Documentation navigation

Documentation / guides

Context Transports

Describe context transport choices exposed by a loop definition and bound runtime.

developer

A context transport couples wire identity to an inference counting posture:

type ContextTransport struct {
	Provider   model.ProviderName
	APIFormat  model.APIFormat
	BaseURL    string
	Capability contextcount.InferenceCapability
}

func WithContextTransports(transports ...ContextTransport) Option
type BoundDefinition interface {
	ContextTransportCapability(model.Model) (contextcount.InferenceCapability, bool)
}
func (d Definition) ValidateContextModel(model.Model) error

The transport key is exactly (Provider, APIFormat, BaseURL). Model name, sampling, caps, limits, and origin do not change transport identity. Effort is a request parameter, not a trust-boundary change.

Declare the set

With a counter and capability, omitting WithContextTransports synthesizes one member from the base WithInference model and WithInferenceCapability. Supplying the option replaces that synthesized set with the complete allowed set. The set must:

contain the base model’s transport with exactly the declared base capability;
contain no duplicate (Provider, APIFormat, BaseURL) member;
use valid capabilities compatible with the loop’s counter;
include every model used by a declared mode.

definition, err := loop.Define(
	loop.WithName("assistant"),
	loop.WithInference(client, primary),
	loop.WithContextCounter(counter),
	loop.WithInferenceCapability(primaryCapability),
	loop.WithContextTransports(
		loop.ContextTransport{
			Provider: primary.Provider, APIFormat: primary.APIFormat,
			BaseURL: primary.BaseURL, Capability: primaryCapability,
		},
		loop.ContextTransport{
			Provider: backup.Provider, APIFormat: backup.APIFormat,
			BaseURL: backup.BaseURL, Capability: backupCapability,
		},
	),
	loop.WithContextObservation(policy),
)
if err != nil {
	return err
}

Membership and switching

Definition.ValidateContextModel and the bound method reject a candidate whose transport is not declared. A live ChangeModel therefore cannot move a loop to an undeclared endpoint or posture. The capability lookup returns (zero, false) for a nonmember; it never falls back to the base capability.

%%{init: {"theme":"dark"}}%%
flowchart TD
    M[Candidate model] --> K{Provider/APIFormat/BaseURL in set?}
    K -->|no| R[reject with ContextTransportNotDeclaredError]
    K -->|yes| C[use member capability]
    C --> V{counter compatible?}
    V -->|no| R2[reject definition or change]
    V -->|yes| A[admit counting and request]

The transport set is immutable and included in Definition.PolicyRevision. Changing a transport, endpoint, or capability is therefore a restore-visible policy change.

Source and proof

← back to documentation