The Microsoft Power Platform provides a tremendous amount of native functionality, enhanced by premium and third-party connectors. But sometimes that's just not enough to get the job done. You need something specific, a plugin that does exactly what the business needs without complex backend configuration, confusing expression syntax or additional per-user cost. In this step-by-step tutorial you will learn how to create a custom connector from scratch, construct an API definition, deploy it to the cloud and make it available to users throughout your tenant so they can easily drop it into their forms and flows.

3. Eric Shupps
Office Servers & Services MVP
@eshupps
sharepointcowboy
slideshare.net/eshupps
linkedin.com/in/eshupps
github.com/eshupps

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6. ARROW INFOGRAPHIC SLIDE
COST
Avoid premium connectors or consolidate multiple
connectors into a single endpoint
FLEXIBILITY
Custom connectors can be adapted to suit various scenarios
and changing requirements
USABILITY
Complex syntax and action sequences can be abstracted or
greatly simplified for better productivity and faster adoption
SUITABILITY
Support specific business scenarios, such as connecting
legacy backend systems or private cloud infrastructure

7. convertTimeZone(triggerBody()?['Start'],'UTC','Eastern Standard
Time','ddd')

8. Action
Provides a visual “drag and drop”
component for users to interact with at
design time
Description
Appearance, target URL, scheme,
endpoint, and authentication method of
the connector
Definition
The actions, triggers, references and
policies that comprise the connector
functionality
API
The target system that performs the
actions specified in the definition and
returns results

9. Title, version, host, base
path, schemes, and
input/output format of the
connector
Information
Individual operations
(endpoints) and their
visibility, headers, verbs,
response definitions, and
parameters
Actions
Timed (polling) or event-
driven (webhook) actions
Triggers
Reusable input and output
objects
References
Templates for modifying
runtime behavior
Policies
A
B
C
D
E

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16. GETYER SWAGGER ON
The UI is limited in advanced functionality,
understanding the OpenAPI specification and
how to properly construct a Swagger file is a
must.
TRIGGERS ARE FOR CLOSERS
Triggers are difficult to construct properly
and very challenging to debug. Get the basics
down first and deploy a functional connector
before tackling the hard stuff.
CORS, CORS, CORS
Test operations in the UI will fail if CORS
policy is not enabled on API endpoint(s) – it’s
a browser thing.
WHERE HAVE ALL THE #REFS GONE?
#ref elements simplify complex definition
files but they can’t be created in the UI –
drop to the Swagger editor instead.
POLICIESFTW
The OpenAPI definition structure is static but
policies provide an advanced level of runtime
flexibility.
AUTH IS HARD
Don’t overcomplicate things in the beginning.
Start with simple authentication then build
up to OAuth for more security.

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