:
return Agent(
config=self.agents_config['reporting_analyst'],
verbose=True
)
@task
def research_task(self) -> Task:
return Task(
config=self.tasks_config['research_task'],
)
@task
def reporting_task(self) -> Task:
return Task(
config=self.tasks_config['reporting_task'],
output_file='report.md'
)
@crew
def crew(self) -> Crew:
"""Creates the LatestAiDevelopment crew"""
return Crew(
agents=self.agents, # Automatically created by the @agent decorator
tasks=self.tasks, # Automatically created by the @task decorator
process=Process.sequential,
verbose=True,
)
main.py
#!/usr/bin/env python
# src/my_project/main.py
import sys
from latest_ai_development.crew import LatestAiDevelopmentCrew
def run():
"""
Run the crew.
"""
inputs = {
'topic': 'AI Agents'
}
LatestAiDevelopmentCrew().crew().kickoff(inputs=inputs)
3. Running Your Crew
Before running your crew, make sure you have the following keys set as environment variables in your .env file:
- An OpenAI API key (or other LLM API key):
OPENAI_API_KEY=sk-... - A Serper.dev API key:
SERPER_API_KEY=YOUR_KEY_HERE
Lock the dependencies and install them by using the CLI command but first, navigate to your project directory:
cd my_project
crewai install (Optional)
To run your crew, execute the following command in the root of your project:
crewai run
or
python src/my_project/main.py
If an error happens due to the usage of poetry, please run the following command to update your crewai package:
crewai update
You should see the output in the console and the report.md file should be created in the root of your project with the full final report.
In addition to the sequential process, you can use the hierarchical process, which automatically assigns a manager to the defined crew to properly coordinate the planning and execution of tasks through delegation and validation of results. See more about the processes here.
Key Features
CrewAI stands apart as a lean, standalone, high-performance multi-AI Agent framework delivering simplicity, flexibility, and precise control—free from the complexity and limitations found in other agent frameworks.
- Standalone & Lean: Completely independent from other frameworks like LangChain, offering faster execution and lighter resource demands.
- Flexible & Precise: Easily orchestrate autonomous agents through intuitive Crews or precise Flows, achieving perfect balance for your needs.
- Seamless Integration: Effortlessly combine Crews (autonomy) and Flows (precision) to create complex, real-world automations.
- Deep Customization: Tailor every aspect—from high-level workflows down to low-level internal prompts and agent behaviors.
- Reliable Performance: Consistent results across simple tasks and complex, enterprise-level automations.
- Thriving Community: Backed by robust documentation and over 100,000 certified developers, providing exceptional support and guidance.
Choose CrewAI to easily build powerful, adaptable, and production-ready AI automations.
Examples
You can test different real life examples of AI crews in the CrewAI-examples repo:
Quick Tutorial
Write Job Descriptions
Check out code for this example or watch a video below:
Trip Planner
Check out code for this example or watch a video below:
Stock Analysis
Check out code for this example or watch a video below:
Using Crews and Flows Together
CrewAI's power truly shines when combining Crews with Flows to create sophisticated automation pipelines.
CrewAI flows support logical operators like or_ and and_ to combine multiple conditions. This can be used with @start, @listen, or @router decorators to create complex triggering conditions.
or_: Triggers when any of the specified conditions are met.and_Triggers when all of the specified conditions are met.
Here's how you can orchestrate multiple Crews within a Flow:
from crewai.flow.flow import Flow, listen, start, router, or_
from crewai import Crew, Agent, Task, Process
from pydantic import BaseModel
# Define structured state for precise control
class MarketState(BaseModel):
sentiment: str = "neutral"
confidence: float = 0.0
recommendations: list = []
class AdvancedAnalysisFlow(Flow[MarketState]):
@start()
def fetch_market_data(self):
# Demonstrate low-level control with structured state
self.state.sentiment = "analyzing"
return {"sector": "tech", "timeframe": "1W"} # These parameters match the task description template
@listen(fetch_market_data)
def analyze_with_crew(self, market_data):
# Show crew agency through specialized roles
analyst = Agent(
role="Senior Market Analyst",
goal="Conduct deep market analysis with expert insight",
backstory="You're a veteran analyst known for identifying subtle market patterns"
)
researcher = Agent(
role="Data Researcher",
goal="Gather and validate supporting market data",
backstory="You excel at finding and correlating multiple data sources"
)
analysis_task = Task(
description="Analyze {sector} sector data for the past {timeframe}",
expected_output="Detailed market analysis with confidence score",
agent=analyst
)
research_task = Task(
description="Find supporting data to validate the analysis",
expected_output="Corroborating evidence and potential contradictions",
agent=researcher
)
# Demonstrate crew autonomy
analysis_crew = Crew(
agents=[analyst, researcher],
tasks=[analysis_task, research_task],
process=Process.sequential,
verbose=True
)
return analysis_crew.kickoff(inputs=market_data) # Pass market_data as named inputs
@router(analyze_with_crew)
def determine_next_steps(self):
# Show flow control with conditional routing
if self.state.confidence > 0.8:
return "high_confidence"
elif self.state.confidence > 0.5:
return "medium_confidence"
return "low_confidence"
@listen("high_confidence")
def execute_strategy(self):
# Demonstrate complex decision making
strategy_crew = Crew(
agents=[
Agent(role="Strategy Expert",
goal="Develop optimal market strategy")
],
tasks=[
Task(description="Create detailed strategy based on analysis",
expected_output="Step-by-step action plan")
]
)
return strategy_crew.kickoff()
@listen(or_("medium_confidence", "low_confidence"))
def request_additional_analysis(self):
self.state.recommendations.append("Gather more data")
return "Additional analysis required"
This example demonstrates how to:
- Use Python code for basic data operations
- Create and execute Crews as steps in your workflow
- Use Flow decorators to manage the sequence of operations
- Implement conditional branching based on Crew results
Connecting Your Crew to a Model
CrewAI supports using various LLMs through a variety of connection options. By default your agents will use the OpenAI API when querying the model. However, there are several other ways to allow your agents to connect to models. For example, you can configure your agents to use a local model via the Ollama tool.
