Ebook File Check

Validates one EPUB (a directly hosted public URL or a file attached in chat) against the EPUB 2/3 specification using a pinned local EPUBCheck 5.4.0 engine run in a no-network sandbox. Each call takes exactly one source: the url parameter or the file attachment, never both. Returns the automated verdict: pass boolean, EPUB version, message counts by severity (fatal/error/warning/usage), findings grouped most-severe-first with EPUBCheck rule id (RSC-005, OPF-014, …), file path and line/column, plus a structural inventory (spine items, media types, remote-resource state), SHA-256 of the exact bytes, and truncation metadata. Use for one-file readiness and diagnosis: 'is this ebook valid', 'does this EPUB have specification problems before upload', 'what is wrong with it'. A pass means only that the bytes satisfied the automated profile; it never renders the book, judges accessibility, or guarantees any store will accept it, and human review of how the book reads and looks is always required. Downloads and validates a live EPUB under a 110-second call deadline; tell the user before the call.

{
  "type": "object",
  "properties": {
    "url": {
      "pattern": "^https?://",
      "type": "string",
      "description": "Direct public HTTP(S) URL to the EPUB file bytes, including the protocol, not a ChatGPT file id, local path, cloud-drive share, archive/viewer page, or authenticated URL needing a login. Each call takes either URL sources or attached-file sources, never both\n\nSTRICT RULE: Ebook check failed: provide either an EPUB URL or an attached EPUB file, not both\nSTRICT RULE: Ebook check failed: provide a public EPUB URL or attach the EPUB file"
    },
    "file": {
      "type": "object",
      "required": [
        "download_url",
        "file_id"
      ],
      "properties": {
        "download_url": {
          "type": "string",
          "description": "Temporary authorized download URL supplied by ChatGPT; fetch it only while handling this tool call"
        },
        "file_id": {
          "type": "string",
          "description": "ChatGPT file id for the attached file"
        },
        "mime_type": {
          "type": "string",
          "description": "MIME type when ChatGPT knows it"
        },
        "file_name": {
          "type": "string",
          "description": "Original file name when ChatGPT knows it"
        }
      },
      "description": "An EPUB file attached in chat, up to 25 MB, validated from its exact bytes. Provide either this attachment or url, never both.",
      "additionalProperties": false
    },
    "maxMessages": {
      "minimum": 1,
      "maximum": 500,
      "type": "integer",
      "description": "Maximum spec findings to return, most severe first (default 200); raise it to see more of a very noisy book, lower it to keep the answer short"
    }
  },
  "additionalProperties": false
}

{
  "type": "object",
  "properties": {
    "requestedUrl": {
      "type": "string",
      "description": "The checked EPUB source: the submitted URL with query and fragment stripped, or the attached file's name"
    },
    "finalUrl": {
      "type": "string",
      "description": "URL after redirects, with query string and fragment stripped"
    },
    "redirects": {
      "type": "number",
      "description": "Redirect hops followed"
    },
    "sha256": {
      "type": "string",
      "description": "SHA-256 hash of the exact validated bytes"
    },
    "bytes": {
      "type": "number",
      "description": "Downloaded EPUB size in bytes"
    },
    "contentType": {
      "type": "string",
      "description": "Content-Type the server returned"
    },
    "fetchedAt": {
      "type": "string",
      "description": "ISO timestamp the EPUB was fetched and validated"
    },
    "engineVersion": {
      "type": "string",
      "description": "EPUBCheck engine version that produced the verdict"
    },
    "ruleProfileDate": {
      "type": "string",
      "description": "Release date of the pinned EPUBCheck rule profile"
    },
    "pass": {
      "type": "boolean",
      "description": "True when the EPUB has no fatal or error messages against the automated profile"
    },
    "epubVersion": {
      "type": "string",
      "description": "Detected EPUB version, e.g. 2.0.1 or 3.0; omitted when the engine could not detect it"
    },
    "epubVersionDetected": {
      "type": "boolean",
      "description": "Distinguished state: false means the version could not be detected, distinct from a detected-but-invalid version"
    },
    "counts": {
      "type": "object",
      "required": [
        "fatal",
        "error",
        "warning",
        "usage"
      ],
      "properties": {
        "fatal": {
          "type": "number",
          "description": "Fatal messages: the container could not be fully processed"
        },
        "error": {
          "type": "number",
          "description": "Error messages: spec violations that fail validation and typically block store uploads"
        },
        "warning": {
          "type": "number",
          "description": "Warning messages: advisory issues that do not fail validation"
        },
        "usage": {
          "type": "number",
