chio-cross-protocol
Shared substrate for Chio's outward protocol edges (A2A, ACP, MCP, and
OpenAI-shaped bridges). It owns one definition of cross-protocol capability
lineage, scope attenuation, route selection, and receipt tracing, run through
one orchestrator, so edge crates do not reimplement that logic against
chio-kernel independently. Edge crates plug in a CapabilityBridge for
their envelope shape and, for non-native targets, a TargetProtocolExecutor;
this crate holds no transport and speaks no protocol wire format itself.
Responsibilities
- Define
discovery::DiscoveryProtocol, the protocol-family enum (Native,Http,Mcp,A2a,Acp,OpenAi) read fromx-chio-target-protocolschema extensions, plus theTargetProtocolRegistrythat resolves a tool's target against registered executors. - Build and validate signed capability lineage across a protocol hop
(
CrossProtocolCapabilityRef,CrossProtocolCapabilityEnvelope) and attenuate a parent capability's scope to the concrete target server/tool. - Run the shared orchestration path,
CrossProtocolOrchestrator::execute: validate request identity, resolve a capability reference via the caller'sCapabilityBridge, plan a route, and dispatch tochio-kernelor a registeredTargetProtocolExecutor. - Plan and sign route selection (
routing::plan_authoritative_route) from governed-intent control-plane hints and per-protocol route availability. - Declare the lifecycle contract that claim-eligible and compatibility-only
A2A/ACP surfaces publish, and derive publication fidelity and semantic
hints from
x-chio-*tool schema extensions. - Provide
sync_bridge_shared::block_on_tool_server_invoke, a synchronous bridge shim shared by compatibility-surface edges that fails closed under a current-thread Tokio runtime instead of deadlocking.
Public API
capability_bridge::{CapabilityBridge, CrossProtocolCapabilityRef, CrossProtocolCapabilityEnvelope}- capability-lineage trait and the signed types it produces.discovery::{DiscoveryProtocol, TargetProtocolRegistry, target_protocol_for_tool}- protocol-family enum and its executor registry.orchestrator::{CrossProtocolOrchestrator, OrchestratedToolCall}- the sharedexecuteentry point and its signed result/metadata.execution::{TargetProtocolExecutor, CrossProtocolExecutionRequest, OpenAiTargetExecutor}- the pluggable executor trait and the built-in OpenAI-shaped executor.routing::{plan_authoritative_route, RouteSelectionEvidence, RouteAvailabilityStatus}- route planning and its signed evidence.lifecycle::{RuntimeLifecycleSurface, RuntimeLifecycleContract, runtime_lifecycle_contract}- claim-eligible vs. compatibility-only lifecycle contracts.semantic_hints::{BridgeFidelity, BridgeSemanticHints, semantic_hints_for_tool}- publication fidelity and semantic-hint derivation from tool schemas.sync_bridge_shared::block_on_tool_server_invoke- shared sync-bridge shim for compatibility-surface edges.error::BridgeError- the crate's error type.
Testing
cargo test -p chio-cross-protocol
See also
chio-kernel- suppliesChioKernel, tool-call evaluation, deny-signing, and receipt issuance that the orchestrator drives.chio-core-types(depended on here under thechio-corename) - suppliesCapabilityToken,ChioScope, governance types, and canonical JSON/hashing used for capability lineage.chio-manifest- suppliesToolDefinitionused for target-protocol and semantic-hint resolution.chio-a2a-edge,chio-acp-edge,chio-acp-proxy,chio-mcp-edge,chio-openai-adapter,chio-http-core- consume this crate's orchestrator and shared types.