Workflow Engine
The workflow engine (internal/workflow) is a Go-native orchestration runtime for composing multi-agent pipelines inside a running harnessd process. Instead of a single agent prompt, you write a Script — a regular Go function — that calls sub-agents, fans work out in parallel, pipes items through stages, tracks a token budget, and emits structured progress events as it runs. The engine handles scheduling, lifecycle tracking, SSE event emission, and failure recovery so your script can focus entirely on what the pipeline needs to do.
Workflow SDK
The Workflow SDK (go-agent-harness/pkg/workflowsdk) is the only client-facing public package of the harness module intended for use in workflow bundles. It is a thin client library you link into a small standalone binary — called a workflow bundle — so that harnessd can discover, compile, and drive it at runtime.
Symphony
symphd is a long-running daemon that turns labeled GitHub Issues into agent runs. It polls a repository for issues carrying a configurable label, provisions an isolated workspace for each one, dispatches a run to harnessd over HTTP, and retries failures with exponential back-off — all without a database. When an issue is resolved the workspace is destroyed; if it exhausts its retry budget, it moves to a dead-letter queue you can inspect via the HTTP API.
Go Relay
Go Relay is the orchestration layer that sits above go-code's execution runtime. While a single harnessd instance executes one run inside one workspace, Relay answers a higher-level question: where, what, and how should each run execute across a fleet of registered workers?