AI agent development · fixed price bands · 2026

AI agents built for production , not for the demo

  • Chatbot / automationEUR 2.7-8.3k · 4-6 weeks
  • RAG knowledge baseEUR 8.3-22k · 2-4 months
  • Custom AI solutionEUR 13.8-41.3k · 3-9 months

We build an agent when the number of steps cannot be predicted in advance. When it can, we write a workflow, because that is cheaper and more stable. The bands from our published price list: chatbot and process automation EUR 2,750-8,250 in 4-6 weeks, RAG knowledge base EUR 8,250-22,000 in 2-4 months, custom AI solution EUR 13,800-41,300 in 3-9 months. Every build ships with an eval harness, an enforced cost ceiling and human approval points. Delivered from Budapest in CET, on EU infrastructure.

Five things worth knowing

  • Three price bands from the published list: chatbot and process automation EUR 2,750-8,250 (4-6 weeks), RAG knowledge base EUR 8,250-22,000 (2-4 months), custom AI solution EUR 13,800-41,300 (3-9 months). Maintenance EUR 83-413 per month.
  • Running cost is driven by the number of loops, not by the model list price. The same 1,000 documents cost USD 8.70 with a single extraction call and USD 232 with an eight-step agent loop on the same Claude Sonnet 5 model (our own modelling on Anthropic official pricing, 2026-08-14).
  • MIT Project NANDA found in summer 2025 that 95% of enterprise generative AI pilots produced no measurable P&L impact. The same study: an internal expert combined with an external partner reached a 67% success rate, internal IT alone 22%.
  • Gartner predicted on 25 June 2025 that more than 40% of agentic AI projects will be cancelled by the end of 2027, typically over cost, unclear business value or missing risk controls.
  • EU AI Act Article 50 transparency duties apply from 2 August 2026. If your agent talks to a natural person, that must be disclosed. This is immediate, not part of the package delayed to 2027.

What we mean by an AI agent

An AI agent is a program that receives a goal rather than a script. It decides at runtime which tool to call in which order and when to stop. A chatbot produces an answer in one step, a workflow runs a pre-written sequence, an agent plans for itself. That distinction is also the cost and the risk distinction.

DimensionChatbotWorkflow (n8n, Make, Zapier)AI agent
What the system decidesthe wording of the answernothing, the sequence is codedthe order of steps and when to stop
Steps per run1fixed, budgetablevariable, typically 8-20
When it is the right choicerepeat questions, one knowledge baseprocess steps are known upfrontstep count cannot be predicted
Main riskwrong or unsourced answerper-step pricing runs awayloop count and spend run away
AppForge bandEUR 2.7-8.3kEUR 0.3-6.9k per workflowEUR 8.3-41.3k

Anthropic's own engineering guidance (Building Effective Agents, 2024-12-19) states that a pre-coded workflow beats an autonomous agent for most tasks. That is our default position too. In roughly half of our scoping calls we end up proposing a much cheaper workflow instead of an agent. The three layers are compared in detail in our chatbot, n8n and custom agent article, and the conceptual background to ReAct and tool use is in AI agents fundamentals.

Which agents we deliver

Four types reach production with us: document processing, customer service, internal knowledge base and process orchestration. Each has its own price band, its own lead time and its own risk profile. Three of the four start with a pilot, because that is where you find out whether the underlying data is good enough.

Agent typeWhat it doesPriceTimeline
Document processing agentReads, validates and posts incoming invoices, delivery notes, contracts and receipts. Wherever a structured source of truth exists (e-invoicing feed, EDI, supplier portal), we use it first and reserve image recognition for the remainder.EUR 6,900-27,5001-2 week pilot, then iterative rollout
Customer service agentHandles first-line requests with cited sources, looks up order and invoice data, escalates with a written summary. The AI Act Article 50 disclosure ships as part of the reply.EUR 2,750-8,2504-6 weeks
Internal knowledge base (RAG)Policies, technical documentation, contracts and minutes behind one search surface, with per-user permissions and cited passages. Hybrid search plus a reranker, not a bare embedding index.EUR 8,250-22,0002-4 months
Process orchestratorRuns a process across several systems: purchase request, approval, ERP posting, reporting. Several agents work here, each with its own tool set and its own permissions.EUR 13,800-41,3003-9 months

Structured data first, OCR second

Reading pixels is the expensive and error-prone path. Where a structured feed already exists, we treat it as ground truth and reconcile the document against it. We built exactly this for the Hungarian market against the NAV Online Invoice 3.0 interface, whose digest and data queries are designed for booking incoming invoices. The same pattern transfers to any e-invoicing or EDI feed a German or Austrian client already runs.

