Domain terms and metric definitions. Keep this file authoritative; if a term in code disagrees with the glossary, fix the code or update the glossary in the same change.
- Agent — A program that takes natural-language input, plans, calls tools and/or model APIs, and produces a final output. Could be LangGraph, OpenAI Agents SDK, CrewAI, or hand-rolled.
- Trajectory — The ordered sequence of steps an agent took during a single run.
- Step — One unit of trajectory: a
model_call, atool_call, or adecision. Each hasinput,output,latency, optionaltokensandcost, and aparent_idfor branching. - Recording — A serialized agent run:
RunMeta+ orderedStep[]+final_output+env_snapshot+ optionaltool_specs[]. Versioned (recording_schema_version). - RunMeta — Agent framework + version, model config, seeds, timestamps, redaction state.
- ToolSpec — Optional declarative description of a tool (name, signature, JSON schema for inputs/outputs, optional source/OpenAPI pointer). Used by the Tier-2 simulator to answer un-recorded inputs faithfully.
- EnvSnapshot — Initial state of the simulated world: file system, DB rows, API mock state, etc.
- Scenario — A deterministic mutation of a
Recordingthat probes a failure class. Examples:drop_tool_result,corrupt_field,inject_latency,ambiguous_user_turn,prompt_injection,reorder_steps,long_horizon_repeat. Each is seeded and labeled. - Simulated Environment — Stateful mock of the agent's external world. Tier-1 = deterministic replay from cache; Tier-2 = source-/trace-informed synthesis for un-recorded inputs.
- Run — A single execution of an agent against a
SimulatedEnvironmentunder aScenario. - Reliability Report — The multi-dimensional output of the Reliability Engine for a Run or a set of Runs. Includes the four metrics below + a single ship/no-ship verdict.
- Diff — A structural comparison of two
Runs (or twoRecordings) that identifies the earliest differing step and, where wired up, the responsible git commit.
Determinism and accuracy are uncorrelated. We must report all four; never collapse to one score.
- Trajectory determinism — Across N repeated runs of the same agent on the same scenario, do the trajectories take the same shape (same tools in the same order)? Reported as a fraction ∈ [0, 1] plus a per-step divergence map.
- Decision determinism — Do repeated runs reach the same final decision / output? Same fraction ∈ [0, 1]. May be high even when trajectory determinism is low (multiple paths, same conclusion).
- Faithfulness — Is the final output grounded in the evidence and tool results the agent actually saw? Detects hallucinations / fabrications. Scored 0..1 by a local judge model.
- Consistency-under-repetition — Distribution of outcomes across N runs. Crucially distinguishes "consistent 50% pass" (always borderline) from "catastrophic on some runs" (sometimes total failure). Reported as a histogram + a single scalar (e.g., 5th-percentile pass).
- Local judge — A small open-weight model running via Ollama, used as the default LLM-as-judge for faithfulness scoring. $0 marginal cost.
- Frontier API — Anthropic / OpenAI hosted models. Opt-in only; subject to per-project token + dollar cap.
- Replay mode — All model and tool calls are served from the recording or the simulator; no network calls leave the runner. This is the default for CI.
- Live mode — Original behavior (real model APIs, real tools). Used only at record time, or explicitly when the developer wants to refresh a recording.
- Resume here — The single concrete next task listed at the top of
docs/STATUS.md. The session START ritual reads this; the session END ritual updates it. - ADR — Architecture Decision Record. Numbered file in
docs/adr/. Written for every meaningful or hard-to-reverse choice. - Self-check / dogfood — A CI workflow that runs Volo on Volo's own example agents. The product proving itself on every push is also marketing.