Principle:Langgenius Dify App Type Selection
| Knowledge Sources | |
|---|---|
| Domains | LLM Application Architecture Interaction Design |
| Last Updated | 2026-02-08 00:00 GMT |
Overview
Application archetype selection determines the interaction pattern and runtime behavior of an LLM-powered application by mapping use case requirements to one of several predefined paradigms.
Description
When creating a new AI application, the first and most consequential decision is choosing the application mode. Each mode defines a distinct interaction contract between the user and the language model:
- Chat (chat) -- A simple conversational interface where the user exchanges messages with the LLM in a turn-based dialogue. The platform manages conversation history automatically. Best suited for customer support bots, Q&A assistants, and general-purpose chatbots that do not require complex orchestration.
- Advanced Chat (advanced-chat) -- Also known as Chatflow, this mode layers a visual workflow editor on top of the conversational paradigm. Developers can design multi-step processing pipelines (retrieval, transformation, conditional branching) that execute before or after the LLM generates a response. Ideal for RAG-powered chatbots, multi-tool assistants, and applications requiring deterministic pre-/post-processing logic.
- Agent Chat (agent-chat) -- An autonomous agent mode where the LLM can reason about which tools to invoke, plan multi-step actions, and iterate until a goal is reached. The platform provides a tool-calling loop with observation/action cycles. Appropriate for research assistants, code interpreters, and applications where the LLM must dynamically decide its next action.
- Workflow (workflow) -- A non-conversational automation mode where the application executes a directed acyclic graph (DAG) of processing nodes. There is no persistent chat session; each run is an independent invocation. Best for batch processing, document generation, data transformation pipelines, and any use case that does not require interactive dialogue.
- Completion (completion) -- A single-shot text generation mode where the user provides input (typically via a form) and receives a generated output. There is no conversation context or multi-turn interaction. Suitable for text summarization, translation, content generation, and structured output tasks.
The choice of mode is immutable after creation for most modes (though the platform offers a conversion path from basic chat to chatflow). This makes upfront selection critical.
Usage
Select the application type when:
- Starting a new project and defining the interaction contract
- Evaluating whether a use case requires autonomous reasoning (agent), orchestrated pipelines (workflow/chatflow), or simple dialogue (chat/completion)
- Migrating an existing application from one paradigm to another (limited support via conversion utilities)
Theoretical Basis
The five modes map to well-established patterns in AI application design:
| Pattern | Mode | Characteristics |
|---|---|---|
| Conversational AI | chat | Stateful, multi-turn, history-managed |
| Orchestrated Dialogue | advanced-chat | Stateful + DAG-based pre/post processing |
| Autonomous Agent | agent-chat | Tool-calling loop with planning and reflection |
| Pipeline Automation | workflow | Stateless DAG execution, no dialogue |
| Single-Shot Generation | completion | Stateless, prompt-in / text-out |
The selection heuristic can be expressed as:
IF use_case requires autonomous tool selection:
mode = agent-chat
ELSE IF use_case requires multi-step orchestration:
IF use_case involves interactive dialogue:
mode = advanced-chat
ELSE:
mode = workflow
ELSE IF use_case involves multi-turn conversation:
mode = chat
ELSE:
mode = completion
Key trade-offs:
- Complexity vs. control -- Agent mode offers the most flexibility but is the hardest to debug and constrain. Workflow mode offers maximum control but no conversational affordance.
- Latency -- Workflow and agent modes introduce additional processing steps that increase end-to-end latency compared to simple chat or completion.
- Cost -- Agent mode may invoke the LLM multiple times per user request (reasoning loops), significantly increasing token consumption.