server/

OVERVIEW

Binary entry point + orchestration layer. CliMain (workerd.c++) dispatches subcommands (serve, compile, test, fuzzilli, pyodide-lock) via kj::MainBuilder. Server (server.c++, ~6K lines) is the god object: parses workerd.capnp config, constructs all service types as nested inner classes, wires sockets/bindings/actors, runs the event loop.

KEY FILES

File	Role
workerd.c++	CliMain: subcommand dispatch, config loading, file watching, signal handling
server.h/c++	Server class: 15+ nested inner classes (WorkerService, NetworkService, ExternalHttpService, DiskDirectoryService, etc.). Two-phase init: startServices() then listenOnSockets()
workerd.capnp	Config schema: Config, Service, Worker, Socket, Extension. Capability-based security model
workerd-api.h/c++	WorkerdApi: registers all JS API types with JSG, compiles modules/globals, extracts source from config. Global struct has 20+ binding variants as kj::OneOf
alarm-scheduler.h/c++	DO alarm scheduling with SQLite-backed persistence
json-logger.h/c++	Structured JSON logging for tail workers
channel-token.h/c++	Opaque token encoding for cross-service channel references
v8-platform-impl.h/c++	Custom v8::Platform bridging V8 tasks to KJ event loop
fallback-service.h/c++	Module fallback resolution via external service
container-client.h/c++	Experimental (2025): Docker container lifecycle for DO containers
docker-api.capnp	Cap'n Proto schema for container management
pyodide.h/c++	Python worker preloading and snapshot management

TEST INFRASTRUCTURE

server-test.c++ (~6K lines): integration tests using inline Cap'n Proto config strings. Tests full server lifecycle with real V8 isolates.

tests/server-harness.mjs: Node.js harness spawning workerd child processes for E2E tests. Subdirectories: compile-tests, container-client, extensions, inspector, python, structured-logging, unsafe-eval, unsafe-module, weakref.

Pattern: unit tests (*-test.c++) at directory level; integration/E2E tests in tests/ using the harness.