A number we will actually commit to

Data entry accounts for 30-35% of total invoice processing cost and exception handling for another 20-25% (IOFM figures, cited in the Lido benchmark compilation of 22 July 2026). So AI addresses roughly half the cost, not all of it. Vendors claim 85-92% touchless processing while independent benchmarks report 25-35%. For a mid-sized company with a mixed supplier base, 55-75% in year one is the defensible commitment.

For the knowledge base agent the boundary matters: RAG handles search and answers, while the document agent extracts structured values. The two often live in one project but are measured differently. The engineering side of writing back into ERP, CRM or WMS is covered on our system integration page.

How a production agent is put together

Seven layers: orchestration, tool layer, integration, permissions, cost ceiling, human approval and fallback. The difference between a demo and a production system is precisely the last six. Very few vendors publish an actual architecture, so here is ours in full.

LayerWhat it solves
OrchestrationLangGraph (1.0 GA on 2025-10-22): explicit graph control, durable checkpoints, retries and rollback. If the sequence of steps is predictable we write a workflow instead of an agent, because it is cheaper and more stable.
Tool layerNative tool calling with schema-constrained output. The original ReAct pattern extracted actions from free text with regular expressions, so any formatting slip became a runtime error. Structured tool calls remove that failure mode.
IntegrationAn MCP server or an API adapter towards ERP, CRM, WMS and banking systems. Service Layer and DI API for SAP Business One, REST or OData elsewhere. Where no API exists, a read replica or a file-based channel. Idempotency keys, rate limits and exponential retry throughout.
PermissionsTool allowlist, least privilege behind the tool (read-only database user, tenant scope) and identity binding, so the tool call runs as the end user rather than as one service account with access to everything.
Cost ceilingA run-scoped token and euro limit enforced by the platform. A monthly budget cap is not protection, because it triggers after the month is totalled and the runaway run has already finished. On top of that: maximum iteration count, subagent depth, per-step timeouts and model routing, with the cheap model handling routine steps.
Human approvalLangGraph interrupt() and Command(resume) with a durable checkpointer: the graph stops, state is persisted, and approval can resume it a day later. At protocol level the MCP 2026-07-28 specification does the same through its input_required response.
FallbackIf the model is unavailable or confidence stays below threshold, the task goes to a human queue instead of guessing. Every step is replayable from the checkpoint, and the replaced process keeps running in parallel for 30 to 60 days after go-live.

What we do not gloss over about integration

MCP is convenient and it is also attack surface. The MCPTox benchmark reports that instructions hidden in tool metadata are both common and high impact, and that most examined clients perform insufficient static validation. Unauthenticated MCP Inspector instances allowed arbitrary command execution (CVE-2025-49596, CVSS 9.4). So every MCP server we run sits on an allowlist, outbound network traffic is restricted, and tools with write access live in a separate agent that never sees untrusted content. That is the architectural break-up of what Simon Willison described on 16 June 2025 as the lethal trifecta: private data, untrusted content and an outbound channel in one place.

One engineering detail that saves real money: when the agent writes code that filters intermediate data in a sandbox instead of making separate tool calls, context collapses. In Anthropic's measured example (4 November 2025) a Drive to Salesforce copy task went from 150,000 tokens to 2,000. It does not apply to every task, but for steps that move large data sets we use it.

How you know the agent actually works

Through a golden dataset and an eval harness. The golden dataset is 100-300 hand-annotated real cases from your own material, each with the correct output. Every prompt, model and schema change runs against it, and in CI that run is a gate. A regression does not ship. Without it the system cannot be maintained, only hoped about.

  • Retrieval quality, with numbers

    In Anthropic's measurement a plain embedding index gave a 5.7% retrieval failure rate, contextual embeddings 3.7%, adding lexical search 2.9%, and reranking 1.9% (Contextual Retrieval, 19 September 2024). That is why hybrid search and a reranker are standard equipment in our builds rather than an upsell.

