MCP Tools

Dagu intentionally exposes three MCP tools.

Tool	Purpose
dagu_read	Read DAG specs, DAG details, DAG-run details, logs, list views, and Dagu MCP reference resources.
dagu_change	Validate and optionally apply a DAG YAML upsert.
dagu_execute	Start, enqueue, retry, or stop DAG runs.

dagu_read

Use dagu_read for current Dagu state.

Input	Values
target	dags, dag, dag_spec, runs, run, run_logs, or reference
name	DAG name for DAG and run targets
dagRunId	DAG-run ID for run and log targets
query	URL query string for list and log targets, such as page=1&perPage=100 or tail=100
uri	Direct resource URI, such as dagu://reference/authoring

Examples:

{ "target": "dags", "query": "page=1&perPage=100" }

{ "target": "dag_spec", "name": "nightly-report" }

{ "uri": "dagu://runs/nightly-report/latest/logs?tail=100" }

dagu_change

Use dagu_change for DAG YAML edits. The only current change type is upsert_dag.

Input	Values
mode	preview or apply; defaults to preview
type	upsert_dag; defaults to upsert_dag
name	DAG name to create or update
spec	Full DAG YAML specification

Preview validates the spec without writing it:

{
  "mode": "preview",
  "type": "upsert_dag",
  "name": "nightly-report",
  "spec": "steps:\n  - name: hello\n    command: echo hello\n"
}

Apply writes only after validation succeeds:

{
  "mode": "apply",
  "type": "upsert_dag",
  "name": "nightly-report",
  "spec": "steps:\n  - name: hello\n    command: echo hello\n"
}

dagu_execute

Use dagu_execute for run control.

Input	Values
action	start, enqueue, retry, or stop
targetType	dag, inline_spec, or run; inferred when omitted
name	DAG name or optional inline spec name
spec	Inline DAG YAML for start or enqueue with targetType=inline_spec
dagRunId	Run ID override for start/enqueue, or target run for retry/stop
params	Runtime parameters as a JSON string
queue	Queue override for enqueue
singleton	Prevent duplicate running or queued runs when supported
labels	Labels as key=value or key-only strings
stepName	Optional step name for retry

Start a stored DAG:

{ "action": "start", "targetType": "dag", "name": "nightly-report" }

Enqueue a stored DAG:

{ "action": "enqueue", "name": "nightly-report", "queue": "default" }

Retry a run:

{ "action": "retry", "name": "nightly-report", "dagRunId": "20260522T010000" }

Stop a run:

{ "action": "stop", "name": "nightly-report", "dagRunId": "20260522T010000" }

When a run can be identified, dagu_execute returns resource links for run details and logs. Clients that support subscriptions can subscribe to the returned run resource.