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Studio Power Tools

Phase 4 adds five surfaces on top of the read and write APIs. They’re optional — none of them change the CRUD contract — but they’re what makes Studio useful as an admin tool rather than just a row browser.

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SQL preview

GET /api/targets/:key/models/:model/sql?op=list|get|create|update|delete&pk=…
Renders the SQL Studio would run for an operation without touching the database. Lets you understand what the abstraction is doing before pulling the trigger, or copy it into a query tool to tweak by hand. Bound parameters are returned alongside the SQL text so you don’t have to read the placeholders. 
curl 'http://127.0.0.1:7878/api/targets/catalog/models/Post/sql?op=update&pk=p1'
# {
#   "driver": "postgres",
#   "sql": "WITH updated AS ( UPDATE \"posts\" SET \"title\" = $1 WHERE \"id\" = $2 RETURNING * ) ...",
#   "params": [
#     { "index": 1, "binding": "title", "kind": "text" },
#     { "index": 2, "binding": "p1",    "kind": "text" }
#   ]
# }
API-backed targets return 501 UNSUPPORTED — Studio doesn’t render SQL it doesn’t run.

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Drift

GET /api/targets/:key/drift
Compares the schema’s declared columns to the live database (information_schema on Postgres, PRAGMA table_info on SQLite) and reports the result per model:
statusMeaning
okLive columns match the schema’s declared shape.
driftSome columns differ — missing_columns and extra_columns are populated.
missing_tableThe table doesn’t exist (the migration hasn’t been run).
unsupportedThis target can’t be inspected (API-only).
skippedResolution failed (no @id or unsupported PK type).
curl 'http://127.0.0.1:7878/api/targets/catalog/drift'
# {
#   "target": "catalog",
#   "models": [
#     { "model": "Post",     "status": "ok" },
#     { "model": "Customer", "status": "drift", "missing_columns": ["phone"] }
#   ]
# }
The UI renders a small ⚠ drift chip next to drifting models in the sidebar and ✕ table for missing tables.

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CSV/JSON export

GET /api/targets/:key/models/:model/export?format=csv|json&limit=N
Pulls up to limit rows (capped at 10 000) through cursor pagination internally and returns one body. Sets Content-Disposition: attachment; filename="<target>-<table>.<ext>" so the browser downloads the file straight from the link. CSV uses RFC-4180-style escaping (quote-wrap on commas, quotes, or newlines; double up embedded quotes). JSON is a flat array of objects, field names as keys. 
curl 'http://127.0.0.1:7878/api/targets/catalog/models/Post/export?format=csv&limit=1000' \
  -o posts.csv
The export endpoint is bounded — it’s for “developer pulling a sample for a notebook,” not “ETL.” For multi-million-row dumps, hit the database directly. 
GET /api/targets/:key/search?q=<term>
Case-insensitive substring over models, fields (including the Model.field path and the field’s type), enums and their variants, mixins, types, and procedures. Empty query returns { "hits": [] }. 
curl 'http://127.0.0.1:7878/api/targets/catalog/search?q=author'
# {
#   "hits": [
#     { "kind": "field", "model": "Post", "name": "author",  "detail": "Customer required" },
#     { "kind": "field", "model": "Post", "name": "authorId","detail": "Int required" }
#   ]
# }
Hit kind is one of model, field, type, enum, mixin, procedure. The UI renders an inline dropdown directly under the search bar in the header.

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Audit log

GET /api/audit?limit=N
Studio holds every successful write (CREATE / UPDATE / DELETE) in an in-memory ring buffer, capped at 500 entries, FIFO when full. Entries are returned newest-first: 
{
  "entries": [
    {
      "id": 42,
      "at": "2026-05-15T12:34:56Z",
      "target": "catalog",
      "model": "Post",
      "op": "UPDATE",
      "pk": "p1"
    }
  ]
}
The buffer lives in process memory only — Studio is a local admin tool, not a logging pipeline. Restarting the binary clears the log. The UI’s “Audit” button in the header opens an overlay listing the most recent 100 entries.

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Constraint errors → VALIDATION_ERROR

Studio used to surface driver constraint failures as DATABASE_ERROR (500). Phase 4 maps the well-known codes back to the same per-field VALIDATION_ERROR envelope as the in-process validators:
SourceCode
PG 23505 / SQLite SQLITE_CONSTRAINT_UNIQUE / …_PRIMARYKEYUNIQUE
PG 23503 / SQLite SQLITE_CONSTRAINT_FOREIGNKEYFOREIGN_KEY
PG 23502 / SQLite SQLITE_CONSTRAINT_NOTNULLREQUIRED
PG 22001 (string truncation)LENGTH
PG 22P02 (invalid text representation)TYPE_MISMATCH
PG 23514 / SQLite SQLITE_CONSTRAINT_CHECKREGEX
Unrecognized errors still come back as DATABASE_ERROR. The wire envelope is identical to the in-process validator path (see the write API page), so the UI doesn’t care whether the rejection came from Studio’s pre-flight check or the database’s constraint engine.