          "description": "Usage messages: informational notices about optional or unusual constructs"
        }
      },
      "description": "Counts of EPUBCheck findings grouped by severity",
      "additionalProperties": false
    },
    "findings": {
      "type": "array",
      "items": {
        "type": "object",
        "required": [
          "label",
          "ruleId",
          "severity",
          "message",
          "additionalLocations"
        ],
        "properties": {
          "label": {
            "type": "string",
            "description": "Short display identity combining the EPUBCheck rule id with its primary file path and reported line"
          },
          "ruleId": {
            "type": "string",
            "description": "EPUBCheck message id, e.g. RSC-005, OPF-014, HTM-004"
          },
          "severity": {
            "type": "string",
            "description": "FATAL, ERROR, WARNING, or USAGE"
          },
          "message": {
            "type": "string",
            "description": "What the rule reports"
          },
          "path": {
            "type": "string",
            "description": "File path inside the EPUB where the issue was found"
          },
          "line": {
            "type": "number",
            "description": "Line number of the issue, when the engine reports one"
          },
          "column": {
            "type": "number",
            "description": "Column number of the issue, when the engine reports one"
          },
          "additionalLocations": {
            "type": "number",
            "description": "How many further locations share this finding beyond the one shown"
          },
          "suggestion": {
            "type": "string",
            "description": "Engine-provided remediation hint, when present"
          }
        },
        "additionalProperties": false
      },
      "description": "Bounded spec findings, most severe first, capped by maxMessages"
    },
    "inventory": {
      "type": "object",
      "required": [
        "spineItemCount",
        "containerItemCount",
        "mediaTypes",
        "scripted",
        "fixedFormat",
        "hasAudio",
        "hasVideo",
        "hasEncryption",
        "embeddedFontCount",
        "remoteResources",
        "containerEntryCount",
        "decompressedBytes"
      ],
      "properties": {
        "spineItemCount": {
          "type": "number",
          "description": "Number of reading-order spine items"
        },
        "containerItemCount": {
          "type": "number",
          "description": "Number of manifest/container items EPUBCheck inspected"
        },
        "mediaTypes": {
          "type": "array",
          "items": {
            "type": "string"
          },
          "description": "Distinct declared media types present in the publication"
        },
        "scripted": {
          "type": "boolean",
          "description": "True when the publication contains scripting"
        },
        "fixedFormat": {
          "type": "boolean",
          "description": "True for fixed-layout publications"
        },
        "hasAudio": {
          "type": "boolean",
          "description": "True when the publication embeds audio"
        },
        "hasVideo": {
          "type": "boolean",
          "description": "True when the publication embeds video"
        },
        "hasEncryption": {
          "type": "boolean",
          "description": "True when the container declares encryption"
        },
        "embeddedFontCount": {
          "type": "number",
          "description": "Number of fonts embedded in the container"
        },
        "remoteResources": {
          "type": "object",
          "required": [
            "state",
            "referencedFontCount"
          ],
          "properties": {
            "state": {
              "anyOf": [
                {
                  "const": "referenced",
                  "type": "string",
                  "description": "Distinguished state: 'referenced' when remote resources or remote fonts are used, 'none-detected' when the engine found none (absence of evidence, not a guarantee of none)"
                },
                {
                  "const": "none-detected",
                  "type": "string",
                  "description": "Distinguished state: 'referenced' when remote resources or remote fonts are used, 'none-detected' when the engine found none (absence of evidence, not a guarantee of none)"
                }
              ],
              "description": "Distinguished state: 'referenced' when remote resources or remote fonts are used, 'none-detected' when the engine found none (absence of evidence, not a guarantee of none)"
            },
            "referencedFontCount": {
              "type": "number",
              "description": "Count of remotely referenced fonts"
            }
          },
          "description": "Detected remote-resource references and referenced font count",
          "additionalProperties": false
        },
        "containerEntryCount": {
          "type": "number",
          "description": "Total ZIP entries in the container"
        },
        "decompressedBytes": {
          "type": "number",
