AI Use Cases Guide: Chat, Skills, Agents & More

— a practical guide to applying AI in 2026. /* === Reset & Base === */ .ai-guide * { box-sizing: border-box; margin: 0; padding: 0; } .ai-guide { font-family: -apple-system, BlinkMacSystemFont, ‚Segoe UI‘, Roboto, sans-serif; font-size: 15px; line-height: 1.6; color: #1a1a1a; max-width: 780px; margin: 0 auto; padding: 0 0 40px; } /* === Section Label === */ .ai-guide .section-label { font-size: 11px; font-weight: 600; letter-spacing: 0.08em; text-transform: uppercase; color: #888; margin: 0 0 12px; } /* === Use Case Cards === */ .ai-guide .use-case-card { border: 1px solid #e5e5e5; border-radius: 12px; padding: 16px 18px; margin-bottom: 10px; cursor: pointer; transition: border-color 0.15s, box-shadow 0.15s; background: #fff; } .ai-guide .use-case-card:hover { border-color: #bbb; box-shadow: 0 1px 6px rgba(0,0,0,0.06); } .ai-guide .use-case-card.active { border: 2px solid #3b82f6; box-shadow: 0 2px 10px rgba(59,130,246,0.1); } .ai-guide .card-header { display: flex; align-items: center; gap: 12px; } .ai-guide .card-icon { width: 36px; height: 36px; border-radius: 8px; display: flex; align-items: center; justify-content: center; font-size: 17px; flex-shrink: 0; } .ai-guide .card-title { font-size: 15px; font-weight: 600; color: #111; } .ai-guide .card-subtitle { font-size: 12px; color: #888; margin-top: 2px; } .ai-guide .card-chevron { margin-left: auto; font-size: 13px; color: #aaa; transition: transform 0.2s; flex-shrink: 0; } .ai-guide .use-case-card.active .card-chevron { transform: rotate(180deg); } /* === Card Detail === */ .ai-guide .card-detail { display: none; margin-top: 14px; border-top: 1px solid #f0f0f0; padding-top: 14px; } .ai-guide .card-detail.open { display: block; } .ai-guide .card-detail p { font-size: 13.5px; color: #555; line-height: 1.65; margin: 0 0 10px; } /* === Flow Steps === */ .ai-guide .flow { display: flex; flex-wrap: wrap; align-items: center; gap: 5px; margin: 10px 0 12px; } .ai-guide .flow-step { font-size: 11px; font-weight: 500; padding: 4px 10px; border-radius: 20px; background: #f5f5f5; color: #555; border: 1px solid #e8e8e8; white-space: nowrap; } .ai-guide .flow-arrow { font-size: 12px; color: #aaa; } /* === Tags === */ .ai-guide .tags { display: flex; flex-wrap: wrap; gap: 6px; margin: 8px 0 12px; } .ai-guide .tag { font-size: 11px; font-weight: 500; padding: 3px 9px; border-radius: 20px; } .ai-guide .tag-blue { background: #dbeafe; color: #1d4ed8; } .ai-guide .tag-green { background: #dcfce7; color: #166534; } .ai-guide .tag-amber { background: #fef3c7; color: #92400e; } .ai-guide .tag-red { background: #fee2e2; color: #991b1b; } /* === Complexity Bar === */ .ai-guide .complexity-label { font-size: 11px; color: #aaa; margin-bottom: 5px; } .ai-guide .complexity-bar { display: flex; gap: 3px; margin-bottom: 12px; } .ai-guide .cb { height: 5px; flex: 1; border-radius: 3px; background: #eee; } .ai-guide .cb.on { background: #3b82f6; } /* === When to use === */ .ai-guide .when-to-use { font-size: 13px; color: #444; background: #f9f9f9; border-left: 3px solid #3b82f6; padding: 8px 12px; border-radius: 0 6px 6px 0; } .ai-guide .when-to-use strong { color: #111; font-weight: 600; } /* === Divider === */ .ai-guide .divider { height: 1px; background: #eee; margin: 24px 0; } /* === Model Grid === */ .ai-guide .model-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(175px, 1fr)); gap: 10px; margin-top: 0; } .ai-guide .model-card { background: #f8f8f8; border-radius: 10px; padding: 13px 15px; border: 1px solid #eee; } .ai-guide .model-name { font-size: 13px; font-weight: 600; color: #111; margin-bottom: 5px; } .ai-guide .model-badge { display: inline-block; font-size: 10px; font-weight: 600; padding: 2px 8px; border-radius: 12px; margin-bottom: 6px; } .ai-guide .badge-openai { background: #dbeafe; color: #1d4ed8; } .ai-guide .badge-anthropic { background: #ede9fe; color: #5b21b6; } .ai-guide .badge-google { background: #dcfce7; color: #166534; } .ai-guide .badge-meta { background: #f1f5f9; color: #475569; } .ai-guide .badge-mistral { background: #fef3c7; color: #92400e; } .ai-guide .model-price { font-size: 10.5px; color: #888; font-family: ‚SF Mono‘, ‚Fira Mono‘, monospace; margin-bottom: 6px; line-height: 1.5; } .ai-guide .model-use { font-size: 11.5px; color: #666; line-height: 1.55; } /* === Decision Grid === */ .ai-guide .decision-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 8px; } .ai-guide .decision-card { background: #f8f8f8; border-radius: 10px; padding: 12px 14px; border: 1px solid #eee; } .ai-guide .decision-q { font-size: 12px; font-weight: 600; color: #111; margin-bottom: 5px; } .ai-guide .decision-a { font-size: 11.5px; color: #555; } /* === Responsive === */ @media (max-width: 520px) { .ai-guide .decision-grid { grid-template-columns: 1fr; } .ai-guide .model-grid { grid-template-columns: 1fr 1fr; } } @media (max-width: 380px) { .ai-guide .model-grid { grid-template-columns: 1fr; } }
💬
Chat / Q&A
Single-turn or conversational exchanges
▼

