Example 06: Cancellation

What It Is

Cancellation is how a host stops The Archivist without turning a half-finished run into mystery meat. A visitor can close the tab, an HTTP request can disconnect, or the host can enforce a hard deadline; the same signal reaches every node.

The DAG does not change for cancellation. The execution options change, the lifecycle records the interrupted terminal state, and the result cursor says where a later resume can continue.

How It Works

The dispatcher composes the caller AbortSignal with deadlineMs and passes the resulting signal to every node as context.signal. Nodes pass that signal into adapters, tools, and retry policies. When the signal aborts, work exits through the dispatcher lifecycle as cancelled or timed_out, and result.cursor records where a checkpoint can resume later.

The Archivist scouts are the important proof point. External calls and RetryPolicy waits both receive context.signal, so aborting during a backoff or slow provider call does not wait for the happy-path timeout.

Diagrams, Examples, and Outputs

DAG registration and diagram

The Archivist sometimes talks to slow external APIs. The graph is unchanged by cancellation; the caller supplies execution options, and the same DAG records a structured interrupted lifecycle when the signal fires.

The Archivist parent DAG

55 placements

DAG JSON-LD registered with the dispatcher

{
  "@context": {
    "@version": 1.1,
    "name": {
      "@id": "https://noocodec.dev/ontology/dag/name"
    },
    "version": {
      "@id": "https://noocodec.dev/ontology/dag/version"
    },
    "entrypoints": {
      "@id": "https://noocodec.dev/ontology/dag/entrypoints",
      "@container": "@index"
    },
    "nodes": {
      "@id": "https://noocodec.dev/ontology/dag/nodes",
      "@container": "@set"
    },
    "outputs": {
      "@id": "https://noocodec.dev/ontology/dag/outputs"
    },
    "node": {
      "@id": "https://noocodec.dev/ontology/dag/node"
    },
    "dag": {
      "@id": "https://noocodec.dev/ontology/dag/dag"
    },
    "body": {
      "@id": "https://noocodec.dev/ontology/dag/body"
    },
    "source": {
      "@id": "https://noocodec.dev/ontology/dag/source"
    },
    "sources": {
      "@id": "https://noocodec.dev/ontology/dag/sources",
      "@container": "@index"
    },
    "itemKey": {
      "@id": "https://noocodec.dev/ontology/dag/itemKey"
    },
    "execution": {
      "@id": "https://noocodec.dev/ontology/dag/execution"
    },
    "concurrency": {
      "@id": "https://noocodec.dev/ontology/dag/concurrency"
    },
    "throttle": {
      "@id": "https://noocodec.dev/ontology/dag/throttle"
    },
    "reservoir": {
      "@id": "https://noocodec.dev/ontology/dag/reservoir"
    },
    "gather": {
      "@id": "https://noocodec.dev/ontology/dag/gather"
    },
    "dagReference": {
      "@id": "https://noocodec.dev/ontology/dag/dagReference",
      "@type": "@id"
    },
    "DagReference": {
      "@id": "https://noocodec.dev/ontology/dag/DagReference"
    },
    "from": {
      "@id": "https://noocodec.dev/ontology/dag/from"
    },
    "path": {
      "@id": "https://noocodec.dev/ontology/dag/path"
    },
    "candidates": {
      "@id": "https://noocodec.dev/ontology/dag/candidates",
      "@container": "@set"
    },
    "candidateDag": {
      "@id": "https://noocodec.dev/ontology/dag/candidateDag",
      "@type": "@id"
    },
    "selectedDag": {
      "@id": "https://noocodec.dev/ontology/dag/selectedDag",
      "@type": "@id"
    },
    "resultField": {
      "@id": "https://noocodec.dev/ontology/dag/resultField"
    },
    "policy": {
      "@id": "https://noocodec.dev/ontology/dag/policy"
    },
    "reducer": {
      "@id": "https://noocodec.dev/ontology/dag/reducer"
    },
    "outcome": {
      "@id": "https://noocodec.dev/ontology/dag/outcome"
    },
    "phase": {
      "@id": "https://noocodec.dev/ontology/dag/phase"
    },
    "stateMapping": {
      "@id": "https://noocodec.dev/ontology/dag/stateMapping"
    },
    "container": {
      "@id": "https://noocodec.dev/ontology/dag/container"
    },
    "DAG": {
      "@id": "https://noocodec.dev/ontology/dag/DAG"
    },
    "Placement": {
      "@id": "https://noocodec.dev/ontology/dag/Placement"
    },
    "SingleNode": {
      "@id": "https://noocodec.dev/ontology/dag/SingleNode"
    },
    "ScatterNode": {
      "@id": "https://noocodec.dev/ontology/dag/ScatterNode"
    },
    "EmbeddedDAGNode": {
      "@id": "https://noocodec.dev/ontology/dag/EmbeddedDAGNode"
    },
    "GatherNode": {
      "@id": "https://noocodec.dev/ontology/dag/GatherNode"
    },
    "TerminalNode": {
      "@id": "https://noocodec.dev/ontology/dag/TerminalNode"
    },
    "PhaseNode": {
      "@id": "https://noocodec.dev/ontology/dag/PhaseNode"
    }
  },
  "@id": "urn:noocodec:dag:the-archivist",
  "@type": "DAG",
  "name": "the-archivist",
  "version": "6.0",
  "entrypoints": {
    "main": "urn:noocodec:dag:the-archivist/node/park-for-input"
  },
  "nodes": [
    {
      "@id": "urn:noocodec:dag:the-archivist/node/setup",
      "@type": "PhaseNode",
      "name": "setup",
      "node": "urn:noocodec:node:pre-run-setup",
      "phase": "pre"
    },
    {
      "@id": "urn:noocodec:dag:the-archivist/node/park-for-input",
      "@type": "SingleNode",
      "name": "park-for-input",
      "node": "urn:noocodec:node:park-for-input",
      "outputs": {
        "parked": "urn:noocodec:dag:the-archivist/node/park-for-input",
        "resumed": "urn:noocodec:dag:the-archivist/node/recall-context"
      }
    },
    {
      "@id": "urn:noocodec:dag:the-archivist/node/recall-context",
      "@type": "SingleNode",
      "name": "recall-context",
      "node": "urn:noocodec:node:recall-context",
      "outputs": {
        "recalled": "urn:noocodec:dag:the-archivist/node/classify-intent"
      }
    },
    {
      "@id": "urn:noocodec:dag:the-archivist/node/classify-intent",
      "@type": "SingleNode",
      "name": "classify-intent",
      "node": "urn:noocodec:node:classify-intent",
      "outputs": {
        "lookup-author": "urn:noocodec:dag:the-archivist/node/author-search",
        "find-reviews": "urn:noocodec:dag:the-archivist/node/reviews-extract",
        "describe-book": "urn:noocodec:dag:the-archivist/node/describe-extract",
        "recommend-similar": "urn:noocodec:dag:the-archivist/node/recommend-similar",
        "recall-memories": "urn:noocodec:dag:the-archivist/node/memory-recall",
        "on-topic": "urn:noocodec:dag:the-archivist/node/on-topic-search",
        "recommend-top-rated": "urn:noocodec:dag:the-archivist/node/recommend-extract",
        "off-topic": "urn:noocodec:dag:the-archivist/node/decline-off-topic",
        "retry": "urn:noocodec:dag:the-archivist/node/classify-intent",
        "salvage": "urn:noocodec:dag:the-archivist/node/classify-intent-salvage"
      }
    },
    {
      "@id": "urn:noocodec:dag:the-archivist/node/classify-intent-salvage",
      "@type": "SingleNode",
      "name": "classify-intent-salvage",
