# natural-language-report-service A user asks for a report in Dutch. An LLM turns the question into a spec. A fixed program turns the spec into small SPARQL queries, joins the results and writes a CSV. The LLM writes no SPARQL and sees no report data. Ad-hoc reports only. The scheduled reports stay in `loket-report-generation-service`. ## Two modes: refine, then execute Every turn is classified first. One small LLM call (`src/llm/mode.js`) returns true/false: does the user's last message clearly say "run it now" or not. The answer picks one of two deterministic code paths. **Refinement (Modus A).** The LLM proposes a spec and explains in Dutch what it will list and filter. It may call `lookup_values` to search code lists for candidate values, so its filter suggestions name real values instead of guesses. It never runs a report and never learns what a spec would match: the database it reads may differ from the one the report runs on, so a lookup is a suggestion, not a check. The user must confirm before anything executes. As long as the user has not given a clear command, the turn stays in this mode. **Execution (Modus B).** The user has confirmed. The LLM writes the agreed spec, validates it and calls `run_report` once, then stops. `run_report` returns only the report URI, the row count and the file URI. No cell value ever reaches the model; the service may count results, but no data is fed to the LLM. The two modes share `list_profiles`, `describe_profile` and `validate_spec`. Refinement adds `lookup_values`; execution adds `run_report`. The tool set is the only thing that differs; the code path from the classifier's answer is deterministic. ## How it works Two documents drive everything: | | Who writes it | When | Where | |---|---|---|---| | **profile** | the app | once, committed | `config/report-profiles/*.ttl`, mounted at `/config/profiles/` | | **spec** | the LLM | one per question | in the request, not stored | A **profile** is a SHACL shapes graph: one `sh:NodeShape` per entity, fields as `sh:property`, code lists via `sh:class`, links via `sh:node`. The service ships no profile and knows no vocabulary; profiles live in the app repo. A **spec** is `rep:ReportSpec` + `sh:NodeShape`: `sh:property` selects the subjects, `rep:columns` says what the CSV holds. The two never interact. The namespace is `http://mu.semte.ch/vocabularies/reporting/` (`rep:`). The run: check → seed (`SELECT DISTINCT ?s`, paged) → columns (per group, per chunk of subjects) → assemble (dedup + `rep:collect`) → CSV → register file + report resource. One run per question; the loop stops after `run_report` returns. ## One identity: mu-authorization's All SPARQL goes through the template's own helpers (`mu`'s `query` and `update`). They attach the caller's session from the request context, and mu-authorization decides graphs and visibility; the service never touches an auth header. The context lives for the whole run, also past the `202` the chat turn answers with, so background writes stay the caller's. The tools the LLM calls return URIs, counts, statuses and column names — never a cell value. ### The service scope The LLM's own reads during refinement (`describe_profile`'s code lists and `lookup_values`) run under a service scope, not the caller's session. mu's `query(q, { scope })` sends `mu-auth-scope`; the sparql-parser config grants that scope read access to `http://mu.semte.ch/graphs/public` only. So refinement reads only public code lists, regardless of who calls. Execution (`run_report`) still runs as the caller, so the report contains what they may see, and the LLM sees none of it. The scope URI is `SERVICE_SCOPE` (default `http://services.semantic.works/natural-language-report`) and must match the `with-scope` grant in the app's sparql-parser `config.lisp`. Do not set `DEFAULT_MU_AUTH_SCOPE` on the service: that would scope every query (including the run and the chat store) and break them. ## Two endpoints ``` POST /ask { question, history? } → { answer, toolCalls } POST /assistant/conversations/:id/turns { content } → 202 { id } ``` `/ask` is synchronous: a Dutch question in, the turn is classified, and the matching mode's loop runs inside the service (profiles, spec, validate, refine or run), and the answer in Dutch comes back with a trace of the tool calls. The CSV lands in `data/files/`. `history` carries the earlier turns for follow-ups; the conversation lives on the caller's side, the service stores nothing. One question makes one report; the execution loop stops after `run_report`. `/assistant` is the chat. The