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

# Plan admission

> Bind a graph description to a host admission record.

Use `resolveGraphPlan(description, resolution)` after you compile a graph.
It returns a frozen plan, canonical JSON, and a SHA-256 digest.

The plan is data. It cannot execute code or grant a permission.

## Host admission

The host provides a `PlanResolution`. It contains:

* The graph package source, version, and digest.
* The same package identity in the host admission record.
* The permissions that the host admits.
* One effective execution target for each declared execution lane.
* An optional ordered fallback list for each lane. An omitted list means no
  fallback.

The package identity in the resolution and admission record must match exactly.
The graph package asks for permissions in `describe()`. Each requested
permission must match an admitted permission by name and JSON scope. If it does
not match, `resolveGraphPlan` throws `GraphValidationError` with
`PERMISSION_NOT_ADMITTED`.

Extra admitted permissions do not become graph permissions. The resolved plan
keeps requested and admitted permissions as separate lists.

## Resolve execution lanes

Each described lane names a requested adapter, provider, model family, model,
and tools. A graph can also declare known substitutions.

The host resolves every described lane exactly once. An effective target must
equal the requested target or one declared substitution. Unknown, missing, or
extra lane resolutions are rejected.

The resolved plan records the requested target, effective target, and fallback
order. A change to an adapter, provider, model family, model, tools, allowed
substitution, or fallback order changes the plan digest.

## Plan snapshot

Resolve the plan before a host starts work. The returned plan snapshot is
frozen. Its package identity, permissions, lanes, policies, and bounds stay in
the snapshot that its digest identifies.

Run parameters are not part of the resolved plan or its digest. The run record
keeps resolved inputs as part of the frozen run.

## Run parameters

`run(job, { params })` accepts a JSON object. If `params` is `undefined`, the
run uses a frozen empty object. `null`, arrays, and other invalid roots are
rejected with `JsonValueError` before work or environment setup starts.

For a valid object, `run` clones and freezes `params` before work starts. The
root job and each child job receive the same frozen object as `ctx.params`. A
later change to the caller's `params` object cannot change `ctx.params`.
Non-JSON nested values also throw `JsonValueError`. Its `path` identifies the
invalid value.

## Trusted package boundary

An outside graph type is trusted package code. The conformance kit checks its
public behavior. It is not a security sandbox.

The host owns package discovery, signature checks, and sandboxing. The graph
contract only validates the package identity, admission record, and plan data
that the host provides.

## Limits

Plan admission does not schedule nodes, store runs, provide built-in graph
forms, or execute work on another machine.