Crate aion_server 

Deployable HTTP, gRPC, WebSocket, and worker endpoint for Aion workflows.

This crate wraps the transport-agnostic engine with API handlers, namespace isolation, observability, shutdown handling, ops-console assets, and remote-worker task dispatch.

Example

use aion_server::ServerConfig;

let config = ServerConfig::default();
println!("serving gRPC on {}", config.server.grpc_address);

Re-exports

pub use build_identity::BuildIdentity;

pub use config::ServerConfig;

pub use deploy::DeployGuard;

pub use dev_ui::ActivityMockRegistry;

pub use dev_ui::DevMockingDispatcher;

pub use dev_ui::MockedActivity;

pub use error::ServerError;

pub use error::StreamFailure;

pub use mcp::AionToolService;

pub use mcp::McpRuntime;

pub use namespace::CallerIdentity;

pub use namespace::DISPLAY_NAME_ATTRIBUTE;

pub use namespace::NAMESPACE_ATTRIBUTE;

pub use namespace::NamespaceGuard;

pub use namespace::NamespaceMinter;

pub use namespace::NamespaceOperation;

pub use namespace::NamespaceResolver;

pub use namespace::ScheduleNamespaceSource;

pub use namespace::ScheduleTarget;

pub use namespace::ScopedEngine;

pub use namespace::StaticScheduleNamespaces;

pub use namespace::StaticWorkflowNamespaces;

pub use namespace::SubscriptionScope;

pub use namespace::TASK_QUEUE_ATTRIBUTE;

pub use namespace::WorkflowAttribution;

pub use namespace::WorkflowNamespaceSource;

pub use namespace::WorkflowTarget;

pub use run::run;

pub use state::ServerState;

pub use worker::HeartbeatSweeper;

pub use worker::HeartbeatTracker;

pub use worker::HeartbeatUpdate;

pub use worker::InFlightActivity;

pub use worker::LostWorkerReport;

pub use worker::TaskLiveness;

Modules

activity_publisher

NOI-5 transcript sequencer + live fan-out — commit-allocated store_seq over the durable O keyspace, plus the resumable transcript broadcast. NOI-5 transcript sequencer + fan-out — the durability-critical server bridge.

api

Module declarations.

assistant

The built-in assistant: the embedded AWL document, its boot install, and the description the server serves of it. The built-in assistant: the aion authoring assistant ships INSIDE the server binary, present the moment aion server runs.

authoring

Server-side Gleam authoring surface (compile, type-check, package, hot-load). Server-side Gleam authoring surface: compile, type-check, package, and hot-load submitted workflow source.

build_identity

What code this server is: the revision stamped into the binary at build time, so a running server can be asked rather than guessed about (#123). What code is this server (#123).

changelog

The release changelog embedded in the binary, serving the console’s “What’s new” panel: what changed in the version this server RUNS, never a file read from disk. The release changelog, embedded so the installed binary carries it.

cluster

SS-5b automatic multi-node failover detection (cluster supervisor). Only meaningful for a distributed ([store.cluster]) boot; dormant otherwise. SS-5b: automatic multi-node failover detection.

cluster_publisher

WS3 cluster topology/ownership broadcast publisher. The ops console’s cluster channel is served on every boot, showing calm state with no peers on a single-node server. WS3 cluster topology/ownership broadcast publisher.

config

Runtime configuration loading and validation. Runtime configuration loading and validation for aion-server.

control

Server control from the operator’s desk: the pid file the server writes, the incarnation checks that make it trustworthy, the shutdown outcome record that crosses the process boundary, and the stop flow built on all three. aion server stop / aion server status render these; the logic and its types live here so the server crate owns one truth about its own lifecycle records.

death_note

Durable record of what killed the server process on paths that never reach the graceful-shutdown log. The server’s death note: a durable record of what is killing the process on paths that never reach the graceful-shutdown log.

deploy

Operator deploy surface authorization. Operator deploy surface: authorization guard for the deploy API.

dev_ui

Local dev-server surface: trigger a run, stream it over the existing firehose, mock a named activity per-run, and replay a failed run — all over the real engine, store, and event stream. Local dev-server surface with production parity.

error

Server error and stream-failure types. ServerError taxonomy for server library modules.

mcp

The Model Context Protocol surface (2026-07-28 stateless revision): the tool catalog, the tool implementations, and the /mcp mount. Module declarations.

namespace

Namespace resolution and authorization guard types. Namespace authorization and routing support.

observability

Health, metrics, and tracing support. Server-level observability surfaces.

ops_console

Ops-console asset serving helpers. Embedded ops-console asset serving support.

routing

Distributed request routing: the gRPC-edge availability layer over the fence. Distributed request routing — the gRPC-edge availability layer over the epoch fence (DISTRIBUTED-ROUTING-DESIGN §2).

run

Server run loop: configuration load, transports, and graceful shutdown. Run loop for the Aion workflow server: tracing initialization, configuration load, transport startup, and signal-driven graceful shutdown.

shutdown

Cooperative shutdown and drain handling. Graceful shutdown and single-node activity drain coordination.

state

Shared server state construction and access. Shared server state constructed once at startup.

stream

WebSocket event-streaming support. Event subscription streaming surfaces.

update_check

The built-in manual-only update check: embedded document, boot install, completed-check recording, and the served last-check state. The built-in update check: “does a newer aion-cli exist?” — slice one, know and show.

worker

Remote-worker registry, heartbeat, and dispatch support. Module declarations.