> ## Documentation Index
> Fetch the complete documentation index at: https://docs.blobhub.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Job Types

> The job_type discriminator on a section, and the supported types

`job_type` is the discriminator that selects how the worker handles a section. Every section in
`~/.blobhub-worker/config.yaml` declares one, and the worker dispatches the section to the matching
job-type implementation. For the user-level mental model of sections, sessions, and agents, see
[Concepts](/worker/concepts); this page is the specification of what the discriminator selects.

A section's `job_type` determines three things:

* **Required blocks** — which job-type-specific blocks the section must declare under it (e.g.
  `session_agent_harness` requires a `session` block).
* **Top-level blocks** — which additional top-level config blocks apply to the section (e.g.
  `session_agent_harness` consults the `agents` block for agent settings).
* **Runtime behavior** — what the worker actually **does** with the section: what it attaches to,
  what it polls, and what it posts.

The generic `start` flow handles process startup, identity checks, config load, and section
dispatch. Once a section is dispatched, the per-job-type implementation owns its lifetime — including
recovery on restart.

## Supported job types

| `job_type`              | Purpose                                                                                                                                            | Reference                                                                  |
| ----------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------- | -------------------------------------------------------------------------- |
| `session_agent_harness` | Attach to one BlobHub session, watch its thread session objects, and drive a coding agent (Claude Code, Codex) per thread that the user hands off. | [Session Agent Harness → Overview](/worker/session-agent-harness/overview) |

Each job type has its own group under **Specification** containing its full notation: the session
objects it drives, its filesystem layout, its workflows, and its reference (error codes and
limitations). The generic `config.yaml` blocks are shared by all job types and documented once under
[Configuration](/worker/configuration).

## Adding a new job type

Future job types land as their own navigation group alongside Session Agent Harness, following the
same shape (overview, filesystem layout, session objects, workflows, reference). The generic Overview
pages and the shared `config.yaml` reference do not change when a job type is added; only that job
type's `sections` shape and its top-level block usage are new.

## See also

* [Concepts](/worker/concepts) — the user-level mental model of sections, sessions, and agents.
* [Configuration](/worker/configuration) — generic `config.yaml` blocks shared by all job types.
* [`blobhub-worker start`](/worker/cli/start)