# Audita LLM Runtime

## Client Boundary

`llm.NewRuntime` assembles one PromptKit engine for both roles. It loads embedded
prompt and schema assets, registers application backends, and inspects the
selected proposal and validation profiles offline. A role-bound `llm.RoleClient`
implements `structuredoutput.Client`; proposal and validator contracts alias that
interface during migration. Both roles share engine-local backend capacity.

For each logical call, the adapter starts an operation context and a diagnostic
record before preparation. It supplies the reserved hardening text, the selected
profile and resolved backend credential, and the complete embedded schema/repair
contract. `PrepareExecution` produces the exact messages and hashes retained in
an Audita snapshot. The adapter checks the prepared backend and endpoint before
`RunPrepared`. It records available final content, usage, model, and profile
metadata and decodes only a validated result. Call hooks expose logical
start/finish records and PromptKit execution events for the report collector.

The [integration contract](../integrations/openai-compatible-llm.md) describes
wire ownership and failure behavior. `structuredoutput.Failure` has a safe
message and a typed cause; only exhausted structural repair is a malformed
output failure. Secrets from all configured backends, including unselected
ones, are available to the diagnostics redaction boundary.

## Current Orchestration

The old `llm.Scheduler` and runner instrumentation still exist pending the
orchestration migration. The final runtime uses PromptKit backend admission,
retry, and repair rather than that scheduler. `llm.DiagnosticsWriter` remains
the current protected artifact writer.

Focused adapter tests use controlled local HTTP responses. Complete runner and
CLI integration checks follow the caller and orchestration migration.