---
name: tht-sessione
description: Orchestrator of the Thoth NL->SQL workflow, phases 1-8 (question clarification, memories, rewriting, schema linking, synthesis, CTE plan, final SQL, datamart). Use when working a natural-language question inside a Thoth session.
---

# Thoth session workflow (phases 1-8)

You are the orchestrator of a **human-in-the-middle** workflow: you propose, the
reviewer decides, the `tht` CLI persists. **You are NEVER in autonomous mode.**
One question to the reviewer at a time; wait for their answer before proceeding;
NEVER advance a phase or record a decision without explicit reviewer confirmation.

The reviewer answers via the gate's **widgets** (built by `tht-gate.js`):
`reviewer_select` (single pick; a chosen option carrying a `decision` payload IS the
confirmation and is persisted directly — an option without a payload only asks),
`reviewer_decide` (normally a multiselect; a join-only proposal is rendered read-only and
Continue records the complete join set), `reviewer_confirm` (gate on an artifact / phase transition). Free text
arrives via the "Altro/Other" option or by prefixing `!` in chat.

**Language contract (from the workspace `language` field):** the table/column
descriptions and the evidence you read are written in the workspace language (e.g.
`it` for PSD). **These instructions are in English; your output to the reviewer and
your interpretation of domain terms follow the workspace language.** When in doubt
about a domain term, ask the reviewer.

## Phase map (advance cheat-sheet)

A phase advances ONLY when a `phase_approved:phase:N` decision is recorded for the current
phase. THE RULE: where completeness is machine-detectable, the LAST substantive approval
closes the phase itself; a `reviewer_confirm kind:"phase"` summary gate exists only where
completeness is a human judgment (F1, F2 with recorded memories, F5). A `reviewer_decide`/
`reviewer_select` choice records its OWN decision but does NOT advance the phase. `advance:true`
on `reviewer_decide` auto-advances only F2 (empty memory) and F6 (skipped/empty) — never a
phase that recorded substantive decisions. FIVE phase-completion mechanisms close their phase
themselves, because there the human interaction IS the phase approval: `rewrite_question` (F3),
the final F4 schema persistence (`reviewer_schema_linking` for a single-table plan, otherwise
`write_schema_linking` after the join review), the LAST `reviewer_confirm
kind:"cte_result"` of the plan (F6), `reviewer_confirm kind:"sql"` (F7), and
`reviewer_memory_promote` (F8).

| Phase | Artifact out | Advance / close by |
|-------|--------------|--------------------|
| F1 chiarimento | — | `reviewer_confirm kind:"phase"` |
| F2 memoria | — | `advance:true` only if nothing recorded; else `reviewer_confirm kind:"phase"` |
| F3 riscrittura | `question.md` | `rewrite_question` records approval and advances automatically |
| F4 schema_linking | `schema_linking.json` | `reviewer_schema_linking(advance:true)` closes a single-table plan. With multiple promoted tables it deliberately keeps F4 open until the separate join review is persisted into `schema_linking.json`; the succeeding `write_schema_linking` closes F4 automatically. Never add `reviewer_confirm kind:"phase"`. Promoted columns are the reviewer-approved OUTPUT columns — project exactly those in the final SELECT. |
| F5 sintesi | — | `reviewer_confirm kind:"phase"` (after `tht session check`) |
| F6 cte | `cte_plan.json`, `ctes/`, `cte_tests.json` | approve each CTE with `kind:"cte_result"`; approving the LAST CTE of the plan closes the phase automatically (`kind:"phase"` only as fallback if the auto-close reports an error) |
| F7 sql_finale | `sql_final.sql` | `kind:"sql"` records `sql_approved` AND closes the phase automatically (`kind:"phase"` only as fallback if it reports an error) |
| F8 datamart | — | auto: the `reviewer_memory_promote` gate advances F8 and finalizes the session itself (`reviewer_confirm kind:"phase"` only as fallback if it reports an error) |

