# Principles > What Spooldoc believes, and what every change is checked against. Source: https://spooldoc.com/docs/principles/ Spooldoc grows one change at a time, by people and by coding agents. Each change can make sense on its own and still leave the whole worse. These principles are what a change is checked against. When a change and a principle disagree, the change gives way, or the pull request changes this page and says why. ## Nothing changes on the IBM i unless the user asks Spooldoc reads what programs already print. It installs nothing and asks for no program changes. It creates a data queue only when the user turns on real-time watching, and it holds, moves or deletes a spooled file only as the job's finish step says. It writes files to the IFS only through an IFS destination the user set up, and only in the folder chosen there. In practice: - An action that changes the IBM i is named in the UI before it happens: the object, and what will be done to it. - An action that destroys something on the IBM i, such as deleting spooled files, asks for confirmation when it goes live. - When Spooldoc lacks an authority, it says which one and gives the command an operator can run. It does not ask for more authority than the job needs. - An IFS destination never creates the folder. It writes each file under a temporary name and renames it when it is complete, so a program that watches the folder sees whole files only. A file with the same name is replaced, kept with a new number, or fails the run, as the destination says. To replace one, the old file is renamed aside to a name that ends in `.old`, and deleted once the new one is in place, so a failed write never loses both. See [IFS folder](https://spooldoc.com/docs/destinations/#ifs-folder). ## Reading and layout stay apart A definition reads pages into JSON. A template lays out that JSON. A template never sees lines and columns, and a definition never knows what the document looks like. The one exception is the Excel template of the whole spooled file. Every other template lays out one page group at a time; this one gets every page group at once and makes one workbook with a row per table line, the flat sheet people filter and sum. It still reads the JSON, not the printed lines and columns. See [What each file holds](https://spooldoc.com/docs/templates/#what-each-file-holds). In practice: - Values are typed once, in the definition. Templates format them. - New output formats and destinations take the same JSON. Nothing downstream reads the spooled file again. - The extraction can be checked before anything is rendered. ## Every spooled file becomes a document, or the user can see why not Spooldoc stands between a program and a customer waiting for an invoice. A file that is quietly not delivered is the worst thing it can do. In practice: - No error is caught and dropped. It is logged, and when it affects a run or a queue, it shows in the Job log or in Needs attention. - No list is cut off without saying so. - A run that stops part way is marked failed with the reason, soon, not hours later. - A fallback, such as real-time watching dropping to polling, is shown, not just taken. ## Speak IBM i, in the user's terms The people who run Spooldoc know their system. Messages use their words: output queue, spooled file, user profile, library. IBM i terms are not jargon to them. Everything else is plain English. In practice: - An IBM i error says what went wrong and what to do next: which object, which authority, which command fixes it. The original message text is kept for support, one step away, not in the headline. - A timeout names the host and the ports to check. ## The page is the truth, and a person decides The user checks every extracted value next to the page it came from. The agent proposes; it does not decide. What it writes is plain YAML, HTML, and Word and Excel files that a person can read, edit and keep without it. In practice: - Spooldoc works without a model. The agent saves time, it is not a requirement. - A Word template the agent makes is an ordinary `.docx` the user opens and changes in Word, made of Word's own paragraphs, tables and styles. An Excel template is an ordinary `.xlsx` of Excel's own cells, styles and formulas, which the user opens and keeps working on in Excel. The agent designs both as data that Spooldoc builds; no code the model writes runs on the server. - The agent never overwrites what the user made. A Word or Excel file it writes or edits is a new file, and the earlier one stays to go back to. - Where values go is the user's choice, made in Settings and shown in the agent panel: as printed, so the model can read them, or masked before page text leaves the server. A local model keeps them on the user's network either way. - Nothing the agent proposes runs on the IBM i or goes live until the user saves and activates it. ## Show only what works The app and the guides under `docs/` describe what Spooldoc does today. Plans live only in the [README](https://github.com/Strom-Capital/spooldoc/blob/v0.3.1/README.md#status) Status section and in the issues. In practice: - No "coming later" lists, disabled placeholders or settings that do nothing yet. A guide says what works, not what is planned; at most it links to the README Status section. - A message never points to something that does not exist, such as an administrator page that is not there. ## One way to do a thing The same thing looks, reads and behaves the same everywhere. In practice: - One component for each pattern: selects, empty states, loading states, confirmations, hints. Look in `components/ui`, `components/page.tsx`, `components/empty-state.tsx` and `components/hint.tsx` before adding one. A list loads with `Loading`; a table already on screen keeps its shape with `SkeletonRows`. - A table row works the same in every table. A click on the row, or on its name, opens it. At most two actions show on the row, the ones people come to that table for: quiet ghost buttons with an icon and a label. An action only some rows have goes first, so the ones every row has line up. The ⋯ menu at the end of the row holds every row action, those included and in the same order, with destructive ones last after a separator. - One word for each state and action. A paused job is "paused" in the list, the builder and the toast. - Errors read "Could not ..." and say what to do. Success toasts say what was done and name the thing: "Deleted MYJOB", "Saved version 3". - A button whose label alone does not say what it does, or that is disabled, has a hint made with `Hint` (`components/hint.tsx`): what it does, what it changes and whether that can be undone, or why it is disabled. Every icon-only button has a hint and an `aria-label`. A hint that only repeats the label is left out. - Every control works from the keyboard and reads in dark mode. ## Fewer features, finished Adding is easier than reshaping, so it is the change to be wary of. Before adding a feature, ask whether an existing one should change instead. In practice: - A feature is done when its empty, loading and error states, its docs and its tests are done, not when the happy path works. - A new setting needs a reason a default cannot cover. - What to build next comes from real use, not from the order of a list. ## Writing The UI and the docs are written the same way: - Short sentences and plain words. One idea per sentence. - Sentence case for headings, buttons and menu items. - No middle dot (`·`) as a separator. Use a comma, a line break or a separate element. - No em or en dashes in prose, not even in ranges: write "2025 to 2028". Use a period, a comma, a colon or parentheses instead. Hyphens inside words, such as read-only, are fine. - American spelling: license, color, behavior, organize. - IBM i terms are not jargon to our readers. Write `*SCS`, CCSID and user profile. In prose, write output queue, not OUTQ, and spooled file, not splf. - One word for each thing: spooled file, output queue, definition, template, page group, job, run, destination, job log. - The feature is "the agent", never "assistant" or "copilot", and it has no sparkle icon. "AI" is a plain fact, such as "the agent uses an AI model you choose", at most once or twice on a page and never a label. - Invented names only: `MYLIB`, `MYOUTQ`, `ibmi.example.com`. See [No real names](https://spooldoc.com/docs/contributing/#no-real-names).