* Add generated Flow Definition authoring skill
Generate a portable skill from the Flow Definition schema so agents can
author valid declarative flows with the same reference CrewAI uses to
validate them. New declarative flow projects now write this skill.
```python
from crewai.flow.flow_definition import FlowDefinition
skill = FlowDefinition.skill(skips=(), examples_format="yaml")
```
* `examples_format` accepts `"yaml"` or `"json"`.
* Supported skips: `conversational`, `non_linear_flows`, `each`, `hitl`, `persistence`, `config`, `expression_action`, `script_action`, `tool_action`
The generated skill includes authoring rules, a routed crew example, and
an API reference extracted from the Flow, action, state, agent, crew,
and task Pydantic schemas.
* Fix declarative flow scaffold without framework import
* Fix skipped expression action guidance
* Fix markdown links in skill
* Require explicit CrewAI project definitions
JSON crews and declarative flows now resolve from `[tool.crewai]`
metadata instead of implicit filename discovery. This makes project type
selection deterministic, prevents stray `crew.json(c)` files from changing
CLI behavior, and centralizes definition path validation for run, install,
deploy validation, plotting, and memory reset paths.
`[tool.crewai].definition` must be a project-local file path. Absolute
paths, `~`, missing files, directories, and paths escaping the project root
are rejected so deploy and runtime commands use the same contract.
Breaking changes and migration paths:
* JSON crew projects are no longer discovered from `crew.json` or
`crew.jsonc` alone. Add explicit metadata:
```toml
[tool.crewai]
type = "crew"
definition = "crew.jsonc"
```
* Declarative flow projects must use a valid project-local definition path:
```toml
[tool.crewai]
type = "flow"
definition = "flows/research.yaml"
```
* `Flow.from_definition(definition)` is removed. Use:
```python
Flow.from_declaration(contents=definition)
```
* `FlowDefinition.to_json()` and `FlowDefinition.to_yaml()` are removed.
Use `FlowDefinition.to_dict()` and serialize with the caller's JSON or
YAML library.
* `FlowDefinition.from_dict()` is removed. Use:
```python
FlowDefinition.from_declaration(contents=data)
```
* `FlowDefinition.json_schema()` is removed. Use Pydantic's schema API only
where schema generation is intentionally needed:
```python
FlowDefinition.model_json_schema(by_alias=True)
```
* `crewai_cli.run_crew.find_crew_json_file()` and `_has_json_crew()` are
removed. Use `configured_project_json_crew()` or the shared
`crewai_core.project.configured_project_definition("crew")` helper.
* `crewai reset-memories` now only loads JSON crews declared through
`[tool.crewai].definition`, and invalid declared JSON crew definitions
fail instead of silently falling back to classic crew discovery.
* Address code review comments
Add a single declaration loader shared by API and CLI callers.
- Add FlowDefinition.from_declaration for FlowDefinition instances, dictionaries, YAML/JSON strings, and file paths
- Add Flow.from_declaration to build runnable flows directly from the same inputs
- Route declarative flow CLI loading through Flow.from_declaration so path handling and validation stay centralized
```
# Load just the serializable definition when you do not need to run it yet.
definition = FlowDefinition.from_declaration(path="flows/research.crewai")
definition = FlowDefinition.from_declaration(contents=flow_yaml)
definition = FlowDefinition.from_declaration(contents=flow_dict)
# Build a runnable flow directly from the same declaration inputs.
flow = Flow.from_declaration(path="flows/research.crewai")
flow = Flow.from_declaration(contents=flow_yaml)
flow = Flow.from_declaration(contents=flow_dict)
flow = Flow.from_declaration(contents=definition)
# Run it like any other flow.
result = flow.kickoff(inputs={"topic": "AI agents"})
# The CLI now goes through the same path-based loader.
# crewai run --definition flows/research.crewai
```
This commit fixes a bug where a router method could not be the start
method of a flow.
This is useful when you want to route against the initial state, or even
stack two routers.
* Add single agent action to Flow definitions
Lets a flow method build and run a single CrewAI agent directly, without
wrapping it in a crew. Same idea as the existing `crew` action, but for
one agent.
methods:
answer:
do:
call: agent
with:
role: Analyst
goal: Answer questions
backstory: Knows things.
input: "${state.question}"
start: true
* `input` is required and interpolated from flow state, like
`${state.question}` or `${item}` inside an `each` loop
* optional `response_format` points at a Pydantic model (`{"python":
"models.AnswerModel"}`) to get structured output
* `input` must be a string and its CEL is validated at load time, so bad
expressions like `${state.}` fail early
* Simplify test code
* Use explicit name/action shape for each.do steps
* Add optional `if` expression to `each.do` steps
Lets a step inside an `each` action run conditionally based on a CEL
expression evaluated against `item` and prior step `outputs`.
Add a description and examples to every FlowDefinition field and
standardize on `typing.Literal`, so the generated JSON schema documents
itself — each action discriminator, state branch, and config option
explains what it is and shows a realistic value.
Examples live on individual fields only, never at the model level, which
keeps the schema readable for tooling that renders field-level help.
Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
* Add script/code blocks to FlowDefinition
Let a Flow method run trusted inline Python with `call: script`. The code
is compiled once into a generated function and receives the runtime
values as arguments.
```yaml
methods:
normalize:
start: true
do:
call: script
code: |
import math
state["rounded"] = math.ceil(state["raw_score"])
return f"rounded:{state['rounded']}"
```
Even though this shares the same surface of tools (custom code), I
decided to make it opt-in for now, using
`CREWAI_ALLOW_FLOW_SCRIPT_EXECUTION=1`.