      "node": "urn:noocodec:node:classify-intent-salvage",
      "outputs": {
        "done": "urn:noocodec:dag:the-archivist/node/on-topic-search"
      }
    },
    {
      "@id": "urn:noocodec:dag:the-archivist/node/on-topic-search",
      "@type": "EmbeddedDAGNode",
      "name": "on-topic-search",
      "outputs": {
        "success": "urn:noocodec:dag:the-archivist/node/compose-loop",
        "error": "urn:noocodec:dag:the-archivist/node/compose-empty"
      },
      "dag": "urn:noocodec:dag:book-search-scatter",
      "stateMapping": {
        "output": {
          "terms": "terms",
          "toolPlan": "toolPlan",
          "candidates": "candidates",
          "shortlist": "shortlist",
          "priorContext": "priorContext",
          "failureCause": "failureCause"
        }
      }
    },
    {
      "@id": "urn:noocodec:dag:the-archivist/node/author-search",
      "@type": "EmbeddedDAGNode",
      "name": "author-search",
      "outputs": {
        "success": "urn:noocodec:dag:the-archivist/node/group-by-year",
        "error": "urn:noocodec:dag:the-archivist/node/compose-empty"
      },
      "dag": "urn:noocodec:dag:book-search-scatter",
      "stateMapping": {
        "output": {
          "terms": "terms",
          "toolPlan": "toolPlan",
          "candidates": "candidates",
          "shortlist": "shortlist",
          "priorContext": "priorContext",
          "failureCause": "failureCause"
        }
      }
    },
    {
      "@id": "urn:noocodec:dag:the-archivist/node/group-by-year",
      "@type": "SingleNode",
      "name": "group-by-year",
      "node": "urn:noocodec:node:group-by-year",
      "outputs": {
        "ordered": "urn:noocodec:dag:the-archivist/node/compose-loop"
      }
    },
    {
      "@id": "urn:noocodec:dag:the-archivist/node/reviews-extract",
      "@type": "SingleNode",
      "name": "reviews-extract",
      "node": "urn:noocodec:node:extract-query",
      "outputs": {
        "success": "urn:noocodec:dag:the-archivist/node/reviews-decide-tools",
        "retry": "urn:noocodec:dag:the-archivist/node/reviews-extract",
        "salvage": "urn:noocodec:dag:the-archivist/node/reviews-extract-salvage"
      }
    },
    {
      "@id": "urn:noocodec:dag:the-archivist/node/reviews-extract-salvage",
      "@type": "SingleNode",
      "name": "reviews-extract-salvage",
      "node": "urn:noocodec:node:extract-query-salvage",
      "outputs": {
        "done": "urn:noocodec:dag:the-archivist/node/reviews-decide-tools"
      }
    },
    {
      "@id": "urn:noocodec:dag:the-archivist/node/reviews-decide-tools",
      "@type": "SingleNode",
      "name": "reviews-decide-tools",
      "node": "urn:noocodec:node:decide-tools",
      "outputs": {
        "tools": "urn:noocodec:dag:the-archivist/node/reviews-build-worksets",
        "no-tools": "urn:noocodec:dag:the-archivist/node/reviews-build-worksets",
        "retry": "urn:noocodec:dag:the-archivist/node/reviews-decide-tools",
        "salvage": "urn:noocodec:dag:the-archivist/node/reviews-decide-tools-salvage"
      }
    },
    {
      "@id": "urn:noocodec:dag:the-archivist/node/reviews-decide-tools-salvage",
      "@type": "SingleNode",
      "name": "reviews-decide-tools-salvage",
      "node": "urn:noocodec:node:decide-tools-salvage",
      "outputs": {
        "done": "urn:noocodec:dag:the-archivist/node/reviews-build-worksets"
      }
    },
    {
      "@id": "urn:noocodec:dag:the-archivist/node/reviews-build-worksets",
      "@type": "SingleNode",
      "name": "reviews-build-worksets",
      "node": "urn:noocodec:node:build-book-worksets",
      "outputs": {
        "ready": "urn:noocodec:dag:the-archivist/node/reviews-scatter"
      }
    },
    {
      "@id": "urn:noocodec:dag:the-archivist/node/reviews-scatter",
      "@type": "ScatterNode",
      "name": "reviews-scatter",
      "source": "bookWorksets",
      "body": {
        "dag": {
          "@type": "DagReference",
          "from": "item",
          "path": "dagIri",
          "candidates": [
            "urn:noocodec:tool:web_search_books",
            "urn:noocodec:tool:google_books_search",
            "urn:noocodec:tool:subject_search",
            "urn:noocodec:tool:wikipedia_summary"
          ]
        }
      },
      "outputs": {
        "success": "urn:noocodec:dag:the-archivist/node/reviews-gather",
        "error": "urn:noocodec:dag:the-archivist/node/reviews-gather",
        "empty": "urn:noocodec:dag:the-archivist/node/reviews-rank"
      },
      "itemKey": "currentItem",
      "reducer": "any-success",
      "execution": {
        "mode": "item",
        "concurrency": 4
      }
    },
    {
      "@id": "urn:noocodec:dag:the-archivist/node/reviews-gather",
      "@type": "GatherNode",
      "name": "reviews-gather",
      "sources": {
        "urn:noocodec:dag:the-archivist/node/reviews-scatter": {}
      },
      "gather": {
        "strategy": "tool-candidate-merge"
      },
      "outputs": {
        "success": "urn:noocodec:dag:the-archivist/node/reviews-rank",
        "error": "urn:noocodec:dag:the-archivist/node/reviews-rank",
        "empty": "urn:noocodec:dag:the-archivist/node/reviews-rank"
      }
    },
    {
      "@id": "urn:noocodec:dag:the-archivist/node/reviews-rank",
      "@type": "SingleNode",
      "name": "reviews-rank",
      "node": "urn:noocodec:node:rank-by-rating",
      "outputs": {
        "ranked": "urn:noocodec:dag:the-archivist/node/reviews-merge"
      }
    },
    {
      "@id": "urn:noocodec:dag:the-archivist/node/reviews-merge",
      "@type": "SingleNode",
      "name": "reviews-merge",
      "node": "urn:noocodec:node:merge-candidates",
      "outputs": {
        "ranked": "urn:noocodec:dag:the-archivist/node/reviews-record",
        "empty": "urn:noocodec:dag:the-archivist/node/compose-empty"
      }
    },
    {
      "@id": "urn:noocodec:dag:the-archivist/node/reviews-record",
      "@type": "SingleNode",
      "name": "reviews-record",
      "node": "urn:noocodec:node:record-findings",
      "outputs": {
        "recorded": "urn:noocodec:dag:the-archivist/node/reviews-gate"
      }
    },
    {
      "@id": "urn:noocodec:dag:the-archivist/node/reviews-gate",
      "@type": "SingleNode",
      "name": "reviews-gate",
      "node": "urn:noocodec:node:has-citations-gate",
      "outputs": {
        "pass": "urn:noocodec:dag:the-archivist/node/reviews-recall",
        "fail": "urn:noocodec:dag:the-archivist/node/compose-empty"
      }
    },
    {
      "@id": "urn:noocodec:dag:the-archivist/node/reviews-recall",
      "@type": "SingleNode",
      "name": "reviews-recall",
      "node": "urn:noocodec:node:recall-past-visits",
      "outputs": {
        "recalled": "urn:noocodec:dag:the-archivist/node/compose-loop"
      }
    },
    {
      "@id": "urn:noocodec:dag:the-archivist/node/recommend-extract",
      "@type": "SingleNode",
      "name": "recommend-extract",
      "node": "urn:noocodec:node:extract-query",
      "outputs": {