Please refer to the Connect CrewAI to LLMs page for details on configuring your agents' connections to models.
How CrewAI Compares
CrewAI's Advantage: CrewAI combines autonomous agent intelligence with precise workflow control through its unique Crews and Flows architecture. The framework excels at both high-level orchestration and low-level customization, enabling complex, production-grade systems with granular control.
- LangGraph: While LangGraph provides a foundation for building agent workflows, its approach requires significant boilerplate code and complex state management patterns. The framework's tight coupling with LangChain can limit flexibility when implementing custom agent behaviors or integrating with external systems.
P.S. CrewAI demonstrates significant performance advantages over LangGraph, executing 5.76x faster in certain cases like this QA task example (see comparison) while achieving higher evaluation scores with faster completion times in certain coding tasks, like in this example (detailed analysis).
- Autogen: While Autogen excels at creating conversational agents capable of working together, it lacks an inherent concept of process. In Autogen, orchestrating agents' interactions requires additional programming, which can become complex and cumbersome as the scale of tasks grows.
- ChatDev: ChatDev introduced the idea of processes into the realm of AI agents, but its implementation is quite rigid. Customizations in ChatDev are limited and not geared towards production environments, which can hinder scalability and flexibility in real-world applications.
Contribution
CrewAI is open-source and we welcome contributions. If you're looking to contribute, please:
- Fork the repository.
- Create a new branch for your feature.
- Add your feature or improvement.
- Send a pull request.
- We appreciate your input!
Installing Dependencies
uv lock
uv sync
Virtual Env
uv venv
Pre-commit hooks
pre-commit install
Running Tests
uv run pytest .
Running static type checks
uvx mypy src
Packaging
uv build
Installing Locally
pip install dist/*.tar.gz
Telemetry
CrewAI uses anonymous telemetry to collect usage data with the main purpose of helping us improve the library by focusing our efforts on the most used features, integrations and tools.
It's pivotal to understand that NO data is collected concerning prompts, task descriptions, agents' backstories or goals, usage of tools, API calls, responses, any data processed by the agents, or secrets and environment variables, with the exception of the conditions mentioned. When the share_crew feature is enabled, detailed data including task descriptions, agents' backstories or goals, and other specific attributes are collected to provide deeper insights while respecting user privacy. Users can disable telemetry by setting the environment variable OTEL_SDK_DISABLED to true.
Data collected includes:
- Version of CrewAI
- So we can understand how many users are using the latest version
- Version of Python
- So we can decide on what versions to better support
- General OS (e.g. number of CPUs, macOS/Windows/Linux)
- So we know what OS we should focus on and if we could build specific OS related features
- Number of agents and tasks in a crew
- So we make sure we are testing internally with similar use cases and educate people on the best practices
- Crew Process being used
- Understand where we should focus our efforts
- If Agents are using memory or allowing delegation
- Understand if we improved the features or maybe even drop them
- If Tasks are being executed in parallel or sequentially
- Understand if we should focus more on parallel execution
- Language model being used
- Improved support on most used languages
- Roles of agents in a crew
- Understand high level use cases so we can build better tools, integrations and examples about it
- Tools names available
- Understand out of the publicly available tools, which ones are being used the most so we can improve them
Users can opt-in to Further Telemetry, sharing the complete telemetry data by setting the share_crew attribute to True on their Crews. Enabling share_crew results in the collection of detailed crew and task execution data, including goal, backstory, context, and output of tasks. This enables a deeper insight into usage patterns while respecting the user's choice to share.
License
CrewAI is released under the MIT License.
Frequently Asked Questions (FAQ)
General
- What exactly is CrewAI?
