# reading/Writing OPC tags from a python script outside Ignition

**URL:** <https://forum.inductiveautomation.com/t/reading-writing-opc-tags-from-a-python-script-outside-ignition/38665>\
**Category:** Ignition\
**Tags:** ignition79, scripting\
**Created:** [September 14, 2020, 6:46pm UTC](https://forum.inductiveautomation.com/t/reading-writing-opc-tags-from-a-python-script-outside-ignition/38665 "2020-09-14T18:46:46Z")\
**Posts on this page:** 1\
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**Author:** ![pturmel](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/pturmel/32/3295_2.png) [@pturmel](https://forum.inductiveautomation.com/u/pturmel)\
**Post date:** [September 15, 2020, 11:57am UTC](https://forum.inductiveautomation.com/t/reading-writing-opc-tags-from-a-python-script-outside-ignition/38665/2 "2020-09-15T11:57:31Z")

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Ignition has no API for external access to tags. There are two supported ways and one unsupported way:

1. Set Ignition to Expose Tags via OPC (an all-or-nothing setting) and then use and OPC _client_ to access the tags,

2. Install Ignition’s WebDev module and use its features to implement your own http(s) API. The jython scripting within such an API can expose pretty much anything inside Ignition to external clients, or

3. Write your own 3rd-party module that registers a java servlet and implement your own http(s) API in java, much like (2). You are pretty much on your own with this one.

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