        "success": "urn:noocodec:dag:the-archivist/node/recommend-decide-tools",
        "retry": "urn:noocodec:dag:the-archivist/node/recommend-extract",
        "salvage": "urn:noocodec:dag:the-archivist/node/recommend-extract-salvage"
      }
    },
    {
      "@id": "urn:noocodec:dag:the-archivist/node/recommend-extract-salvage",
      "@type": "SingleNode",
      "name": "recommend-extract-salvage",
      "node": "urn:noocodec:node:extract-query-salvage",
      "outputs": {
        "done": "urn:noocodec:dag:the-archivist/node/recommend-decide-tools"
      }
    },
    {
      "@id": "urn:noocodec:dag:the-archivist/node/recommend-decide-tools",
      "@type": "SingleNode",
      "name": "recommend-decide-tools",
      "node": "urn:noocodec:node:decide-tools",
      "outputs": {
        "tools": "urn:noocodec:dag:the-archivist/node/recommend-build-worksets",
        "no-tools": "urn:noocodec:dag:the-archivist/node/recommend-build-worksets",
        "retry": "urn:noocodec:dag:the-archivist/node/recommend-decide-tools",
        "salvage": "urn:noocodec:dag:the-archivist/node/recommend-decide-tools-salvage"
      }
    },
    {
      "@id": "urn:noocodec:dag:the-archivist/node/recommend-decide-tools-salvage",
      "@type": "SingleNode",
      "name": "recommend-decide-tools-salvage",
      "node": "urn:noocodec:node:decide-tools-salvage",
      "outputs": {
        "done": "urn:noocodec:dag:the-archivist/node/recommend-build-worksets"
      }
    },
    {
      "@id": "urn:noocodec:dag:the-archivist/node/recommend-build-worksets",
      "@type": "SingleNode",
      "name": "recommend-build-worksets",
      "node": "urn:noocodec:node:build-book-worksets",
      "outputs": {
        "ready": "urn:noocodec:dag:the-archivist/node/recommend-scatter"
      }
    },
    {
      "@id": "urn:noocodec:dag:the-archivist/node/recommend-scatter",
      "@type": "ScatterNode",
      "name": "recommend-scatter",
      "source": "bookWorksets",
      "body": {
        "dag": {
          "@type": "DagReference",
          "from": "item",
          "path": "dagIri",
          "candidates": [
            "urn:noocodec:tool:web_search_books",
            "urn:noocodec:tool:google_books_search",
            "urn:noocodec:tool:subject_search",
            "urn:noocodec:tool:wikipedia_summary"
          ]
        }
      },
      "outputs": {
        "success": "urn:noocodec:dag:the-archivist/node/recommend-gather",
        "error": "urn:noocodec:dag:the-archivist/node/recommend-gather",
        "empty": "urn:noocodec:dag:the-archivist/node/recommend-rank"
      },
      "itemKey": "currentItem",
      "reducer": "any-success",
      "execution": {
        "mode": "item",
        "concurrency": 4
      }
    },
    {
      "@id": "urn:noocodec:dag:the-archivist/node/recommend-gather",
      "@type": "GatherNode",
      "name": "recommend-gather",
      "sources": {
        "urn:noocodec:dag:the-archivist/node/recommend-scatter": {}
      },
      "gather": {
        "strategy": "tool-candidate-merge"
      },
      "outputs": {
        "success": "urn:noocodec:dag:the-archivist/node/recommend-rank",
        "error": "urn:noocodec:dag:the-archivist/node/recommend-rank",
        "empty": "urn:noocodec:dag:the-archivist/node/recommend-rank"
      }
    },
    {
      "@id": "urn:noocodec:dag:the-archivist/node/recommend-rank",
      "@type": "SingleNode",
      "name": "recommend-rank",
      "node": "urn:noocodec:node:rank-by-rating",
      "outputs": {
        "ranked": "urn:noocodec:dag:the-archivist/node/recommend-merge"
      }
    },
    {
      "@id": "urn:noocodec:dag:the-archivist/node/recommend-merge",
      "@type": "SingleNode",
      "name": "recommend-merge",
      "node": "urn:noocodec:node:merge-candidates",
      "outputs": {
        "ranked": "urn:noocodec:dag:the-archivist/node/recommend-record",
        "empty": "urn:noocodec:dag:the-archivist/node/compose-empty"
      }
    },
    {
      "@id": "urn:noocodec:dag:the-archivist/node/recommend-record",
      "@type": "SingleNode",
      "name": "recommend-record",
      "node": "urn:noocodec:node:record-findings",
      "outputs": {
        "recorded": "urn:noocodec:dag:the-archivist/node/recommend-gate"
      }
    },
    {
      "@id": "urn:noocodec:dag:the-archivist/node/recommend-gate",
      "@type": "SingleNode",
      "name": "recommend-gate",
      "node": "urn:noocodec:node:has-citations-gate",
      "outputs": {
        "pass": "urn:noocodec:dag:the-archivist/node/recommend-recall",
        "fail": "urn:noocodec:dag:the-archivist/node/compose-empty"
      }
    },
    {
      "@id": "urn:noocodec:dag:the-archivist/node/recommend-recall",
      "@type": "SingleNode",
      "name": "recommend-recall",
      "node": "urn:noocodec:node:recall-past-visits",
      "outputs": {
        "recalled": "urn:noocodec:dag:the-archivist/node/compose-loop"
      }
    },
    {
      "@id": "urn:noocodec:dag:the-archivist/node/describe-extract",
      "@type": "SingleNode",
      "name": "describe-extract",
      "node": "urn:noocodec:node:extract-query",
      "outputs": {
        "success": "urn:noocodec:dag:the-archivist/node/describe-decide-tools",
        "retry": "urn:noocodec:dag:the-archivist/node/describe-extract",
        "salvage": "urn:noocodec:dag:the-archivist/node/describe-extract-salvage"
      }
    },
    {
      "@id": "urn:noocodec:dag:the-archivist/node/describe-extract-salvage",
      "@type": "SingleNode",
      "name": "describe-extract-salvage",
      "node": "urn:noocodec:node:extract-query-salvage",
      "outputs": {
        "done": "urn:noocodec:dag:the-archivist/node/describe-decide-tools"
      }
    },
    {
      "@id": "urn:noocodec:dag:the-archivist/node/describe-decide-tools",
      "@type": "SingleNode",
      "name": "describe-decide-tools",
      "node": "urn:noocodec:node:decide-tools",
      "outputs": {
        "tools": "urn:noocodec:dag:the-archivist/node/describe-build-worksets",
        "no-tools": "urn:noocodec:dag:the-archivist/node/describe-build-worksets",
        "retry": "urn:noocodec:dag:the-archivist/node/describe-decide-tools",
        "salvage": "urn:noocodec:dag:the-archivist/node/describe-decide-tools-salvage"
      }
    },
    {
      "@id": "urn:noocodec:dag:the-archivist/node/describe-decide-tools-salvage",
      "@type": "SingleNode",
      "name": "describe-decide-tools-salvage",
      "node": "urn:noocodec:node:decide-tools-salvage",
      "outputs": {
        "done": "urn:noocodec:dag:the-archivist/node/describe-build-worksets"
      }
    },
    {
      "@id": "urn:noocodec:dag:the-archivist/node/describe-build-worksets",
      "@type": "SingleNode",
      "name": "describe-build-worksets",
      "node": "urn:noocodec:node:build-book-worksets",
      "outputs": {
        "ready": "urn:noocodec:dag:the-archivist/node/describe-scatter"
      }
    },
    {
      "@id": "urn:noocodec:dag:the-archivist/node/describe-scatter",
      "@type": "ScatterNode",
      "name": "describe-scatter",
      "source": "bookWorksets",
