Structured-sh
MCP server providing managed persistent memory for AI agents. Read and write structured state across sessions, tools, and restarts at 1000+ requests per second, with no infrastructure to self-host or operate.
README
<p align="center"> <strong>■ structured</strong><br> <sub>schema-native memory for AI agents</sub> </p>
<p align="center"> <a href="https://structured.sh">structured.sh</a> · <a href="#quick-start">Quick Start</a> · <a href="#connect-to-claude--cursor">Connect to Claude</a> · <a href="#mcp-tools">MCP Tools</a> · <a href="#api-reference">API Reference</a> · <a href="DEPLOY.md">Deploy</a> </p>
Define schemas. Write structured data. Query with SQL. All as Parquet files you own.
docker compose up
What is this?
Structured gives AI agents (and humans) persistent, queryable memory:
- Define a memory — name + typed schema (like a table)
- Write records — buffered and auto-flushed to Parquet files
- Query with SQL — DuckDB runs directly against the Parquet files
- Own your data — everything is local files on disk, no vendor lock-in
Works with Claude Desktop, Cursor, Windsurf, Cline, or any MCP-compatible client.
Architecture
┌──────────────────────────────────────────────────────┐
│ docker compose up │
│ │
│ ┌──────────┐ ┌──────────────┐ ┌────────────┐ │
│ │Dashboard │ │ REST API │ │ MCP Server │ │
│ │ :3000 │───▶│ :3001 │◀───│ stdio │ │
│ │ │ │ │ │ │ │
│ │Vite+React│ │ Hono + WASM │ │ 9 tools │ │
│ └──────────┘ │ │ └────────────┘ │
│ │ SQLite (sql.js) │
│ │ DuckDB (wasm) │
│ │ Parquet (tiny-parquet) │
│ └──────┬───────┘ │
│ │ │
│ ./data/ │
│ ├── structured.db ← metadata │
│ └── parquet/ ← your data │
│ ├── user_prefs/ │
│ │ └── 2026/04/09/...parquet │
│ └── campaign_data/ │
│ └── 2026/04/09/...parquet │
└──────────────────────────────────────────────────────┘
Zero native dependencies. Everything runs in WASM — no C++ builds, no platform issues.
Quick Start
1. Clone and configure
git clone https://github.com/structured-sh/structured.git
cd structured
Edit docker-compose.yml and set your credentials:
environment:
- API_KEY=your-secret-api-key # Used by MCP clients & scripts
- DASHBOARD_PASSWORD=your-password # Protects the dashboard UI
Two separate credentials:
API_KEY— machine auth for MCP clients, scripts, and analytics ingestionDASHBOARD_PASSWORD— human auth for the web dashboard. Leave unset to disable login (local-only use).
2. Start the stack
docker compose up -d
| Service | URL |
|---|---|
| Dashboard | http://localhost:3000 |
| API | http://localhost:3001 |
| MCP | stdio (auto-connected) |
3. Create a memory
curl -X POST http://localhost:3001/memories \
-H "Authorization: Bearer your-secret-api-key" \
-H "Content-Type: application/json" \
-d '{
"name": "user_preferences",
"fields": [
{ "name": "key", "type": "string" },
{ "name": "value", "type": "string" },
{ "name": "priority", "type": "int32" }
],
"description": "User preference settings"
}'
4. Write data
curl -X POST http://localhost:3001/memories/user_preferences/write \
-H "Authorization: Bearer your-secret-api-key" \
-H "Content-Type: application/json" \
-d '{
"data": [
{ "key": "theme", "value": "dark", "priority": 1 },
{ "key": "language", "value": "en", "priority": 2 }
]
}'
5. Query with SQL
curl -X POST http://localhost:3001/query \
-H "Authorization: Bearer your-secret-api-key" \
-H "Content-Type: application/json" \
-d '{ "sql": "SELECT * FROM user_preferences ORDER BY priority" }'
Memory names work as table names — DuckDB resolves them to Parquet files automatically.
6. Access raw files
# Files on disk
ls ./data/parquet/user_preferences/
# DuckDB CLI
duckdb -c "SELECT * FROM read_parquet('./data/parquet/user_preferences/**/*.parquet')"
# Python
import duckdb
duckdb.sql("SELECT * FROM './data/parquet/user_preferences/**/*.parquet'").show()
Connect to Claude / Cursor
Local (Docker)
Add to ~/Library/Application Support/Claude/claude_desktop_config.json:
{
"mcpServers": {
"structured": {
"command": "docker",
"args": ["exec", "-i", "structured-mcp", "node", "index.js"]
}
}
}
For Cursor, add to Settings → Features → MCP Servers:
{
"structured": {
"command": "docker",
"args": ["exec", "-i", "structured-mcp", "node", "index.js"]
}
}
Cloud (structured.sh)
Coming soon — hosted version at structured.sh
{
"mcpServers": {
"structured": {
"command": "npx",
"args": ["-y", "@anthropic-ai/mcp-proxy", "https://mcp.structured.sh"]
}
}
}
MCP Tools
Once connected, just talk naturally. The AI picks the right tool.
