nedb-engine-client 2.4.0

Async Python client for nedbd — the nedb-engine server daemon

nedb-engine-client

Async Python client for nedbd — the NEDB server daemon.

Connect to any running nedbd instance — local or remote — with a clean async API. No engine code embedded, no Rust toolchain required. Just HTTP.

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Install

pip install nedb-engine-client

Requires Python ≥ 3.8 and httpx.

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Quick start

import asyncio
from nedb_client import NedbClient

async def main():
    async with NedbClient("http://127.0.0.1:7070", db="mydb") as db:

        # Write a document
        await db.put("blocks", "618000", {
            "height": 618000,
            "hash": "000000000000000000024bead8df69990852c202db0e0097c1a12ea637d7e96d",
            "tx_count": 2734,
        })

        # Query with NQL
        rows = await db.query("FROM blocks ORDER BY height DESC LIMIT 10")

        # Time-travel: what did the DB look like at seq 100?
        old = await db.query("FROM blocks AS OF 100 WHERE height > 600000")

        # Bi-temporal: what was true on 2024-06-15?
        valid = await db.query('FROM policy VALID AS OF "2024-06-15"')

        # Causal trace: why was this written?
        trace = await db.query("FROM blocks TRACE caused_by")

        # BLAKE2b Merkle head — changes on every write, anchorable
        head = await db.head()
        print(f"head: {head}")

        # Tamper-evidence check across all objects
        report = await db.verify()
        assert report["ok"], "tamper detected!"

asyncio.run(main())

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nedbd — start the server

pip install nedb-engine

# v1 AOF engine (default)
nedbd --data ./data

# v2 DAG engine (recommended — instant cold start, tamper-evident)
NEDBD_DAG=1 nedbd --data ./data

# With AES-256-GCM encryption
NEDBD_DAG=1 NEDB_TMK=<32-byte-hex> nedbd --data ./data

# Check health
curl http://127.0.0.1:7070/health
# {"ok":true,"version":"2.0.8","service":"nedbd","encrypted":true}

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API reference

Client lifecycle

# Async context manager (recommended)
async with NedbClient(url, db=name, token=token) as db:
    ...

# Manual
db = NedbClient(url="http://127.0.0.1:7070", db="mydb", token="secret")
await db.open()
await db.close()

Writes

Method	Description
await db.put(coll, id, doc, **opts)	Write a document
await db.delete(coll, id)	Tombstone delete (history preserved in DAG)
await db.batch(ops)	Batch put/del in one HTTP round-trip
await db.create_index(coll, field)	Create sorted index for ORDER BY

Put options:

await db.put("claims", "c1", {"fact": "..."}, 
    caused_by=["abc123hash"],   # DAG causal provenance
    valid_from="2024-01-01",    # bi-temporal valid window
    valid_to="2024-12-31",
    evidence="sensor-42",       # human-readable provenance note
    confidence=0.95,            # confidence score 0–1
    idem="dedup-key",           # idempotency key
)

Reads

Method	Description
await db.get(coll, id)	Fetch current version of a document
await db.query(nql)	NQL query → list of dicts
await db.query_full(nql)	NQL query → full response (rows + seq + head)

NQL — NEDB Query Language

FROM <collection>
  [AS OF <seq>]                  transaction time (when was it written?)
  [VALID AS OF "<date>"]         valid time (when was it true in the world?)
  [WHERE field = value [AND ...]] op: = != < <= > >=
  [ORDER BY field [DESC]]
  [LIMIT n]
  [GROUP BY field COUNT|SUM|AVG|MIN|MAX]
  [TRACE caused_by [REVERSE]]    causal graph traversal
  [SEARCH "text"]                full-text search

Integrity

Method	Description
await db.verify()	BLAKE2b tamper-evidence check across all objects
await db.head()	Current Merkle root — changes on every write
await db.seq()	Current global sequence number
await db.log(limit)	Recent write log
await db.checkpoint()	Explicit checkpoint (no-op on v2 DAG)

Server management

Method	Description
await db.health()	Server health — version, databases, encryption
await db.ping()	Boolean reachability check
await db.list_databases()	All databases on this server
await db.create_database()	Create this database explicitly
await db.drop_database()	Drop this database (irreversible)

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Error handling

from nedb_client import NedbClient, NedbError

async with NedbClient("http://127.0.0.1:7070", db="mydb") as db:
    try:
        await db.put("coll", "id", {"data": "value"})
    except NedbError as e:
        print(f"HTTP {e.status}: {e.message}")

Queries on missing collections return [] rather than raising — resilient by default.

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Links

• Engine: pip install nedb-engine · npm install nedb-engine
• JS/TS client: npm install nedb-engine-client
• Source: github.com/Eth-Interchained/nedb
• Studio: studio.interchained.org

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