      "body": {
        "dag": {
          "@type": "DagReference",
          "from": "item",
          "path": "dagIri",
          "candidates": [
            "urn:noocodec:tool:web_search_books",
            "urn:noocodec:tool:google_books_search",
            "urn:noocodec:tool:subject_search",
            "urn:noocodec:tool:wikipedia_summary"
          ]
        }
      },
      "outputs": {
        "success": "urn:noocodec:dag:the-archivist/node/describe-gather",
        "error": "urn:noocodec:dag:the-archivist/node/compose-empty",
        "empty": "urn:noocodec:dag:the-archivist/node/compose-empty"
      },
      "itemKey": "currentItem",
      "reducer": "any-success",
      "execution": {
        "mode": "item",
        "concurrency": 4
      }
    },
    {
      "@id": "urn:noocodec:dag:the-archivist/node/describe-gather",
      "@type": "GatherNode",
      "name": "describe-gather",
      "sources": {
        "urn:noocodec:dag:the-archivist/node/describe-scatter": {}
      },
      "gather": {
        "strategy": "tool-candidate-merge"
      },
      "outputs": {
        "success": "urn:noocodec:dag:the-archivist/node/describe-pick",
        "error": "urn:noocodec:dag:the-archivist/node/compose-empty",
        "empty": "urn:noocodec:dag:the-archivist/node/compose-empty"
      }
    },
    {
      "@id": "urn:noocodec:dag:the-archivist/node/describe-pick",
      "@type": "SingleNode",
      "name": "describe-pick",
      "node": "urn:noocodec:node:pick-best-match",
      "outputs": {
        "picked": "urn:noocodec:dag:the-archivist/node/describe-merge"
      }
    },
    {
      "@id": "urn:noocodec:dag:the-archivist/node/describe-merge",
      "@type": "SingleNode",
      "name": "describe-merge",
      "node": "urn:noocodec:node:merge-candidates",
      "outputs": {
        "ranked": "urn:noocodec:dag:the-archivist/node/describe-record",
        "empty": "urn:noocodec:dag:the-archivist/node/compose-empty"
      }
    },
    {
      "@id": "urn:noocodec:dag:the-archivist/node/describe-record",
      "@type": "SingleNode",
      "name": "describe-record",
      "node": "urn:noocodec:node:record-findings",
      "outputs": {
        "recorded": "urn:noocodec:dag:the-archivist/node/describe-gate"
      }
    },
    {
      "@id": "urn:noocodec:dag:the-archivist/node/describe-gate",
      "@type": "SingleNode",
      "name": "describe-gate",
      "node": "urn:noocodec:node:has-citations-gate",
      "outputs": {
        "pass": "urn:noocodec:dag:the-archivist/node/describe-recall",
        "fail": "urn:noocodec:dag:the-archivist/node/compose-empty"
      }
    },
    {
      "@id": "urn:noocodec:dag:the-archivist/node/describe-recall",
      "@type": "SingleNode",
      "name": "describe-recall",
      "node": "urn:noocodec:node:recall-past-visits",
      "outputs": {
        "recalled": "urn:noocodec:dag:the-archivist/node/compose-loop"
      }
    },
    {
      "@id": "urn:noocodec:dag:the-archivist/node/recommend-similar",
      "@type": "SingleNode",
      "name": "recommend-similar",
      "node": "urn:noocodec:node:recommend-similar",
      "outputs": {
        "seeded": "urn:noocodec:dag:the-archivist/node/similar-search",
        "empty": "urn:noocodec:dag:the-archivist/node/compose-empty"
      }
    },
    {
      "@id": "urn:noocodec:dag:the-archivist/node/similar-search",
      "@type": "EmbeddedDAGNode",
      "name": "similar-search",
      "outputs": {
        "success": "urn:noocodec:dag:the-archivist/node/compose-loop",
        "error": "urn:noocodec:dag:the-archivist/node/compose-empty"
      },
      "dag": "urn:noocodec:dag:book-search-scatter",
      "stateMapping": {
        "output": {
          "terms": "terms",
          "toolPlan": "toolPlan",
          "candidates": "candidates",
          "shortlist": "shortlist",
          "priorContext": "priorContext",
          "failureCause": "failureCause"
        }
      }
    },
    {
      "@id": "urn:noocodec:dag:the-archivist/node/compose-loop",
      "@type": "EmbeddedDAGNode",
      "name": "compose-loop",
      "outputs": {
        "success": "urn:noocodec:dag:the-archivist/node/respond-to-visitor",
        "error": "urn:noocodec:dag:the-archivist/node/compose-empty"
      },
      "dag": "urn:noocodec:dag:compose-retry-loop",
      "stateMapping": {
        "output": {
          "draft": "draft",
          "approvalState": "approvalState"
        }
      }
    },
    {
      "@id": "urn:noocodec:dag:the-archivist/node/respond-to-visitor",
      "@type": "SingleNode",
      "name": "respond-to-visitor",
      "node": "urn:noocodec:node:respond-to-visitor",
      "outputs": {
        "success": "urn:noocodec:dag:the-archivist/node/end"
      }
    },
    {
      "@id": "urn:noocodec:dag:the-archivist/node/memory-recall",
      "@type": "SingleNode",
      "name": "memory-recall",
      "node": "urn:noocodec:node:recall-memories",
      "outputs": {
        "recalled": "urn:noocodec:dag:the-archivist/node/compose-memory-recall"
      }
    },
    {
      "@id": "urn:noocodec:dag:the-archivist/node/compose-memory-recall",
      "@type": "SingleNode",
      "name": "compose-memory-recall",
      "node": "urn:noocodec:node:compose-memory-response",
      "outputs": {
        "drafted": "urn:noocodec:dag:the-archivist/node/respond-to-visitor",
        "retry": "urn:noocodec:dag:the-archivist/node/compose-memory-recall",
        "salvage": "urn:noocodec:dag:the-archivist/node/compose-memory-salvage"
      }
    },
    {
      "@id": "urn:noocodec:dag:the-archivist/node/compose-memory-salvage",
      "@type": "SingleNode",
      "name": "compose-memory-salvage",
      "node": "urn:noocodec:node:compose-memory-salvage",
      "outputs": {
        "done": "urn:noocodec:dag:the-archivist/node/respond-to-visitor"
      }
    },
    {
      "@id": "urn:noocodec:dag:the-archivist/node/decline-off-topic",
      "@type": "SingleNode",
      "name": "decline-off-topic",
      "node": "urn:noocodec:node:decline-off-topic",
      "outputs": {
        "success": "urn:noocodec:dag:the-archivist/node/end"
      }
    },
    {
      "@id": "urn:noocodec:dag:the-archivist/node/compose-empty",
      "@type": "SingleNode",
      "name": "compose-empty",
      "node": "urn:noocodec:node:compose-empty",
      "outputs": {
        "drafted": "urn:noocodec:dag:the-archivist/node/respond-to-visitor",
        "retry": "urn:noocodec:dag:the-archivist/node/compose-empty",
        "salvage": "urn:noocodec:dag:the-archivist/node/compose-empty-salvage"
      }
    },
    {
      "@id": "urn:noocodec:dag:the-archivist/node/compose-empty-salvage",
      "@type": "SingleNode",
      "name": "compose-empty-salvage",
      "node": "urn:noocodec:node:compose-empty-salvage",
      "outputs": {
        "done": "urn:noocodec:dag:the-archivist/node/respond-to-visitor"
      }
    },
    {
      "@id": "urn:noocodec:dag:the-archivist/node/end",
      "@type": "TerminalNode",
      "name": "end",
      "outcome": "completed"
    }
  ]
}

