Microsoft Agent Framework Multi-Agent Workflow Architecture for Automated Kubernetes Assessments
Why this system generates tests (design rationale) This project does not generate tests just to "check code." It generates tests because, in a Kubernetes learning game, the test suite is the grading contract. The design goals are: Scale content creation: instructors should not hand-author every task and checker. Keep grading objective: student success is measured against Kubernetes API state, not subjective review. Avoid fragile tasks: generated tasks must survive empty/wrong cluster states without crashing. Make failures repairable: when checks break, the system should patch and re-validate automatically. So the pipeline generates a full task package (setup, answer, check, cleanup) where tests define exactly what "correct" means. Lifecycle: from concept to production-ready grader Reader mental model: this is a content compiler with validation stages, not a single chat completion. Phase 1: Pedagogical intent -> structured concept The Idea Agent converts a topic into a constrained concept object (objective, progression, task IDs, difficulty variants). Memory rules block duplicates and previously failed concepts. Phase 2: Concept -> executable grading package The Generator Agent turns that concept into files: student instructions (instruction.md) learning material (concept.md) parameter source (session.json) setup and answer manifests (setup.template.yaml, answer.template.yaml) deterministic pytest flow (test_01 ... test_06) At this point, output is still untrusted draft content. Phase 3: Structural correctness gate Deterministic validation checks file presence, syntax, JSON/YAML shape, and template correctness. This catches basic integrity issues before cluster execution. Phase 4: Behavioral correctness gate (real cluster) Pytest executes against Kubernetes and verifies runtime behavior using real kubectl-derived state. This proves that generated checks actually evaluate cluster resources as intended. Phase 5: Anti-false-positive gate (skip-answer mode) The same suite runs with SKIP_ANSWER_TESTS=True to verify grader integrity: answer deployment is skipped test_05_check.py must fail If it still passes, the grader is invalid (it would accept wrong student submissions). Phase 6: Self-healing repair loop On any failure, deterministic error logs are fed into the Fixer Agent, which patches only broken files. The workflow then re-enters validation + test gates. Phase 7: Finalization If all gates pass -> task is kept as production-ready content. If retries are exhausted -> task is moved to unsuccessful/ with FAILURE_REPORT.txt for human triage. This lifecycle explains the core architecture decision: LLMs generate candidate graders, deterministic execution certifies them. Concrete generated sample (what the pipeline actually produces) Below is a representative generated task for topic: ConfigMap Environment Variable Injection. Generated directory layout tests/game01/050_configmap_env_injection/ ├── __init__.py ├── instruction.md ├── concept.md ├── session.json ├── setup.template.yaml ├── answer.template.yaml ├── test_01_setup.py ├── test_02_ready.py ├── test_03_answer.py ├── test_05_check.py └── test_06_cleanup.py session.json (runtime variables) { "namespace": "{{random_name()}}{{random_number(100,999)}}{{student_id()}}", "configmap_name": "{{random_name()}}", "deployment_name": "{{random_name()}}", "container_name": "app", "env_key": "APP_MODE", "env_value": "production" } Why this exists: task values are randomized per student/session, so tests verify behavior by variable contract instead of hardcoded names. setup.template.yaml (baseline state only) apiVersion: v1 kind: Namespace metadata: name: {{ namespace }} Why this exists: setup should create prerequisites only. It must not accidentally include the final answer. answer.template.yaml (expected correct solution) apiVersion: v1 kind: ConfigMap metadata: name: {{ configmap_name }} namespace: {{ namespace }} data: {{ env_key }}: "{{ env_value }}" --- apiVersion: apps/v1 kind: Deployment metadata: name: {{ deployment_name }} namespace: {{ namespace }} spec: replicas: 1 selector: matchLabels: app: env-demo template: metadata: labels: app: env-demo spec: containers: - name: {{ container_name }} image: nginx:latest env: - name: {{ env_key }} valueFrom: configMapKeyRef: name: {{ configmap_name }} key: {{ env_key }} Why this exists: defines canonical "correct cluster state" that graders must detect. test_02_ready.py (wait for setup resources) import json import time from tests.helper.kubectrl_helper import build_kube_config, run_kubectl_command class TestReady: def test_001_namespace_active(self, json_input): kube_config = build_kube_config( json_input["cert_file"], json_input["key_file"], json_input["host"] ) time.sleep(2) result = run_kubectl_command( kube_config, f"kubectl get namespace {json_input['namespace']} -o json", ) data = json.loads(result) assert data.get("status", {}).get("phase") == "Active" Why this matters: validates setup-stage readiness only. It should not check answer resources yet. test_05_check.py (student grading contract) import json from tests.helper.kubectrl_helper import build_kube_config, run_kubectl_command class TestCheck: def