> ## Documentation Index > Fetch the complete documentation index at: https://docs.scalacomputing.com/llms.txt > Use this file to discover all available pages before exploring further. # API Changelog > All notable API changes will be documented in this file. All notable API changes will be documented in this file. The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/), and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html). *** ## \[Unreleased] - 2026-03-06 ### Added * **Simple simulation endpoint**: `POST /api/v1/simple/simulations` — submit a collective-operation workload (AllReduce, Broadcast, etc.) with a single request. The platform handles topology derivation, traceset synthesis, and simulation launch automatically. * **Topology constraints**: `topologyConstraints` object on `SimpleSimulationRequest` with `switchRadix` (enum: `64x800G`, `128x400G`, `256x200G`) and `subscriptionRatio` (enum: `1:1`, `2:1`, `3:1`, `4:1`). Enables arbitrary rank counts by deriving a valid 2-tier CLOS topology from hardware constraints. ### Fixed * **Simulation results endpoints**: Removed non-functional workspace ownership check that blocked all users from accessing results. `DefaultWorkspace.owner = 'system'` caused `verify_workspace_access` to reject every real user. Endpoints now correctly return results for any authenticated user. Affected: `GET /simulations/{id}/results`, `GET /simulations/{id}/results/download-url`, `GET /simulations/{id}/results/data`. ### Changed * **Presigned URL expiry reduced**: Simulation result download URLs (`GET /simulations/{id}/results` and `GET /simulations/{id}/results/download-url`) now expire after **15 minutes (900 s)** instead of the previous 60 minutes (3600 s). This is a defense-in-depth hardening to limit exposure if a URL leaks. Clients that fetch a presigned URL and consume it after a delay greater than 15 minutes will receive an HTTP 403 from S3. The `expiresAt` field in the `download-url` response reflects the actual expiry. No known consumers cache presigned URLs beyond this window. * **BREAKING**: `SimpleWorkload.ranks` changed from integer enum (`[64, 128, 256, 512, 1024, 4096]`) to `integer` with `minimum: 1`. Without `topologyConstraints`, the server still restricts to the 6 reference values. With `topologyConstraints`, any positive value satisfying the constraint solver is accepted. * **BREAKING**: `TracesetFile` renamed to `FileResponse` in the Python client. Adds required field `metadata_status`. Update imports: `from python_client.models import FileResponse` (was `TracesetFile`). * **BREAKING**: `ContainerDefinition.type_` and `AllowedTypesResponse.container_type` now use `ContainerType` instead of `ComponentType` in the Python client. Both are `str` enums with identical string values, so equality comparisons by value still work. Update `isinstance` checks if used. * **BREAKING**: `DlrmMetadata`, `TraceMetadata`, and `TraceMetadataWorkloadType` removed from the Python client. These types are no longer part of the API surface. Remove any imports that reference them. * **Traceset listing scope widened**: `GET /api/v1/tracesets?workspaceId=X` now returns all non-deleted tracesets visible to the workspace, including promoted tracesets with scope `tenant` or `public`. Previously, only `workspace`-scoped tracesets were returned. This ensures promoted tracesets remain visible after promotion. * **TrafficType output consolidation**: API responses now return `"chakra"` where `"coordinated"` was previously emitted for the `trafficType` field. Input is backward-compatible: both `"chakra"` and `"coordinated"` are accepted via serde alias. This reflects the A5 schema migration consolidating Coordinated into Chakra. * **BREAKING**: `PATCH /api/v1/configurations/{config_id}/traceset` now requires the traceset's metadata extraction to be complete before attaching. The endpoint previously accepted any valid traceset regardless of library state; it now enforces that `rank_count` is resolved and positive (required to populate `NumOfChakraFiles` in the Chakra workload model). Two new error responses are returned when the traceset metadata is incomplete or invalid: | Condition | Status | Error code | | -------------------------------------------------------------- | -------------------------- | ---------------------- | | `rank_count` is `NULL` — metadata extraction still in progress | `409 Conflict` | `CONFLICT` | | `rank_count` is present but ≤ 0 — data invariant violation | `422 Unprocessable Entity` | `UNPROCESSABLE_ENTITY` | **Migration**: If you call this endpoint immediately after uploading a traceset, poll until the traceset's `metadataStatus` is `complete` before attaching. A `409` response indicates the traceset is not yet ready; retry after a short backoff. A `422` response indicates a permanent problem with the traceset metadata and will not resolve on retry. ## \[Previous Unreleased] - 2024-12-23 ### Changed * **BREAKING**: `Pagination.limit` renamed to `Pagination.count` in API responses * Affected: All paginated list endpoints * Before: `{"limit": 10, "hasMore": true, "cursor": "..."