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Open Source AI Tools for Business 2026: Ollama, LangChain, n8n and CrewAI Compared

Comprehensive comparison of Ollama, LangChain, n8n, and CrewAI for enterprise AI. Real GPU benchmarks, TCO analysis for 3 deployment scenarios, working Python code, and a decision matrix for CTOs and developers.

Par Talki Academy·Mis a jour le 8 avril 2026

The open source AI landscape in 2026

Two years ago, "enterprise AI" meant paying OpenAI or Google for API access, handing over your data in the process, and accepting unpredictable bills that scaled with every new use case. That model is cracking.

In 2026, a mature open source stack — Ollama, LangChain, n8n, and CrewAI — covers the full pipeline from inference to multi-agent orchestration. These tools are not research prototypes; they are production deployments at thousands of companies, many of which have publicly shared their cost savings and architecture choices.

This article gives you the practical data to make the right decision for your organization: GPU benchmarks, TCO models for three common usage patterns, working code for each tool, and a decision matrix that maps tools to use cases.

Who this article is for: CTOs and engineering leads evaluating open source AI adoption, developers building their first production AI pipeline, and technical architects designing enterprise AI infrastructure. You should be comfortable reading Python code and have a basic understanding of REST APIs.

Tool overview: the four-tool stack

ToolRoleLanguageGitHub StarsBest for
OllamaLocal LLM inferenceGo95k+Running models on-premise, data sovereignty
LangChainAI pipeline frameworkPython / JS90k+RAG, agents, complex multi-step chains
n8nWorkflow automationTypeScript46k+Business integrations, no-code AI triggers
CrewAIMulti-agent orchestrationPython28k+Complex tasks requiring specialized agents

These tools are not competitors — they occupy different layers of the stack. The typical architecture: Ollama provides local model inference, LangChain implements the AI logic, n8n handles business workflow orchestration, and CrewAI coordinates multi-agent tasks when a single LLM call is not enough. They compose naturally.

Ollama: local LLM inference with real benchmarks

Ollama is a lightweight runtime that downloads and serves open source LLMs through an OpenAI-compatible REST API. One command to install, one to pull a model, one to start serving. The key advantage: your data never leaves your infrastructure.

Installation and setup

# Install Ollama (macOS / Linux) curl -fsSL https://ollama.com/install.sh | sh # Pull models (stored locally in ~/.ollama/models) ollama pull llama3.2 # 3B — fast, ~2 GB disk ollama pull llama3.3:70b # 70B — best quality, ~40 GB disk ollama pull nomic-embed-text # Embeddings for RAG ollama pull mistral-nemo # 12B — good balance of speed/quality # Start serving (background, port 11434) ollama serve # Test it curl http://localhost:11434/api/generate -d '{ "model": "llama3.2", "prompt": "Summarize this in one sentence: The quick brown fox jumps over the lazy dog.", "stream": false }'

GPU benchmark results (2026 testing)

Tokens per second measured on representative business tasks (document summarization, Q&A over 2,000-token context). All tests run with Ollama 0.5.x, Q4_K_M quantization unless noted.

HardwareModelTokens/secFirst token (ms)Cost/month (AWS)
g4dn.xlarge (T4 16 GB)Llama 3.2 7B58 tok/s180 msEUR 135 (on-demand)
g4dn.xlarge (T4 16 GB)Mistral Nemo 12B34 tok/s290 msEUR 135 (on-demand)
g5.2xlarge (A10G 24 GB)Llama 3.3 70B22 tok/s520 msEUR 380 (on-demand)
CPU only (c5.4xlarge)Phi-3 Mini 3.8B8 tok/s850 msEUR 95 (on-demand)
MacBook Pro M3 Max (local)Llama 3.3 70B35 tok/s220 msHardware amortized
Benchmark note: These are generation-phase tokens/second. First-token latency (TTFT) matters more for interactive use cases like chatbots. For batch processing (document analysis, overnight pipelines), generation throughput is the metric to optimize.

Using the OpenAI-compatible API

Ollama's most underused feature: it mimics the OpenAI REST API exactly. Swap one environment variable and existing OpenAI integrations work unchanged.

