# `GET /v1/workspace/books/{bookId}/file` — Read a file

Part of the [Bkper Managed Agent API](https://bkper.com/docs/api/managed-agent.md). Read its guide for authentication, conventions, and examples.

One file of the working copy, or with `version=base` as published at the base (404 not_found when the base has none). For those who can view the Book; changes for its editors and owner (403 workspace_forbidden).

## Operation contract

```json
{
  "operationId": "getBookContextFile",
  "tags": [
    "Workspace"
  ],
  "summary": "Read a file",
  "security": [
    {
      "bearerAuth": []
    }
  ],
  "parameters": [
    {
      "name": "bookId",
      "in": "path",
      "required": true,
      "schema": {
        "type": "string",
        "pattern": "^[A-Za-z0-9_-]{1,128}$"
      }
    },
    {
      "name": "path",
      "in": "query",
      "required": true,
      "schema": {
        "type": "string",
        "minLength": 1,
        "maxLength": 512
      }
    },
    {
      "name": "version",
      "in": "query",
      "schema": {
        "type": "string",
        "enum": [
          "base"
        ]
      },
      "description": "base: the file as published at the base, as the working copy's changes are compared with. Absent: the working copy's."
    }
  ],
  "description": "One file of the working copy, or with `version=base` as published at the base (404 not_found when the base has none). For those who can view the Book; changes for its editors and owner (403 workspace_forbidden).",
  "responses": {
    "200": {
      "description": "Success",
      "content": {
        "application/json": {
          "schema": {
            "$ref": "#/components/schemas/WorkspaceFile"
          }
        }
      }
    },
    "400": {
      "description": "Rejected; never contains credentials or upstream payloads.",
      "content": {
        "application/json": {
          "schema": {
            "$ref": "#/components/schemas/Error"
          }
        }
      }
    },
    "401": {
      "description": "Rejected; never contains credentials or upstream payloads.",
      "content": {
        "application/json": {
          "schema": {
            "$ref": "#/components/schemas/Error"
          }
        }
      }
    },
    "403": {
      "description": "Rejected; never contains credentials or upstream payloads.",
      "content": {
        "application/json": {
          "schema": {
            "$ref": "#/components/schemas/Error"
          }
        }
      }
    },
    "404": {
      "description": "Rejected; never contains credentials or upstream payloads.",
      "content": {
        "application/json": {
          "schema": {
            "$ref": "#/components/schemas/Error"
          }
        }
      }
    },
    "409": {
      "description": "Rejected; never contains credentials or upstream payloads.",
      "content": {
        "application/json": {
          "schema": {
            "$ref": "#/components/schemas/Error"
          }
        }
      }
    },
    "410": {
      "description": "Rejected; never contains credentials or upstream payloads.",
      "content": {
        "application/json": {
          "schema": {
            "$ref": "#/components/schemas/Error"
          }
        }
      }
    },
    "411": {
      "description": "Rejected; never contains credentials or upstream payloads.",
      "content": {
        "application/json": {
          "schema": {
            "$ref": "#/components/schemas/Error"
          }
        }
      }
    },
    "413": {
      "description": "Rejected; never contains credentials or upstream payloads.",
      "content": {
        "application/json": {
          "schema": {
            "$ref": "#/components/schemas/Error"
          }
        }
      }
    },
    "422": {
      "description": "Rejected; never contains credentials or upstream payloads.",
      "content": {
        "application/json": {
          "schema": {
            "$ref": "#/components/schemas/Error"
          }
        }
      }
    },
    "503": {
      "description": "Rejected; never contains credentials or upstream payloads.",
      "content": {
        "application/json": {
          "schema": {
            "$ref": "#/components/schemas/Error"
          }
        }
      }
    }
  }
}
```

## Schemas

### WorkspaceFile

```json
{
  "type": "object",
  "properties": {
    "path": {
      "type": "string"
    },
    "size": {
      "type": "number",
      "description": "Bytes."
    },
    "sha": {
      "description": "The file's Git blob ID, up to 256 KiB: what a write names as `previous`.",
      "type": "string"
    },
    "text": {
      "description": "UTF-8 text up to 256 KiB. Absent for other files: PNG and JPEG pictures show through `/image`; others are only listed.",
      "type": "string"
    }
  },
  "required": [
    "path",
    "size"
  ]
}
```

### Error

```json
{
  "type": "object",
  "properties": {
    "error": {
      "type": "object",
      "properties": {
        "code": {
          "type": "string",
          "description": "Stable code, e.g. not_found, idempotency_conflict, session_working, usage_limit_exceeded. Open."
        },
        "type": {
          "description": "Category, e.g. invalid_request_error, authentication_error, usage_limit_error. Open.",
          "type": "string"
        },
        "message": {
          "type": "string"
        },
        "host": {
          "description": "host_in_use: the host another service holds.",
          "type": "string"
        },
        "service": {
          "description": "host_in_use: the id of the service that holds the host.",
          "type": "string"
        },
        "reason": {
          "description": "file_invalid: why the change, or a picture, was refused. Open: path | text | size | skill | skills | count | type.",
          "type": "string"
        },
        "paths": {
          "description": "file_exists from an add: every path of the request where a file is and `replace` was not set, all at once, so the person can be asked once. publish_conflict: the files someone published changes to the same lines of.",
          "type": "array",
          "items": {
            "type": "string"
          }
        },
        "publishers": {
          "description": "publish_conflict: who published those changes, by name.",
          "type": "array",
          "items": {
            "type": "string"
          }
        }
      },
      "required": [
        "code"
      ]
    }
  },
  "required": [
    "error"
  ]
}
```

## Authentication

```json
{
  "bearerAuth": {
    "type": "http",
    "scheme": "bearer"
  }
}
```