test_001_configmap_key_exists(self, json_input): kube_config = build_kube_config( json_input["cert_file"], json_input["key_file"], json_input["host"] ) result = run_kubectl_command( kube_config, f"kubectl get configmap {json_input['configmap_name']} -n {json_input['namespace']} -o json", ) data = json.loads(result) assert data["data"][json_input["env_key"]] == json_input["env_value"] def test_002_deployment_uses_configmap_env(self, json_input): kube_config = build_kube_config( json_input["cert_file"], json_input["key_file"], json_input["host"] ) result = run_kubectl_command( kube_config, f"kubectl get deployment {json_input['deployment_name']} -n {json_input['namespace']} -o json", ) data = json.loads(result) env = data["spec"]["template"]["spec"]["containers"][0].get("env", []) matched = [ e for e in env if e.get("name") == json_input["env_key"] and e.get("valueFrom", {}).get("configMapKeyRef", {}).get("name") == json_input["configmap_name"] and e.get("valueFrom", {}).get("configMapKeyRef", {}).get("key") == json_input["env_key"] ] assert matched, "Deployment container must consume env var from ConfigMap key" Why this matters: this is the real grading logic. If a student deploys wrong resource wiring, this test fails with explicit reason. Why skip-answer validation is essential for this sample When SKIP_ANSWER_TESTS=True, answer deployment is skipped. In this mode: test_03_answer.py should be skipped test_05_check.py must fail (ConfigMap/Deployment wiring is absent) If test_05_check.py still passes, the grader is broken (false positive), and the workflow routes to Fixer. Rule Builder Workflow Flowchart Multi-graph architecture views 1) Control-plane graph (orchestration DAG) 2) Runtime sequence (who calls what) 3) State machine (task lifecycle) 4) Prompt lifecycle graph (how prompts evolve) 5) MCP + Kubernetes execution boundary graph Core Agent Framework Primitives Used This repository is a practical example of Agent Framework as a graph orchestrator, not just an agent wrapper. WorkflowBuilder builds a typed DAG with explicit edges. @executor functions implement deterministic nodes (validation, pytest, decisions, routing prep). AgentExecutor wraps LLM agents so they behave as graph nodes. WorkflowContext shared state carries typed data and retry metadata between nodes. add_multi_selection_edge_group(...) + selector functions enforce conditional routing. MCPStdioTool connects filesystem MCP tools into agents for controlled file I/O. Production graph construction (from workflow/builder.py) looks like this: workflow = ( WorkflowBuilder(start_executor=initialize_retry) .add_edge(initialize_retry, generator_executor) .add_edge(generator_executor, parse_generated_task) .add_edge(parse_generated_task, run_validation) .add_edge(run_validation, run_pytest) .add_edge(run_pytest, make_decision) .add_multi_selection_edge_group( make_decision, [keep_task, remove_task], selection_func=select_action, ) .add_edge(keep_task, run_pytest_skip_answer) .add_multi_selection_edge_group( run_pytest_skip_answer, [check_loop, complete_workflow], selection_func=select_skip_answer_action, ) .add_multi_selection_edge_group( check_loop, [fix_task, complete_workflow], selection_func=select_loop_action, ) .add_edge(fix_task, fixer_executor) .add_edge(fixer_executor, parse_generated_task) .build() ) This is the architectural heart of the system: agents and deterministic executors are first-class nodes in the same graph. Detailed Node-by-Node Mechanics 1. Idea Agent (🧠): Concept Synthesis with Memory Constraints The Idea Agent (agents/k8s_task_idea_agent.py) generates a structured concept with three difficulty variations (BEGINNER/INTERMEDIATE/ADVANCED). It is memory-aware: task_ideas_memory.json tracks successful concepts. task_ideas_failure_memory.json tracks concepts that failed downstream. Memory constraints are injected using AgentMiddleware (system-level prompt injection) to avoid duplicate or previously failed concepts. For Responses-only models, the agent switches to a tool-call contract (save_k8s_task_concept) instead of structured response formatting. 2. Generator Agent (⚙️): MCP-Backed File Authoring The Generator Agent receives a strict prompt and writes task files through MCP filesystem tools. Key framework details: Built through chat_client.as_agent(...). MCP tool attached via tools=mcp_tool. Function-call execution observability added with LoggingFunctionMiddleware. Uses absolute-path-only policy in instructions to prevent path drift. 3. Deterministic Validation + Test (✅): Non-LLM Gates After generation, the graph moves through deterministic executors: run_validation calls pure Python checks (k8s_task_validator). run_pytest executes pytest --import-mode=importlib --rootdir=. .... Raw pytest output is persisted in workflow state for later fixing. This is critical: no LLM is asked whether code is correct. 