> ## Documentation Index
> Fetch the complete documentation index at: https://infercrane.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Runtime contract

> The capability, readiness, protocol, cancellation, and evidence contract for inference runtimes.

# Runtime Contract V1

Status: implemented. vLLM is locally qualified; SGLang and declarative custom OCI
workloads exercise the contract through hermetic simulation. Real-GPU evidence remains deferred
until consolidated real-infrastructure qualification.

## Ownership

Inference engines own execution, batching, model loading, cache behavior and engine-native metrics.
InferCrane owns immutable runtime identity, capability validation, lifecycle coordination,
normalized evidence, routing membership and safe revision policy.

## Required contract

A runtime profile declares:

* stable adapter and semantic contract version
* engine/version and immutable workload identity
* protocol and supported operations
* readiness and model-identity inspection
* buffered and streaming behavior
* cancellation and graceful drain/shutdown behavior
* telemetry endpoints and normalized metric mappings
* tool, structured-output and embedding capabilities where tested
* compatibility constraints for artifact, accelerator and runtime arguments

Declared, probed, simulated, locally qualified and real-qualified capabilities remain distinct.
Unsupported behavior fails before paid provisioning whenever it is knowable.

Production composition binds each runtime inspector to its validated `RuntimeProfile`. Provisioning
and reconciliation resolve that immutable binding by runtime identity; an adapter cannot execute
under a different runtime's capability claims, and an unregistered runtime remains unroutable.

## Custom OCI workloads

InferCrane may accept an immutable OCI image plus explicit protocol, port, health, telemetry and
shutdown declarations. It does not build or execute an image builder, sandbox arbitrary code, or
infer compatibility from an `OpenAI-compatible` label alone.

The portable contract persists argv rather than a shell fragment and standardizes `/health`,
`/v1/models`, and `/metrics`. It supports OpenAI-compatible HTTP, HTTP-disconnect cancellation,
connection-generation draining, and a bounded shutdown-grace declaration. See [Custom OCI
workloads](/features/custom-oci) and inspect the exact runtime/provider matrix with
`infercrane integrations`.