You ask a question, the model replies. Simple, stateless (or with short memory). Best for answering questions, brainstorming, summarizing, writing drafts, or explaining concepts.

User message → Model → Response
Low complexity Instant results No setup needed
Complexity
When to use: Quick lookups, creative writing, explaining topics, coding help, translations, summarization.
🛠️
Skills / Tools
Model with access to specific capabilities
▼

The model is given tools it can call — like web search, a calculator, a database, or a code executor. It decides when to invoke them. Results come back and inform the final answer.

User message → Model → Tool call → Result → Model → Response
Medium complexity Needs tool config Real-world data
Complexity
When to use: „Search the web for this“, run code, query a database, look up today’s weather, perform calculations on live data.
🤖
Agent
Multi-step autonomous task executor
▼

Given a goal, the agent plans and executes multiple steps on its own — using tools, memory, and reasoning — until the task is done. You set the objective; the AI figures out the steps.

Goal → Plan → Step 1 → Step 2… → Final output
High complexity Uses more tokens Handles ambiguity
Complexity
When to use: „Research this topic and write a report“, „Fix the bug in my codebase“, „Fill out this form by looking up the right data“.
🔗
Subagent / Multi-agent
Agents orchestrating other agents
▼

An orchestrator agent breaks a big task into subtasks and delegates them to specialised subagents running in parallel or in sequence. Each subagent focuses on one thing. Results are merged.

Goal → Orchestrator → Subagent A ↘ Subagent B → Merge → Output
Highest complexity Highest cost Parallelism Specialisation
Complexity
When to use: Very large, parallelisable tasks — e.g. „Analyse 200 customer feedback responses“, „Build a full app with separate agents for frontend, backend, and tests“.
GPT-4o
OpenAI
In $2.50 / Out $10
Best all-rounder for chat, vision, coding. Fast and multimodal.
o3 / o4-mini
OpenAI
o3: $10/$40 · o4-mini: $1.10/$4.40
Reasoning models. Best for maths, science, complex logic. Use for agents needing deep thinking.
Claude Sonnet 4.5
Anthropic
In $3 / Out $15
Strong at coding, reasoning, long context. Great for agentic workflows and nuanced writing.
Claude Haiku 4.5
Anthropic
In $0.80 / Out $4
Fast and cheap. Best for high-volume tasks, subagent steps, classification, short answers.
Gemini 2.5 Pro
Google
In $1.25 / Out $10
Huge 1M context window. Best for analysing very long documents, codebases, videos.
Gemini 2.0 Flash
Google
In $0.10 / Out $0.40
Extremely cheap and fast. Good for real-time chat, streaming apps, or massive-scale pipelines.
Llama 3.3 70B
Meta (open)
~$0.20 / $0.40 (hosted)
Free to run locally. Strong general model. Best when data privacy or cost at scale matters.
Mistral Large
Mistral
In $2 / Out $6
Strong at multilingual tasks and European languages. Good for EU-regulated environments.
Need a fast cheap answer?
→ Gemini Flash or Haiku 4.5
Complex reasoning or maths?
→ o3 / o4-mini or Claude Sonnet
Very long document / codebase?
→ Gemini 2.5 Pro (1M context)
Build an autonomous agent?
→ Claude Sonnet 4.5 or GPT-4o
Data privacy / on-premise?
→ Llama 3.3 70B (self-hosted)
Multimodal (images/audio)?
→ GPT-4o or Gemini 2.5 Pro
Jan D.
Jan D.

"The only real security that a man will have in this world is a reserve of knowledge, experience, and ability."

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