4. Skip-Answer Test (🧪): Grader Correctness Gate Even if standard tests pass, the workflow enforces a second tier: SKIP_ANSWER_TESTS=True pytest --import-mode=importlib --rootdir=. Implementation detail: the executor writes JUnit XML, parses it, and asserts that: test_03_answer.py is skipped test_05_check.py fails as expected If test_05_check.py does not fail, the task is treated as invalid and sent back to retry/fix. 5. Fixer Agent + Retry Loop (🔧): Bounded Self-Healing On failure, fix_task builds a targeted prompt containing: failure reasons from deterministic nodes full captured pytest output explicit rule to patch only broken files in place The Fixer Agent runs through AgentExecutor, writes patches via MCP, and the graph loops back to parse_generated_task. Retries are stateful (retry_count, max_retries) and hard-bounded. On exhaustion, complete_workflow moves the task to unsuccessful/<game>/ and writes FAILURE_REPORT.txt. Agent Prompt Design (The Part That Makes It Work) If you want to understand why this pipeline works, you need to inspect prompts as operational contracts, not generic instructions. Real Idea Agent Prompt (from code) IDEA_AGENT_INSTRUCTIONS = ( "You are a Kubernetes task idea generator that creates detailed task concepts with three difficulty variations. " "Read official K8s documentation and propose comprehensive learning concepts for a Kubernetes game. " "\n\nYour task:\n" "1. Choose ONE Kubernetes concept not yet covered (check context for existing concepts)\n" "2. Generate exactly 3 variations: BEGINNER, INTERMEDIATE, and ADVANCED\n" "3. Use 3-digit task IDs (001-999) in format: XXX_concept_name_level (e.g., 041_secrets_basic)\n" "4. Each variation should build on the previous one with increasing complexity\n" "5. Include practical, hands-on scenarios covering: Workloads, Services, Storage, Configuration, Security, Scheduling, Policies\n" "\nProvide the concept, tags, description, and 3 variations with task_id, difficulty, title, objective, key_skills, and estimated_time." ) Responses-only models use a stricter tool-call version: IDEA_AGENT_INSTRUCTIONS_TOOL_CALL = ( IDEA_AGENT_INSTRUCTIONS + "\n\n" "**CRITICAL**: You MUST call the save_k8s_task_concept tool to save your generated concept.\n" "...\n" "Always call save_k8s_task_concept with your generated concept." ) Idea Agent Prompt Contract The Idea Agent prompt enforces: one concept per run exactly three difficulty variations strict task ID format (XXX_concept_name_level) practical skill progression Core pattern: You are a Kubernetes task idea generator... 1. Choose ONE Kubernetes concept not yet covered 2. Generate exactly 3 variations: BEGINNER, INTERMEDIATE, ADVANCED 3. Use 3-digit task IDs in format XXX_concept_name_level ... It is strengthened by runtime memory injection: previously generated concepts are blocked previously failed concepts are blocked For Responses-only models, the contract becomes tool-driven: CRITICAL: You MUST call the save_k8s_task_concept tool... This reduces ambiguity in output structure and makes downstream parsing deterministic. Real Generator Agent Prompt (from code) def _get_generator_instructions(): return ( "You are a Kubernetes task generator with filesystem tools.\n" f"The MCP filesystem is rooted at: {PATHS.tests_root.parent}\n" f"You MUST use ABSOLUTE paths for ALL file operations.\n" f"Task directory: {PATHS.game_root}/XXX_task_name/\n" "...\n" "CRITICAL: test_02_ready.py checks resources from setup.template.yaml, NOT answer.template.yaml.\n" "...\n" "MUST use polling loops (60s timeout, 15s interval)\n" "MUST use try/except and safe .get() JSON access\n" ) The generator prompt is long on purpose: it encodes path correctness, file schema, YAML/Jinja structure, and testing strategy in a single deterministic contract. Generator Agent Prompt Contract The Generator prompt is intentionally long and prescriptive because it defines filesystem safety and grading correctness requirements. Key constraints encoded in the prompt: Absolute path writes only (prevents writing to wrong workspace paths) No directory creation (directory is pre-created by executor) Required file set (instruction.md, concept.md, session.json, templates, tests) test-flow invariants: test_01_setup.py deploys setup test_02_ready.py checks setup resources only test_03_answer.py deploys answer test_05_check.py validates final solution robust test coding style: polling loops, try/except, .get()-based JSON parsing, explicit debug output Example contract fragment: CRITICAL PATH RULES: ✅ CORRECT: /abs/path/tests/gameXX/050_task/file.py ❌ WRONG: tests/gameXX/050_task/file.py (relative) CRITICAL: test_02_ready.py checks resources from setup.template.yaml, NOT answer.template.yaml. This is why generation quality is high before the Fixer loop even starts. Real Runtime Retry Prompt Builder (from code) def _build_retry_generation_prompt(combined: CombinedValidationResult) -> str: task_id = combined.test.task_id failure_reasons = _build_failure_reasons(combined) return ( f"Generate a complete Kubernetes learning task with ID '{task_id}' about '{combined.target_topic}'. " f"This is retry attempt {combined.retry_count + 1} of {combined.max_retries}. " f"\n\n⚠️ PREVIOUS ATTEMPT FAILED:" f"\n{chr(10).join([f' - {reason}' for reason in failure_reasons])}" f"\n\nIMPORTANT: You MUST use the exact task ID '{task_id}' - do not generate a new ID." f"\n\n✅ Directory already exists: {PATHS.game_root}/{task_id}/" f"\nWrite all files directly into this directory. Do NOT call create_directory." "..." ) This means retries are not generic retries; they are failure-conditioned retries with precise constraints. Fixer Agent Prompt Contract The Fixer prompt