Mermaid generated from the same DAG

Mermaid source

%%{init: {"flowchart":{"nodeSpacing":92,"rankSpacing":104,"padding":28}}}%%
flowchart TB
  %% the-archivist (v6.0)
  entry_main(["main"])
  entry_main --> urn_noocodec_dag_the-archivist/node/park-for-input
  urn_noocodec_dag_the-archivist/node/setup(["setup (pre)"])
  urn_noocodec_dag_the-archivist/node/park-for-input["park-for-input"]
  urn_noocodec_dag_the-archivist/node/park-for-input -->|parked| urn_noocodec_dag_the-archivist/node/park-for-input
  urn_noocodec_dag_the-archivist/node/park-for-input -->|resumed| urn_noocodec_dag_the-archivist/node/recall-context
  urn_noocodec_dag_the-archivist/node/recall-context["recall-context"]
  urn_noocodec_dag_the-archivist/node/recall-context -->|recalled| urn_noocodec_dag_the-archivist/node/classify-intent
  urn_noocodec_dag_the-archivist/node/classify-intent["classify-intent"]
  urn_noocodec_dag_the-archivist/node/classify-intent -->|lookup-author| urn_noocodec_dag_the-archivist/node/author-search
  urn_noocodec_dag_the-archivist/node/classify-intent -->|find-reviews| urn_noocodec_dag_the-archivist/node/reviews-extract
  urn_noocodec_dag_the-archivist/node/classify-intent -->|describe-book| urn_noocodec_dag_the-archivist/node/describe-extract
  urn_noocodec_dag_the-archivist/node/classify-intent -->|recommend-similar| urn_noocodec_dag_the-archivist/node/recommend-similar
  urn_noocodec_dag_the-archivist/node/classify-intent -->|recall-memories| urn_noocodec_dag_the-archivist/node/memory-recall
  urn_noocodec_dag_the-archivist/node/classify-intent -->|on-topic| urn_noocodec_dag_the-archivist/node/on-topic-search
  urn_noocodec_dag_the-archivist/node/classify-intent -->|recommend-top-rated| urn_noocodec_dag_the-archivist/node/recommend-extract
  urn_noocodec_dag_the-archivist/node/classify-intent -->|off-topic| urn_noocodec_dag_the-archivist/node/decline-off-topic
  urn_noocodec_dag_the-archivist/node/classify-intent -->|retry| urn_noocodec_dag_the-archivist/node/classify-intent
  urn_noocodec_dag_the-archivist/node/classify-intent -->|salvage| urn_noocodec_dag_the-archivist/node/classify-intent-salvage
  urn_noocodec_dag_the-archivist/node/classify-intent-salvage["classify-intent-salvage"]
  urn_noocodec_dag_the-archivist/node/classify-intent-salvage -->|done| urn_noocodec_dag_the-archivist/node/on-topic-search
  urn_noocodec_dag_the-archivist/node/on-topic-search[["on-topic-search"]]
  urn_noocodec_dag_the-archivist/node/on-topic-search -->|success| urn_noocodec_dag_the-archivist/node/compose-loop
  urn_noocodec_dag_the-archivist/node/on-topic-search -->|error| urn_noocodec_dag_the-archivist/node/compose-empty
  urn_noocodec_dag_the-archivist/node/author-search[["author-search"]]
  urn_noocodec_dag_the-archivist/node/author-search -->|success| urn_noocodec_dag_the-archivist/node/group-by-year
  urn_noocodec_dag_the-archivist/node/author-search -->|error| urn_noocodec_dag_the-archivist/node/compose-empty
  urn_noocodec_dag_the-archivist/node/group-by-year["group-by-year"]
  urn_noocodec_dag_the-archivist/node/group-by-year -->|ordered| urn_noocodec_dag_the-archivist/node/compose-loop
  urn_noocodec_dag_the-archivist/node/reviews-extract["reviews-extract"]
  urn_noocodec_dag_the-archivist/node/reviews-extract -->|success| urn_noocodec_dag_the-archivist/node/reviews-decide-tools
  urn_noocodec_dag_the-archivist/node/reviews-extract -->|retry| urn_noocodec_dag_the-archivist/node/reviews-extract
  urn_noocodec_dag_the-archivist/node/reviews-extract -->|salvage| urn_noocodec_dag_the-archivist/node/reviews-extract-salvage
  urn_noocodec_dag_the-archivist/node/reviews-extract-salvage["reviews-extract-salvage"]
  urn_noocodec_dag_the-archivist/node/reviews-extract-salvage -->|done| urn_noocodec_dag_the-archivist/node/reviews-decide-tools
  urn_noocodec_dag_the-archivist/node/reviews-decide-tools["reviews-decide-tools"]
  urn_noocodec_dag_the-archivist/node/reviews-decide-tools -->|tools| urn_noocodec_dag_the-archivist/node/reviews-build-worksets
  urn_noocodec_dag_the-archivist/node/reviews-decide-tools -->|no-tools| urn_noocodec_dag_the-archivist/node/reviews-build-worksets
  urn_noocodec_dag_the-archivist/node/reviews-decide-tools -->|retry| urn_noocodec_dag_the-archivist/node/reviews-decide-tools
  urn_noocodec_dag_the-archivist/node/reviews-decide-tools -->|salvage| urn_noocodec_dag_the-archivist/node/reviews-decide-tools-salvage
  urn_noocodec_dag_the-archivist/node/reviews-decide-tools-salvage["reviews-decide-tools-salvage"]
  urn_noocodec_dag_the-archivist/node/reviews-decide-tools-salvage -->|done| urn_noocodec_dag_the-archivist/node/reviews-build-worksets
  urn_noocodec_dag_the-archivist/node/reviews-build-worksets["reviews-build-worksets"]
  urn_noocodec_dag_the-archivist/node/reviews-build-worksets -->|ready| urn_noocodec_dag_the-archivist/node/reviews-scatter
  urn_noocodec_dag_the-archivist/node/reviews-scatter[/"reviews-scatter"/]
  urn_noocodec_dag_the-archivist/node/reviews-scatter -->|success| urn_noocodec_dag_the-archivist/node/reviews-gather
  urn_noocodec_dag_the-archivist/node/reviews-scatter -->|error| urn_noocodec_dag_the-archivist/node/reviews-gather
  urn_noocodec_dag_the-archivist/node/reviews-scatter -->|empty| urn_noocodec_dag_the-archivist/node/reviews-rank
  urn_noocodec_dag_the-archivist/node/reviews-gather{"reviews-gather"}
  urn_noocodec_dag_the-archivist/node/reviews-gather -->|success| urn_noocodec_dag_the-archivist/node/reviews-rank
  urn_noocodec_dag_the-archivist/node/reviews-gather -->|error| urn_noocodec_dag_the-archivist/node/reviews-rank
  urn_noocodec_dag_the-archivist/node/reviews-gather -->|empty| urn_noocodec_dag_the-archivist/node/reviews-rank
  urn_noocodec_dag_the-archivist/node/reviews-rank["reviews-rank"]
