---
summary: 'Create room API: details of handling initial_state'
---
created: 2016-07-16 11:53:53.0
creator: jimmycuadra
description: |-
  The {{initial_state}} parameter to the create room API accepts a list of state events that will be sent into the newly created room. Synapse implements this using an ordered dict, which has two implications:

  # Order matters. There may not be a specific case where it makes a difference currently, but for future compatibility, the order events are sent should be preserved from the user's input.
  # If the user's input contains more than one of the same (event_type, state_key), ones that come later in the list override previous ones. Only the last event for each unique tuple will actually be created.

  The spec should say that these rules MUST be followed.
id: '12751'
key: SPEC-429
number: '429'
priority: '3'
project: '10001'
reporter: jimmycuadra
resolution: '1'
resolutiondate: 2016-07-18 14:58:41.0
status: '5'
type: '1'
updated: 2016-07-18 14:58:41.0
votes: '0'
watches: '2'
workflowId: '12851'
---
actions:
- author: richvdh
  body: Agreed.
  created: 2016-07-18 11:40:49.0
  id: '13062'
  issue: '12751'
  type: comment
  updateauthor: richvdh
  updated: 2016-07-18 11:40:49.0
- author: richvdh
  body: Hopefully fixed by https://github.com/matrix-org/matrix-doc/pull/362.
  created: 2016-07-18 14:58:32.0
  id: '13064'
  issue: '12751'
  type: comment
  updateauthor: richvdh
  updated: 2016-07-18 14:58:32.0