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Overview

casen-worker-ai is an official casen CLI plugin that brings AI-powered task processing into Camunda 8 workflows. It subscribes to four job types and uses the Anthropic Claude API to complete each job with structured output.

This is the right tool when you need AI logic in a process but don't want to build a full microservice — start the worker once and any process in your cluster can delegate AI tasks to it.

Why a worker instead of the HTTP connector?

The built-in Camunda HTTP connector can call any API but cannot:

• Validate or parse the response and fail the job if the output is malformed
• Route Anthropic rate-limit errors (429) to Camunda's retry budget with back-off
• Throw a typed BPMN error that an error boundary event can catch

The worker handles all three via failJob and throwJobError, giving your process model clean error paths.

Installation

casen plugin install casen-worker-ai

Set your Anthropic API key before starting:

export ANTHROPIC_API_KEY=sk-ant-...
casen ai-worker

Configuration

| Environment variable | Default | Description | |---|---|---| | ANTHROPIC_API_KEY | required | Your Anthropic API key | | AI_MODEL | claude-3-5-haiku-20241022 | Model ID to use | | AI_MAX_TOKENS | 1024 | Token budget per call | | AI_TIMEOUT_MS | 60000 | HTTP timeout in ms |

Operations

com.bpmnkit.ai.classify — Classify text

Classifies text into one of the provided categories.

Input variables:

| Variable | Type | Required | Description | |---|---|---|---| | input | string | ✓ | Text to classify | | categories | string[] | ✓ | Allowed category names | | context | string | — | Optional domain context |

Output variables: category, confidence (0–1), rationale, aiModel, processedAt

BPMN error codes: AI_INVALID_CATEGORY, AI_PARSE_ERROR, AI_API_ERROR, AI_INVALID_INPUT

<bpmn:serviceTask id="ClassifyTicket" name="Classify ticket">
  <bpmn:extensionElements>
    <zeebe:taskDefinition type="com.bpmnkit.ai.classify" retries="3" />
    <zeebe:taskHeaders>
      <zeebe:header key="retryBackoff" value="PT30S" />
    </zeebe:taskHeaders>
    <zeebe:ioMapping>
      <zeebe:input source="=ticket.body" target="input" />
      <zeebe:input source='=["billing","technical","cancellation","general"]' target="categories" />
    </zeebe:ioMapping>
  </bpmn:extensionElements>
</bpmn:serviceTask>

com.bpmnkit.ai.summarize — Summarize text

Summarizes text to a target length and style.

Input variables:

| Variable | Type | Required | Description | |---|---|---|---| | input | string | ✓ | Text to summarize | | maxWords | number | — | Target word count (default: 100) | | style | "bullet" | "paragraph" | — | Output style (default: "paragraph") |

Output variables: summary, wordCount, aiModel, processedAt

com.bpmnkit.ai.extract — Extract structured fields

Extracts named fields from unstructured text. Missing fields are reported but the job still completes — use a gateway on =missingFields to decide whether to auto-proceed or route to manual review.

Input variables:

| Variable | Type | Required | Description | |---|---|---|---| | input | string | ✓ | Unstructured text | | fields | string[] | ✓ | Field names to extract | | schema | object | — | Type hints per field, e.g. { amount: "number" } |

Output variables: extracted (object), missingFields (array), aiModel, processedAt

com.bpmnkit.ai.decide — Make a boolean decision

Answers a yes/no question based on context and an optional policy statement. Use confidence at a gateway to route low-confidence decisions to human review.

Input variables:

| Variable | Type | Required | Description | |---|---|---|---| | question | string | ✓ | The yes/no question | | context | string | ✓ | Relevant facts | | policy | string | — | Natural language policy the model must apply |

Output variables: decision (boolean), rationale, confidence (0–1), aiModel, processedAt

Example workflow: Credit decision

Start Event
  → summarize (summarize application notes, maxWords=150)
  → decide     (question="Approve loan?", policy="Score ≥ 680 and amount ≤ 50k")
  → Gateway: decision=true and confidence≥0.8 → Auto-approve
             decision=false and confidence≥0.8 → Auto-deny
             default                           → Human review

Error handling

Add boundary events to your service tasks to handle AI failures gracefully:

• Error boundary catching AI_PARSE_ERROR → route to a manual input fallback task
• Timer boundary (PT5M) → escalation path if the worker is not running
• Set retries="3" and retryBackoff="PT30S" on the task definition — the worker signals Camunda to retry via failJob on rate limits and network timeouts

Related Packages

| Package | Description | |---------|-------------| | @bpmnkit/core | BPMN/DMN/Form parser, builder, layout engine | | @bpmnkit/canvas | Zero-dependency SVG BPMN viewer | | @bpmnkit/editor | Full-featured interactive BPMN editor | | @bpmnkit/engine | Lightweight BPMN process execution engine | | @bpmnkit/feel | FEEL expression language parser & evaluator | | @bpmnkit/plugins | 22 composable canvas plugins | | @bpmnkit/api | Camunda 8 REST API TypeScript client | | @bpmnkit/ascii | Render BPMN diagrams as Unicode ASCII art | | @bpmnkit/ui | Shared design tokens and UI components | | @bpmnkit/profiles | Shared auth, profile storage, and client factories for CLI & proxy | | @bpmnkit/operate | Monitoring & operations frontend for Camunda clusters | | @bpmnkit/connector-gen | Generate connector templates from OpenAPI specs | | @bpmnkit/cli | Camunda 8 command-line interface (casen) | | @bpmnkit/proxy | Local AI bridge and Camunda API proxy server | | @bpmnkit/cli-sdk | Plugin authoring SDK for the casen CLI | | @bpmnkit/create-casen-plugin | Scaffold a new casen CLI plugin in seconds | | @bpmnkit/casen-report | HTML reports from Camunda 8 incident and SLA data | | @bpmnkit/casen-worker-http | Example HTTP worker plugin — completes jobs with live JSONPlaceholder API data |

License

MIT © BPMN Kit — made by u11g