| Tool | What to say |
|---|---|
create_memory |
"Create a memory for tracking daily sales with fields: date, revenue, units" |
list_memories |
"What memories do I have?" |
describe_memory |
"Show me the schema for daily_sales" |
write_memory |
"Save today's sales: date=2026-04-09, revenue=1250.50, units=42" |
query_memory |
"What's the total revenue this month?" |
store_document |
"Remember this config for later" |
get_document |
"Get the document abc-123" |
flush_memory |
"Flush all pending data to disk" |
delete_memory |
"Delete the test_data memory" |
Ingesting Data from Your Apps
Use the templates in templates/ to send events from external systems:
| Template | Use case |
|---|---|
templates/ingest-app-analytics.js |
Mobile/web app events (installs, actions, purchases) |
templates/ingest-webhook.js |
Stripe, GitHub, Shopify webhooks |
templates/query-report.js |
Generate SQL reports → terminal, Markdown, or Slack |
// Example: track an install from your iOS app
import { track } from './templates/ingest-app-analytics.js';
await track('install', 'user_abc', { platform: 'ios', app_version: '1.0.0' });
Then query across all your events:
SELECT event, COUNT(*) as n, COUNT(DISTINCT user_id) as users
FROM app_events
WHERE timestamp > now() - INTERVAL '30 days'
GROUP BY event ORDER BY n DESC
Dead Letter Queue
Records rejected by strict or evolve schema modes are not dropped — they're automatically written to _dlq_{memory_name} for inspection:
-- See what was rejected and why
SELECT _reason, _payload, _rejected_at
FROM _dlq_app_events
ORDER BY _rejected_at DESC
LIMIT 20
API Key Rotation
Rotate your API key at any time from the dashboard Connect page without restarting:
- Go to Connect → API Key section
- Click Rotate Key
- Copy the new key (shown once)
- Update your MCP config and any scripts
The old key is invalidated immediately.
API Reference
Auth (Dashboard)
| Method | Path | Description |
|---|---|---|
GET |
/auth/status |
Check if dashboard auth is enabled |
POST |
/auth/login |
Login with { password }, returns session token |
GET |
/auth/me |
Validate current session (X-Session-Token header) |
POST |
/auth/logout |
Logout (client discards token) |
Memories
| Method | Path | Description |
|---|---|---|
GET |
/memories |
List all memories |
POST |
/memories |
Create a memory |
GET |
/memories/:name |
Get memory details |
PUT |
/memories/:name |
Update memory |
DELETE |
/memories/:name |
Delete memory |
POST |
/memories/:name/write |
Write records |
POST |
/memories/:name/flush |
Flush to Parquet |
GET |
/memories/:name/preview |
Preview data |
GET |
/memories/:name/files |
List Parquet files |
Query
| Method | Path | Description |
|---|---|---|
POST |
/query |
Execute DuckDB SQL |
Store (Documents)
| Method | Path | Description |
|---|---|---|
POST |
/documents |
Store a JSON document |
GET |
/documents/collections |
List collections |
GET |
/documents/:collection |
List documents |
DELETE |
/documents/:collection/:id |
Delete document |
Settings
| Method | Path | Description |
|---|---|---|
GET |
/settings/api-key |
Get masked current API key |
POST |
/settings/rotate-key |
Generate new API key |
Files
| Method | Path | Description |
|---|---|---|
GET |
/files/* |
Download raw Parquet file |
MCP (SSE)
| Method | Path | Description |
|---|---|---|
GET |
/sse |
SSE stream for MCP clients |
POST |
/messages |
JSON-RPC messages |
Schema Modes
| Mode | Behavior |
|---|---|
flex |
Accept all fields, no validation (default) |
evolve |
Accept all, detect and log schema drift |
strict |
Reject records with mismatched fields → DLQ |
Field Types
| Type | Parquet Type | Notes |
|---|---|---|
string |
BYTE_ARRAY (UTF-8) | Default |
int32 |
INT32 | |
int64 |
INT64 | |
float32 |
FLOAT | |
float64 |
DOUBLE | |
boolean |
BOOLEAN | |
timestamp |
INT64 (millis) | Unix ms, UTC |
Stack
Only 7 npm packages. No native addons — everything runs in WASM or pure JS.
| Package | What it does |
|---|---|
hono + @hono/node-server |
HTTP router — fast, Web-standard API |
@duckdb/duckdb-wasm |
SQL query engine, runs fully in WASM |
sql.js |
SQLite in WASM — stores schema metadata |
tiny-parquet |
Pure-JS Parquet writer, zero native deps |
@modelcontextprotocol/sdk |
MCP server/tool registration |
zod |
Schema validation for API inputs |
Runtime: Node.js ≥ 20
Because everything runs in WASM, there are no C++ builds, no node-gyp, no platform-specific binaries. The Docker image works on any architecture Docker supports.
Development
# Local dev (no Docker)
cd api && npm install && node index.js
cd dashboard && npm install && npm run dev
# Full stack
docker compose up --build
License
Apache 2.0
<p align="center"> <sub>Built with <a href="https://npmjs.com/package/tiny-parquet">tiny-parquet</a> · Powered by <a href="https://duckdb.org">DuckDB</a> · <a href="https://structured.sh">structured.sh</a></sub> </p>
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