          "description": "Total declared decompressed size of the container in bytes"
        }
      },
      "description": "Structural inventory reported for the EPUB container",
      "additionalProperties": false
    },
    "humanReviewRequired": {
      "type": "boolean",
      "description": "Always true: automated conformance never covers how the book reads or renders"
    },
    "humanReviewItems": {
      "type": "array",
      "items": {
        "type": "string"
      },
      "description": "Checks only a qualified human can perform"
    },
    "nonclaims": {
      "type": "array",
      "items": {
        "type": "string"
      },
      "description": "What this automated result does not establish"
    },
    "truncation": {
      "type": "object",
      "required": [
        "findingsTruncated",
        "totalFindings",
        "returnedFindings",
        "maxMessages"
      ],
      "properties": {
        "findingsTruncated": {
          "type": "boolean",
          "description": "True when more findings exist than were returned"
        },
        "totalFindings": {
          "type": "number",
          "description": "Total findings the engine produced"
        },
        "returnedFindings": {
          "type": "number",
          "description": "Findings actually returned after the maxMessages cap"
        },
        "maxMessages": {
          "type": "number",
          "description": "The applied per-call findings cap"
        }
      },
      "description": "Finding totals and the applied limit on returned findings",
      "additionalProperties": false
    },
    "processingMs": {
      "type": "number",
      "description": "Total processing time in milliseconds"
    }
  },
  "required": [
    "requestedUrl",
    "finalUrl",
    "redirects",
    "sha256",
    "bytes",
    "fetchedAt",
    "engineVersion",
    "ruleProfileDate",
    "pass",
    "epubVersionDetected",
    "counts",
    "findings",
    "inventory",
    "humanReviewRequired",
    "humanReviewItems",
    "nonclaims",
    "truncation",
    "processingMs"
  ],
  "additionalProperties": false
}

Runs the identical pinned EPUBCheck 5.4.0 validation over exactly two EPUB builds (directly hosted public URLs or files attached in chat, baseline first, revised second) sequentially under one shared 110-second deadline, then reports which spec findings regressed or were fixed between them. Returns per-build hashes, EPUB versions, pass verdicts and severity counts, a regressions list (rules that appear or worsen in the revised build) and a fixed list (rules removed or reduced), and a ranking by pass state then fewer blocking findings. Use for 'did my re-export get worse', 'which build has fewer problems', and revision-over-revision questions. The ranking orders automated conformance only (it never means one build renders, reads, or sells better), and when both builds tie on pass state and blocking count it names no winner rather than crowning the first submission. It also flags when the two files declare different titles, since that usually means they are not two builds of one book. Human review remains required for both builds. A comparison can take up to 110 seconds under its shared deadline; tell the user before the call.

{
  "type": "object",
  "properties": {
    "urls": {
      "minItems": 2,
      "maxItems": 2,
      "type": "array",
      "items": {
        "pattern": "^https?://",
        "type": "string",
        "description": "Direct public HTTP(S) URL to the EPUB file bytes, including the protocol, not a ChatGPT file id, local path, cloud-drive share, archive/viewer page, or authenticated URL needing a login. Each call takes either URL sources or attached-file sources, never both"
      },
      "description": "Exactly two distinct direct public HTTP(S) EPUB URLs: the baseline build first, the revised build second. Provide either these URLs or files, never both.\n\nSTRICT RULE: Ebook compare failed: provide either two EPUB URLs or two attached EPUB files, not both\nSTRICT RULE: Ebook compare failed: provide two public EPUB URLs or attach two EPUB build files"
    },
    "files": {
      "minItems": 2,
      "maxItems": 2,
      "type": "array",
      "items": {
        "type": "object",
        "required": [
          "download_url",
          "file_id"
        ],
        "properties": {
          "download_url": {
            "type": "string",
            "description": "Temporary authorized download URL supplied by ChatGPT; fetch it only while handling this tool call"
          },
          "file_id": {
            "type": "string",
            "description": "ChatGPT file id for the attached file"
          },
          "mime_type": {
            "type": "string",
            "description": "MIME type when ChatGPT knows it"
          },
          "file_name": {
            "type": "string",
            "description": "Original file name when ChatGPT knows it"
          }
        },
        "description": "An EPUB build file attached in chat, up to 25 MB, validated from its exact bytes.",
        "additionalProperties": false
      },
      "description": "Exactly two distinct EPUB builds attached in chat: the baseline build first, the revised build second. Provide either these attachments or urls, never both."