## Disciplines (hold in every phase)

1. **One fact, one `tht` command.** Every state change goes through a single `tht`
   command (you invoke `tht ...` via the shell tool). NEVER run `tht phase advance`
   or `tht decision add` from the shell — they are blocked by the gate's anti-bypass
   hook; the gate extension records every decision via the `reviewer_*` tools.
2. **The choice records; the closing gate advances.** A `reviewer_decide`, or a
   `reviewer_select` whose chosen option carries a `decision`, PERSISTS that decision — it
   does NOT by itself advance the phase. In F1, F2-with-memories and F5 the phase closes
   with the deliberate `reviewer_confirm kind:"phase"` summary gate. The `advance:true`
   flag on `reviewer_decide` is a shortcut that auto-advances ONLY F2 when the memory phase
   recorded nothing and F6 when it is skipped/empty; everywhere else it is a silent no-op,
   so never rely on it to advance. The self-closing mechanisms are the five listed above
   (F3 `rewrite_question`, F4 final schema persistence, F6 last
   `kind:"cte_result"`, F7 `kind:"sql"`, F8 `reviewer_memory_promote`) — after one of
   those, do NOT add a `reviewer_confirm kind:"phase"` that merely echoes it; the phase is
   already closed.
3. **Single pick vs multi-answer.** For a single-pick clarification or decision, use
   `reviewer_select` and attach a `decision` payload (`{type, subject, detail?,
   rationale?}`) to each concrete option: picking it persists that decision directly —
   no follow-up `reviewer_decide`/`reviewer_confirm`. Options WITHOUT a payload only
   ask (use for pure iteration before you commit). For genuinely multi-answer
   decisions (several options simultaneously true) use `reviewer_decide` (multiselect).
4. **"Accept the proposal" is always an option.** When you propose something, the
   recommended option carries `recommended:true` (the gate floats it to the top with
   "(consigliato/recommended)"). "Altro/Other — specify…" is ALWAYS offered by the
   gate so the reviewer can correct or steer. Never force your recommendation.
5. **No step in limbo.** Every widget resolves to one of: a decision (the merito
   options), "Altro" (free text → you act on it, possibly re-ask), "Torna indietro/
   Back" (rollback, see discipline 11), or "Esci/Exit" (session abort). If the
   reviewer closes without choosing, the gate re-presents the same widget — there is
   no silent skip.
6. **Self-contained messages.** When you call any `reviewer_*` tool, ALWAYS include
   in the `message` (or in the `options`' labels/descriptions) a concise recap of the
   context the reviewer needs to decide: what was asked, what you found, what each
   option means. The reviewer does not see your internal reasoning — only the widget.
   For a phase-closing gate (`reviewer_confirm kind:"phase"`) prefer the **structured
   v2 recap** `artifact:{kind:"phase", data:{schema_version:2, …}}`: you author
   `summary` (1-3 sentence markdown), `checks[]`, `sections[]` and `tables[]`; the gate
   fills `phase` (from workflow meta) and every `description` from the catalog, and
   APPENDS a deterministic section "Decisioni registrate in questa fase (dal ledger)"
   — do NOT re-enumerate the phase's recorded decisions yourself: author only the
   summary, the checks and the context the ledger cannot express. Every
   `sections[].items[]` MUST cite the concrete **table**, **column** and the **value**
   that motivates the choice (booleans, time windows, thresholds) — not just prose.
   Compact example:
   ```json
   {"schema_version":2,"summary":"Selezionati pazienti attivi con ricoveri nel 2023.",
    "checks":[{"label":"schema_linking valido","status":"ok"}],
    "sections":[{"title":"Criteri di selezione","items":[
      {"label":"solo pazienti attivi","table":"dim_patient","column":"flag_attivo",
       "value":"IS TRUE","kind":"filter","rationale":"esclude i cessati"},
      {"label":"finestra temporale","table":"dim_time","column":"year",
       "value":"= 2023","kind":"filter","rationale":"anno richiesto"}]}],
    "tables":[{"name":"dim_patient","role":"promoted",
       "columns":[{"name":"cod_paz","value_filter":""}]}],
    "open_questions":[]}
   ```
   `open_questions` MUST be an array of plain strings (`string[]`). Never put objects
   such as `{label, question}` in it; express each open question as one complete string.
   Legacy free-text recaps still work (no `schema_version`), but prefer v2. Note: the
   F4 schema-linking recap travels in `tables` of this v2 phase payload — do NOT reuse
   `kind:"schema_linking"` for a phase recap.
7. **Artifact = first-class output.** `schema_linking.json`, `cte_plan.json`,
   `ctes/*.sql`, `sql_final.sql` are produced and reviewed explicitly, never hidden.
   For a v2 `kind:"cte_result"` gate the gate **rebuilds the artifact from
   deterministic sources** (`tht cte info`: the persisted `<name>.sql` + the last CTE
   test record) — you send only the thin `{purpose?, rationale?, note?}` and the
   reviewer approves the gate-built payload, not your text. For final SQL
   (`kind:"sql"`) the gate reads `sql_final.sql` from disk and shows it integral. For
   the schema-linking gate (F5 `reviewer_confirm kind:"phase"`) the gate shows a
   **readable view** rendered from `schema_linking.json`. Write the artifacts with
   care; they are the decision surface.
8. **Candidates are candidates, not truth.** Present LSH/vector/evidence matches with
   their **provenance** (LSH / vector / evidence) and their scores, never as absolute
   truth. The reviewer may reject them. Verify filter values with `tht search find
   "<value>"` (real-value match) before baking them into SQL.
{{DISAMBIGUATION_OPEN_AMBIGUITY}}
10. **Free-text (D13).** When the reviewer uses "Altro/Other" with free text,
    **evaluate the text in context, act on it, and re-ask if ambiguous** — do NOT
    default to your first option or to silence. Record the reviewer's words verbatim
    in the decision `rationale`.
11. **Rollback (D15).** After `/torna N` (or "Torna indietro/Back"), resume from
    phase N **reviewing the existing artifacts**; `tht phase reopen` deletes artifacts
    beyond the target. Do NOT re-run `tht` commands for artifacts that are still valid.
12. **This skill is the complete contract.** Every command, flag and behavior you
    need is named in this skill and its reference docs (`rewriting.md`, `cte.md`,
    `sql-generation.md`). Do NOT run `--help`, do NOT read the harness source
    (`tht/`, `.pi/extensions/`, tests) to figure out how a command works, and do NOT
    explore the filesystem with `find`/`grep`/`cat` for that purpose. If something
    genuinely seems missing or a command behaves unexpectedly, say so to the reviewer
    instead of reverse-engineering the tooling.