turn module in `src/chat/` is generic — it imports nothing from `src/llm/` or `src/runner/` and moves between services without edits — and `src/report-assistant.js` is this service's one `answer` hook. It records the question, answers `202` with the message id, then runs the same loop with the conversation's history. A report run becomes an interim message with a pending file (`as:Document` with no `as:url`); the URL is set when the run ends. The browser polls `/chat-conversations/:id?include=messages.attachments` and finds the answer that way. Failure is a message, never a silent loader. `/ask` needs `LLM_BASE_URL` set, and answers 503 without it. A full-org report run takes minutes. ### The internal tools The loop drives a tool set per mode (`src/llm/tools.js`). Both modes share `list_profiles`, `describe_profile`, `validate_spec`. Refinement adds `lookup_values`; execution adds `run_report`. They are machinery, not an external surface — the tool trace in the answer is the only thing a caller sees of them. All LLM-facing text (system prompts, profile menu, tool descriptions, validator errors) is English; the answer the user sees is Dutch. ## Environment | Var | Default | Meaning | |---|---|---| | `MU_SPARQL_ENDPOINT` | — | the auth layer, e.g. `http://database:8890/sparql`. Never virtuoso. | | `REPORT_CLASS` | `…/reporting/Report` | type of the report resource | | `CSV_SEPARATOR` | `;` | CSV column separator | | `SUBJECT_CHUNK_SIZE` | `100` | subjects per column query (VALUES batch size); lower it when the auth layer rejects long queries | | `ROW_LIMIT` | `200000` | seed limit; failing the job beats truncating | | `MAX_PATH_DEPTH` | `8` | longest allowed spec path | | `RUN_TIMEOUT` | `60` | seconds of silence before `run_report` gives up. Every answered query (seed page, column batch) restarts the clock, so a big report only needs the window per batch, not for the whole run. The run itself is never cancelled: the file still lands in the chat. | | `INLINE_VALUES_MAX` | `50` | code lists up to this size are inlined in `describe_profile` | | `VALUES_TTL` | `3600` | seconds the inlined lists are cached | | `LLM_BASE_URL` | — | enables `/ask`; OpenAI-compatible (`https://ollama.com/v1`) | | `LLM_MODEL` | — | e.g. `gpt-oss:120b` | | `LLM_API_KEY` | — | bearer token, optional for local Ollama | | `SEED_PAGE_SIZE` | `5000` | seed page size | | `SUBJECT_CHUNK_SIZE` | `100` | see above | | `SHARE_DIR` | `/share` | where CSVs are written | | `CHAT_ASSISTANT_URI` | — | the `prov:SoftwareAgent` that signs assistant messages; found by lookup when unset | | `CHAT_HISTORY_LIMIT` | `20` | messages of history a turn reads | | `SERVICE_SCOPE` | `http://services.semantic.works/natural-language-report` | the mu-auth-scope for the LLM's own reads (code lists, `lookup_values`). Must match the `with-scope` grant in the app's sparql-parser config. | Do not set `ALLOW_MU_AUTH_SUDO`; the template then refuses sudo queries. ## In the stack `docker-compose.yml`: ```yaml natural-language-report: build: ../natural-language-report-service/ image: lblod/natural-language-report-service:0.1.0 volumes: - ./data/files:/share - ./config/report-profiles/:/config/profiles/ ``` `config/dispatcher/dispatcher.ex`: ```elixir match "/natural-language-reports/*path" do forward conn, path, "http://natural-language-report/" end ``` One route to the service root; `POST /ask` is the endpoint. First deploy: `docker compose build natural-language-report`, then `docker compose up -d natural-language-report dispatcher`. ## Authorization Admin only: `config.ex` grants `reporting:Report` to `LoketAdmin` (`o-admin-rwf`) alone. A toezicht user can run the seed and read the CSV data, but the `reporting:Report` triples are silently dropped by the auth layer (their group may not write that type), so the report URI the tools return is dangling for non-admin callers. Opening this up means adding the type to their group first. ## Rules the code holds to - Query `http://database:8890/sparql`. Never virtuoso. Never sudo. - No `GRAPH` clauses, no property paths, no aggregates, no inline comments: mu-authorization is a SPARQL 1.0 subset. - Generated queries use full URIs, no prefixes (a bare `mu:uuid` prefixed name without its PREFIX line is an opaque 500). ## Libraries - `n3` — Turtle parsing (profiles, specs) - hand-written: CSV writer (quotes only when needed), the query builders, the agent loop (bare `fetch`, no provider SDK) ## What it will not do No counting, no sorting, no top-N, no comparing two subjects, one class per report, suggestions stop at the public graph.