Choosing the Right Building Block¶
Ten building blocks, three layers — but which ones does your workflow actually need? This page gives you comparison tables to quickly differentiate the blocks and a decision guide to match your situation to the right starting point.
Most workflows need just two or three blocks. The goal isn't to use all ten — it's to pick the right ones for the job.
Start simple
Begin with a Prompt and add blocks only when you hit a real limitation. If you're re-typing the same instructions, add a Skill. If you need external data, add MCP. If you need multi-step autonomy, add an Agent. Don't over-engineer — let the workflow tell you what it needs.
At a Glance¶
All ten blocks in one view — use this to quickly orient yourself, then drill into the layer tables below for full details.
| Block | Primary Job | Best For | Typical User |
|---|---|---|---|
| Model | Process and generate | Choosing the right engine for speed, depth, or cost | Everyone |
| Context | Inform | Grounding the model in your specific domain knowledge | Everyone |
| Project | Organize | Persisting instructions and context across conversations | Everyone |
| Memory | Remember | Accumulating preferences and patterns over time | Everyone |
| Prompt | Instruct | One-off or conversational tasks with clear instructions | Everyone |
| Skill | Standardize | Repeatable routines you run the same way every time | Everyone |
| Agent | Execute autonomously | Multi-step workflows requiring planning and tool use | Power user |
| MCP | Connect | Bridging AI to external tools, data, and services | Power user |
| API | Integrate programmatically | Embedding AI in applications and automated pipelines | Developer |
| SDK | Orchestrate in code | Building agent systems with tool use, memory, and handoffs | Developer |
Intelligence Layer¶
The persistent foundation: engine, knowledge, and workspace powering every interaction.
| Model | Context | Project | Memory | |
|---|---|---|---|---|
| What it provides | AI engine that processes inputs and generates outputs | Background knowledge the model doesn't have | Persistent workspace grouping instructions, context, and skills | Accumulated knowledge from past interactions |
| Primary job | Process and generate | Inform | Organize | Remember |
| Persistence | Always available (platform-managed) | Ephemeral (per-conversation) or attached to a project | Persistent across conversations | Persistent and growing across conversations |
| Contains | Trained weights, capability tiers, modality support | Files, docs, data, examples, reference material | Instructions, context files, conversation history, skills | Preferences, decisions, facts, learned patterns |
| When it loads | Selected before or during a conversation | Attached at conversation start or mid-conversation | Active when you open a conversation in the project | Retrieved automatically when relevant |
| Can include code | No (model selection, not authoring) | Yes (code files as reference material) | Yes (code in project knowledge or instructions) | No (system-managed, natural language) |
| Best for | Choosing the right engine for speed, depth, or cost | Grounding the model in your specific domain | Persisting setup so you don't re-upload every time | Adapting AI behavior over time without manual setup |
| Who manages it | Platform (you choose tier) | User-curated | User-curated | System-managed |
| Requires external access | No | No (you bring the files) | No | No |
| Typical user | Everyone | Everyone | Everyone | Everyone |
Orchestration Layer¶
The execution layer: instructions, routines, and autonomous agents that direct and do the work.
| Prompt | Skill | Agent | |
|---|---|---|---|
| What it provides | Natural language instructions to the model | Reusable routine with defined inputs and outputs | Autonomous AI that plans, uses tools, and executes multi-step work |
| Primary job | Instruct | Standardize | Execute autonomously |
| Persistence | Ephemeral (per-conversation) | Persistent (saved as files, reusable across conversations) | Ephemeral (runs for a session) or scheduled |
| Contains | Natural language instructions, examples, constraints | Instructions, reference files, output format specs | Goals, tool access, planning logic, decision-making |
| When it loads | When you type or send a message | Auto-triggered when relevant, or invoked via slash command | Launched explicitly or on a schedule |
| Can include code | No (natural language only) | Yes (scripts, templates, code references) | Yes (reads, writes, and runs code) |
| Best for | One-off or conversational tasks with clear instructions | Repeatable routines you run the same way every time | Multi-step workflows requiring planning and tool use |
| Who manages it | User (typed in the moment) | User-curated (packaged for reuse) | User-launched or developer-built |
| Requires external access | No | No (self-contained instructions) | Often yes (uses tools, files, MCP connections) |
| Typical user | Everyone | Everyone | Power user |
Integration Layer¶
The connection layer: protocols, interfaces, and frameworks that bridge AI to external systems and code.
| MCP | API | SDK | |
|---|---|---|---|
| What it provides | Connector to external tools, services, and databases | Programmatic interface for accessing AI models | Frameworks for building AI workflows in code |
| Primary job | Connect | Integrate programmatically | Orchestrate in code |
| Persistence | Persistent (configured once, available across conversations) | Stateless (each call is independent) | Persistent (code you deploy and maintain) |
| Contains | Server configs, tool definitions, authentication | API keys, endpoint URLs, request/response schemas | Libraries, agent loops, tool abstractions, patterns |
| When it loads | Connected at startup or configured in settings | Called on demand from code | Imported into your application code |
| Can include code | Yes (server implementations) | Yes (code making HTTP requests) | Yes (the primary interface is code) |
| Best for | Bridging AI to external tools, data, and services | Embedding AI in applications and automated pipelines | Building agent systems with tool use, memory, and handoffs |
| Who manages it | User-configured or developer-built | Developer-owned | Developer-owned |
| Requires external access | Yes (bridges to external systems) | Yes (calls external APIs) | Yes (wraps APIs and external services) |
| Typical user | Power user | Developer | Developer |
Decision Guide: "I want to..."¶
Use this table to find your starting point. Most real workflows combine several blocks — this tells you where to begin.
| I want to... | Start with | Add when needed |
|---|---|---|
| Ask AI a question | Prompt | + Context if it needs your specific data |
| Get better answers about my domain | Context + Prompt | + Project to persist the setup |
| Stop re-uploading the same files | Project | + Memory to also retain learned preferences |
| Have AI remember how I like things done | Memory | Already persistent — just keep using it |
| Run the same workflow every week | Skill | + MCP if the skill needs external data |
| Pull live data into a conversation | MCP | + Skill to standardize what you do with the data |
| Automate a multi-step research task | Agent | + MCP for external sources, + Skill for sub-routines |
| Build AI into my app | API | + SDK for complex orchestration |
| Coordinate multiple agents in code | SDK | + MCP for external tool access |
| Choose between fast and deep AI | Model (select the right tier) | All other blocks work with any model |
Related¶
- Building Blocks Overview — what each block is, with cross-platform implementations
- Design Your AI Workflow — mapping workflow steps to building blocks
- Business-First AI Framework — the full Analyze → Deconstruct → Build methodology