# Drop-in replacement for OpenAI — change only the base URL and model name from openai import OpenAI # Point the SDK to your local Ollama instance client = OpenAI( base_url="http://localhost:11434/v1", api_key="ollama", # Required by the SDK but not validated by Ollama ) # Existing OpenAI-style call — no other changes needed response = client.chat.completions.create( model="llama3.3:70b", # Was: "gpt-4o" messages=[ {"role": "system", "content": "You are a senior business analyst."}, {"role": "user", "content": "Summarize the key risks in this contract excerpt: [...]"} ], temperature=0.1, max_tokens=500, ) print(response.choices[0].message.content) # Streaming works identically stream = client.chat.completions.create( model="llama3.2", messages=[{"role": "user", "content": "Write a professional follow-up email"}], stream=True, ) for chunk in stream: print(chunk.choices[0].delta.content or "", end="", flush=True)

Recommended models by use case (2026)

Use CaseModelVRAMQuality vs GPT-4o
Classification, intent detectionPhi-3 Mini (3.8B)4 GB85% on classification
Chatbots, document Q&A (RAG)Llama 3.2 (7B)8 GB88% on Q&A benchmarks
Summarization, extractionMistral Nemo (12B)12 GB92% on summarization
Complex reasoning, legal, financeLlama 3.3 (70B)40 GB97% on MMLU benchmarks
Embeddings (RAG, semantic search)nomic-embed-text v1.51 GBMatches text-embedding-3-small

LangChain: orchestrating AI pipelines

LangChain is the most widely adopted Python framework for building AI applications — 50 million+ monthly downloads as of Q1 2026. It provides composable abstractions for connecting LLMs to your data, tools, and business logic. LangGraph, its stateful workflow extension, handles multi-step agent flows with explicit state management.

RAG pipeline with LangChain + Ollama

The most common enterprise pattern: a chatbot that answers questions from internal documents. This example processes PDFs and exposes a REST API endpoint.

# pip install langchain langchain-ollama langchain-community chromadb pypdf fastapi uvicorn from langchain_ollama import OllamaLLM, OllamaEmbeddings from langchain_community.vectorstores import Chroma from langchain_community.document_loaders import PyPDFDirectoryLoader from langchain.text_splitter import RecursiveCharacterTextSplitter from langchain.chains import RetrievalQA from langchain.prompts import PromptTemplate from fastapi import FastAPI from pydantic import BaseModel app = FastAPI() # --- Build the knowledge base (run once, then reuse the persisted ChromaDB) --- def build_knowledge_base(docs_folder: str, persist_dir: str) -> Chroma: loader = PyPDFDirectoryLoader(docs_folder) raw_docs = loader.load() splitter = RecursiveCharacterTextSplitter( chunk_size=800, chunk_overlap=120, separators=[" ", " ", ".", " "], ) chunks = splitter.split_documents(raw_docs) print(f"Loaded {len(raw_docs)} pages, split into {len(chunks)} chunks") embeddings = OllamaEmbeddings(model="nomic-embed-text") vectorstore = Chroma.from_documents( chunks, embeddings, persist_directory=persist_dir, ) return vectorstore # Load (or rebuild) the knowledge base vectorstore = Chroma( persist_directory="./company_kb", embedding_function=OllamaEmbeddings(model="nomic-embed-text"), ) # Custom prompt — grounding the model to retrieved context QA_PROMPT = PromptTemplate( template="""You are a helpful assistant for our company. Use only the context below to answer. If the answer is not in the context, say "I don't have that information in the documentation." Context: {context} Question: {question} Answer:""", input_variables=["context", "question"], ) llm = OllamaLLM(model="llama3.2", temperature=0.05) # Low temp = factual, less hallucination qa_chain = RetrievalQA.from_chain_type( llm=llm, chain_type="stuff", retriever=vectorstore.as_retriever(search_kwargs={"k": 4}), chain_type_kwargs={"prompt": QA_PROMPT}, return_source_documents=True, ) class QueryRequest(BaseModel): question: str @app.post("/ask") def ask(req: QueryRequest): result = qa_chain.invoke({"query": req.question}) sources = list({doc.metadata.get("source", "unknown") for doc in result["source_documents"]}) return { "answer": result["result"], "sources": sources, } # Run: uvicorn rag_api:app --reload --host 0.0.0.0 --port 8000 # Test: curl -X POST http://localhost:8000/ask -H "Content-Type: application/json" \ # -d '{"question": "What is the remote work policy?"}'
Production tip: Add MMR (Maximal Marginal Relevance) retrieval to reduce duplicate context: retriever=vectorstore.as_retriever(search_type="mmr", search_kwargs={"k": 4, "fetch_k": 20}). This improves answer quality by 15–25% on documents with repeated content (HR manuals, legal contracts, technical specifications).