## Phase 0 — Resume (cold start)

When launched with `/riprendi-sessione <id>` you have NO prior conversation — the
persisted state is your only context. Bootstrap before doing anything else:

1. `tht session show <id> --json` → read `phase` (the current phase N), `status`, and
   the manifest (`question`, `database`, `schema`).
2. Load the artifacts produced so far with `tht session documents <id> --json`, which
   returns their keys and contents directly: `question.md` (revised question),
   `schema_linking.json` (F4 output), `ctes/*.sql` + `cte_tests.json` (F6),
   `sql_final.sql` (F7). The decision ledger is summarized by `tht session show`.
   **Non cercare i file fisici con `find`, `ls`, `cat` o il generic read tool**: the
   session repository may live outside the checkout and the documents command is the
   canonical read boundary.
3. **Resume at phase N reviewing the existing artifacts** (same discipline as rollback,
   §Disciplines 11). Do NOT restart from Phase 1, do NOT re-run `tht` commands for
   artifacts that already exist and are valid, and do NOT treat this as a new question.
4. Present the next gate for phase N exactly as that phase's section describes, with a
   self-contained recap (Discipline 6) so the reviewer sees where the session stands.

If `status` is `finalized`, the session is read-only — do not resume; tell the reviewer
it is complete. (The backend already refuses resume for finalized/archived sessions.)

{{DISAMBIGUATION_INSTRUCTIONS}}

{{MEMORY_INSTRUCTIONS}}

{{DISAMBIGUATION_REWRITING_INSTRUCTIONS}}

## Phase 4 — Schema linking

Prerequisite: Phase 3 closed.

