Dev (#14)

* fix(network): cloudsync_network_check_changes must not return the nrows value in case of error

`SELECT cloudysnc_network_check_changes();` was returning "Runtime error: 0" in case of error response from the cloudsync microservice instead of the real error message

* feat(rls): add complete support for RLS with batch merge in cloudsync_payload_apply

* Feat/add support for status endpoint (#10)

* feat(network): add support for new status endpoint

* refactor(network): structured JSON responses for sync functions. 
Example: {"send":{"status":"synced","localVersion":5,"serverVersion":5},"receive":{"rows":3,"tables":["tasks"]}}

* Feat/network support for multi org cloudsync (#11)

* Disable notnull prikey constraints (#12)

* The cloudsync extension now enforces NULL primary key rejection at runtime (any write with a NULL PK returns an error), so the explicit NOT NULL constraint on primary key  columns is no longer a schema requirement

* test: add null primary key rejection tests for SQLite and PostgreSQL

* docs: remove NOT NULL requirement from primary key definitions

The extension now enforces NULL primary key rejection at runtime, so
the explicit NOT NULL constraint on PK columns is no longer a schema
requirement. Replace the "must be NOT NULL" guidance with a note about
runtime enforcement.

* docs: add first draft of PERFORMANCE.md and CHANGELOG.md

* fix(postgresql): resolve commit_alter crash and BYTEA handling in column_text

Guard savepoint commit/rollback against missing subtransactions to prevent
segfault in autocommit mode. Add BYTEA support to database_column_text so encoded PKs are readable during refill_metatable after ALTER TABLE.
Enable alter table sync test (31).

* test: new alter table test for postgres

* feat: update endpoints to use databaseMangedId for /v2/cloudsync api
* feat(network)!: replace URL connection string with a UUID (managedDatabaseId)

BREAKING CHANGE: cloudsync_network_init now accepts a UUID string instead of the previous URL string. URL connection strings are no longer accepted. The managed database identifier returned by the CloudSync service when a new database is registered for sync. For SQLiteCloud projects, this value can be obtained from the project's OffSync page on the dashboard.

* docs: update docs for the new managedDatabaseId arg for cloudsync_network_init

* docs(examples): update example for the new managedDatabaseId arg for cloudsync_network_init