is a repair protocol, not a regeneration prompt. It includes: exact failure reasons from deterministic validators raw pytest output instruction to read current task files first strict directive to patch only broken files Core behavior constraints: DO NOT rewrite all files. Make TARGETED FIXES to ONLY the broken files. Use ABSOLUTE paths for all file operations. This keeps retries cheap, preserves working artifacts, and improves convergence speed. Real Runtime Fix Prompt Builder (from code) def _build_fix_prompt(combined: CombinedValidationResult, raw_test_output: str) -> str: task_id = combined.test.task_id failure_reasons = _build_failure_reasons(combined) prompt = ( f"Fix the failed Kubernetes task '{task_id}' located in '{PATHS.game_root}/{task_id}/'." f"\n\nThis is fix attempt {combined.retry_count + 1} of {combined.max_retries}." f"\n\n⚠️ TASK FAILED WITH THESE ERRORS:" f"\n{chr(10).join([f' - {reason}' for reason in failure_reasons])}" ) if raw_test_output: prompt += f"\n\n📋 FULL TEST OUTPUT:\n```\n{raw_test_output}\n```" prompt += ( f"\n\n🔍 YOUR TASK:" f"\n1. READ all files from '{PATHS.game_root}/{task_id}/'" f"\n6. Make TARGETED FIXES to ONLY the broken files" f"\n7. WRITE ONLY the fixed files back" f"\n\n⚠️ CRITICAL: DO NOT rewrite all files! Only fix the broken ones!" ) return prompt How Prompt Output Enters the Agent Framework Graph The prompt builders above are used by deterministic executors and sent to agent nodes through AgentExecutorRequest: await ctx.send_message( AgentExecutorRequest( messages=[Message(role="user", contents=[fix_prompt])], should_respond=True ) ) So prompt generation and graph routing are tightly coupled: each route transition emits a specific prompt payload into the next LLM node. Runtime-Constructed Prompts in Executors The most important prompts are built dynamically in workflow executors: _build_retry_generation_prompt(...) _build_fix_prompt(...) These functions inject live context: retry_count / max_retries concept + objective metadata validation/test failure reasons full captured test logs So each retry is context-rich and specific, not another blind generation attempt. Prompt + Middleware + Deterministic Gates = Reliability In this repository, reliability does not come from prompt text alone. It comes from three layers working together: Prompt contracts constrain agent behavior. Middleware injects memory and logs tool invocations. Deterministic executors enforce objective pass/fail gates. That combination is why the workflow remains auditable and predictable even when LLM outputs vary. Agent Framework Execution Model in This Repo Strongly-Typed Message Passing workflow/models.py defines transport models used between nodes: ValidationResult and TestResult (Pydantic) CombinedValidationResult (dataclass with should_keep and should_retry) InitialWorkflowState (seed payload for each run) This keeps node contracts explicit and simplifies selector logic. Fail-Fast Shared State Management Executors use ctx.get_state(...) with a sentinel (_MISSING) and raise explicit exceptions if required state is absent. This prevents hidden fallback behavior and catches graph/data wiring errors early. Conditional Routing with Selectors Selectors (workflow/selectors.py) encode graph decisions: select_action → keep vs remove select_skip_answer_action → complete vs loop select_loop_action → fix vs complete This separates decision policy from executor implementation. Streaming Workflow Runtime workflow.run(initial_state, stream=True) emits output events incrementally. The runner (workflow/runner.py) consumes these events to detect successful completions and update concept memory accordingly. Agent Construction and API Selection Strategy The repository uses Azure CLI auth (AzureCliCredential) and dynamically selects API mode by deployment name (agents/config.py): Chat Completions path: OpenAIChatCompletionClient Responses-only model path: OpenAIChatClient or custom ResponsesAgent Why this matters: some codex-class deployments are Responses-only, so the architecture supports both without changing workflow logic. How MCP Actually Controls Kubernetes (Important Distinction) In this repo, MCP is used for filesystem control; Kubernetes control is done through kubectl tools. 1) MCP server role: controlled file I/O The workflow starts MCP stdio servers (official filesystem server) and mounts them into agents: docs_mcp_tool = MCPStdioTool( name="filesystem_docs", command="npx", args=["-y", "@modelcontextprotocol/server-filesystem", str(PATHS.k8s_docs_root)], load_prompts=False, ) tests_mcp_tool = MCPStdioTool( name="filesystem_tests", command="npx", args=["-y", "@modelcontextprotocol/server-filesystem", str(PATHS.tests_root.parent)], load_prompts=False, ) Those MCP tools are passed into Generator/Fixer agents, which then call MCP file functions (read/write/list) inside allowed roots only. 2) Kubernetes cluster control role: kubectl execution tool Cluster actions are not performed by MCP filesystem server; they are performed by a dedicated function tool: def run_kubectl_command(command: str) -> str: kubeconfig_path = os.environ.get("KUBECONFIG", "/home/developer/.kube/config") cmd_list = ["kubectl"] + command.split() result = subprocess.run( cmd_list, capture_output=True, text=True, check=True, env={**os.environ, "KUBECONFIG": kubeconfig_path}, ) return result.stdout And the Kubernetes agent forces tool usage: agent = responses_client.as_agent( name="KubernetesAgent", instructions="...You MUST use the run_kubectl_command tool...", tools=[run_kubectl_command], default_options={"tool_choice": "required"}, ) So the control plane is: MCP filesystem → manipulate generated task files. kubectl tool → query/mutate real cluster state. deterministic pytest/validator executors → accept or reject results. 