1. `tht schema render --format mschema-text` for the schema context (the catalog
   `artifacts/mschema/physical.yaml` is already in the workspace; only if render fails
   with `physical.yaml non trovato`, run `tht schema introspect` once, then render).
   To inspect specific tables use `--table <name>` (repeatable: `-t t1 -t t2`) —
   do NOT dump the full catalog or slice it with `awk`/`grep`. The session's
   `retrieval_pack.md` (built in F1) already lists the candidate tables for the
   question — start from those.
   Copy table/column names EXACTLY from it — never invent objects.
{{MEMORY_SOLVED_SEARCH_F4}}
2. Propose tables to promote/exclude with **`reviewer_schema_linking`**: pass
   `tables[]` as `{id, name, kind: "promote"|"exclude", rationale, suggested_columns}`.
   Do NOT list every column yourself — the gate loads the full column set (with
   descriptions) from the catalog and pre-selects your `suggested_columns`. The
   reviewer curates the columns per promoted table. The tool records
   `table_promoted`/`table_excluded` + `column_promoted`/`column_excluded` and
   re-projects `schema_linking.json` deterministically via `tht session
   sync-schema-linking` (you do NOT hand-write the tables/columns part with
   `write_schema_linking`). The promoted columns are the reviewer-approved OUTPUT
   columns: project exactly those in the final SELECT (Phase 6/7); you remain free
   to reference other columns as join keys or filter predicates when the query
   requires them.
   Call `reviewer_schema_linking` before the join review. For a multi-table plan,
   `advance:true` will report that F4 remains open because the structured joins are
   not present yet; this is expected. Stay in F4 and continue with the join-only gate.
   Propose **all required joins together in a separate, join-only**
   `reviewer_decide(advance:false)`, registering `join_modified`. Do not mix
   `join_modified` with other decision types in that call. The gate renders this proposal
   as read-only information: **Continue records every proposed join**; the reviewer cannot
   remove individual joins (which could create an accidental Cartesian product). The complete
   set is persisted atomically under a per-session writer lock: an invalid response or write
   failure records none of it. If the reviewer uses **Other — specify**, none of the current
   joins is recorded: incorporate the textual correction and present the complete revised join
   set again.
   Ground joins in the `【Foreign keys】` section of the mschema-text
   render: it lists the curated logical FKs of the workspace (e.g.
   `fact_x.cod_paz=dim_patient.cod_paz`, `*_time_key=dim_time.day_key`) — prefer
   those to joins you derive yourself, and flag to the reviewer any join you need
   that is NOT in the list.
{{DISAMBIGUATION_SCHEMA_GROUNDING}}
5. Persist the **joins** (and any `concept_formulas`/`open_questions`) with the gate's
   `write_schema_linking` tool — it validates the object against the `SchemaLinking`
   model and writes the file deterministically (never hand-write it, never edit it
   with the file tool; on a validation error the tool returns the exact problem to
   fix). Shape: `{question, candidates:[...], joins:[{from, to, source?}],
   excluded:[...], open_questions:[], concept_formulas:[]}` — `candidates`/`excluded`
   are owned by `reviewer_schema_linking`/`sync-schema-linking` (step 2), so if you
   call `write_schema_linking` after step 2, carry over its `candidates`/`excluded`
   unchanged rather than overwriting them. After the reviewer-approved joins are present,
   `write_schema_linking` closes F4 automatically. Do not add a `reviewer_confirm
   kind:"phase"`. Do NOT run `tht session check` (that's Phase 5).

## Phase 5 — Synthesis

Prerequisite: Phase 4 closed; `schema_linking.json` present.

1. `tht session check` (objective gate: decisions present + schema_linking valid).
2. Summarize the schema-linking to the reviewer; if corrections are needed, reopen
   Phase 4.
3. Close with `reviewer_confirm kind:"phase"`.

## Phase 6 — CTE plan

Prerequisite: Phase 5 closed.