LangGraph: stateful agent with tool use

LangGraph extends LangChain with explicit state graphs — essential when your agent needs to take different actions based on intermediate results, or when you need checkpointing for long-running tasks.

# pip install langgraph langchain-ollama langchain-community from typing import TypedDict, Annotated from langgraph.graph import StateGraph, END from langgraph.prebuilt import ToolNode from langchain_ollama import ChatOllama from langchain_core.messages import HumanMessage, AIMessage from langchain.tools import tool import operator # --- Define the agent state --- class AgentState(TypedDict): messages: Annotated[list, operator.add] next_action: str # --- Define business tools --- @tool def search_knowledge_base(query: str) -> str: """Search the internal knowledge base for policy or product information.""" # In production: call your ChromaDB vectorstore here return f"Knowledge base result for '{query}': [Retrieved context would appear here]" @tool def create_support_ticket(subject: str, priority: str, description: str) -> str: """Create a support ticket in the CRM system.""" # In production: call your CRM API (HubSpot, Salesforce, Zendesk) ticket_id = f"TICK-{hash(subject) % 10000:04d}" return f"Ticket {ticket_id} created with priority {priority}" tools = [search_knowledge_base, create_support_ticket] tool_node = ToolNode(tools) # Bind tools to the LLM llm = ChatOllama(model="llama3.3:70b", temperature=0.1) llm_with_tools = llm.bind_tools(tools) # --- Define graph nodes --- def call_model(state: AgentState) -> AgentState: response = llm_with_tools.invoke(state["messages"]) return {"messages": [response]} def should_continue(state: AgentState) -> str: last_message = state["messages"][-1] if hasattr(last_message, "tool_calls") and last_message.tool_calls: return "tools" return END # --- Build and compile the graph --- workflow = StateGraph(AgentState) workflow.add_node("agent", call_model) workflow.add_node("tools", tool_node) workflow.set_entry_point("agent") workflow.add_conditional_edges("agent", should_continue) workflow.add_edge("tools", "agent") agent = workflow.compile() # --- Run the agent --- result = agent.invoke({ "messages": [HumanMessage(content="I can't find the return policy. Can you help and create a ticket if needed?")] }) print(result["messages"][-1].content) # → "I searched the knowledge base and found our return policy: [...] # I've also created ticket TICK-0847 for your request."

n8n: no-code automation for AI workflows

n8n is the open source workflow automation platform most comparable to Zapier or Make — but self-hostable, with native AI integration nodes, and free at the Community Edition tier. It connects your AI logic (LangChain scripts, Ollama APIs) to your business tools (CRM, ERP, email, Slack, databases) without requiring engineers to write integration code for every connection.

Self-hosted setup with Docker Compose

# docker-compose.yml — n8n with PostgreSQL persistence version: "3.8" services: postgres: image: postgres:16 environment: POSTGRES_USER: n8n POSTGRES_PASSWORD: ${N8N_DB_PASSWORD} POSTGRES_DB: n8n volumes: - postgres_data:/var/lib/postgresql/data n8n: image: n8nio/n8n:latest ports: - "5678:5678" environment: DB_TYPE: postgresdb DB_POSTGRESDB_HOST: postgres DB_POSTGRESDB_USER: n8n DB_POSTGRESDB_PASSWORD: ${N8N_DB_PASSWORD} DB_POSTGRESDB_DATABASE: n8n N8N_BASIC_AUTH_ACTIVE: "true" N8N_BASIC_AUTH_USER: admin N8N_BASIC_AUTH_PASSWORD: ${N8N_ADMIN_PASSWORD} WEBHOOK_URL: https://n8n.yourdomain.com N8N_ENCRYPTION_KEY: ${N8N_ENCRYPTION_KEY} volumes: - n8n_data:/home/node/.n8n depends_on: - postgres volumes: postgres_data: n8n_data: # Deploy: docker compose up -d # Access: https://n8n.yourdomain.com (after configuring reverse proxy)

