Glossary

This page defines the terms used across the AIO documentation, with one definition for each term.

The terms are in alphabetical order. Where a term has its own page, the definition links to it.

Term	Definition
Access key and secret key	The credential pair your application uses to send telemetry through the gateway. AIO sends them only when you set both. See Create an API key.
`__REDACTED__`	The value that replaces text matching a redaction pattern. It also replaces content that can't be parsed or couldn't be redacted. See Redact by pattern.
Check kind	How a rule template decides. `deterministic` checks don't call a model. The other kinds are `aggregate`, `judge`, which uses a large language model (LLM) as a judge, and `classifier`, which calls a model that returns a class.
Collector endpoint	The base URL of the OpenTelemetry Protocol (OTLP) collector that receives your spans, logs, and metrics over HTTP.
Content capture	Recording prompt, response, and message content on spans. It's on by default. To turn it off, set `OTEL_INSTRUMENTATION_GENAI_CAPTURE_MESSAGE_CONTENT=false`.
Contract revision	The version of the telemetry contract that the SDK follows. The current revision is `1.0.0`.
Conversation id	The key that groups traces into a session. The SDK sets it as the span attribute `gen_ai.conversation.id`. It's empty when your code didn't set one. See Track users and sessions.
Cost	The estimated cost of LLM calls in US dollars (USD). AIO adds it up only over LLM steps that have a price, and it has no value when none of them do. See Cost tracking.
Digest	A `sha256:<hex>` value that replaces a whole withheld value. A digest shows which value was in use, but not what it said. See Hide system prompts and tool definitions.
Endpoint	The URL of the AIO server. The SDK uses it to find projects by name. Starting with SDK version 1.0.0.dev2, `endpoint` means the AIO server. Before that version, it meant the OTLP collector.
Environment	The deployment environment your application runs in, set as `deployment.environment`. The default is `default`. A rule with no environment watches every environment.
Eval type	One evaluation that AIO can run. Each eval type has an id, a label, a description, an enabled flag, a custom flag, and a threshold score.
Facet	A dimension you can filter on in the filter rail of a list. See Explore traces.
Fail-open	A guard that raises an error is treated as `allow`. This is the default for a guard pipeline.
Guard	A check that runs inside your application on a prompt or a response. See Guard overview.
Guard action	What a guard decides: `allow`, `warn`, `redact`, or `deny`, from least to most severe. When several guards run together in a pipeline, the most severe action wins.
Guard phase	When a guard runs. `preflight` runs on the input before the model call. `postflight` runs on the output after the model call.
Input preview	The user input for an operation, set as `aio.input_preview`. It's cut off at 2,000 characters.
Instrumentor	A library integration that creates spans automatically. The SDK skips any integration whose library isn't installed.
Judge model	A model that must be bound to the workspace before a rule from a template that needs a judge can run.
No value	The facet label for rows where that dimension isn't set.
Offline evaluation	A prompt and response pair that you send from the SDK to be scored against one or more eval types. See Run an eval.
Payload state	How a step's content arrived: `inline`, `truncated`, `redacted`, or `expired`. Previews are taken after redaction and are a few KB in size.
Project	The container your telemetry is sent to. See Create a project.
Project id	A UUIDv7 (universally unique identifier, version 7) that identifies a project.
Project slug	The part of a project's URL that names it. It's unique within a tenant and stays the same when you rename the project.
Project status	The state of a project: Active, Archived, or Setup incomplete.
Redaction policy	The set of rules that withhold content before it leaves your application. Every switch is off by default. See Redaction overview.
Release	The version of your application, taken from `service.version`. When that isn't set, AIO uses the agent version hash.
Root span	The span that `root_span()` opens for one unit of work, also called an operation. Its identity values are added to every span and log record created inside it.
Rule	A saved check that belongs to one project. A rule has a template, name, description, enabled flag, environment, unit, severity, score type, sample rate, and parameters. Editing a rule creates a new rule version. See Rules overview.
Rule template	What a rule is created from, for example `banned_term` or `empty_output`. Each template belongs to a category, such as Output integrity. See Create a rule.
Run id	The id that groups the evaluations of one batch. The default is `batch_` followed by 12 hexadecimal characters.
Sample rate	The fraction of eligible traffic that a rule checks, from 0 to 1.
Score	An evaluation result attached to a span as a `gen_ai.evaluation.result` event.
Score type	The kind of score a rule produces: `bool` or `numeric`.
SDK name	The instrumentation that produced a span.
Service	The name of your instrumented application, set as `service.name`. The default is `unknown_service`.
Session	The traces that share one conversation id. A session is also called a conversation. AIO assumes one user per session. See Track users and sessions.
Severity	How serious a finding is: LOW, MEDIUM, HIGH, or CRITICAL. When no severity is set, the UI shows —.
Span	One operation inside a trace. The UI shows spans on the Spans tab and calls each one a step in labels such as Step id, Parent step, and Steps. The kinds are llm, tool, agent, chain, http, mcp, and retriever. The status is ok, error, or unset.
Storage mode	Where a project's data is kept: Acceldata hosted, Customer store, or Existing OTel. Customer store and Existing OTel require a dataplane. When no mode is set, the UI shows —.
Suppressed span	A span that's never recorded because a redaction rule names it. Every span below it is dropped too. See Drop attributes and spans.
Tenant	The organization that owns the telemetry. Every span carries it as `aio.tenant_id`, and telemetry doesn't start without it.
Threat detected event	A `gen_ai.agent.threat_detected` event attached to a span.
Tokens	Total tokens are input tokens plus output tokens, where input tokens include cached tokens. Billable tokens leave out cached tokens.
Trace	One unit of work. Each trace is one row on the traces list. Its totals can still change while the trace is open. The status is `ok` or `error`. See Tracing overview.
Turn	One trace within a session. Last turn shows the name of the root span of the most recent turn.
Unit	What a rule evaluates: `span`, `trace`, `session`, or `window`.
User id	The end user of your application, set as `aio.user_id`. See Track users and sessions.
Verdict	The outcome of one rule on one span, trace, or session. `VERDICT_PASS` means the check passed. `VERDICT_FAIL` is a finding. `VERDICT_ERROR` means the rule couldn't decide. `VERDICT_SKIPPED` always comes with a reason for the skip.

Glossary

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