* Address code review comments
Replace the single FlowStateDefinition model with a `type`-discriminated
union of FlowDictStateDefinition, FlowPydanticStateDefinition,
FlowJsonSchemaStateDefinition, and FlowUnknownStateDefinition.
Each branch only carries the fields it actually uses and forbids extras,
so an invalid combination like a `dict` state with a `ref` now fails
validation instead of being silently accepted. The runtime reads `ref`
and `json_schema` defensively since they no longer exist on every branch.
```yaml
state:
type: json_schema
json_schema:
type: object
properties:
topic:
type: string
```
Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
A `do:` step can now say `call: tool` and name a CrewAI tool to run,
passing its inputs under `with:`. Before this, a definition could only
point at Python code to run.
```yaml
methods:
search:
start: true
do:
call: tool
ref: crewai_tools:ExaSearchTool
with:
search_query: ai agents
```
* Read flow dispatch from FlowDefinition
Store the definition in a `_definition` PrivateAttr at post-init and
convert the dispatch helpers (`_start_method_names`, `_listener_methods`,
`_start_condition`, `_listen_condition`, `_is_router`) from classmethods
to instance methods that read it. Event names now fall back to
`self._definition.name` instead of `self.__class__.__name__`.
Behavior is identical for decorator subclasses, but the engine no longer
assumes the definition comes from the class. This is the seam for
`Flow.from_definition`, where an instance runs a definition that was
loaded rather than built from a Python subclass.
* Add Flow.from_definition to run flows without a subclass
A FlowDefinition (e.g. loaded from YAML) was only usable for dispatch on
decorator-authored subclasses. Now each method definition records an
importable `module:qualname` handler ref, and `Flow.from_definition`
resolves and binds those handlers to build a runnable flow directly.
* Build flow state from FlowDefinition
Definition-driven flows previously always started with a bare dict
state.
* Replace handler string with structured FlowActionDefinition
`handler: str | None` was optional and opaque — missing handlers only
surfaced at kickoff time. `do: FlowActionDefinition` is required, so
Pydantic rejects invalid definitions at parse time.
The `call: "code"` discriminator prepares the schema for future
non-Python action types (e.g. MCP tool, crew) without touching
`FlowMethodDefinition`. Resolution logic is extracted to
`runtime/_action_resolvers.py` to keep the dispatch point isolated.
* Fix conversational start router missing required do field
FlowMethodDefinition.do became required when the handler string was
replaced with FlowActionDefinition, but _conversation_start_router still
built its fragment without it, breaking crewai import entirely.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
* Add event scoping to flow test
* Change lib/crewai/tests/test_flow_from_definition.py
---------
Co-authored-by: Claude Fable 5 <noreply@anthropic.com>
* improve one less route
* flows in flows, new agent executor causing early trace batch finalization
* addressing comments
* addressing comments pt2
* lint and typecheck fix
* decouple convo logic from runtime and added a conversational_definition
* type check fix
* always defer traces for convo and so fix tests to reflect that
* Migrate @listen/@router runtime to read from FlowDefinition
The runtime now resolves listener conditions, router status, and emit
values from `FlowMethodDefinition` instead of legacy method metadata and
the `_listeners`/`_routers`/`_router_emit` registries.
* Evaluate AND/OR listener conditions over the definition shape via
`_evaluate_definition_condition`
* Drop the class registries and the `FlowMeta` extraction that built
them; stop stamping `__trigger_methods__`, `__is_router__`,
`__router_emit__`, and friends
* `@human_feedback` emit now lives only on its config
* Simplify conditionals DSL
* Remove `_start_methods` and `__is_start_method__` stamping
* Add helpers to read start info from the definition
* Scan `__dict__` instead of `dir()` to find flow methods
Centralize FlowTrigger and FlowMethodDecorator so start/listen/router and the boolean trigger helpers share one authoring contract. This preserves decorated method signatures for static checking while allowing route-label strings in nested FlowCondition data.
Export the shared typing helpers for static analyzers, use an explicit Protocol body, align condition validation with Sequence-backed condition data, and drop the stale call-arg ignore exposed by the signature-preserving decorators.
Update the flow guide to use or_(...) for multi-label listeners.
The Flow DSL lived in one 1033-line `dsl.py` that mixed every decorator
(`@start`/`@listen`/`@router`), the `human_feedback` decorator,
condition combinators, and FlowDefinition extraction helpers in a single
file.
Split it into a `dsl/` package where each decorator gets its own module
(`start.py` 68 lines, `listen.py` 55, `router.py` 164,
`human_feedback.py` 98) and the shared extraction/condition helpers stay
in `utils.py`. The public API is re-exported from `dsl/__init__.py`, so
import paths are unchanged.
This is simpler because each decorator is now read and changed in
isolation instead of scanning a 1000-line file to find one of them, and
router-specific annotation parsing no longer sits next to unrelated
start/listen logic.
* Build FlowDefinition from Flow DSL metadata
Introduce `FlowDefinition`, a serializable model built from the Flow
DSL's runtime metadata. It becomes the structural contract for Flow
methods, triggers, routers, state, and configuration.
The visualization layer is the first consumer: `flow_structure` and
`build_flow_structure` now project from the definition instead of
re-introspecting the class. The runner still executes from live
registries, but the definition gives future runners a single static
contract to read.
This replaces AST source parsing for router return values, crew
references, and state schema with runtime metadata plus explicit
`@router(paths=...)` or `Literal`/`Enum` return hints. AST parsing was
fragile and could silently fail for dynamic or non-inspectable methods.
The refactor removes obsolete introspection and serializer code:
* Delete `flow_serializer.py`, `flow/utils.py`, and
`visualization/schema.py`
* Move flow structure modeling into `flow_definition.py`
* Simplify visualization building around the static definition contract
* Format files