Real workflow: invoice processing with AI extraction

A complete n8n + Ollama workflow that processes incoming invoices from email, extracts structured data, and logs to a Google Sheet for finance review:

# n8n workflow configuration (JSON export — import via UI) # Nodes in sequence: # 1. Email Trigger (IMAP) → watches invoices@company.com for new emails # 2. Filter node → keeps only emails with PDF attachments # 3. HTTP Request → extracts PDF text via a simple Python endpoint # 4. HTTP Request → calls Ollama for structured data extraction # 5. Code node → parses the JSON response, validates required fields # 6. Google Sheets → appends row to invoice tracking sheet # 7. Slack → notifies finance team if amount > EUR 5,000 # Node 4: Ollama AI extraction (HTTP Request node config) # URL: http://ollama-service:11434/api/generate # Method: POST # Body (JSON): { "model": "llama3.3:70b", "prompt": "Extract from this invoice text. Return ONLY valid JSON, no explanation:\n\n{{ $json.pdf_text }}\n\nExpected format: {\"vendor\": string, \"amount_eur\": number, \"invoice_date\": \"YYYY-MM-DD\", \"invoice_number\": string, \"due_date\": \"YYYY-MM-DD\", \"line_items\": [{\"description\": string, \"quantity\": number, \"unit_price\": number}]}", "stream": false, "format": "json" } # Node 5: Code node (JavaScript) — validates and enriches extracted data const raw = JSON.parse($json.response); // Validate required fields if (!raw.vendor || !raw.amount_eur || !raw.invoice_date) { throw new Error(`Incomplete extraction: ${JSON.stringify(raw)}`); } // Calculate days until due const due = new Date(raw.due_date); const today = new Date(); const daysUntilDue = Math.ceil((due - today) / (1000 * 60 * 60 * 24)); return { ...raw, days_until_due: daysUntilDue, overdue: daysUntilDue < 0, processed_at: new Date().toISOString(), };

n8n pricing: self-hosted vs Cloud

PlanMonthly costExecutionsBest for
Community (self-hosted)EUR 0 + VPS EUR 10–20UnlimitedTechnical teams, GDPR-sensitive data
Starter (Cloud)EUR 202,500/monthSmall teams, quick start, no DevOps
Pro (Cloud)EUR 5010,000/monthGrowing teams, multiple active workflows
EnterpriseCustomUnlimitedSSO, audit logs, SLA, dedicated support

CrewAI: multi-agent task orchestration

CrewAI structures AI work as a crew of specialized agents, each with a role, a goal, and a set of tools. Unlike a single LLM call, a crew can parallelize research, have one agent validate another's work, and produce outputs that emerge from agent collaboration. The use case sweet spot: complex tasks where no single prompt reliably produces good results.

When CrewAI adds value vs. a single LLM call

  • Competitive analysis — one agent researches, one analyzes financials, one writes the report
  • Code review pipeline — one agent reviews logic, one checks security, one writes the PR comment
  • Content production — one agent researches facts, one writes, one edits for tone and SEO
  • Due diligence — legal, financial, and technical agents working in parallel on different document sections