}` * After: `{"count": 10, "hasMore": true, "cursor": "..."}` * Semantic change: `count` represents the actual number of items returned (may be less than requested limit) * Note: Query parameter `?limit=N` remains unchanged; only the response field name changed * Migration: Update client code to read `count` instead of `limit` from pagination responses * **BREAKING**: `ParameterDefinition.default` type changed from JSON value to string * Affected: `GET /api/v1/models/{id}`, `GET /api/v1/components/{id}` * Before: `{"default": 100}` or `{"default": true}` * After: `{"default": "100"}` or `{"default": "true"}` * Migration: Parse the string value according to the parameter's `type` field * **BREAKING**: `ComponentDeclaration.model` format changed to use standardized model reference * Affected: `GET /api/v1/templates/{id}`, `GET /api/v1/configurations/{id}`, `GET /api/v1/configurations/{id}/versions/{v}`, `POST /api/v1/templates/{id}/clone` * Before: `{"model": "ScalaSwitch:3.2.1", "name": "spine-1"}` (model in internal format, name user-defined) * After: `{"model": "scala-switch-v3.2.1", "name": "spine-1"}` (model standardized to API format, name remains user-manageable) * Format: Model field is standardized to API format (`scala-switch-v{version}`) * Name field: Remains user-manageable and unchanged from input * Benefit: Model field can be parsed to extract model reference for use with `GET /api/v1/models/{model_id}` * Migration: Update any code that parses or displays component model fields * **BREAKING**: Only referenced components are returned in configuration responses * Affected: `GET /api/v1/templates/{id}`, `GET /api/v1/configurations/{id}`, `POST /api/v1/templates/{id}/clone` * Before: All components declared in the configuration were returned, including unused ones * After: Only components referenced in `topology.components`, `topology.containers`, or `containers[].components` are returned * Rationale: Reduces response size and focuses on components actually used in the topology * Migration: If your code relies on seeing all declared components, use the stored configuration data directly * **Template cloning preserves original data format** * Affected: `POST /api/v1/templates/{id}/clone` * Change: Cloned configurations now preserve the original template's data format (legacy or new format) * Before: Template data was transformed to new format during cloning * After: Template data format is preserved, only metadata fields (version, workspaceId, name, status, parent\_config\_id) are updated * Benefit: Maintains compatibility with existing templates and allows format-specific handling ### Removed * **BREAKING**: Removed fields from `ParameterDefinition`: * `componentType` - was used for nested component type references * `model` - was used for model references within parameters * `parameters` - was used for nested parameter definitions * Migration: These fields were not widely used. If you relied on nested parameter structures, contact the API team for migration guidance. ### Added * **Model Metadata Enrichment**: Templates API now fetches model metadata from `model_version` * Affected: `GET /api/v1/templates/{id}` * Components are enriched with parameter schemas and type information from the database * When a component references a model (e.g., `ScalaSwitch:4.0.0`), the API looks up the model in `model_version` and includes the full parameter schema * Benefit: Clients receive complete model metadata without needing separate API calls to `/api/v1/models/{model_id}` * **Parameter Extraction**: Extended parameter extraction to include coordinator-level parameters * Application models now expose parameters from `Coordinators`, `ModelProfiles`, and `TrafficPattern` sections * Parameters include group information (e.g., `Delay.CoordinatorAttributes`) ***