  urn_noocodec_dag_the-archivist/node/reviews-rank -->|ranked| urn_noocodec_dag_the-archivist/node/reviews-merge
  urn_noocodec_dag_the-archivist/node/reviews-merge["reviews-merge"]
  urn_noocodec_dag_the-archivist/node/reviews-merge -->|ranked| urn_noocodec_dag_the-archivist/node/reviews-record
  urn_noocodec_dag_the-archivist/node/reviews-merge -->|empty| urn_noocodec_dag_the-archivist/node/compose-empty
  urn_noocodec_dag_the-archivist/node/reviews-record["reviews-record"]
  urn_noocodec_dag_the-archivist/node/reviews-record -->|recorded| urn_noocodec_dag_the-archivist/node/reviews-gate
  urn_noocodec_dag_the-archivist/node/reviews-gate["reviews-gate"]
  urn_noocodec_dag_the-archivist/node/reviews-gate -->|pass| urn_noocodec_dag_the-archivist/node/reviews-recall
  urn_noocodec_dag_the-archivist/node/reviews-gate -->|fail| urn_noocodec_dag_the-archivist/node/compose-empty
  urn_noocodec_dag_the-archivist/node/reviews-recall["reviews-recall"]
  urn_noocodec_dag_the-archivist/node/reviews-recall -->|recalled| urn_noocodec_dag_the-archivist/node/compose-loop
  urn_noocodec_dag_the-archivist/node/recommend-extract["recommend-extract"]
  urn_noocodec_dag_the-archivist/node/recommend-extract -->|success| urn_noocodec_dag_the-archivist/node/recommend-decide-tools
  urn_noocodec_dag_the-archivist/node/recommend-extract -->|retry| urn_noocodec_dag_the-archivist/node/recommend-extract
  urn_noocodec_dag_the-archivist/node/recommend-extract -->|salvage| urn_noocodec_dag_the-archivist/node/recommend-extract-salvage
  urn_noocodec_dag_the-archivist/node/recommend-extract-salvage["recommend-extract-salvage"]
  urn_noocodec_dag_the-archivist/node/recommend-extract-salvage -->|done| urn_noocodec_dag_the-archivist/node/recommend-decide-tools
  urn_noocodec_dag_the-archivist/node/recommend-decide-tools["recommend-decide-tools"]
  urn_noocodec_dag_the-archivist/node/recommend-decide-tools -->|tools| urn_noocodec_dag_the-archivist/node/recommend-build-worksets
  urn_noocodec_dag_the-archivist/node/recommend-decide-tools -->|no-tools| urn_noocodec_dag_the-archivist/node/recommend-build-worksets
  urn_noocodec_dag_the-archivist/node/recommend-decide-tools -->|retry| urn_noocodec_dag_the-archivist/node/recommend-decide-tools
  urn_noocodec_dag_the-archivist/node/recommend-decide-tools -->|salvage| urn_noocodec_dag_the-archivist/node/recommend-decide-tools-salvage
  urn_noocodec_dag_the-archivist/node/recommend-decide-tools-salvage["recommend-decide-tools-salvage"]
  urn_noocodec_dag_the-archivist/node/recommend-decide-tools-salvage -->|done| urn_noocodec_dag_the-archivist/node/recommend-build-worksets
  urn_noocodec_dag_the-archivist/node/recommend-build-worksets["recommend-build-worksets"]
  urn_noocodec_dag_the-archivist/node/recommend-build-worksets -->|ready| urn_noocodec_dag_the-archivist/node/recommend-scatter
  urn_noocodec_dag_the-archivist/node/recommend-scatter[/"recommend-scatter"/]
  urn_noocodec_dag_the-archivist/node/recommend-scatter -->|success| urn_noocodec_dag_the-archivist/node/recommend-gather
  urn_noocodec_dag_the-archivist/node/recommend-scatter -->|error| urn_noocodec_dag_the-archivist/node/recommend-gather
  urn_noocodec_dag_the-archivist/node/recommend-scatter -->|empty| urn_noocodec_dag_the-archivist/node/recommend-rank
  urn_noocodec_dag_the-archivist/node/recommend-gather{"recommend-gather"}
  urn_noocodec_dag_the-archivist/node/recommend-gather -->|success| urn_noocodec_dag_the-archivist/node/recommend-rank
  urn_noocodec_dag_the-archivist/node/recommend-gather -->|error| urn_noocodec_dag_the-archivist/node/recommend-rank
  urn_noocodec_dag_the-archivist/node/recommend-gather -->|empty| urn_noocodec_dag_the-archivist/node/recommend-rank
  urn_noocodec_dag_the-archivist/node/recommend-rank["recommend-rank"]
  urn_noocodec_dag_the-archivist/node/recommend-rank -->|ranked| urn_noocodec_dag_the-archivist/node/recommend-merge
  urn_noocodec_dag_the-archivist/node/recommend-merge["recommend-merge"]
  urn_noocodec_dag_the-archivist/node/recommend-merge -->|ranked| urn_noocodec_dag_the-archivist/node/recommend-record
  urn_noocodec_dag_the-archivist/node/recommend-merge -->|empty| urn_noocodec_dag_the-archivist/node/compose-empty
  urn_noocodec_dag_the-archivist/node/recommend-record["recommend-record"]
  urn_noocodec_dag_the-archivist/node/recommend-record -->|recorded| urn_noocodec_dag_the-archivist/node/recommend-gate
  urn_noocodec_dag_the-archivist/node/recommend-gate["recommend-gate"]
  urn_noocodec_dag_the-archivist/node/recommend-gate -->|pass| urn_noocodec_dag_the-archivist/node/recommend-recall
  urn_noocodec_dag_the-archivist/node/recommend-gate -->|fail| urn_noocodec_dag_the-archivist/node/compose-empty
  urn_noocodec_dag_the-archivist/node/recommend-recall["recommend-recall"]
  urn_noocodec_dag_the-archivist/node/recommend-recall -->|recalled| urn_noocodec_dag_the-archivist/node/compose-loop
  urn_noocodec_dag_the-archivist/node/describe-extract["describe-extract"]
  urn_noocodec_dag_the-archivist/node/describe-extract -->|success| urn_noocodec_dag_the-archivist/node/describe-decide-tools
  urn_noocodec_dag_the-archivist/node/describe-extract -->|retry| urn_noocodec_dag_the-archivist/node/describe-extract
  urn_noocodec_dag_the-archivist/node/describe-extract -->|salvage| urn_noocodec_dag_the-archivist/node/describe-extract-salvage
  urn_noocodec_dag_the-archivist/node/describe-extract-salvage["describe-extract-salvage"]
  urn_noocodec_dag_the-archivist/node/describe-extract-salvage -->|done| urn_noocodec_dag_the-archivist/node/describe-decide-tools
  urn_noocodec_dag_the-archivist/node/describe-decide-tools["describe-decide-tools"]
  urn_noocodec_dag_the-archivist/node/describe-decide-tools -->|tools| urn_noocodec_dag_the-archivist/node/describe-build-worksets
