What is Azure AI Foundry Agent Service and how is it different from Azure OpenAI Service?
Azure AI Foundry is the unified platform that replaces the standalone Azure OpenAI Service portal experience. The Foundry Agent Service is the agent-runtime capability inside AI Foundry — a code-first, server-managed runtime that handles agent lifecycle, thread state, parallel tool calling, run scheduling, evaluation, and observability. Azure OpenAI Service models (GPT-4o, GPT-4.1, o-series, GPT-5-class) are still the underlying model layer; Foundry adds the agent runtime, the unified Foundry catalog (open-weight models alongside Azure OpenAI), the evaluation harness, the responsible AI tooling, and project-level governance. Customers using the legacy Azure OpenAI standalone portal are migrating to Foundry projects as Microsoft consolidates the experience. The model endpoints remain Azure OpenAI; the developer surface is now Foundry.
How do I migrate from the Azure OpenAI Assistants API to the Foundry Agent Service?
Foundry Agent Service maintains a compatible API contract with the Azure OpenAI Assistants API — threads, runs, messages, and steps remain first-class objects with the same semantics, and the SDK call shapes are nearly identical. A typical migration is three steps. First, point the SDK base URL at the Foundry project endpoint and update the authentication to use Azure RBAC against the Foundry project (rather than Azure OpenAI resource RBAC). Second, recreate agents in the Foundry project — the create-agent payload accepts the same model, instructions, and tool list with minor schema additions for Foundry-specific features like knowledge sources and connector tools. Third, migrate any existing thread state if continuity matters; new threads typically just flow into the Foundry runtime. EPC Group has run this migration across customers with multi-agent Assistants-API deployments in 2025 and ships the migration plan as part of the Phase 1 Foundry Accelerator deliverable.
When should I use Azure AI Foundry Agent Service versus Microsoft Copilot Studio?
Use Foundry Agent Service when the build team is code-first (Python, .NET, JavaScript developers), when the agent will run inside a custom application or product rather than inside Microsoft 365 surfaces, when fine-grained control over the model call (model, temperature, function-calling shape, streaming, reasoning-budget) is required, when the integration surface is dominated by non-Microsoft systems or by APIs that need OpenAPI-tool import, when token-level cost optimization and PTU reservation matter, or when multi-agent orchestration patterns (planner-executor, supervisor-with-specialists) require explicit programmatic control. Use Microsoft Copilot Studio (see /microsoft-copilot-studio-agents-enterprise-2026) when the build team is low-code, when the agent lives primarily inside Teams, Microsoft 365 Copilot, or web chat, and when out-of-the-box Purview governance is preferred over custom controls. Many enterprises run both — Foundry for the product-grade and custom-application agents, Copilot Studio for the Microsoft-surface departmental agents.
What is the cost model for Foundry Agent Service — PTU versus pay-as-you-go?
Foundry Agent Service runtime is billed on the underlying model and tool surface. Model calls follow Azure OpenAI pricing — Provisioned Throughput Units (PTU) for reserved capacity with predictable latency and a monthly or annual reservation discount, or pay-as-you-go (PAYG) per input and output token for variable workloads. Code Interpreter sandbox sessions are billed per session-hour. File Search vector-store storage is billed per gigabyte-month, and ingest is billed per token embedded. Function tools execute in the customer Azure subscription (Functions, Container Apps, AKS) and bill against those services directly. Defender for Cloud AI workload protection has its own SKU. EPC Group sizes the capacity model in Phase 1 using projected run volume, average tool-call count per run, model mix, and channel-mix to recommend a PTU-plus-PAYG hybrid that minimizes idle reservation cost while protecting latency for the primary user-facing workload.
How does multi-agent orchestration work in Foundry Agent Service?
Foundry supports multi-agent orchestration through three composable patterns. The handoff pattern uses a triage agent that classifies the incoming request and transfers thread ownership to a specialist child agent. The supervisor pattern keeps a parent agent in conversational control and uses function tools (each tool wraps a child agent invocation) to delegate discrete subtasks; the parent reasons over the consolidated result. The planner-executor pattern uses a reasoning model to produce a structured multi-step plan and a faster executor model to run each step, with a final reasoning pass over the consolidated output. Foundry exposes these patterns through SDK primitives rather than a no-code orchestrator, which gives developers explicit control over the cost-versus-quality trade-offs at every step. EPC Group selects the pattern per agent in the Phase 2 Design deliverable based on subdomain separability, response composition needs, and token cost profile.
How does Foundry handle responsible AI, content safety, and prompt injection defense?
Foundry agents run inside the Azure responsible AI layer with multiple defenses. Azure AI Content Safety runs pre-call and post-call moderation for jailbreak attempts, protected material detection, groundedness violations, PII surfacing, and harmful content across six harm categories — each with severity thresholds the build team tunes per use case. Defender for Cloud AI workload protection monitors the Foundry project for prompt injection, model theft attempts, sensitive-data exposure, and adversarial input patterns, and routes alerts into Microsoft Defender XDR and Sentinel. Customer-managed abuse monitoring lets enterprises opt out of human review of stored prompts for highly regulated workloads. Purview audit covers Microsoft 365 content access through Foundry knowledge sources. The combined layer is the production-grade equivalent of what Copilot Studio bundles in low-code — but exposed to developers for explicit configuration and tunable thresholds.
Can I deploy Foundry agents in HIPAA, FedRAMP, FINRA, or CMMC environments?
Yes. Azure AI Foundry and the Foundry Agent Service are covered by the Microsoft Business Associate Agreement (BAA) for HIPAA, are on the FedRAMP High path inside Azure Government, support FINRA-aligned audit through Purview and customer-managed retention, and align to CMMC 2.0 Level 2 boundary controls inside Azure Government for the defense industrial base. The compliance posture is anchored on the customer-chosen Foundry project region, data residency commitments, abuse-monitoring opt-out, and the broader Azure platform compliance baseline. EPC Group runs the Phase 4 governance hardening against the customer regulatory profile, produces the auditor evidence package mapped to the relevant control framework, and cross-links to HIPAA, SOC 2, FedRAMP, FINRA, CMMC, GxP as documented in the standards alignment map.
What does an EPC Group Foundry Agent engagement cost and how long does it take?
EPC Group Foundry Agent engagements are fixed-fee, ranging from $200K to $700K for a first agent depending on complexity, multi-agent orchestration scope, knowledge-source breadth, and evaluation-suite depth. Typical timeline is 10 to 18 weeks across the five-phase accelerator (Assess, Design, Build + Ground, Governance Harden, Operate), with managed Foundry agent services available on a quarterly or annual basis once production is live. The first agent is the most expensive because the platform baseline (Foundry project provisioning, Defender for Cloud AI enablement, Content Safety tuning, evaluation-harness wiring, observability plumbing) is set up once and reused. Subsequent agents land at 40 to 60 percent of first-agent cost. EPC Group is a 29-year Microsoft Solutions Partner with senior-architect-led delivery across 70+ Fortune 500 clients and 11,000+ engagements; the Foundry Accelerator is the standard delivery vehicle for code-first agent programs.