  • Language-specific measurement

    Global embedding leaderboards do not predict domain performance in a morphologically rich language. For Hungarian there is no maintained public retrieval benchmark as of August 2026, and the most recent independent test (Harang, 9 January 2025, 2,132 sentence pairs) found substantial overlap between the similarity distributions of related and unrelated pairs. German compound nouns create a related problem for lexical search. In both cases a project-specific eval set is mandatory, not optional.

  • Deterministic validation after the model

    For documents: arithmetic reconciliation (net plus VAT equals gross, line items sum to the total), format checks on VAT numbers, IBANs and dates, and cross-checking on critical fields. The most dangerous vision-model failure is a value that is formally perfect and factually wrong, which no reviewer catches by eye.

  • Observability, at published prices

    Langfuse self-hosted USD 0 licence (MIT), Langfuse Core USD 29 per month, LangSmith Plus USD 39 per seat per month, Braintrust Pro USD 249 per month (vendor price pages, 2026-08-14). Our default is self-hosted Langfuse inside the EU. The comparison is in our LangFuse and LangSmith article.

Most proposals skip this section, and not by accident. The eval harness is the least impressive part of the project and the most expensive one to retrofit: building it later costs the same as building it upfront, except the system is already making mistakes on live data while you do.

Where the data goes, and what leaves your estate

EU-region endpoints by default, with the data processing agreement part of the project. We never route client data through free API tiers. Where data cannot leave the building, the whole chain runs on premise: both the document parsing and the model stay on your hardware.

DataWhere it goesControl
Structured invoice header datae-invoicing or EDI feed querynever reaches a model
Scanned attachments, receiptsEU-region model endpoint or on-premise parserzero data retention option, ephemeral upload
Personal data (CVs, health records)on premise or pseudonymisedhuman decision point under GDPR Article 22
System prompt, tool definitionsat the model providerwhich is why they hold no secrets or permissions
Embedded document chunkspgvector on your existing Postgresstays inside your own infrastructure

Two specifics that shape the vendor decision. On the Gemini API free tier Google states that content is used for product improvement, which rules it out for client data. Anthropic states that uploaded images are not used for model training, that uploads are ephemeral, and that a zero data retention option is available for PDF processing. For a fully closed setup and self-hosted open-weights models, see our article on local AI deployment and the GDPR-compliant chatbot with EU hosting page.

What the EU AI Act and GDPR require

AI Act Article 50 transparency applies from 2 August 2026: if the agent interacts with a natural person, that person must be informed they are dealing with an AI, and synthetic output must be marked in a machine-readable way. High-risk deadlines moved, which gives you planning room but not an exemption.

  • · The Digital Omnibus on AI regulation ((EU) 2026/1744) was published on 24 July 2026 and entered into force on 27 July.
  • · Annex III high-risk systems now have a compliance deadline of 2 December 2027. Annex I systems embedded in regulated products: 2 August 2028.
  • · GDPR Article 22 requires the right to obtain human intervention, to express a point of view and to contest a decision that is based solely on automated processing and produces legal effects.
  • · In practice: invoice coding can be fully automated, while CV screening (Annex III 4a), credit assessment (5b) and claims decisions need a human decision point.

The disclosure, the audit log and the approval hooks are part of the build, not a later bolt-on. For classification, risk assessment and Annex IV technical documentation as a fixed-price package, see our EU AI Act compliance page.

What it costs, and what you pay monthly

Delivery runs between EUR 2,750 and EUR 41,300 depending on type, with maintenance between EUR 83 and EUR 413 per month. Raw model spend is small next to that: 500 conversations a month costs between 470 and 9,900 HUF (roughly EUR 1.30 to EUR 27) depending on model choice. Most of the monthly fee is human work, not tokens.