  urn_noocodec_dag_the-archivist/node/describe-decide-tools -->|no-tools| urn_noocodec_dag_the-archivist/node/describe-build-worksets
  urn_noocodec_dag_the-archivist/node/describe-decide-tools -->|retry| urn_noocodec_dag_the-archivist/node/describe-decide-tools
  urn_noocodec_dag_the-archivist/node/describe-decide-tools -->|salvage| urn_noocodec_dag_the-archivist/node/describe-decide-tools-salvage
  urn_noocodec_dag_the-archivist/node/describe-decide-tools-salvage["describe-decide-tools-salvage"]
  urn_noocodec_dag_the-archivist/node/describe-decide-tools-salvage -->|done| urn_noocodec_dag_the-archivist/node/describe-build-worksets
  urn_noocodec_dag_the-archivist/node/describe-build-worksets["describe-build-worksets"]
  urn_noocodec_dag_the-archivist/node/describe-build-worksets -->|ready| urn_noocodec_dag_the-archivist/node/describe-scatter
  urn_noocodec_dag_the-archivist/node/describe-scatter[/"describe-scatter"/]
  urn_noocodec_dag_the-archivist/node/describe-scatter -->|success| urn_noocodec_dag_the-archivist/node/describe-gather
  urn_noocodec_dag_the-archivist/node/describe-scatter -->|error| urn_noocodec_dag_the-archivist/node/compose-empty
  urn_noocodec_dag_the-archivist/node/describe-scatter -->|empty| urn_noocodec_dag_the-archivist/node/compose-empty
  urn_noocodec_dag_the-archivist/node/describe-gather{"describe-gather"}
  urn_noocodec_dag_the-archivist/node/describe-gather -->|success| urn_noocodec_dag_the-archivist/node/describe-pick
  urn_noocodec_dag_the-archivist/node/describe-gather -->|error| urn_noocodec_dag_the-archivist/node/compose-empty
  urn_noocodec_dag_the-archivist/node/describe-gather -->|empty| urn_noocodec_dag_the-archivist/node/compose-empty
  urn_noocodec_dag_the-archivist/node/describe-pick["describe-pick"]
  urn_noocodec_dag_the-archivist/node/describe-pick -->|picked| urn_noocodec_dag_the-archivist/node/describe-merge
  urn_noocodec_dag_the-archivist/node/describe-merge["describe-merge"]
  urn_noocodec_dag_the-archivist/node/describe-merge -->|ranked| urn_noocodec_dag_the-archivist/node/describe-record
  urn_noocodec_dag_the-archivist/node/describe-merge -->|empty| urn_noocodec_dag_the-archivist/node/compose-empty
  urn_noocodec_dag_the-archivist/node/describe-record["describe-record"]
  urn_noocodec_dag_the-archivist/node/describe-record -->|recorded| urn_noocodec_dag_the-archivist/node/describe-gate
  urn_noocodec_dag_the-archivist/node/describe-gate["describe-gate"]
  urn_noocodec_dag_the-archivist/node/describe-gate -->|pass| urn_noocodec_dag_the-archivist/node/describe-recall
  urn_noocodec_dag_the-archivist/node/describe-gate -->|fail| urn_noocodec_dag_the-archivist/node/compose-empty
  urn_noocodec_dag_the-archivist/node/describe-recall["describe-recall"]
  urn_noocodec_dag_the-archivist/node/describe-recall -->|recalled| urn_noocodec_dag_the-archivist/node/compose-loop
  urn_noocodec_dag_the-archivist/node/recommend-similar["recommend-similar"]
  urn_noocodec_dag_the-archivist/node/recommend-similar -->|seeded| urn_noocodec_dag_the-archivist/node/similar-search
  urn_noocodec_dag_the-archivist/node/recommend-similar -->|empty| urn_noocodec_dag_the-archivist/node/compose-empty
  urn_noocodec_dag_the-archivist/node/similar-search[["similar-search"]]
  urn_noocodec_dag_the-archivist/node/similar-search -->|success| urn_noocodec_dag_the-archivist/node/compose-loop
  urn_noocodec_dag_the-archivist/node/similar-search -->|error| urn_noocodec_dag_the-archivist/node/compose-empty
  urn_noocodec_dag_the-archivist/node/compose-loop[["compose-loop"]]
  urn_noocodec_dag_the-archivist/node/compose-loop -->|success| urn_noocodec_dag_the-archivist/node/respond-to-visitor
  urn_noocodec_dag_the-archivist/node/compose-loop -->|error| urn_noocodec_dag_the-archivist/node/compose-empty
  urn_noocodec_dag_the-archivist/node/respond-to-visitor["respond-to-visitor"]
  urn_noocodec_dag_the-archivist/node/respond-to-visitor -->|success| urn_noocodec_dag_the-archivist/node/end
  urn_noocodec_dag_the-archivist/node/memory-recall["memory-recall"]
  urn_noocodec_dag_the-archivist/node/memory-recall -->|recalled| urn_noocodec_dag_the-archivist/node/compose-memory-recall
  urn_noocodec_dag_the-archivist/node/compose-memory-recall["compose-memory-recall"]
  urn_noocodec_dag_the-archivist/node/compose-memory-recall -->|drafted| urn_noocodec_dag_the-archivist/node/respond-to-visitor
  urn_noocodec_dag_the-archivist/node/compose-memory-recall -->|retry| urn_noocodec_dag_the-archivist/node/compose-memory-recall
  urn_noocodec_dag_the-archivist/node/compose-memory-recall -->|salvage| urn_noocodec_dag_the-archivist/node/compose-memory-salvage
  urn_noocodec_dag_the-archivist/node/compose-memory-salvage["compose-memory-salvage"]
  urn_noocodec_dag_the-archivist/node/compose-memory-salvage -->|done| urn_noocodec_dag_the-archivist/node/respond-to-visitor
  urn_noocodec_dag_the-archivist/node/decline-off-topic["decline-off-topic"]
  urn_noocodec_dag_the-archivist/node/decline-off-topic -->|success| urn_noocodec_dag_the-archivist/node/end
  urn_noocodec_dag_the-archivist/node/compose-empty["compose-empty"]
  urn_noocodec_dag_the-archivist/node/compose-empty -->|drafted| urn_noocodec_dag_the-archivist/node/respond-to-visitor
  urn_noocodec_dag_the-archivist/node/compose-empty -->|retry| urn_noocodec_dag_the-archivist/node/compose-empty
  urn_noocodec_dag_the-archivist/node/compose-empty -->|salvage| urn_noocodec_dag_the-archivist/node/compose-empty-salvage
  urn_noocodec_dag_the-archivist/node/compose-empty-salvage["compose-empty-salvage"]
  urn_noocodec_dag_the-archivist/node/compose-empty-salvage -->|done| urn_noocodec_dag_the-archivist/node/respond-to-visitor
  urn_noocodec_dag_the-archivist/node/end((("end")))