3) End-to-end command flow in practice When generated tests run, they execute real kubectl get ... -o json checks in test code, and the deterministic runner captures raw output: pytest_command = f"pytest --import-mode=importlib --rootdir=. {task_with_val.task_directory}/" result = run_pytest_command(pytest_command) ctx.set_state(f"raw_output_{task_with_val.task_id}", raw_output) This means Kubernetes state verification is always grounded in live command output, not model speculation. Should MCP run Kubernetes tests? Short answer: not in this design. Current architecture keeps test execution deterministic and local: pytest is run by run_pytest_command(...) (pure Python subprocess runner) test results are parsed and stored in workflow state retry/fix routing uses those deterministic outputs This is intentional. If test execution were delegated to an LLM-facing MCP command tool, you would lose strict control over execution semantics and error handling. Recommended pattern: Use MCP for file/document access and controlled editing. Use deterministic executors for pytest and validation. Use LLM agents only for generation and repair. If you still want MCP-driven test execution, add a separate locked-down command MCP server (only whitelisted pytest/kubectl commands), but keep pass/fail decision logic in deterministic executors. How tests are run in this workflow (with code) The workflow executes tests in deterministic executors, not inside LLM agents. 1) Workflow node calls pytest runner run_pytest executor builds the command and calls the pure Python runner: @executor(id="run_pytest") async def run_pytest(task_with_val: TaskWithValidation, ctx: WorkflowContext[TestResult]) -> None: from agents.pytest_runner import run_pytest_command pytest_command = f"pytest --import-mode=importlib --rootdir=. {task_with_val.task_directory}/" result = run_pytest_command(pytest_command) raw_output = result["details"][0] if result.get("details") else "" ctx.set_state(f"raw_output_{task_with_val.task_id}", raw_output) ... 2) Deterministic subprocess execution The runner normalizes command flags and executes pytest via subprocess: def run_pytest_command(command: str) -> dict[str, Any]: normalized_command = _normalize_pytest_command(command) # adds -s if needed cmd_list = shlex.split(normalized_command) result = subprocess.run( cmd_list, capture_output=True, text=True, check=False, cwd=str(PATHS.pytest_rootdir), ) combined_output = result.stdout + "\n" + result.stderr _save_test_output(normalized_command, combined_output, skip_answer) ... Exit codes are interpreted deterministically: 0 → pass 5 → no tests collected (fail) others → fail with exit code reason 3) Skip-answer validation tier After normal pass, the workflow runs pytest again with SKIP_ANSWER_TESTS=True and parses JUnit XML: os.environ["SKIP_ANSWER_TESTS"] = "True" pytest_command = f"pytest --import-mode=importlib --rootdir=. --junitxml={junit_path} {task_dir}/" result = run_pytest_command(pytest_command) test_05_failed, test_03_skipped = _parse_skip_answer_junit(junit_path) The parser checks per-testcase outcomes: if "test_05_check.py" in context and has_failure_or_error: test_05_failed = True if "test_03_answer.py" in context and has_skipped: test_03_skipped = True 4) How failures trigger fix loop If pytest fails (or skip-answer logic fails), failure reasons and raw output are pushed into state, then the Fixer Agent receives a generated fix prompt containing that output: ctx.set_state(f"failure_reasons_{task_id}", reasons) ctx.set_state(f"raw_output_{task_id}", raw_output) fix_prompt = _build_fix_prompt(combined, raw_test_output) await ctx.send_message( AgentExecutorRequest( messages=[Message(role="user", contents=[fix_prompt])], should_respond=True ) ) That is the key loop: deterministic test output drives LLM repair, then deterministic tests re-run. ResponsesAgent Internals (Advanced Agent Framework Pattern) The custom ResponsesAgent (agents/responses_agent.py) demonstrates a lower-level integration pattern: Connect MCP tool lazily. Call Responses API. Parse ResponseFunctionToolCall items. Execute tools (MCP + custom callables). Feed function_call_output back to model. Repeat until final text response. It also runs a middleware chain around tool invocations, preserving observability and consistency with standard agent paths. Why This Architecture Is Robust This design works because Agent Framework is used as a deterministic orchestration layer around probabilistic generation: LLM creativity is constrained by typed state and strict prompts. deterministic executors act as objective quality gates. retries are targeted, bounded, and auditable. failures produce durable forensic artifacts (FAILURE_REPORT.txt + test logs). For Kubernetes education pipelines, this yields high throughput without sacrificing grader reliability. GitHub Repo - https://github.com/wongcyrus/k8s-game-rule-builder About the Author Cyrus Wong is the senior lecturer of Hong Kong Institute of Information Technology (HKIIT) @ IVE(Lee Wai Lee).and he focuses on teaching public Cloud technologies. He is a passionate advocate for the adoption of cloud technology across various media and events. With his extensive knowledge and expertise, he has earned prestigious recognitions such as AWS AI Hero, Microsoft MVP- Microsoft Foundry, and Google Developer Expert - Cloud(AI).Building with Azure OpenAI Sora: A Complete Guide to AI Video Generation