PackagePrice (project, net)TimelineWhat is included
Chatbot / process automationEUR 2,750-8,2504-6 weekschatbot on one knowledge base, n8n automation, basic integrations, monitoring dashboard, 1 month of support
RAG knowledge base systemEUR 8,250-22,0002-4 monthscompany document ingestion, vector search, user-level access control, admin dashboard, cloud or local model, source citations
Custom AI solutionEUR 13,800-41,3003-9 monthsmodel fine-tuning, LangGraph agents, local LLM deployment, predictive analytics, GDPR and data sovereignty
Process automation, per workflowEUR 275-27,5001-2 week pilot, ROI 3-9 monthssimple 1-3 step flow EUR 275-1,380, multi-system integration with error handling EUR 1,380-6,900, AI-driven complex automation EUR 6,900-27,500
MaintenanceEUR 83-413 / monthongoingprompt and model updates with regression runs, exception handling, monitoring

Bands come from the AppForge published price list (updated 2026-08-14), converted at the Hungarian National Bank mid-rate of 1 EUR = 363.28 HUF on 2026-08-14. All figures net; Hungarian VAT of 27% may apply depending on customer country and B2B reverse-charge rules. We invoice EU clients in EUR. Fixed price after a 30-minute scoping call, quote within 24 hours.

On the rate side: Musketeers Tech (2 April 2026) puts Western European AI engineering at USD 100-180 per hour and Central and Eastern Europe at USD 50-100. We found no DACH-specific published rate survey for 2026, so treat the Western European figure as a proxy rather than a quote. We do not publish hourly rates ourselves, because every engagement is scoped as a fixed-range project. The full price list is on our pricing page, the payback maths with your own numbers is in the AI ROI calculator, and the nearshore case for a German or Austrian buyer is set out on the nearshore development page.

How a project runs, week by week

A RAG agent in the EUR 8,250-22,000 band typically takes 12 weeks, and the system has no write access until halfway through. That is deliberate. The most common failure mode is not the model: it is granting production permissions before anyone has measured how accurate the thing is.

  1. Week 0: scoping call

    30 minutes, free, in CET. Output: which process, measured on which number, who owns it on your side. If the process itself is broken, we say so instead of selling AI on top of it.

  2. Weeks 1-2: discovery and golden dataset

    We collect 100-300 real cases with their correct output. That becomes the benchmark for the rest of the project. Success gets a number here, not at the closing demo.

  3. Weeks 3-4: tool layer and integration

    Read access to ERP, CRM or the document management system, the permission model, an MCP server or API adapter, idempotency and error handling. No write access yet.

  4. Weeks 5-8: agent loop, guardrails, eval harness

    Planning separated from execution, cost ceiling, human approval points, tracing. The golden dataset moves into CI as a gate.

  5. Weeks 9-10: shadow run

    The agent runs on live data but does not write. A daily variance report against the human decision shows where another approval point is needed.

  6. Weeks 11-12: go-live on a narrow scope

    One supplier group, one customer type, one process. Expansion follows the measurements. Handover includes source code and runbook documentation.

In the chatbot band this compresses to 4-6 weeks; for a process orchestrator it stretches to 3-9 months. Working in CET means the review loop closes the same day for a Munich, Vienna or Zurich team rather than overnight. The full automation service description is on our process automation page.

Let us look at one concrete process

The scoping call is not a pitch. We walk through one process: how many cases per month, who handles it now, where it stalls. If there is no business case in it, we say so. Call +36 30 098 0767, write to balint@appforge.hu, or visit us in person. We work in Hungarian, English and German.

Budapest office: Bank Center, Szabadsag ter 7., 2nd floor, office 217, 1054 Budapest, Hungary · Mon-Fri 9:00-18:00 by appointment.
GYIK

AI agent development: frequently asked questions

Our published price list has three bands. Chatbot and process automation 1,000,000 – 3,000,000 HUF (roughly EUR 2,750 – 8,250), 4-6 weeks. RAG knowledge base system 3,000,000 – 8,000,000 HUF (EUR 8,250 – 22,000), 2-4 months. Custom AI solution with LangGraph agents, fine-tuning and local LLM deployment 5,000,000 – 15,000,000 HUF (EUR 13,800 – 41,300), 3-9 months. Workflow-style process automation is priced per workflow: 100,000 – 10,000,000 HUF, where a simple 1-3 step flow is 100,000 – 500,000 HUF, a multi-system integration with error handling 500,000 – 2,500,000 HUF, and AI-driven complex automation (invoice OCR, AI classification, approval flow) 2,500,000 – 10,000,000 HUF. Maintenance 30,000 – 150,000 HUF per month. We invoice EU clients in EUR at the Hungarian National Bank mid-rate. Fixed price after a 30-minute scoping call, quote within 24 hours.

Do you even need an agent? Thirty minutes will tell

After the scoping call you get a concrete price and timeline, and an honest answer if a cheaper workflow does the same job.

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