> ## 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. # Export OTLP traces > OpenTelemetry OTLP/HTTP trace receiver. Point an exporter's base endpoint at `https://pillarforge.corepillar.ai/api` (exporters append `/v1/traces`) and send the tracing key as `Authorization: Bearer ...`. Accepts protobuf or JSON. gRPC isn't supported. Spans are converted to AgentHub spans (kind, model, tokens, cost from the model catalog, input and output), merged with earlier exports of the same trace, and stitched across fragments of one session. Responds with an OTLP `ExportTraceServiceResponse`, not the `{ data }` envelope. See [OpenTelemetry (OTLP)](/agenthub/developers/opentelemetry). ## OpenAPI ````yaml /api-reference/openapi.json post /traces 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: /traces: post: tags: - Ingestion summary: Export OTLP traces description: >- OpenTelemetry OTLP/HTTP trace receiver. Point an exporter's base endpoint at `https://pillarforge.corepillar.ai/api` (exporters append `/v1/traces`) and send the tracing key as `Authorization: Bearer ...`. Accepts protobuf or JSON. gRPC isn't supported. Spans are converted to AgentHub spans (kind, model, tokens, cost from the model catalog, input and output), merged with earlier exports of the same trace, and stitched across fragments of one session. Responds with an OTLP `ExportTraceServiceResponse`, not the `{ data }` envelope. See [OpenTelemetry (OTLP)](/agenthub/developers/opentelemetry). operationId: exportOtlpTraces parameters: - name: Content-Encoding in: header required: false schema: type: string enum: - identity - gzip - deflate requestBody: required: true description: >- An OTLP `ExportTraceServiceRequest` (or the metrics/logs equivalent). Optionally `gzip` or `deflate` compressed; up to 32 MiB decompressed. content: application/x-protobuf: schema: type: string format: binary application/json: schema: type: object additionalProperties: true properties: resourceSpans: type: array items: type: object additionalProperties: true responses: '200': description: >- OTLP ExportTraceServiceResponse, in the request's encoding. Empty on full success; `partialSuccess` when some spans were dropped. content: application/json: schema: type: object properties: partialSuccess: type: object properties: rejectedSpans: type: string errorMessage: type: string example: {} application/x-protobuf: schema: type: string format: binary '400': description: >- Unsupported `Content-Encoding`, payload over 32 MiB, or undecodable payload (`VALIDATION_ERROR`). content: application/json: schema: $ref: '#/components/schemas/ErrorEnvelope' '401': description: Tracing key missing, malformed, unknown or revoked (`UNAUTHORIZED`). content: application/json: schema: $ref: '#/components/schemas/ErrorEnvelope' '415': description: >- `Content-Type` isn't `application/x-protobuf`, `application/protobuf` or `application/json` (`VALIDATION_ERROR`). content: application/json: schema: $ref: '#/components/schemas/ErrorEnvelope' '500': description: Unexpected server error (`INTERNAL_ERROR`). content: application/json: schema: $ref: '#/components/schemas/ErrorEnvelope' security: - tracingKey: [] - tracingKeyHeader: [] components: schemas: 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. securitySchemes: tracingKey: type: http scheme: bearer bearerFormat: tk_live_ / tk_test_ + 48 hex description: >- Project tracing key, from Settings → Tracing keys. `Authorization: Bearer tk_live_...`. The word `Bearer` is case-sensitive. tracingKeyHeader: type: apiKey in: header name: x-tracing-key description: >- Alternative to the Authorization header. Used only when no `Authorization: Bearer` header is present. ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.