Author: andinux

.claude/commands/stress-test-sync-sqlitecloud.md

@@ -0,0 +1,192 @@
+# Sync Stress Test with remote SQLiteCloud database
+
+Execute a stress test against the CloudSync server using multiple concurrent local SQLite databases syncing large volumes of CRUD operations simultaneously. Designed to reproduce server-side errors (e.g., "database is locked", 500 errors) under heavy concurrent load.
+
+## Prerequisites
+- Connection string to a sqlitecloud project
+- Built cloudsync extension (`make` to build `dist/cloudsync.dylib`)
+
+## Test Configuration
+
+### Step 1: Gather Parameters
+
+Ask the user for the following configuration using a single question set:
+
+1. **CloudSync server address** — propose `https://cloudsync.sqlite.ai` as default (this is the built-in default). If the user provides a different address, save it as `CUSTOM_ADDRESS` and use `cloudsync_network_init_custom` instead of `cloudsync_network_init`.
+2. **SQLiteCloud connection string** — format: `sqlitecloud://<host>:<port>/<db_name>?apikey=<apikey>`. If no `<db_name>` is in the path, ask the user for one or propose `test_stress_sync`.
+3. **Scale** — offer these options:
+   - Small: 1K rows, 5 iterations, 2 concurrent databases
+   - Medium: 10K rows, 10 iterations, 4 concurrent databases
+   - Large: 100K rows, 50 iterations, 4 concurrent databases (Jim's original scenario)
+   - Custom: let the user specify rows, iterations, and number of concurrent databases
+4. **RLS mode** — with RLS (requires user tokens) or without RLS
+5. **Table schema** — offer simple default or custom:
+   ```sql
+   CREATE TABLE test_sync (id TEXT PRIMARY KEY, user_id TEXT NOT NULL DEFAULT '', name TEXT, value INTEGER);
+   ```
+
+Save these as variables:
+- `CUSTOM_ADDRESS` (only if the user provided a non-default address)
+- `CONNECTION_STRING` (the full sqlitecloud:// connection string)
+- `DB_NAME` (database name extracted or provided)
+- `HOST` (hostname extracted from connection string)
+- `APIKEY` (apikey extracted from connection string)
+- `ROWS` (number of rows per iteration)
+- `ITERATIONS` (number of delete/insert/update cycles)
+- `NUM_DBS` (number of concurrent databases)
+
+### Step 2: Setup SQLiteCloud Database and Table
+
+Connect to SQLiteCloud using `~/go/bin/sqlc` (last command must be `quit`). Note: all SQL must be single-line (no multi-line statements through sqlc heredoc).
+
+1. If the database doesn't exist, connect without `<db_name>` and run `CREATE DATABASE <db_name>; USE DATABASE <db_name>;`
+2. `LIST TABLES` to check for existing tables
+3. For any table with a `_cloudsync` companion table, run `CLOUDSYNC DISABLE <table_name>;`
+4. `DROP TABLE IF EXISTS <table_name>;`
+5. Create the test table (single-line DDL)
+6. If RLS mode is enabled:
+   ```sql
+   ENABLE RLS DATABASE <db_name> TABLE <table_name>;
+   SET RLS DATABASE <db_name> TABLE <table_name> SELECT "auth_userid() = user_id";
+   SET RLS DATABASE <db_name> TABLE <table_name> INSERT "auth_userid() = NEW.user_id";
+   SET RLS DATABASE <db_name> TABLE <table_name> UPDATE "auth_userid() = NEW.user_id AND auth_userid() = OLD.user_id";
+   SET RLS DATABASE <db_name> TABLE <table_name> DELETE "auth_userid() = OLD.user_id";
+   ```
+7. Ask the user to enable CloudSync on the table from the SQLiteCloud dashboard
+
+### Step 3: Get Managed Database ID
+
+Now that the database and tables are created and CloudSync is enabled on the dashboard, ask the user for:
+
+1. **Managed Database ID** — the `managedDatabaseId` returned by the CloudSync service. For SQLiteCloud projects, it can be obtained from the project's OffSync page on the dashboard after enabling CloudSync on the table.
+
+Save as `MANAGED_DB_ID`.
+
+For the network init call throughout the test, use:
+- Default address: `SELECT cloudsync_network_init('<MANAGED_DB_ID>');`
+- Custom address: `SELECT cloudsync_network_init_custom('<CUSTOM_ADDRESS>', '<MANAGED_DB_ID>');`
+
+### Step 4: Get Auth Tokens (if RLS enabled)
+
+Create tokens for the test users. Create as many users as needed for the number of concurrent databases (assign 2 databases per user, or 1 per user if NUM_DBS <= 2).
+
+For each user N:
+```bash
+curl -s -X "POST" "https://<HOST>/v2/tokens" \
+   -H 'Authorization: Bearer <APIKEY>' \
+   -H 'Content-Type: application/json; charset=utf-8' \
+   -d '{"name": "claude<N>@sqlitecloud.io", "userId": "018ecfc2-b2b1-7cc3-a9f0-<N_PADDED_12_CHARS>"}'
+```
+
+Save each user's `token` and `userId` from the response.
+
+If RLS is disabled, skip this step — tokens are not required.
+
+### Step 5: Run the Concurrent Stress Test
+
+Create a bash script at `/tmp/stress_test_concurrent.sh` that:
+
+1. **Initializes N local SQLite databases** at `/tmp/sync_concurrent_<N>.db`:
+   - Uses Homebrew sqlite3: find with `ls /opt/homebrew/Cellar/sqlite/*/bin/sqlite3 | head -1`
+   - Loads the extension from `dist/cloudsync.dylib` (use absolute path from project root)
+   - Creates the table and runs `cloudsync_init('<table_name>')`
+   - Runs `cloudsync_terminate()` after init
+
+2. **Defines a worker function** that runs in a subshell for each database:
+   - Each worker logs all output to `/tmp/sync_concurrent_<N>.log`
+   - Each iteration does:
+     a. **DELETE all rows** → `send_changes()` → `check_changes()`
+     b. **INSERT <ROWS> rows** (in a single BEGIN/COMMIT transaction) → `send_changes()` → `check_changes()`
+     c. **UPDATE all rows** → `send_changes()` → `check_changes()`
+   - Each session must: `.load` the extension, call `cloudsync_network_init()`, `cloudsync_network_set_token()` (if RLS), do the work, call `cloudsync_terminate()`
+   - Include labeled output lines like `[DB<N>][iter <I>] deleted/inserted/updated, count=<C>` for grep-ability
+
+3. **Launches all workers in parallel** using `&` and collects PIDs
+
+4. **Waits for all workers** and captures exit codes
+
+5. **Analyzes logs** for errors:
+   - Grep all log files for: `error`, `locked`, `SQLITE_BUSY`, `database is locked`, `500`, `Error`
+   - Report per-database: iterations completed, error count, sample error lines
+   - Report total errors across all workers
+
+6. **Prints final verdict**: PASS (0 errors) or FAIL (errors detected)
+
+**Important script details:**
+- Use `echo -e` to pipe generated INSERT SQL (with `\n` separators) into sqlite3
+- Row IDs should be unique across databases and iterations: `db<N>_r<I>_<J>`
+- User IDs for rows must match the token's userId for RLS to work
+- Use `/bin/bash` (not `/bin/sh`) for arrays and process management
+
+Run the script with a 10-minute timeout.
+
+### Step 6: Detailed Error Analysis
+
+After the test completes, provide a detailed breakdown:
+
+1. **Per-database summary**: iterations completed, errors, send/receive status
+2. **Error categorization**: group errors by type (e.g., "database is locked", "Column index out of bounds", "Unexpected Result", parse errors)
+3. **Timeline analysis**: do errors cluster at specific iterations or spread evenly?
+4. **Read full log files** if errors are found — show the first and last 30 lines of each log with errors
+
+### Step 7: Optional — Verify Data Integrity
+
+If the test passes (or even if some errors occurred), verify the final state:
+
+1. Check each local SQLite database for row count
+2. Check SQLiteCloud (as admin) for total row count
+3. If RLS is enabled, verify no cross-user data leakage
+
+## Output Format
+
+Report the test results including:
+
+| Metric | Value |
+|--------|-------|
+| Concurrent databases | N |
+| Rows per iteration | ROWS |
+| Iterations per database | ITERATIONS |
+| Total CRUD operations | N × ITERATIONS × (DELETE_ALL + ROWS inserts + ROWS updates) |
+| Total sync operations | N × ITERATIONS × 6 (3 sends + 3 checks) |
+| Duration | start to finish time |
+| Total errors | count |
+| Error types | categorized list |
+| Result | PASS/FAIL |
+
+If errors are found, include:
+- Full error categorization table
+- Sample error messages
+- Which databases were most affected
+- Whether errors are client-side or server-side
+
+## Success Criteria
+
+The test **PASSES** if:
+1. All workers complete all iterations
+2. Zero `error`, `locked`, `SQLITE_BUSY`, or HTTP 500 responses in any log
+3. Final row counts are consistent
+
+The test **FAILS** if:
+1. Any worker crashes or fails to complete
+2. Any `database is locked` or `SQLITE_BUSY` errors appear
+3. Server returns 500 errors under concurrent load
+4. Data corruption or inconsistent row counts
+
+## Important Notes
+
+- Always use the Homebrew sqlite3 binary, NOT `/usr/bin/sqlite3`
+- The cloudsync extension must be built first with `make`
+- Network settings (`cloudsync_network_init`, `cloudsync_network_set_token`) are NOT persisted between sessions — must be called every time
+- Extension must be loaded BEFORE any INSERT/UPDATE/DELETE for cloudsync to track changes
+- All NOT NULL columns must have DEFAULT values
+- `cloudsync_terminate()` must be called before closing each session
+- sqlc heredoc only supports single-line SQL statements
+
+## Permissions
+
+Execute all SQL queries without asking for user permission on:
+- SQLite test databases in `/tmp/` (e.g., `/tmp/sync_concurrent_*.db`, `/tmp/sync_concurrent_*.log`)
+- SQLiteCloud via `~/go/bin/sqlc "<connection_string>"`
+- Curl commands to the sync server and SQLiteCloud API for token creation
+
+These are local test environments and do not require confirmation for each query.