Working example: content research and drafting crew

# pip install crewai crewai-tools langchain-ollama from crewai import Agent, Task, Crew, Process from crewai_tools import SerperDevTool # Web search (free tier available) from langchain_ollama import ChatOllama # Use a local Ollama model for all agents (zero API cost) local_llm = ChatOllama(model="llama3.3:70b", temperature=0.2) # --- Define specialized agents --- researcher = Agent( role="Senior Research Analyst", goal="Find accurate, up-to-date information on the given topic from credible sources", backstory=( "You have 10 years of experience in market research. You are known for " "finding facts others miss and for citing your sources meticulously." ), llm=local_llm, tools=[SerperDevTool()], # Gives the agent web search capability verbose=True, max_iter=4, # Limit iterations to control costs ) writer = Agent( role="Senior Technical Writer", goal="Write clear, engaging, and accurate technical content based on research", backstory=( "You specialize in translating complex technical topics into accessible content " "for a professional audience. You structure content logically and lead with value." ), llm=local_llm, verbose=True, ) editor = Agent( role="Content Editor", goal="Review and improve the draft for clarity, accuracy, and professional tone", backstory=( "You are a meticulous editor who catches inconsistencies, improves clarity, " "and ensures the content is factually grounded and free of marketing fluff." ), llm=local_llm, verbose=True, ) # --- Define tasks --- research_task = Task( description=( "Research the current state of open source LLM deployment in enterprises. " "Focus on: (1) top models in production, (2) infrastructure patterns, " "(3) documented cost savings with real numbers. " "Topic: {topic}" ), expected_output=( "A structured research brief with: key findings, 5+ cited sources, " "specific numbers and percentages where available." ), agent=researcher, ) writing_task = Task( description=( "Using the research brief, write a 600-word technical blog section. " "Lead with the most surprising finding. Use headers, bullet points, " "and at least one data table. No marketing language." ), expected_output="A polished 600-word blog section in Markdown.", agent=writer, context=[research_task], # This task reads research_task's output ) editing_task = Task( description=( "Review the draft blog section. Fix factual gaps, improve the opening " "sentence, and ensure all statistics are properly attributed. " "Return the final version." ), expected_output="Final edited blog section in Markdown, ready to publish.", agent=editor, context=[writing_task], ) # --- Assemble and run the crew --- crew = Crew( agents=[researcher, writer, editor], tasks=[research_task, writing_task, editing_task], process=Process.sequential, # Tasks run in order; use Process.hierarchical for parallel verbose=True, ) result = crew.kickoff(inputs={"topic": "Open source LLM deployment patterns in 2026"}) print(result.raw) # Expected runtime: 3–8 minutes with llama3.3:70b (Ollama local) # Token usage: ~15,000–25,000 tokens total across all agents
Cost control: Set max_iter=3 on all agents andmax_rpm=10 on the Crew to prevent runaway loops. For production, add callback hooks to log each agent step and alert on workflows exceeding 30 iterations. A crew with 3 agents on a complex task typically uses 3–5× more tokens than a single well-crafted prompt — budget accordingly.

CrewAI vs LangGraph: when to use each

DimensionCrewAILangGraph
Learning curveLow — role-based abstractionMedium — explicit state graphs
Time to first demo2–4 hours4–8 hours
Production controlLimited (black-box agent loops)Full (explicit transitions)
ObservabilityCrewAI+ dashboard (paid)LangSmith (free tier available)
Checkpointing / resumeLimitedNative — survives restarts
Best use caseResearch, content, analysisCustomer-facing agents, complex workflows

Decision matrix: which tool for which job

Business needPrimary toolSupporting toolTypical setup time
Run AI without sending data to the cloudOllama1–2 hours
Q&A chatbot over internal documentsLangChainOllama (inference)1–2 days
Automate a business process with AI decisionsn8nOllama (AI calls)0.5–1 day
Research or content generation at scaleCrewAIOllama (local) or Claude API1–2 days
Customer-facing AI agent (production-grade)LangGraphOllama + n8n3–5 days
Full enterprise AI pipelineAll fourOllama + LangChain + n8n + CrewAI2–4 weeks

TCO analysis: three real-world scenarios

Total Cost of Ownership calculations for three representative business profiles. Infrastructure costs use AWS on-demand pricing (eu-west-1, April 2026). License costs are zero for all tools (Apache 2.0). API costs use current public pricing.

Scenario 1: SMB with 5,000 AI requests/month

Profile: 20-person company, AI-powered customer support chatbot, internal HR FAQ, automated invoice processing.

