ansible.builtin.set_fact – Set host facts from a task


This module is part of ansible-base and included in all Ansible installations. In most cases, you can use the short module name set_fact even without specifying the collections: keyword. Despite that, we recommend you use the FQCN for easy linking to the module documentation and to avoid conflicting with other collections that may have the same module name.

New in version 1.2: of ansible.builtin


  • This module allows setting new variables.

  • Variables are set on a host-by-host basis just like facts discovered by the setup module.

  • These variables will be available to subsequent plays during an ansible-playbook run.

  • Set cacheable to yes to save variables across executions using a fact cache. Variables created with set_fact have different precedence depending on whether they are or are not cached.

  • Per the standard Ansible variable precedence rules, many other types of variables have a higher priority, so this value may be overridden.

  • This module is also supported for Windows targets.


This module has a corresponding action plugin.


Parameter Choices/Defaults Comments
added in 2.4 of ansible.builtin
  • no ←
  • yes
This boolean converts the variable into an actual 'fact' which will also be added to the fact cache, if fact caching is enabled.
Normally this module creates 'host level variables' and has much higher precedence, this option changes the nature and precedence (by 7 steps) of the variable created.
This actually creates 2 copies of the variable, a normal 'set_fact' host variable with high precedence and a lower 'ansible_fact' one that is available for persistance via the facts cache plugin. This creates a possibly confusing interaction with meta: clear_facts as it will remove the 'ansible_fact' but not the host variable.
string / required
The set_fact module takes key=value pairs as variables to set in the playbook scope. Or alternatively, accepts complex arguments using the args: statement.



  • The var=value notation can only create strings or booleans. If you want to create lists/arrays or dictionary/hashes use var: [val1, val2].

  • Since ‘cacheable’ is now a module param, ‘cacheable’ is no longer a valid fact name as of Ansible 2.4.

  • This module is also supported for Windows targets.

See Also

See also


The official documentation on the ansible.builtin.include_vars module.

Variable precedence: Where should I put a variable?

More information related to variable precedence and which type of variable wins over others.


- name: Setting host facts using key=value pairs, note that this always creates strings or booleans
  set_fact: one_fact="something" other_fact="{{ local_var }}"

- name: Setting host facts using complex arguments
    one_fact: something
    other_fact: "{{ local_var * 2 }}"
    another_fact: "{{ some_registered_var.results | map(attribute='ansible_facts.some_fact') | list }}"

- name: Setting facts so that they will be persisted in the fact cache
    one_fact: something
    other_fact: "{{ local_var * 2 }}"
    cacheable: yes

# As of Ansible 1.8, Ansible will convert boolean strings ('true', 'false', 'yes', 'no')
# to proper boolean values when using the key=value syntax, however it is still
# recommended that booleans be set using the complex argument style:
- name:  Setting booleans using complex argument style
    one_fact: yes
    other_fact: no


  • Dag Wieers (@dagwieers)