In this comprehensive guide, we'll explore how to integrate both Sora 1 and Sora 2 models from Azure OpenAI Service into a production web application. We'll cover API integration, request body parameters, cost analysis, limitations, and the key differences between using Azure AI Foundry endpoints versus OpenAI's native API. Table of Contents Introduction to Sora Models Azure AI Foundry vs. OpenAI API Structure API Integration: Request Body Parameters Video Generation Modes Cost Analysis per Generation Technical Limitations & Constraints Resolution & Duration Support Implementation Best Practices Introduction to Sora Models Sora is OpenAI's groundbreaking text-to-video model that generates realistic videos from natural language descriptions. Azure AI Foundry provides access to two versions: Sora 1: The original model focused primarily on text-to-video generation with extensive resolution options (480p to 1080p) and flexible duration (1-20 seconds) Sora 2: The enhanced version with native audio generation, multiple generation modes (text-to-video, image-to-video, video-to-video remix), but more constrained resolution options (720p only in public preview) Azure AI Foundry vs. OpenAI API Structure Key Architectural Differences Sora 1 uses Azure's traditional deployment-based API structure: Endpoint Pattern: https://{resource-name}.openai.azure.com/openai/deployments/{deployment-name}/... Parameters: Uses Azure-specific naming like n_seconds, n_variants, separate width/height fields Job Management: Uses /jobs/{id} for status polling Content Download: Uses /video/generations/{generation_id}/content/video Sora 2 adapts OpenAI's v1 API format while still being hosted on Azure: Endpoint Pattern: https://{resource-name}.openai.azure.com/openai/deployments/{deployment-name}/videos Parameters: Uses OpenAI-style naming like seconds (string), size (combined dimension string like "1280x720") Job Management: Uses /videos/{video_id} for status polling Content Download: Uses /videos/{video_id}/content Why This Matters? This architectural difference requires conditional request formatting in your code: const isSora2 = deployment.toLowerCase().includes('sora-2'); if (isSora2) { requestBody = { model: deployment, prompt, size: `${width}x${height}`, // Combined format seconds: duration.toString(), // String type }; } else { requestBody = { model: deployment, prompt, height, // Separate dimensions width, n_seconds: duration.toString(), // Azure naming n_variants: variants, }; } API Integration: Request Body Parameters Sora 1 API Parameters Standard Text-to-Video Request: { "model": "sora-1", "prompt": "Wide shot of a child flying a red kite in a grassy park, golden hour sunlight, camera slowly pans upward.", "height": "720", "width": "1280", "n_seconds": "12", "n_variants": "2" } Parameter Details: model (String, Required): Your Azure deployment name prompt (String, Required): Natural language description of the video (max 32000 chars) height (String, Required): Video height in pixels width (String, Required): Video width in pixels n_seconds (String, Required): Duration (1-20 seconds) n_variants (String, Optional): Number of variations to generate (1-4, constrained by resolution) Sora 2 API Parameters Text-to-Video Request: { "model": "sora-2", "prompt": "A serene mountain landscape with cascading waterfalls, cinematic drone shot", "size": "1280x720", "seconds": "12" } Image-to-Video Request (uses FormData): const formData = new FormData(); formData.append('model', 'sora-2'); formData.append('prompt', 'Animate this image with gentle wind movement'); formData.append('size', '1280x720'); formData.append('seconds', '8'); formData.append('input_reference', imageFile); // JPEG/PNG/WebP Video-to-Video Remix Request: Endpoint: POST .../videos/{video_id}/remix Body: Only { "prompt": "your new description" } The original video's structure, motion, and framing are reused while applying the new prompt Parameter Details: model (String, Optional): Your deployment name prompt (String, Required): Video description size (String, Optional): Either "720x1280" or "1280x720" (defaults to "720x1280") seconds (String, Optional): "4", "8", or "12" (defaults to "4") input_reference (File, Optional): Reference image for image-to-video mode remix_video_id (String, URL parameter): ID of video to remix Video Generation Modes 1. Text-to-Video (Both Models) The foundational mode where you provide a text prompt describing the desired video. Implementation: const response = await fetch(endpoint, { method: 'POST', headers: { 'Content-Type': 'application/json', 'api-key': apiKey, }, body: JSON.stringify({ model: deployment, prompt: "A train journey through mountains with dramatic lighting", size: "1280x720", seconds: "12", }), }); Best Practices: Include shot type (wide, close-up, aerial) Describe subject, action, and environment Specify lighting conditions (golden hour, dramatic, soft) Add camera movement if desired (pans, tilts, tracking shots) 2. Image-to-Video (Sora 2 Only) Generate a video anchored to or starting from a reference image. Key Requirements: Supported formats: JPEG, PNG, WebP Image dimensions must exactly match the selected video resolution Our implementation automatically resizes uploaded images to match Implementation Detail: // Resize image to match video dimensions const targetWidth = parseInt(width); const targetHeight = parseInt(height); const resizedImage = await resizeImage(inputReference, targetWidth, targetHeight); // Send as multipart/form-data formData.append('input_reference', resizedImage); 3. Video-to-Video Remix (Sora 2 Only) Create variations of existing videos while preserving their structure and motion. Use Cases: Change weather conditions in the same scene Modify time of day while keeping camera movement Swap subjects while maintaining composition Adjust artistic style or color grading Endpoint Structure: POST {base_url}/videos/{original_video_id}/remix?api-version=2024-08-01-preview Implementation: let requestEndpoint = endpoint; if (isSora2 && remixVideoId) { const [baseUrl, queryParams] = endpoint.split('?'); const root = baseUrl.replace(/\/videos$/, ''); requestEndpoint = `${root}/videos/${remixVideoId}/remix${queryParams ? '?' + queryParams : ''}`; } Cost Analysis per Generation Sora 1 Pricing Model Base Rate: ~$0.05 per second per variant at 720p Resolution Scaling: Cost scales linearly with pixel count Formula: const basePrice = 0.05; const basePixels = 1280 * 720; // Reference resolution const currentPixels = width * height; const resolutionMultiplier = currentPixels / basePixels; const totalCost = basePrice * duration * variants * resolutionMultiplier; Examples: 720p (1280×720), 12 seconds, 1 variant: $0.60 1080p (1920×1080), 12 seconds, 1 variant: $1.35 720p, 12 seconds, 2 variants: $1.20 Sora 2 Pricing Model Flat Rate: $0.10 per second per variant (no resolution scaling in public preview) Formula: const totalCost = 0.10 * duration * variants; Examples: 720p (1280×720), 4 seconds: $0.40 720p (1280×720), 12 seconds: $1.20 720p (720×1280), 8 seconds: $0.80 Note: Since Sora 2 currently only supports 720p in public preview, resolution doesn't affect cost, only duration matters. Cost Comparison Scenario Sora 1 (720p) Sora 2 (720p) Winner 4s video $0.20 $0.40 Sora 1 12s video $0.60 $1.20 Sora 1 12s + audio N/A (no audio) $1.20 Sora 2 (unique) Image-to-video N/A $0.40-$1.20 Sora 2 (unique) Recommendation: Use Sora 1 for cost-effective silent videos at various resolutions. Use Sora 2 when you need audio, image/video inputs, or remix capabilities. Technical Limitations & Constraints Sora 1 Limitations Resolution Options: 9 supported resolutions from 480×480 to 1920×1080 Includes square, portrait, and landscape formats Full list: 480×480, 480×854, 854×480, 720×720, 720×1280, 1280×720, 1080×1080, 1080×1920, 1920×1080 Duration: Flexible: 1 to 20 seconds Any integer value within range Variants: Depends on resolution: 1080p: Variants disabled (n_variants must be 1) 720p: Max 2 variants Other resolutions: Max 4 variants Concurrent Jobs: Maximum 2 jobs running simultaneously Job Expiration: Videos expire 24 hours after generation Audio: No audio generation (silent videos only) Sora 2 Limitations Resolution Options (Public Preview): Only 2 options: 720×1280 (portrait) or 1280×720 (landscape) No square formats No 1080p support in current preview Duration: Fixed options only: 4, 8, or 12 seconds No custom durations Defaults to 4 seconds if not specified Variants: Not prominently supported in current API documentation Focus is on single high-quality generations with audio Concurrent Jobs: Maximum 2 jobs (same as Sora 1) Job Expiration: 24 hours (same as Sora 1) Audio: Native audio generation included (dialogue, sound effects, ambience) Shared Constraints Concurrent Processing: Both models enforce a limit of 2 concurrent video jobs per Azure resource. You must wait for one job to complete before starting a third. Job Lifecycle: queued → preprocessing → processing/running → completed Download Window: Videos are available for 24 hours after completion. After expiration, you must regenerate the video. Generation Time: Typical: 1-5 minutes depending on resolution, duration, and API load Can occasionally take longer during high demand Resolution & Duration Support Matrix Sora 1 Support Matrix Resolution Aspect Ratio Max Variants Duration Range Use Case 480×480 Square 4 1-20s Social thumbnails 480×854 Portrait 4 1-20s Mobile stories 854×480 Landscape 4 1-20s Quick previews 720×720 Square 4 1-20s Instagram posts 720×1280 Portrait 2 1-20s TikTok/Reels 1280×720 Landscape 2 1-20s YouTube shorts 1080×1080 Square 1 1-20s Premium social 1080×1920 Portrait 1 1-20s Premium vertical 1920×1080 Landscape 1 1-20s Full HD content Sora 2 Support Matrix Resolution Aspect Ratio Duration Options Audio Generation Modes 720×1280 Portrait 4s, 8s, 12s ✅ Yes Text, Image, Video Remix 1280×720 