- How do I install CrewAI?
- Does CrewAI depend on LangChain?
- Is CrewAI open-source?
- Does CrewAI collect data from users?
Features and Capabilities
- Can CrewAI handle complex use cases?
- Can I use CrewAI with local AI models?
- What makes Crews different from Flows?
- How is CrewAI better than LangChain?
- Does CrewAI support fine-tuning or training custom models?
Resources and Community
Enterprise Features
- What additional features does CrewAI AMP offer?
- Is CrewAI AMP available for cloud and on-premise deployments?
- Can I try CrewAI AMP for free?
Q: What exactly is CrewAI?
A: CrewAI is a standalone, lean, and fast Python framework built specifically for orchestrating autonomous AI agents. Unlike frameworks like LangChain, CrewAI does not rely on external dependencies, making it leaner, faster, and simpler.
Q: How do I install CrewAI?
A: Install CrewAI using pip:
pip install crewai
For additional tools, use:
pip install 'crewai[tools]'
Q: Does CrewAI depend on LangChain?
A: No. CrewAI is built entirely from the ground up, with no dependencies on LangChain or other agent frameworks. This ensures a lean, fast, and flexible experience.
Q: Can CrewAI handle complex use cases?
A: Yes. CrewAI excels at both simple and highly complex real-world scenarios, offering deep customization options at both high and low levels, from internal prompts to sophisticated workflow orchestration.
Q: Can I use CrewAI with local AI models?
A: Absolutely! CrewAI supports various language models, including local ones. Tools like Ollama and LM Studio allow seamless integration. Check the LLM Connections documentation for more details.
Q: What makes Crews different from Flows?
A: Crews provide autonomous agent collaboration, ideal for tasks requiring flexible decision-making and dynamic interaction. Flows offer precise, event-driven control, ideal for managing detailed execution paths and secure state management. You can seamlessly combine both for maximum effectiveness.
Q: How is CrewAI better than LangChain?
A: CrewAI provides simpler, more intuitive APIs, faster execution speeds, more reliable and consistent results, robust documentation, and an active community—addressing common criticisms and limitations associated with LangChain.
Q: Is CrewAI open-source?
A: Yes, CrewAI is open-source and actively encourages community contributions and collaboration.
Q: Does CrewAI collect data from users?
A: CrewAI collects anonymous telemetry data strictly for improvement purposes. Sensitive data such as prompts, tasks, or API responses are never collected unless explicitly enabled by the user.
Q: Where can I find real-world CrewAI examples?
A: Check out practical examples in the CrewAI-examples repository, covering use cases like trip planners, stock analysis, and job postings.
Q: How can I contribute to CrewAI?
A: Contributions are warmly welcomed! Fork the repository, create your branch, implement your changes, and submit a pull request. See the Contribution section of the README for detailed guidelines.
Q: What additional features does CrewAI AMP offer?
A: CrewAI AMP provides advanced features such as a unified control plane, real-time observability, secure integrations, advanced security, actionable insights, and dedicated 24/7 enterprise support.
Q: Is CrewAI AMP available for cloud and on-premise deployments?
A: Yes, CrewAI AMP supports both cloud-based and on-premise deployment options, allowing enterprises to meet their specific security and compliance requirements.
Q: Can I try CrewAI AMP for free?
A: Yes, you can explore part of the CrewAI AMP Suite by accessing the Crew Control Plane for free.
Q: Does CrewAI support fine-tuning or training custom models?
A: Yes, CrewAI can integrate with custom-trained or fine-tuned models, allowing you to enhance your agents with domain-specific knowledge and accuracy.
Q: Can CrewAI agents interact with external tools and APIs?
A: Absolutely! CrewAI agents can easily integrate with external tools, APIs, and databases, empowering them to leverage real-world data and resources.
Q: Is CrewAI suitable for production environments?
A: Yes, CrewAI is explicitly designed with production-grade standards, ensuring reliability, stability, and scalability for enterprise deployments.
Q: How scalable is CrewAI?
A: CrewAI is highly scalable, supporting simple automations and large-scale enterprise workflows involving numerous agents and complex tasks simultaneously.
Q: Does CrewAI offer debugging and monitoring tools?
A: Yes, CrewAI AMP includes advanced debugging, tracing, and real-time observability features, simplifying the management and troubleshooting of your automations.
Q: What programming languages does CrewAI support?
A: CrewAI is primarily Python-based but easily integrates with services and APIs written in any programming language through its flexible API integration capabilities.
Q: Does CrewAI offer educational resources for beginners?
A: Yes, CrewAI provides extensive beginner-friendly tutorials, courses, and documentation through learn.crewai.com, supporting developers at all skill levels.
Q: Can CrewAI automate human-in-the-loop workflows?
A: Yes, CrewAI fully supports human-in-the-loop workflows, allowing seamless collaboration between human experts and AI agents for enhanced decision-making.