    },
    "maxMessages": {
      "minimum": 1,
      "maximum": 300,
      "type": "integer",
      "description": "Maximum findings to collect per build for the comparison (default 150)"
    }
  },
  "description": "STRICT RULE: Ebook compare failed: the two sources must be distinct builds",
  "additionalProperties": false
}

{
  "type": "object",
  "properties": {
    "engineVersion": {
      "type": "string",
      "description": "EPUBCheck engine version that produced the verdicts"
    },
    "ruleProfileDate": {
      "type": "string",
      "description": "Release date of the pinned EPUBCheck rule profile"
    },
    "documents": {
      "type": "array",
      "items": {
        "type": "object",
        "required": [
          "url"
        ],
        "properties": {
          "url": {
            "type": "string",
            "description": "The checked EPUB source: the submitted URL with query and fragment stripped, or the attached file's name"
          },
          "failed": {
            "type": "string",
            "description": "Why this build could not be validated, when it could not"
          },
          "sha256": {
            "type": "string",
            "description": "SHA-256 hash of the exact validated bytes"
          },
          "bytes": {
            "type": "number",
            "description": "Downloaded EPUB size in bytes"
          },
          "epubVersion": {
            "type": "string",
            "description": "Detected EPUB version"
          },
          "pass": {
            "type": "boolean",
            "description": "True when the build has no fatal or error messages"
          },
          "counts": {
            "type": "object",
            "required": [
              "fatal",
              "error",
              "warning",
              "usage"
            ],
            "properties": {
              "fatal": {
                "type": "number",
                "description": "Fatal messages: the container could not be fully processed"
              },
              "error": {
                "type": "number",
                "description": "Error messages: spec violations that fail validation and typically block store uploads"
              },
              "warning": {
                "type": "number",
                "description": "Warning messages: advisory issues that do not fail validation"
              },
              "usage": {
                "type": "number",
                "description": "Usage messages: informational notices about optional or unusual constructs"
              }
            },
            "description": "Counts of EPUBCheck findings grouped by severity for this build",
            "additionalProperties": false
          },
          "findingsTruncated": {
            "type": "boolean",
            "description": "True when this build's findings were capped by maxMessages"
          }
        },
        "additionalProperties": false
      },
      "description": "Per-build hashes, versions, and verdicts in submitted order (baseline first, revised second)"
    },
    "regressions": {
      "type": "array",
      "items": {
        "type": "object",
        "required": [
          "ruleId",
          "severity",
          "description",
          "baselineCount",
          "revisedCount"
        ],
        "properties": {
          "ruleId": {
            "type": "string",
            "description": "EPUBCheck message id that differs between builds"
          },
          "severity": {
            "type": "string",
            "description": "Severity of the rule in the build where it appears"
          },
          "description": {
            "type": "string",
            "description": "Representative message text for the rule"
          },
          "baselineCount": {
            "type": "number",
            "description": "Occurrences in the first (baseline) build"
          },
          "revisedCount": {
            "type": "number",
            "description": "Occurrences in the second (revised) build"
          }
        },
        "additionalProperties": false
      },
      "description": "Rules that appear or worsen in the revised build versus the baseline"
    },
    "fixed": {
      "type": "array",
      "items": {
        "type": "object",
        "required": [
          "ruleId",
          "severity",
          "description",
          "baselineCount",
          "revisedCount"
        ],
        "properties": {
          "ruleId": {
            "type": "string",
            "description": "EPUBCheck message id that differs between builds"
          },
          "severity": {
            "type": "string",
            "description": "Severity of the rule in the build where it appears"
          },
          "description": {
            "type": "string",
            "description": "Representative message text for the rule"
          },
          "baselineCount": {
            "type": "number",
            "description": "Occurrences in the first (baseline) build"
          },
          "revisedCount": {
            "type": "number",
            "description": "Occurrences in the second (revised) build"
          }
        },
        "additionalProperties": false
      },
      "description": "Rules removed or reduced in the revised build versus the baseline"
    },
    "ranking": {
      "type": "array",
      "items": {
        "type": "object",
        "required": [
          "rank",
          "url"
        ],
        "properties": {
          "rank": {
            "type": "number",
            "description": "1-based rank by automated conformance evidence"
          },
          "url": {
            "type": "string",
            "description": "Build source: the submitted URL query- and fragment-stripped, or the attached file's name"
          },
          "pass": {
            "type": "boolean",
            "description": "Automated pass verdict"
          },
          "blockingCount": {
            "type": "number",
            "description": "Fatal + error messages for this build"
          },
          "failed": {
            "type": "string",
            "description": "Why this build could not be validated, when it could not"
          }
        },
        "additionalProperties": false
      },
      "description": "Builds ranked by pass state then fewer blocking findings; unvalidatable builds last"
    },
    "limits": {
      "type": "array",
      "items": {
        "type": "string"
      },
      "description": "Conclusions this automated comparison cannot support"
    },
    "humanReviewRequired": {
      "type": "boolean",
      "description": "Always true: automated conformance never covers how either build reads or renders"
    },
    "humanReviewItems": {
      "type": "array",
      "items": {
        "type": "string"
      },
      "description": "Checks only a qualified human can perform"
    },
    "nonclaims": {
      "type": "array",
      "items": {
        "type": "string"
      },
      "description": "What these automated results do not establish"
    },
    "truncated": {
      "type": "boolean",
      "description": "True when either build's findings were truncated, which can make the difference table incomplete"
    },
    "processingMs": {
      "type": "number",
      "description": "Total processing time in milliseconds"
    },
    "comparedAt": {
      "type": "string",
      "description": "ISO timestamp of the comparison"
    }
  },
  "required": [
    "engineVersion",
    "ruleProfileDate",
    "documents",
    "regressions",
    "fixed",
    "ranking",
    "limits",
    "humanReviewRequired",
    "humanReviewItems",
    "nonclaims",
    "truncated",
    "processingMs",
    "comparedAt"
  ],
  "additionalProperties": false
}