Landscape 4s, 8s, 12s ✅ Yes Text, Image, Video Remix Note: Sora 2's limited resolution options in public preview are expected to expand in future releases. Implementation Best Practices 1. Job Status Polling Strategy Implement adaptive backoff to avoid overwhelming the API: const maxAttempts = 180; // 15 minutes max let attempts = 0; const baseDelayMs = 3000; // Start with 3 seconds while (attempts < maxAttempts) { const response = await fetch(statusUrl, { headers: { 'api-key': apiKey }, }); if (response.status === 404) { // Job not ready yet, wait longer const delayMs = Math.min(15000, baseDelayMs + attempts * 1000); await new Promise(r => setTimeout(r, delayMs)); attempts++; continue; } const job = await response.json(); // Check completion (different status values for Sora 1 vs 2) const isCompleted = isSora2 ? job.status === 'completed' : job.status === 'succeeded'; if (isCompleted) break; // Adaptive backoff const delayMs = Math.min(15000, baseDelayMs + attempts * 1000); await new Promise(r => setTimeout(r, delayMs)); attempts++; } 2. Handling Different Response Structures Sora 1 Video Download: const generations = Array.isArray(job.generations) ? job.generations : []; const genId = generations[0]?.id; const videoUrl = `${root}/${genId}/content/video`; Sora 2 Video Download: const videoUrl = `${root}/videos/${jobId}/content`; 3. Error Handling try { const response = await fetch(endpoint, fetchOptions); if (!response.ok) { const error = await response.text(); throw new Error(`Video generation failed: ${error}`); } // ... handle successful response } catch (error) { console.error('[VideoGen] Error:', error); // Implement retry logic or user notification } 4. Image Preprocessing for Image-to-Video Always resize images to match the target video resolution: async function resizeImage(file: File, targetWidth: number, targetHeight: number): Promise<File> { return new Promise((resolve, reject) => { const img = new Image(); const canvas = document.createElement('canvas'); const ctx = canvas.getContext('2d'); img.onload = () => { canvas.width = targetWidth; canvas.height = targetHeight; ctx.drawImage(img, 0, 0, targetWidth, targetHeight); canvas.toBlob((blob) => { if (blob) { const resizedFile = new File([blob], file.name, { type: file.type }); resolve(resizedFile); } else { reject(new Error('Failed to create resized image blob')); } }, file.type); }; img.onerror = () => reject(new Error('Failed to load image')); img.src = URL.createObjectURL(file); }); } 5. Cost Tracking Implement cost estimation before generation and tracking after: // Pre-generation estimate const estimatedCost = calculateCost(width, height, duration, variants, soraVersion); // Save generation record await saveGenerationRecord({ prompt, soraModel: soraVersion, duration: parseInt(duration), resolution: `${width}x${height}`, variants: parseInt(variants), generationMode: mode, estimatedCost, status: 'queued', jobId: job.id, }); // Update after completion await updateGenerationStatus(jobId, 'completed', { videoId: finalVideoId }); 6. Progressive User Feedback Provide detailed status updates during the generation process: const statusMessages: Record<string, string> = { 'preprocessing': 'Preprocessing your request...', 'running': 'Generating video...', 'processing': 'Processing video...', 'queued': 'Job queued...', 'in_progress': 'Generating video...', }; onProgress?.(statusMessages[job.status] || `Status: ${job.status}`); Conclusion Building with Azure OpenAI's Sora models requires understanding the nuanced differences between Sora 1 and Sora 2, both in API structure and capabilities. Key takeaways: Choose the right model: Sora 1 for resolution flexibility and cost-effectiveness; Sora 2 for audio, image inputs, and remix capabilities Handle API differences: Implement conditional logic for parameter formatting and status polling based on model version Respect limitations: Plan around concurrent job limits, resolution constraints, and 24-hour expiration windows Optimize costs: Calculate estimates upfront and track actual usage for better budget management Provide great UX: Implement adaptive polling, progressive status updates, and clear error messages The future of AI video generation is exciting, and Azure AI Foundry provides production-ready access to these powerful models. As Sora 2 matures and limitations are lifted (especially resolution options), we'll see even more creative applications emerge. Resources: Azure AI Foundry Sora Documentation OpenAI Sora API Reference Azure OpenAI Service Pricing This blog post is based on real-world implementation experience building LemonGrab, my AI video generation platform that integrates both Sora 1 and Sora 2 through Azure AI Foundry. The code examples are extracted from production usage.AI Agents in Production: From Prototype to Reality - Part 10
This blog post, the tenth and final installment in a series on AI agents, focuses on deploying AI agents to production. It covers evaluating agent performance, addressing common issues, and managing costs. The post emphasizes the importance of a robust evaluation system, providing potential solutions for performance issues, and outlining cost management strategies such as response caching, using smaller models, and implementing router models.
