# `GenAgent.Backends.Claude`
[🔗](https://github.com/genagent/gen_agent/blob/gen_agent_claude-v0.2.0/integrations/claude/lib/gen_agent/backends/claude.ex#L1)

`GenAgent.Backend` implementation backed by `ClaudeWrapper`.

Each session wraps a set of `ClaudeWrapper` options (config +
query-level) and threads the Claude CLI's `session_id` across turns
so that a persistent conversation is maintained without any
`ClaudeWrapper.Session` or `ClaudeWrapper.SessionServer` involvement.

## Options

`start_session/1` accepts `ClaudeWrapper.stream/2` options except
`:no_session_persistence`, which cannot be enabled because this backend
resumes the CLI session on later turns:

  * Config: `:binary`, `:working_dir` (aliased as `:cwd`), `:env`,
    `:timeout`, `:verbose`, `:debug`
  * Query: `:model`, `:system_prompt`, `:append_system_prompt`,
    `:max_turns`, `:max_budget_usd`, `:permission_mode`,
    `:dangerously_skip_permissions`, `:effort`, `:json_schema`,
    `:agent`, `:brief`, `:include_partial_messages` (on by default)

Plus a backend-only option:

  * `:stream_fn` -- a 2-arity function `(prompt, opts) -> Enumerable.t()`
    that replaces the default `&ClaudeWrapper.stream/2`. Intended for
    tests; production code should leave this alone.

## Session continuation

On the first turn, no `:resume` flag is passed. When the terminal
`:result` event arrives, `update_session/2` captures `session_id`
from the event data and stores it on the session struct. Under GenAgent,
`prompt/3` also checkpoints a raw `system` or terminal ID as soon as it
arrives, so failed and interrupted turns can resume. Subsequent
turns pass that id through Claude's `--resume` flag, without forwarding
the first turn's `:session_id` or `:continue_session` options.

`terminate_session/1` has no native process to close. GenAgent cancels
its prompt task on interrupt, watchdog, stop, or agent death, but the
default Port runner closes pipes without guaranteeing that the CLI and
its subprocesses have exited. Choose a runner with process-group
termination when OS-level settlement is required.

# `t`

```elixir
@type t() :: %GenAgent.Backends.Claude{
  opts: keyword(),
  session_id: String.t() | nil,
  stream_fn: (String.t(), keyword() -> Enumerable.t())
}
```

---

*Consult [api-reference.md](api-reference.md) for complete listing*