OpenAPI Specification
openapi: 3.1.0
info:
title: AspenTech Inmation Web Data API
description: The AspenTech Inmation Web API provides HTTP and WebSocket interfaces for external applications to interact with the AspenTech Inmation industrial IoT and time-series data platform. RPC-based REST APIs enable access to process data, system services, and automation functions for manufacturing and energy operations.
version: 1.108.0
contact:
name: AspenTech Support
url: https://atdocs.inmation.com/api/1.108/webapi/index.html
servers:
- url: http://{hostname}:8002
description: Inmation Web API server
variables:
hostname:
default: localhost
description: Inmation server hostname or IP address
security:
- basicAuth: []
- bearerToken: []
tags:
- name: Data
description: Read and write process data points
paths:
/api:
post:
operationId: executeRpcCall
summary: Execute RPC call
description: Execute an Inmation RPC (Remote Procedure Call) operation. The Inmation Web API uses a unified POST endpoint with JSON-RPC-style requests to perform data reads, writes, and system operations.
tags:
- Data
requestBody:
required: true
content:
application/json:
schema:
$ref: '#/components/schemas/RpcRequest'
examples:
readData:
summary: Read current value of a data item
value:
jsonrpc: '2.0'
method: data.read
params:
paths:
- /System/Core/Tag1
id: 1
writeData:
summary: Write value to a data item
value:
jsonrpc: '2.0'
method: data.write
params:
items:
- path: /System/Core/Tag1
value: 42.5
id: 2
responses:
'200':
description: RPC response
content:
application/json:
schema:
$ref: '#/components/schemas/RpcResponse'
'400':
description: Invalid RPC request
content:
application/json:
schema:
$ref: '#/components/schemas/RpcErrorResponse'
'401':
$ref: '#/components/responses/Unauthorized'
/api/data/read:
post:
operationId: readDataItems
summary: Read current process data values
description: Read the current value of one or more process data items (tags) by path.
tags:
- Data
requestBody:
required: true
content:
application/json:
schema:
type: object
required:
- paths
properties:
paths:
type: array
description: List of item paths to read
items:
type: string
example:
- /System/Core/Temperature
- /System/Core/Pressure
responses:
'200':
description: Data values for requested items
content:
application/json:
schema:
type: object
properties:
result:
type: array
items:
$ref: '#/components/schemas/DataItem'
/api/data/write:
post:
operationId: writeDataItems
summary: Write process data values
description: Write values to one or more process data items (tags) by path.
tags:
- Data
requestBody:
required: true
content:
application/json:
schema:
type: object
required:
- items
properties:
items:
type: array
items:
$ref: '#/components/schemas/DataWriteRequest'
responses:
'200':
description: Write result
content:
application/json:
schema:
type: object
properties:
result:
type: array
items:
$ref: '#/components/schemas/WriteResult'
components:
schemas:
DataWriteRequest:
type: object
required:
- path
- value
properties:
path:
type: string
value:
description: Value to write (numeric, string, or boolean)
timestamp:
type: string
format: date-time
DataItem:
type: object
description: Current value of a process data item
properties:
path:
type: string
description: Full item path
value:
description: Current process value (numeric, string, or boolean)
quality:
type: integer
description: OPC quality code (192 = Good, 0 = Bad)
timestamp:
type: string
format: date-time
description: Timestamp of the current value
error:
type: string
description: Error message if item could not be read
RpcErrorResponse:
type: object
properties:
jsonrpc:
type: string
error:
type: object
properties:
code:
type: integer
message:
type: string
data:
type: object
id:
oneOf:
- type: integer
- type: string
WriteResult:
type: object
properties:
path:
type: string
success:
type: boolean
error:
type: string
RpcRequest:
type: object
required:
- jsonrpc
- method
- id
properties:
jsonrpc:
type: string
enum:
- '2.0'
method:
type: string
description: RPC method name (e.g., data.read, data.write, sys.info)
params:
type: object
additionalProperties: true
id:
oneOf:
- type: integer
- type: string
Error:
type: object
properties:
code:
type: integer
message:
type: string
RpcResponse:
type: object
properties:
jsonrpc:
type: string
result:
description: Response result (type varies by method)
id:
oneOf:
- type: integer
- type: string
responses:
Unauthorized:
description: Unauthorized - invalid credentials
content:
application/json:
schema:
$ref: '#/components/schemas/Error'
securitySchemes:
basicAuth:
type: http
scheme: basic
bearerToken:
type: http
scheme: bearer