> ## Documentation Index > Fetch the complete documentation index at: https://docs.corepillar.ai/llms.txt > Use this file to discover all available pages before exploring further. # Generate scenarios (streaming) > Same as **Generate scenarios**, but streams newline-delimited JSON events as scenarios are produced: - `{"type":"run","run_id","estimate","requested"}` - `{"type":"scenarios","scenarios":[...]}` (repeated) - `{"type":"done","run_id","scenario_count","partial_failures","model_generation_error"}` - `{"type":"error","message"}` - `{"type":"ping"}` heartbeat every 10 seconds Auth and validation errors are returned as normal JSON errors before the stream starts. Can run for up to 800 seconds. **Auth:** session. **Permission:** `run_agents` or `manage_agents`. ## OpenAPI ````yaml /api-reference/openapi.json post /projects/{projectId}/cost-calculator/generate-scenarios/stream openapi: 3.1.0 info: title: CorePillar API version: 1.0.0 description: >- REST API for AgentHub and ModelHub. Ingestion endpoints authenticate with a project tracing key; all other endpoints use the signed-in user's browser session. servers: - url: https://pillarforge.corepillar.ai/api/v1 description: AgentHub security: [] tags: - name: Ingestion description: 'Send traces with a tracing key: JSON ingest and OpenTelemetry (OTLP).' - name: Traces description: Read traces and spans. - name: Evaluations description: Evaluate traces with evaluator collections. - name: Evaluators description: Built-in and custom evaluators. - name: Evaluator collections description: Ordered groups of evaluators. - name: Organizations description: Organizations you belong to. - name: Members description: Organization members, invites and roles. - name: Projects description: Projects inside an organization. - name: SSO description: Okta SSO configuration. - name: Tracing keys description: Create, list and revoke project tracing keys. - name: Cost calculator description: Estimate, generate and execute scenario runs. - name: Synthetic description: Synthetic agent and data setup from source material. - name: Chat description: ModelHub chat. Served at https://modelhub.corepillar.ai/api/v1. - name: Auth description: Sign-in helpers. - name: E2E description: Internal end-to-end encryption key directory. paths: /projects/{projectId}/cost-calculator/generate-scenarios/stream: post: tags: - Cost calculator summary: Generate scenarios (streaming) description: >- Same as **Generate scenarios**, but streams newline-delimited JSON events as scenarios are produced: - `{"type":"run","run_id","estimate","requested"}` - `{"type":"scenarios","scenarios":[...]}` (repeated) - `{"type":"done","run_id","scenario_count","partial_failures","model_generation_error"}` - `{"type":"error","message"}` - `{"type":"ping"}` heartbeat every 10 seconds Auth and validation errors are returned as normal JSON errors before the stream starts. Can run for up to 800 seconds. **Auth:** session. **Permission:** `run_agents` or `manage_agents`. operationId: generateScenariosStream parameters: - name: projectId in: path required: true description: Project id. schema: type: string format: uuid requestBody: required: true content: application/json: schema: type: object required: - agent_config - scenario_count properties: agent_config: $ref: '#/components/schemas/AgentConfig' model_config_id: type: - string - 'null' format: uuid scenario_count: type: integer minimum: 1 maximum: 1000 include_multi_turn: type: boolean default: false org_slug: type: string maxLength: 200 description: Used only to refresh the Cost Calculator page afterwards. project_slug: type: string maxLength: 200 description: Used only to refresh the Cost Calculator page afterwards. responses: '200': description: Event stream. content: application/x-ndjson: schema: type: string description: One JSON object per line. example: > {"type":"run","run_id":"…","estimate":{},"requested":10} {"type":"scenarios","scenarios":[]} {"type":"done","run_id":"…","scenario_count":10,"partial_failures":[],"model_generation_error":null} '400': description: Invalid body, or more than 1,000 scenarios (`VALIDATION_ERROR`). content: application/json: schema: $ref: '#/components/schemas/ErrorEnvelope' '401': description: Not signed in (`UNAUTHORIZED`). content: application/json: schema: $ref: '#/components/schemas/ErrorEnvelope' '403': description: >- Not a member of the organization, or missing the required permission (`FORBIDDEN`). content: application/json: schema: $ref: '#/components/schemas/ErrorEnvelope' '404': description: Project not found or not visible to you (`PROJECT_NOT_FOUND`). content: application/json: schema: $ref: '#/components/schemas/ErrorEnvelope' security: - session: [] components: schemas: AgentConfig: type: object required: - system_prompt description: The agent the Cost Calculator simulates. properties: system_prompt: type: string minLength: 1 maxLength: 20000 tone: type: string maxLength: 2000 default: '' tools: type: array maxItems: 50 items: $ref: '#/components/schemas/AgentTool' default: [] memory: type: string maxLength: 4000 default: '' ErrorEnvelope: type: object required: - error properties: error: type: object required: - code - message properties: code: type: string description: Stable machine-readable code. Branch on this, not on `message`. examples: - VALIDATION_ERROR message: type: string description: Human-readable description. May change. details: type: object additionalProperties: true description: Extra context; often empty. AgentTool: type: object required: - name properties: kind: type: string enum: - skill - memory - tool - connector default: tool name: type: string minLength: 1 maxLength: 200 mode: type: string enum: - simulated - real default: simulated description: type: string maxLength: 512 default: '' content: type: string maxLength: 20000 securitySchemes: session: type: apiKey in: cookie name: session description: >- The session cookie set when you sign in to AgentHub or ModelHub in a browser. The cookie name shown here is illustrative. There are no API tokens for these endpoints. ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.