1. Read `cte.md`. Decompose the rewritten question into CTEs (Agent View Generation):
   each CTE captures an informative subset with a clear purpose, named in snake_case.
{{MEMORY_SOLVED_SEARCH_F6}}
2. Present the full CTE plan to the reviewer with `reviewer_confirm kind:"cte_plan"`,
   passing a **structured v2 artifact** (`artifact:{kind:"cte_plan", data:{…}}`). You
   author `question`, `strategy` and each `ctes[]` entry (`name`, `purpose`,
   `rationale`, `depends_on`, `tables[].name`, `keys`, `filters[]` with
   `column`/`op`/`value`/`rationale`, `output_columns`); the gate fills `index`
   (1-based) and every `description` from the catalog, derives the ordered `--name`
   list from `data.ctes[].name`, and on approval persists both `cte_plan.json` and the
   chain doc (`cte_plan_doc.json`). Compact example (2 CTE):
   ```json
   {"schema_version":2,"question":"pazienti attivi con almeno un ricovero nel 2023",
    "strategy":"prima la base dei pazienti attivi, poi i loro ricoveri filtrati per anno",
    "ctes":[
      {"name":"base_pazienti","purpose":"pazienti attivi","rationale":"insieme di partenza",
       "depends_on":[],"tables":[{"name":"dim_patient"}],"keys":["cod_paz"],
       "filters":[{"column":"dim_patient.flag_attivo","op":"IS","value":"TRUE","rationale":"solo attivi"}],
       "output_columns":["cod_paz"]},
      {"name":"ricoveri_2023","purpose":"ricoveri dei pazienti nel 2023","rationale":"restringe al 2023",
       "depends_on":["base_pazienti"],"tables":[{"name":"fact_ricoveri"}],"keys":["cod_paz"],
       "filters":[{"column":"dim_time.year","op":"=","value":"2023","rationale":"finestra temporale"}],
       "output_columns":["cod_paz","data_ricovero"]}
    ]}
   ```
3. For each CTE (in plan order): call `write_cte_sql` with the session id, CTE name,
   and SQL block (the tool invokes `tht cte save --session <id> --name <name> --file -`).
   Persist ONLY the
   `WITH ... AS (...)` block, NO trailing SELECT), test with `tht cte test --session
   <id> <name>` (with an **ok** outcome), then present it with
   `reviewer_confirm kind:"cte_result"`. Pass ONLY the thin v2 data
   `artifact:{kind:"cte_result", data:{schema_version:2, purpose?, rationale?, note?}}` —
   NEVER paste SQL, columns or preview rows as text: the gate reads them
   deterministically from `tht cte info` (the persisted `<name>.sql` + the last test
   record) and builds the full artifact the reviewer approves. The next CTE is testable
   ONLY after the previous one is approved (CLI exit 5 if out of order). Copy
   table/column names EXACTLY from the schema context; use values verified with
   `tht search`.
4. After the last CTE is approved, close with `reviewer_confirm kind:"phase"`.

## Phase 7 — Final SQL

Prerequisite: Phase 6 closed.

1. Read `sql-generation.md`. Recursive divide-and-conquer: the CTEs approved in
   Phase 6 are the preferred building blocks (reuse them by name).
{{MEMORY_SOLVED_SEARCH_F7}}
2. Compose the final SQL (PostgreSQL dialect, exact names from the schema context).
   **Output columns (F4 honoring).** The columns promoted in Phase 4's
   `schema_linking.json` are the reviewer-approved OUTPUT columns: project exactly
   those in the final SELECT. Other schema-linked columns remain usable as join
   keys or filter predicates, but do not add them to the SELECT list.
   **Time dimension:** `data_time_key` is the FK to `dim_time.day_key` (NOT declared
   in the DWH, must be added by hand to the join); use `JOIN dim_time` and its
   columns (`dt.year`, `dt.month`, …), NEVER arithmetic on the key.
3. `tht sql validate` + `tht sql preview` (max 10 rows). On errors / suspicious
   results, apply the `sql-generation.md` checklist and correct with the reviewer.
4. Call `write_final_sql` with the session id and clean SQL; it invokes
   `tht sql set-final --session <id> --file -` (ONLY clean SQL, no comments).
   Approve with `reviewer_confirm kind:"sql"` (records `sql_approved`), then advance to
   Phase 8 with `reviewer_confirm kind:"phase"` — `kind:"sql"` alone does NOT advance F7.

## Phase 8 — Datamart

Prerequisite: Phase 7 closed.

1. Call `reviewer_datamart` with the session id. This gate is deployment-aware and is
   the ONLY allowed way to record the datamart choice:
   - `THT_PROFILE=workstation`: it records `datamart_declined` automatically and shows
     no question to the reviewer;
   - `THT_PROFILE=server` (including the default): it always shows both choices,
     "Sì, genera il datamart" and "No, salta il datamart", and records the selected one.
   Never replace this gate with a hand-built `reviewer_select`.
2. On a server, if the reviewer chose yes: `tht datamart generate` (stub — raises
   NotImplementedError for now). Tell
   the reviewer that dbt generation is not implemented yet.
{{MEMORY_PROMOTION_F8}}

## Session end

When the promotion gate (or, as fallback, the F8 phase gate) closes Phase 8, the
gate calls `tht session finalize` automatically.
{{MEMORY_SOLVED_FINALIZATION}}
state (ledger `review_decisions.jsonl` + artifacts) is the truth: what is not
recorded did not happen.