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ContextProvider

contextgraph_host::provider

Trait ContextProvider 

Source 
pub trait ContextProvider: Send + Sync {
    // Required methods
    fn id(&self) -> &str;
    fn info(&self) -> &ProviderInfo;
    fn capabilities(&self) -> &Capabilities;
    fn query<'life0, 'life1, 'async_trait>(
        &'life0 self,
        query: &'life1 ContextQuery,
    ) -> Pin<Box<dyn Future<Output = Result<ContextQueryResult, HostError>> + Send + 'async_trait>>
       where Self: 'async_trait,
             'life0: 'async_trait,
             'life1: 'async_trait;

    // Provided methods
    fn verify<'life0, 'life1, 'async_trait>(
        &'life0 self,
        request: &'life1 VerifyRequest,
    ) -> Pin<Box<dyn Future<Output = Result<VerifyResponse, HostError>> + Send + 'async_trait>>
       where Self: 'async_trait,
             'life0: 'async_trait,
             'life1: 'async_trait { ... }
    fn shutdown<'life0, 'async_trait>(
        &'life0 self,
    ) -> Pin<Box<dyn Future<Output = Result<(), HostError>> + Send + 'async_trait>>
       where Self: 'async_trait,
             'life0: 'async_trait { ... }
}
Expand description

A registered Context Graph Protocol provider, queryable behind one handle regardless of transport. info()/capabilities() return values cached at handshake time, so they are cheap synchronous getters even for out-of-process providers.

Required Methods§

Source

fn id(&self) -> &str

The provider’s host-facing id — its routing key and its consent key (SPEC.md §4 and §10).

Source

fn info(&self) -> &ProviderInfo

Identity + declared data-flow direction, surfaced at consent time (SPEC.md §3, ).

Source

fn capabilities(&self) -> &Capabilities

Capabilities negotiated at the handshake (SPEC.md §3): which frame kinds this provider serves, whether it echoes a correlation id, does graph, names an embedding space, answers context/verify, which frame representations it can return, and whether it answers context/resolve.

That is the whole of Capabilities — seven fields. This comment used to describe upsert, subscriptions and filters, which ADR 0004 removed because nothing implemented them. The sentence outlived them and was copied into docs/implementing-a-provider.md, so a provider author read it as the contract (#151).

Source

fn query<'life0, 'life1, 'async_trait>( &'life0 self, query: &'life1 ContextQuery, ) -> Pin<Box<dyn Future<Output = Result<ContextQueryResult, HostError>> + Send + 'async_trait>>
where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait,

Answer a context query with budgeted, provenance-carrying frames (SPEC.md §5). The host — not the provider — enforces the budget and consent; a provider that over-runs its budget is caught by the host, not trusted (crate::host).

§Signing

A provider that signs what it serves populates frame_attestations and result_attestation on the result it returns (SPEC.md §6.5.5). There is no second method and no second channel: the evidence is part of the answer, so an in-process provider and a transport-backed one carry it identically, and a host can never be handed signatures that disagree with the frames they cover (ADR 0014).

This trait previously offered a defaulted query_attested returning an AttestedQueryResult, from the months when the frames envelope had nowhere to put an attestation. It does now, so both are gone.

The host checks whatever arrives against its TrustStore and records the outcome in the composition audit. Whatever it finds, the frames are served either way (SPEC.md F9).

Provided Methods§

Source

fn verify<'life0, 'life1, 'async_trait>( &'life0 self, request: &'life1 VerifyRequest, ) -> Pin<Box<dyn Future<Output = Result<VerifyResponse, HostError>> + Send + 'async_trait>>
where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait,

Revalidate frames the host already holds, without any frame body travelling (docs/context-reuse.md §4 context/verify).

Defaults to answering Verdict::Unknown for every requested identity, so an existing provider implements nothing and is simply treated as unable to vouch for its frames — the host then re-queries them. A provider that overrides this MUST also advertise Capabilities::verify, since the host only asks providers that declare support.

Source

fn shutdown<'life0, 'async_trait>( &'life0 self, ) -> Pin<Box<dyn Future<Output = Result<(), HostError>> + Send + 'async_trait>>
where Self: 'async_trait, 'life0: 'async_trait,

Shut the provider down cleanly (SPEC.md §3 lifecycle). In-process providers default to a no-op; transport-backed providers send shutdown and reap their child. Overridable.

Dyn Compatibility§

This trait is dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors§