runner-developer

name	runner-developer
description	Primary skill for working with the BlueLibs Runner Framework. Use it for general Runner questions, framework implementation work, and Runner-specific topics such as resources, tasks, events and hooks, middleware, tags, runtime lifecycle, serialization and validation, observability, testing, Remote Lanes (RPC and Events), and Durable Workflows. Use when this capability is needed.
metadata	{"author":"bluelibs"}

Runner

Start with ./references/readmes/COMPACT_GUIDE.md. It is the fast path for Runner's core mental model, public API shape, and common contracts.

BlueLibs Runner: Ultra Compact Guide

The Vibe

Runner is a contract-first composition engine. You define a typed graph of resources, tasks, events, hooks, middleware, tags, and errors. Then run(app) compiles that graph into a runtime that enforces behavior, isolation, lifecycle, and observability.

The first mental flip:

• You describe architecture first (*.build()), and execution comes only after run().
• Bad wiring is usually a boot-time failure, not a runtime surprise.

Core Primitives

• resource: lifecycle owner for shared state and service boundaries.
• task: typed business action with DI, middleware, validation, and typed output.
• error: typed domain failure contract.
• event + hook: explicit publish-and-react model.
• middleware: cross-cutting policy layer (identity, retries, timeout, caching, etc.).
• tag: typed metadata for discovery and policy attachment.

What Runner Changes for You

• Builder declarations are explicit and fail fast when composition is invalid.
• localId is your design language; canonical IDs are Runner’s runtime addressing.
• run(app) gives a stable runtime surface: runTask, emitEvent, getHealth, dispose, and mode/state.
• Runtime lifecycle is intentional: init → ready → running → cooldown → disposing.
• cooldown() stops accepting new external work; dispose() is final teardown.

Composition Is Real, Not Cosmetic

isolate and subtree policies make boundaries enforceable. You can define what a subtree exports, what it may depend on, and what is hidden by default.

local IDs are how teams think; canonical IDs are how the framework enforces ownership and visibility.

Context and Contract

Runner splits context cleanly:

• executionContext for runtime tracing and cancellation.
• asyncContext for business/request state (tenant, user, identity, locale).

When this split is in place, observability and policy are easier to reason about.

Testing and Safe Evolution

Most teams evolve Runner systems with:

• a minimal root resource for tests,
• run(...),
• r.override(...) for targeted behavior swaps.

This keeps behavior and contract changes isolated while preserving ids and topology.

Core Docs

Use ./references/guide-units/ for the structured framework chapters. Use this exact mapping (file -> concern):

• ./references/guide-units/02-resources.md → resources (state, lifecycle, ownership, health)
• ./references/guide-units/02b-tasks.md → tasks (typed IO, DI, runtime execution, cancellation)
• ./references/guide-units/02c-events-and-hooks.md → events and hooks (publish, subscribe, transaction, ordering)
• ./references/guide-units/02d-middleware.md → middleware (cross-cutting, retry, timeout, rate/queue control, ratelimit, caching, identity)
• ./references/guide-units/02e-tags.md → tags (metadata, discovery, discovery policy, contracts)
• ./references/guide-units/02f-errors.md → errors (typed domain errors, structured data, remediation)
• ./references/guide-units/03-runtime-lifecycle.md → runtime lifecycle (boot, ready, cooldown, shutdown)
• ./references/guide-units/04-features.md → features (HTTP shutdown, signal propagation, executionContext, runtime behavior patterns)
• ./references/guide-units/04b-serialization-validation.md → serialization and validation (schema contracts, boundary safety, custom types)
• ./references/guide-units/04c-security.md → (, , , )

For documentation authoring or guide composition, also read:

• ./references/guide-units/DOCS_STYLE_GUIDE.md
• ./references/guide-units/INDEX_GUIDE.md
• ./references/guide-units/INDEX_README.md

Topic Docs

Use ./references/readmes/ for task-specific references and alternate viewpoints. Available docs include:

• COMPACT_GUIDE.md
• ARCHITECTING_WITH_RUNNER.md
• MULTI_PLATFORM.md
• DURABLE_WORKFLOWS.md
• DURABLE_WORKFLOWS_AI.md
• REMOTE_LANES.md
• REMOTE_LANES_AI.md
• REMOTE_LANES_HTTP_POLICY.md
• SERIALIZER_PROTOCOL.md
• OOP.md
• FUNCTIONAL.md
• FLUENT_BUILDERS.md
• COMPARISON.md
• ENTERPRISE.md
• BENCHMARKS.md
• CRITICAL_THINKING.md

Read only the files that match the task.

For application structure, architectural boundaries, folder organization, subtree and isolate policy, tag reuse, and long-term maintainability, also read:

• ./references/readmes/ARCHITECTING_WITH_RUNNER.md

Snippets

Use ./references/snippets/ when the task matches a common Runner authoring shape and a canonical starting point is better than inventing one from scratch.

• app-basic.snippet for the smallest complete app shell
• task-basic.snippet for a normal runtime-backed task with DI and schemas
• task-resilient.snippet for retry, timeout, health-gating, metadata, and cancellation-aware task design
• resource-service.snippet for a long-lived dependency value with init(...) and dispose(...)
• resource-complex.snippet for typed config, child registration, context, health, and full lifecycle ownership
• resource-isolate-subtree-identity.snippet for exported surface control plus subtree identity and middleware policy
• security-identity-layering.snippet for explicit identityChecker, middleware identityScope, and subtree task identity gates
• event-hook-pipeline.snippet for exact-event emission plus hook reaction
• event-hook-transactional.snippet for reversible transactional hooks with undo closures
• middleware-task.snippet for a canonical task middleware wrapper
• tag-contract.snippet for target-scoped tags with config schema and compile-time contracts
• test-runtime-task.snippet for a runtime-backed task integration test

Prefer these snippets for starter shapes before writing custom examples. They are builder-first, use local ids, and aim to be runtime-complete rather than half-finished pseudocode. When a snippet needs failure paths, model them with typed Runner errors and prefer throw myError.new({ ... }) in examples for cleaner TypeScript inference and one less helper frame in the stack. Keep .throw(...) documented as valid shorthand, but do not treat it as the default style for new snippets.

Durable Workflows

• Read ./references/readmes/COMPACT_GUIDE.md first.
• ./references/readmes/DURABLE_WORKFLOWS.md for the main guide and canonical examples.
• ./references/readmes/DURABLE_WORKFLOWS_AI.md for the shorter token-friendly field guide.

Remote Lanes

• Read ./references/readmes/COMPACT_GUIDE.md first.
• ./references/readmes/REMOTE_LANES.md for the main guide and canonical examples.
• ./references/readmes/REMOTE_LANES_AI.md for the compact AI field guide when you need a faster refresher.
• ./references/readmes/REMOTE_LANES_HTTP_POLICY.md only when the task is specifically about HTTP transport policy.

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Source: bluelibs/runner — distributed by TomeVault.