You can create custom actions in Sigma using an OpenAPI 3.0 or 3.1 specification of an API. This enables your AI agents to interact with REST APIs and trigger workflows in external systems.
Include only the endpoints you want your agent to call in the OpenAPI spec. Remove any endpoints you don’t want the agent to access.

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Setting Up Custom Actions

1

Navigate to the Actions Dashboard

Click your user profile icon and select Admin Panel, then click the Actions tab in the sidebar.Actions dashboard in Sigma Admin Panel
2

Create an OpenAPI Action

Click From OpenAPI schema under Create Action.Paste your OpenAPI spec and configure any required authentication or headers.Creating an OpenAPI action in Sigma Admin Panel

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Example

The below OpenAPI spec can be used to create a Custom Action for fetching and creating Agents in Sigma.
OpenAPI
{
  "openapi": "3.1.0",
  "info": {
    "title": "Agents API",
    "version": "1.0.0",
    "description": "Minimal OpenAPI schema for creating and fetching agents in Sigma"
  },
  "servers": [
    {
      "url": "https://cloud.Sigma.app/api"
    }
  ],
  "paths": {
    "/persona": {
      "post": {
        "summary": "Create Agent (Persona)",
        "operationId": "create_persona",
        "requestBody": {
          "required": true,
          "content": {
            "application/json": {
              "schema": {
                "type": "object",
                "properties": {
                  "name": { "type": "string" },
                  "description": { "type": "string" },
                  "document_set_ids": {
                    "type": "array",
                    "items": { "type": "integer" }
                  },
                  "num_chunks": { "type": "number" },
                  "is_public": { "type": "boolean" },
                  "recency_bias": {
                    "type": "string",
                    "enum": ["favor_recent", "base_decay", "no_decay", "auto"]
                  },
                  "llm_filter_extraction": { "type": "boolean" },
                  "llm_relevance_filter": { "type": "boolean" },
                  "tool_ids": {
                    "type": "array",
                    "items": { "type": "integer" }
                  },
                  "system_prompt": { "type": "string" },
                  "task_prompt": { "type": "string" },
                  "datetime_aware": { "type": "boolean" }
                },
                "required": [
                  "name",
                  "description",
                  "document_set_ids",
                  "num_chunks",
                  "is_public",
                  "recency_bias",
                  "llm_filter_extraction",
                  "llm_relevance_filter",
                  "tool_ids",
                  "system_prompt",
                  "task_prompt",
                  "datetime_aware"
                ]
              }
            }
          }
        },
        "responses": {
          "200": { "description": "Created" }
        }
      }
    },
    "/persona/{persona_id}": {
      "get": {
        "summary": "Get Agent (Persona) By ID",
        "operationId": "get_persona",
        "parameters": [
          {
            "name": "persona_id",
            "in": "path",
            "required": true,
            "schema": { "type": "integer" }
          }
        ],
        "responses": {
          "200": { "description": "OK" }
        }
      }
    }
  }
}