OpenShell/proto

Protobuf API conventions

This directory defines OpenShell's gRPC contracts. These conventions are the source of truth for public protobuf API design. Apply them to new APIs and when changing existing APIs; generated SDK naming follows from these definitions.

Entity references

• Use name for the primary resource targeted by an RPC.
• Use the resource's role for a related resource reference, such as sandbox, provider, service, or rule.
• Do not append _name to a canonical entity reference. Its value is already the canonical name. Descriptive values, local map keys, implementation labels, and configured registration names that are not entity references may retain the suffix. Examples include display_name, file_name, driver_name, runtime_class_name, rule_name, and middleware_name.
• Public callers reference entities by canonical name. Keep immutable IDs at authentication, persistence, compute-driver, and other internal boundaries.

For example:

message GetSandboxRequest {
  openshell.datamodel.v1.WorkspaceSelector workspace_scope = 2;
  string name = 1;
}

message ExposeServiceRequest {
  openshell.datamodel.v1.WorkspaceSelector workspace_scope = 5;
  string sandbox = 1;
  string name = 2;
}

GetSandboxRequest.name identifies the RPC's primary resource. ExposeServiceRequest.sandbox identifies a related sandbox while name identifies the service being exposed.

Workspace scope

• Public workspace-scoped requests declare workspace_scope before every other field. Existing wire field numbers do not need to follow declaration order.
• Type workspace_scope as openshell.datamodel.v1.WorkspaceSelector.
• Requests operating in one workspace require a non-empty canonical WorkspaceSelector.workspace. The default workspace is an explicit name, not an omitted-value fallback.
• Accept WorkspaceSelector.all_workspaces only on collection-list RPCs that explicitly document and authorize cross-workspace access. The supported public collections are sandboxes, sandbox templates, providers, and services.
• Requests whose primary resource is a workspace use name, not workspace_scope.
• Document every request that permits an omitted selector. Current exceptions are platform provider-profile scope and authenticated sandbox bootstrap.

Field and message design

• Prefer a dedicated request and response message for each RPC, including requests that are currently empty.
• Use google.protobuf.Timestamp for absolute time and google.protobuf.Duration for elapsed time.
• Use optional presence when omitted and explicitly empty values have different meanings. Do not infer presence from a protobuf scalar's default value.
• Keep public request fields in semantic reading order. Field numbers preserve wire identity and may therefore differ from declaration order.
• Document authorization-sensitive selector variants and omission semantics on the containing request.

Schema evolution

• Treat field numbers and fully qualified message names as durable wire identities.
• When removing or renaming a field, reserve its old number and source name. Do not reuse either for a different meaning.
• Review changes against both the public descriptor closure and durable stored protobuf closure. The public_and_durable_schema_inventories_are_complete test in openshell-server owns both inventories.
• Regenerate Rust, Python, Go, and TypeScript bindings after contract changes. Run mise run pre-commit, the affected SDK checks, and relevant server tests before submitting the change.

Supervisor host protocol

supervisor_host.proto is the private stream between a gateway and the supervisor process it shares among its sandboxes: the supervisor attaches, the gateway sends complete assignment snapshots, and the supervisor reports what it hosts. It is a version-locked deployment protocol served on the gateway listener but authorized only for the gateway-minted supervisor token (auth_mode: "supervisor"). It is not imported by openshell.proto, so SDK generation and gRPC reflection exclude it; the server's schema inventory test classifies it explicitly. SandboxInstanceAssignment.launch_material carries the existing JSON sandbox instance registration of openshell-supervisor-control and is marked secret.

Isolation backend protocol

isolation_backend.proto defines backend discovery, boundary binding, and optional suspend/resume RPCs. sandbox_protocol.proto defines typed workload control, process I/O, and network mediation over the bound boundary. Both are supervisor-to-backend contracts, not gateway RPCs. Backend authors can generate bindings independently from these definitions. The negotiated Sandbox Protocol version covers the gRPC services, typed messages, streaming, and lifecycle semantics.