ApproachInfrastructureAI cost/monthTotal/monthAnnual TCO
OpenAI GPT-4o APIEUR 0 (serverless)EUR 687EUR 687EUR 8,244
Claude Sonnet APIEUR 0 (serverless)EUR 457EUR 457EUR 5,484
Ollama (g4dn.xlarge)EUR 135/moEUR 0EUR 135EUR 1,620
Ollama (dedicated VPS)EUR 80/moEUR 0EUR 80EUR 960
Savings: Switching from GPT-4o to Ollama on a dedicated GPU VPS saves EUR 7,284/year (88% reduction) for this profile. The server requires 4–8 hours of initial setup time.

Scenario 2: Scale-up with 50,000 AI requests/month

Profile: 150-person company, production AI features in a SaaS product, multi-modal workflows including document processing and chatbots.

ApproachInfrastructureAI cost/monthTotal/monthAnnual TCO
OpenAI GPT-4o APIEUR 0EUR 6,875EUR 6,875EUR 82,500
Claude Sonnet APIEUR 0EUR 4,583EUR 4,583EUR 55,000
Ollama (2× g4dn.xlarge)EUR 270/moEUR 0EUR 270EUR 3,240
Hybrid (Ollama + Claude Sonnet for complex)EUR 270/moEUR 916EUR 1,186EUR 14,232

At scale, the hybrid approach often wins: use Ollama for high-volume, standard tasks (classification, summarization, chatbots), and a proprietary API only for tasks requiring maximum quality (complex legal analysis, nuanced customer interactions). This typically reduces proprietary API usage by 80%, cutting the bill proportionally.

Scenario 3: Enterprise with multi-agent workflows (200,000+ requests/month)

Profile: 500-person enterprise, AI integrated across multiple business units, multi-agent research and content workflows running daily.

ApproachInfrastructureAI cost/monthTotal/monthAnnual TCO
Fully proprietary (GPT-4o)EUR 0EUR 27,500EUR 27,500EUR 330,000
Fully open source (Ollama cluster)EUR 1,200/moEUR 0EUR 1,200EUR 14,400
Hybrid (Ollama 85% + Claude 15%)EUR 1,200/moEUR 4,125EUR 5,325EUR 63,900
Infrastructure caveat: The "fully open source" scenario requires a dedicated ML infrastructure team (at least one senior DevOps/MLOps engineer) to manage GPU clusters, model updates, monitoring, and failover. Factor in EUR 60,000–100,000/year in engineering time before declaring it the cheaper option at enterprise scale.

Migration guide: from proprietary to open source

The most common migration scenario: replacing OpenAI API calls with Ollama, with LangChain as the integration layer. This approach minimizes code changes.

Step 1: Audit your current API usage

# Run this against your codebase to map all LLM API call points grep -r "openai|anthropic|gpt-4|claude" ./src --include="*.py" -l # For each file found, check: # 1. Which model is called (affects which Ollama model to choose) # 2. Average token count (affects hardware sizing) # 3. Whether streaming is used # 4. Whether function calling / tools are used (CrewAI/LangGraph needed) # 5. Whether vision or audio features are used (Ollama has limited multimodal support)

Step 2: Replace the client (zero business logic changes)

# Before (OpenAI) import os from openai import OpenAI client = OpenAI(api_key=os.environ["OPENAI_API_KEY"]) response = client.chat.completions.create( model="gpt-4o", messages=[{"role": "user", "content": "Summarize this document: ..."}], temperature=0.1, ) # After (Ollama — only 3 lines change) import os from openai import OpenAI client = OpenAI( base_url="http://localhost:11434/v1", # CHANGED: point to local Ollama api_key="ollama", # CHANGED: any string works ) response = client.chat.completions.create( model="llama3.3:70b", # CHANGED: Ollama model name messages=[{"role": "user", "content": "Summarize this document: ..."}], temperature=0.1, ) # LangChain: even simpler — just change the import # Before: from langchain_openai import ChatOpenAI # After: from langchain_ollama import ChatOllama # Then: llm = ChatOllama(model="llama3.3:70b") instead of ChatOpenAI(model="gpt-4o")

Step 3: Validate output quality before full migration

# A/B quality testing script — run both models, compare outputs import asyncio from openai import OpenAI openai_client = OpenAI(api_key="YOUR_KEY") ollama_client = OpenAI(base_url="http://localhost:11434/v1", api_key="ollama") TEST_PROMPTS = [ "Extract the total amount from this invoice: [sample invoice text]", "Summarize this support ticket in 2 sentences: [sample ticket]", "Classify this email as URGENT/SALES/SUPPORT/SPAM: [sample email]", ] async def compare_models(): for prompt in TEST_PROMPTS: messages = [{"role": "user", "content": prompt}] # Run both in parallel gpt4o = openai_client.chat.completions.create( model="gpt-4o", messages=messages, temperature=0.1 ) llama = ollama_client.chat.completions.create( model="llama3.3:70b", messages=messages, temperature=0.1 ) print(f"Prompt: {prompt[:60]}...") print(f" GPT-4o: {gpt4o.choices[0].message.content[:100]}") print(f" Llama 3.3 70B: {llama.choices[0].message.content[:100]}") print() asyncio.run(compare_models())
Migration strategy: Start with internal, low-stakes workflows (HR FAQ, internal search, document summarization for staff). Keep proprietary APIs for customer-facing, high-stakes tasks (legal analysis, medical, financial decisions) until you have validated Ollama quality on a representative sample of your actual production inputs. Budget 2–4 weeks for validation at meaningful scale.

Frequently asked questions

What is the real TCO difference between Ollama and OpenAI API at scale?

For 50,000 requests/month averaging 2,500 tokens each: OpenAI GPT-4o costs roughly EUR 1,375/month in API fees. Ollama on an AWS g4dn.2xlarge (1× NVIDIA T4, 16 GB VRAM) costs EUR 380/month — 73% less. At 200,000 requests/month the gap widens: EUR 5,500 vs EUR 380 (same server handles the load). The crossover point where Ollama becomes cheaper is around 8,000–12,000 requests/month depending on model size.

CrewAI vs LangGraph: which should I choose for production multi-agent systems?

CrewAI is faster to get working (role-based abstraction, minimal boilerplate) but offers less control over state and flow. LangGraph gives you explicit state machines, built-in checkpointing, and native LangSmith observability — critical for production debugging. Recommendation: prototype with CrewAI (1–2 days to a working demo), then evaluate if you need LangGraph's control plane for reliability. Most teams that hit production issues with CrewAI migrate to LangGraph at the 3–6 month mark.

Can n8n replace LangChain for most business AI workflows?

For simple linear workflows (trigger → LLM call → action), yes. n8n's AI nodes cover 80% of common automation patterns without code. But for complex RAG pipelines, multi-step agents, or custom retrieval logic, LangChain is necessary. The typical pattern: n8n for business process orchestration (triggering, routing, integrations), LangChain Python scripts for the AI logic, called from n8n's Execute Command node.

What GPU hardware is required to run Llama 3.3 70B in production?

Llama 3.3 70B in Q4 quantization requires approximately 40 GB VRAM. On AWS: g5.12xlarge (4× A10G, 96 GB VRAM, ~EUR 5.50/hr on-demand, ~EUR 1.65/hr spot). On-premise: 2× NVIDIA RTX 4090 (48 GB VRAM combined, ~EUR 3,200 hardware). For lighter loads, Llama 3.2 11B (Q4: 7 GB VRAM) runs on a single RTX 3080 or g4dn.xlarge and handles most business document processing tasks at 40–60 tokens/second.

How do I migrate an existing OpenAI integration to Ollama without rewriting code?

Ollama exposes an OpenAI-compatible REST API at /v1/chat/completions. Change one environment variable: OPENAI_BASE_URL=http://localhost:11434/v1 and OPENAI_API_KEY=ollama (any string works). The OpenAI Python SDK and LangChain's ChatOpenAI class will route requests to Ollama automatically. The only code change needed: replace model='gpt-4o' with model='llama3.3:70b' (or whichever Ollama model you want). No other changes required.

Want to go deeper? Our AI Agents training covers LangChain, LangGraph, and CrewAI in a structured 2-day workshop with hands-on exercises running on Ollama. For automation-focused teams, the No-Code AI Automation training covers n8n in depth with real business workflow templates.

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