API

otell exposes query APIs over three transports:

• UDS line-delimited JSON (default local transport)
• TCP line-delimited JSON
• HTTP JSON endpoints

It ingests telemetry over OTLP:

• gRPC: 4317 (default)
• HTTP protobuf: 4318 (default)

Query Protocol (UDS/TCP)

Each request is one JSON line encoded as ApiRequest. Each response is one JSON line encoded as ApiResponse.

Request variants:

• Search(SearchRequest)
• Trace(TraceRequest)
• Span(SpanRequest)
• Traces(TracesRequest)
• Metrics(MetricsRequest)
• MetricsList(MetricsListRequest)
• ResolveHandle(QueryHandle)
• Status

Response variants:

• Search(SearchResponse)
• Trace(TraceResponse)
• Span(SpanResponse)
• Traces(Vec<TraceListItem>)
• Metrics(MetricsResponse)
• MetricsList(MetricsListResponse)
• Status(StatusResponse)
• Error(String)

HTTP Query Endpoints

Base address: --query-http-addr (default 127.0.0.1:1778)

• POST /v1/search body: SearchRequest
• POST /v1/trace body: TraceRequest
• GET /v1/trace/{trace_id} (bounded logs, no root override)
• POST /v1/span body: SpanRequest
• POST /v1/traces body: TracesRequest
• POST /v1/metrics body: MetricsRequest
• POST /v1/metrics/list body: MetricsListRequest
• GET /v1/status

All endpoints return ApiResponse JSON.

MCP (stdio)

Run otell mcp and communicate over stdin/stdout.

Supported JSON-RPC methods:

• initialize
• tools/list
• tools/call

Supported tool names:

• search
• trace
• span
• traces
• metrics
• metrics.list
• status
• resolve_handle