Explorer is in Public Preview. See Feature Maturity Definitions for what this means.
Overview
The Explorer is a spans-first exploration surface for GenAI applications. It gives you a paginated, filterable, searchable view of every span ingested into a single application — useful for debugging individual requests, investigating evaluator failures, drilling into latency outliers, and validating instrumentation. Open the Explorer tab on any GenAI Application Details page.Concepts
| Term | Meaning |
|---|---|
| Span | A single unit of work in your application — an LLM call, a tool invocation, an agent step, or a chain step. The Explorer grid is one row per span. |
| Trace | A collection of spans that share a trace_id and represent one end-to-end request through your application. |
| Session | A higher-level grouping (typically a multi-turn conversation) identified by a session_id. A session may contain multiple traces. |
| Time range | Mandatory. The Explorer always filters by a time window. The UI defaults to the last 7 calendar days (ending at end-of-day UTC). The time range is enforced server-side to keep queries fast against the underlying ClickHouse partitioning. |
Using the UI
Where it lives
Open any GenAI Application Details page, then select the Explorer tab.The DataGrid
Each row in the grid is a span. The grid is server-side paginated and sorted, with rich column controls.Columns visible by default
| Column | Notes |
|---|---|
| Type | Span type — typically one of llm, tool, agent, chain |
| Name | Span operation name |
| Input | LLM or tool input content. Query via the search bar with the Input scope selector (see Searching in the UI). |
| Output | LLM or tool output content. Query via the search bar with the Output scope selector (see Searching in the UI). |
| Timestamp | When the span started |
| Duration | Span duration (displayed in human-friendly units) |
| Status | OpenTelemetry status code (Ok, Error, Unset) |
| Actions | Pinned to the right of the grid; always visible. Contains the View Trace icon. |
Columns hidden by default
These columns are available via the column picker but are not shown out of the box:- Session ID
- Trace ID
- Span ID
- Agent
- Agent ID
Dynamic columns
Explorer adds columns automatically based on your application’s schema:- Evaluator output columns — one column per output of every evaluator rule configured for the application.
- User-defined span attribute columns — one column per attribute you’ve instrumented (for example,
user_id,model_version,environment). - Token count columns —
gen_ai.usage.input_tokens,gen_ai.usage.output_tokens,gen_ai.usage.total_tokens.
Filtering in the UI
Open the filter panel from any filterable column header, or from the toolbar. Filters are applied server-side. By default, filter rules are combined with AND; the MUI filter panel also lets you switch to OR within a single column.- ID columns (
Session ID,Trace ID,Span ID) —equalsonly in the UI (enable the column via the column picker first; these are hidden by default). - String columns (Name, Agent, span attributes) —
is,is not,is any of(autocomplete) orequals/does not equal(free text), depending on whether the field has a known value set. - Numeric columns (Duration, token counts, numeric attributes) —
=,!=,>,>=,<,<=. - Enum columns (Type, Status) — single- or multi-select.
- Boolean evaluator outputs —
isoris notwith valuestrueorfalse.
Searching in the UI
Use the search bar at the top of the grid to run a case-insensitive substring match against prompt and response content captured on your spans.| Setting | Detail |
|---|---|
| Length | 3 to 64 characters |
| Match | Case-insensitive substring |
| Index | Backed by a dedicated content table with n-gram and token bloom-filter indexes for fast lookups |
| Scope | Searches |
|---|---|
| All (default) | LLM input, LLM output, tool input, tool output |
| Input | LLM input + tool input |
| Output | LLM output + tool output |
Sorting in the UI
The grid is sorted by Timestamp (most recent first) by default. Click the Timestamp or Duration column header to change the sort. Other columns are not sortable in the UI in this release.Opening the trace drawer
To inspect the full trace context for a span, click the View Trace (eye) icon in the rightmost Actions column. This opens a side drawer that loads every span in the row’s session and renders them as a tree.- The drawer is session-scoped, not trace-scoped — if a session contains multiple traces, all of them are visible in the drawer.
- The View Trace icon is disabled for spans without a
session_id, with the tooltip “No trace found”.
Related Resources
- Custom Metrics for Agentic Applications — define custom metrics over the same span data using FQL
- Span and Resource Attributes — full attribute catalog and naming conventions
- Agentic Observability — overview of dashboards, metrics, and integrations
- OpenTelemetry Trace Export — export pre-existing OpenTelemetry traces to Fiddler from your own storage or pipeline
Limitations & Roadmap (Public Preview)
The following are not available in this release and are tracked for future work:- Session-attribute filters. You can filter by
session_id, but filters over session-level attributes are not yet supported. - Multi-pattern structural filters. Constructs such as “trace contains tool X then LLM Y” or “trace where root has positive feedback” — sometimes written with
->(temporal) or=>(parent / child) operators in other tools — are not yet supported. - Saved filter sets. Filters live for the current session; they cannot be named, saved, or shared yet.
- CSV / notebook export. Bulk export of filtered results is not yet available.