Run

npx tsx examples/the-archivist/runArchivist.ts

What It Lets You Do

Cancellation lets applications stop work without corrupting DAG state or leaking in-flight retries. Use it when a browser tab closes, an HTTP request disconnects, a user presses cancel, or a host enforces a hard execution budget.

For product teams, this means long-running model or tool workflows can behave like normal web infrastructure. They can be cancelled, observed, checkpointed, and resumed instead of being treated as fire-and-forget background jobs.

Code Samples

Dispatcher + signal + deadline

The #cancellation-run region shows the AbortController, the signal + deadlineMs execute options, and the lifecycle switch that reads the terminal state:

// Caller-driven cancellation: the visitor closes the page.
const visitorClosedSignal = Signal.timeout(800);

const cancelVisitor = new ArchivistState();
cancelVisitor.query = "What's a book about a labyrinth?";

const cancelResult = await dispatcher.execute(ARCHIVIST_DAG_IRI, cancelVisitor, {
  'signal':     visitorClosedSignal,
  'deadlineMs': 5000,              // hard 5s ceiling regardless of signal
});

// lifecycle.variant is a discriminated union:
//   'pending' | 'running' | 'completed' | 'failed' | 'cancelled' | 'timed_out' | 'awaiting-input'.
// Each arm carries only the fields relevant to that outcome (e.g. reason, finishedAt).
const lc = cancelResult.state.lifecycle;
type LifecycleVariant = typeof lc.variant;
const lifecycleLog: Record<LifecycleVariant, () => void> = {
  'completed':      () => { logger.result(`responded: ${cancelResult.state.draft}`); },
  'cancelled':      () => {
    if (lc.variant === 'cancelled') {
      logger.result(`visitor abandoned at: ${lc.reason}`);
    }
  },
  'timed_out':      () => { logger.result(`hit deadline at: ${lc.finishedAt}`); },
  'failed':         () => { logger.result(`execution failed at: ${lc.finishedAt}`); },
  'pending':        () => { logger.result('lifecycle: pending'); },
  'running':        () => { logger.result('lifecycle: running'); },
  'awaiting-input': () => { logger.result(`parked — awaiting human input (key: ${lc.correlationKey})`); },
};
lifecycleLog[lc.variant]();

// result.cursor is the next node that would have run; pass it to
// Checkpoint.capture to persist and resume in a later process.
if (cancelResult.cursor !== null) {
  logger.result(`stopped at ${cancelResult.cursor} (resumable)`);
}

Scout signal pass-through

The #tool-candidate-gather-strategy region shows how openLibraryScout propagates context.signal through the scoutRetry policy and into the tool call. When the signal fires, the retry policy aborts mid-backoff instead of waiting:

// ── ToolCandidateGatherStrategy ('tool-candidate-merge') ─────────────────────
// Folds each tool clone's output (a CandidateType[] returned by the tool) into
// the parent state's `candidates` array. Reads clone output via StateAccessor
// so there are no unsafe casts — the strategy never knows the parent state's
// concrete class, only the state path names.
//
// Each scatter clone ran a tool DAG IRI on a fresh
// ToolInvocationState. On success, ToolInvokeNode sets `toolState.output` to
// the tool's return value (a CandidateType[]). On error the clone's output
// stays at its default value of null, so the Array.isArray check below
// safely no-ops.

class ToolCandidateGatherStrategy extends GatherStrategy {
  readonly name = 'tool-candidate-merge';
  readonly '@id' = 'urn:noocodec:node:tool-candidate-merge';

  private static readonly candidateValidator = Validator.compile<CandidateType>(CandidateSchema);

  /**
   * Type predicate: narrows an element to CandidateType without a cast.
   * A CandidateType must carry a `book` object with an `identity` sub-object.
   */
  static isCandidateType(el: unknown): el is CandidateType {
    return ToolCandidateGatherStrategy.candidateValidator.is(el);
  }

  override reduce(
    config: GatherConfigType,
    batch: Batch<GatherRecordType>,
    state: NodeStateInterface,
    accessor: StateAccessorInterface,
  ): void {
    void config;
    const languageValue = accessor.get(state, 'userLanguage');
    const userLanguage = typeof languageValue === 'string' ? languageValue : 'en';
    const candidatesValue = accessor.get(state, 'candidates');
    const existing: CandidateType[] = Array.isArray(candidatesValue)
      ? candidatesValue.filter(ToolCandidateGatherStrategy.isCandidateType)
      : [];
    const merged: CandidateType[] = [...existing];

    for (const item of batch) {
      const record = item.state;
      const rawOutput = accessor.get(record.cloneState, 'output');
      if (!Array.isArray(rawOutput)) continue;

      const toolCandidates = rawOutput.filter(ToolCandidateGatherStrategy.isCandidateType);
      const filtered = ScoutUtils.filterByLanguage(toolCandidates, userLanguage);

      if (filtered.length === 0 && toolCandidates.length > 0) {
        // All candidates were language-filtered out; note the loss but don't log the source name
        // (the strategy doesn't know which tool produced this clone).
        const causeValue = accessor.get(state, 'failureCause');
        const current = typeof causeValue === 'string' ? causeValue : '';
        accessor.set(state, 'failureCause', `${current}Tool scout: 0 hits after language filter. `);
      } else if (filtered.length === 0) {
        const causeValue = accessor.get(state, 'failureCause');
        const current = typeof causeValue === 'string' ? causeValue : '';
        accessor.set(state, 'failureCause', `${current}Tool scout: 0 results. `);
      }

      for (const candidate of filtered) {
        merged.push(candidate);
      }
    }

    accessor.set(state, 'candidates', merged);
  }
}

GatherStrategies.register(new ToolCandidateGatherStrategy());
// GatherStrategies.resolve('tool-candidate-merge') now works in any scatter placement.

Details for Nerds

• signal + deadlineMs composition. Signal.compose (from @studnicky/signal) combines the caller-supplied AbortSignal with the deadline into one internal signal passed to every node via context.signal. Neither option is required; both can be used together — when neither is supplied, context.signal is Signal.never(), a valid never-aborting AbortSignal.
• Nodes propagate the signal. Every scout passes context.signal as the second argument to scoutRetry.run(task, signal). The retry policy aborts mid-wait when the signal fires, so scouts do not wait through the full backoff window.
• Lifecycle records the exact terminal state. cancelled carries the abort reason string; timed_out carries the deadline-finished timestamp. completed means all nodes ran to their terminal outputs.
• result.cursor. Records the next node that would have run. When non-null, the flow was interrupted. Pair with Checkpoint.capture (see Example 08) to resume in a later process.

See this in action in the Archivist live demo; the cancel button fires the same AbortController.abort() path.

Related Concepts

• Running domain: The Archivist
• Cancellation guide
• Example 07: Retry Flow - RetryPolicy.run honors the same signal
• Example 08: Checkpoint and Resume
• Reference: Runtime, Signal
• Reference: Lifecycle