Spans for what an agent did, receipts for proof it did it. This hub covers OTLP/JSON gen_ai trace tooling: composing a resourceSpans/scopeSpans/spans trace by hand with gen_ai attribute presets for invoke_agent, chat, and execute_tool spans, and linting any OTLP/JSON trace against a pinned semantic-convention snapshot. Runs entirely in your browser: no OTLP collector, no network export, no account.
A composer and a linter for OTLP/JSON gen_ai traces, in one page.
Snapshot-pinning caveat: the gen_ai semantic-convention namespace (open-telemetry/semantic-conventions-genai) has no tagged upstream releases. The linter checks your trace against an attribute set pinned as of the tool's semconv_snapshot value, not against a released standard. Every artifact this tool emits stamps its snapshot version so a lint result stays traceable to the rules it was actually checked against, but expect upstream churn: re-check older traces if the snapshot moves.
Compose a hand-rolled OTLP/JSON trace: resource attributes, spans with hex traceId/spanId, nanosecond timestamps, parent links, attributes, and events. gen_ai presets build an invoke_agent span with child chat/execute_tool spans carrying the pinned gen_ai.* attribute set (request.model, usage.input_tokens/output_tokens, tool name, and more). Paste in existing OTLP/JSON to edit it, or switch to linter mode to validate structure and gen_ai attribute conformance against the pinned snapshot. Zero network export: everything stays in the browser and exports to a file.
v1.0 · Jul 2026 · 1 Tool · Cat-MCP · Agent Observability
Open T556 and build an OTLP/JSON trace from a gen_ai preset, or paste in a trace exported from your own agent run. The composer fills in hex traceId/spanId, nanosecond timestamps, and parent-span links so the output loads clean in any external OTLP viewer.
Switch to linter mode and paste in any OTLP/JSON trace. The tool checks structural validity and gen_ai attribute conformance against its stamped semconv_snapshot, flagging missing or malformed attributes before the trace goes anywhere near a dashboard.
Build a reference OTLP/JSON gen_ai trace for a new agent workflow before wiring up a real collector, or lint traces your agents already emit to catch missing gen_ai attributes early.
Check third-party or in-house agent instrumentation against the pinned gen_ai attribute set without standing up an OTel collector. Useful for reviewing a vendor's trace export before it enters your pipeline.