# Clickhouse Js Node Coding > Write idiomatic application code with the ClickHouse Node.js client (`@clickhouse/client`). Use this skill whenever a user is *building* against the Node.js client — configuring the client, pinging, inserting rows in JSON or raw formats, selecting and parsing results, binding query parameters, managing sessions and temporary tables, working with data types or customizing JSON parsing. Do NOT use for browser/Web client code. Fuente: https://skillsagentes.com/skills/clickhouse/agent-skills/clickhouse-js-node-coding Markdown: https://skillsagentes.com/skills/clickhouse/agent-skills/clickhouse-js-node-coding.md Repositorio: https://github.com/ClickHouse/agent-skills Autor: ClickHouse Licencia: Apache-2.0 Actualizado: el mes pasado Coste de contexto: 107 tok instalada, 2.8k tok al activarse, 20.9k tok con todos los archivos del bundle Bundle: 13 archivos, 82 KB Permisos que pide: ninguno declarado ## Instalación Un skill son archivos markdown: los mismos archivos valen para cualquier agente y lo único que cambia es el directorio de destino, es decir la bandera `--agent`. Añade `-g` para instalarlo en todos los proyectos de la máquina. ```bash # Claude Code npx -y skills add ClickHouse/agent-skills --skill clickhouse-js-node-coding --agent claude-code # Cursor npx -y skills add ClickHouse/agent-skills --skill clickhouse-js-node-coding --agent cursor # Codex npx -y skills add ClickHouse/agent-skills --skill clickhouse-js-node-coding --agent codex # Gemini CLI npx -y skills add ClickHouse/agent-skills --skill clickhouse-js-node-coding --agent gemini # Windsurf npx -y skills add ClickHouse/agent-skills --skill clickhouse-js-node-coding --agent windsurf # Cline npx -y skills add ClickHouse/agent-skills --skill clickhouse-js-node-coding --agent cline ``` ## Archivos - SKILL.md — 11 KB - reference/async-insert.md — 4 KB - reference/client-configuration.md — 5 KB - reference/compression.md — 5 KB - reference/custom-json.md — 7 KB - reference/data-types.md — 11 KB - reference/insert-columns.md — 3 KB - reference/insert-formats.md — 6 KB - reference/insert-values.md — 6 KB - reference/ping.md — 5 KB - reference/query-parameters.md — 5 KB - reference/select-formats.md — 7 KB - reference/sessions.md — 7 KB ## SKILL.md Reproducido tal cual desde ClickHouse/agent-skills bajo Apache-2.0. Esta sección es el documento original y está en inglés. # ClickHouse Node.js Client — Coding Reference: https://clickhouse.com/docs/integrations/javascript > **⚠️ Node.js runtime only.** This skill covers the `@clickhouse/client` > package running in a **Node.js runtime** exclusively — including **Next.js > Node runtime** API routes, React Server Components, Server Actions, and > standard Node.js processes. Do **not** apply this skill to browser client > components, Web Workers, **Next.js Edge runtime**, Cloudflare Workers, or > any usage of `@clickhouse/client-web`. For browser/edge environments, the > correct package is `@clickhouse/client-web`. --- ## How to Use This Skill 1. **Match the user's intent** to a row in the Task Index below and read the corresponding reference file before writing code. After reading it, scan any **Answer checklist** in that reference and make sure the final answer covers each relevant item; those checklists capture details users usually need but are easy to omit in short answers. 2. **Always import from `@clickhouse/client`** (never `@clickhouse/client-web`) and create a client with `createClient({ url })` or rely on supported defaults when appropriate. Close it with `await client.close()` preferably when it's no longer needed or during graceful shutdown for global resources. 3. **Prefer `JSONEachRow` for typical row inserts/selects** unless the user has already chosen another format or is streaming raw bytes (CSV / TSV / Parquet — see `examples/node/performance/`). **Note on `clickhouse_settings`:** settings passed to `createClient` are defaults for every request; they can be overridden per-call by passing `clickhouse_settings` directly to `insert()`, `query()`, or `command()`. Always mention this when the user configures settings at the client level. 4. **Always use `query_params` for user-supplied values** — never template- literal-interpolate them into SQL. See `reference/query-parameters.md`. **When answering a parameter-binding question, your response must explicitly name template-literal interpolation as a "SQL injection risk"** — even when the user only asked about syntax and did not raise security. The literal phrase "SQL injection" needs to appear; this is the most common mistake from PostgreSQL/MySQL users and the security framing is part of the correct answer, not an optional aside. 5. **Pick the right method for the job:** - `client.insert()` — write rows. - `client.query()` + `resultSet.json()` / `.text()` / `.stream()` — read rows that return data. - `client.command()` — DDL and other statements that don't return rows (`CREATE`, `DROP`, `TRUNCATE`, `ALTER`, `SET` in a session, etc.). - `client.exec()` — when you need the raw response stream of an arbitrary statement (rare in coding scenarios). - `client.ping()` — health check; returns `{ success, error? }`, never throws on connection failure. 6. **Note version constraints** when relevant. Examples: - `pathname` config option: client `>= 1.0.0`. - `BigInt` values in `query_params`: client `>= 1.15.0`. - `TupleParam` and JS `Map` in `query_params`: client `>= 1.9.0`. - Configurable `json.parse` / `json.stringify`: client `>= 1.14.0`. - `Time` / `Time64` data types: ClickHouse server `>= 25.6`. - `QBit` data type: ClickHouse server `>= 25.10` (GA on `26.x`). - `Dynamic` / `Variant` / new `JSON` types: ClickHouse server `>= 24.1` / `24.5` / `24.8` (no longer experimental since `25.3`). --- ## Task Index Identify the user's task and read the matching reference file. | Task | Triggers / symptoms | Reference file | | -------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ----------------------------------- | | **Configure / connect the client** | Building a `createClient` call, URL parameters, `clickhouse_settings`, default format, custom HTTP headers | `reference/client-configuration.md` | | **Compress requests / responses** | `compression`, gzip vs `zstd`, `{ codec }` option shape, Node version requirements, web limitations | `reference/compression.md` | | **Ping the server** | Health checks, readiness probes, "is ClickHouse up?" | `reference/ping.md` | | **Choose an insert format** | "Which format should I use to insert?", JSON vs raw, `JSONEachRow` vs `JSON` vs `JSONObjectEachRow` | `reference/insert-formats.md` | | **Insert into a subset of columns / different database** | `insert({ columns })`, excluding columns, ephemeral columns, cross-DB inserts | `reference/insert-columns.md` | | **Insert values, expressions, dates, decimals** | `INSERT … VALUES` with SQL functions, `Date`/`DateTime` from JS, `Decimal` precision, `INSERT … SELECT`; inserting a UUID into a `UInt128` column is tricky — use when the user is writing code that stores a UUID as `UInt128` | `reference/insert-values.md` | | **Async inserts (server-side batching)** | `async_insert=1`, fire-and-forget vs wait-for-ack | `reference/async-insert.md` | | **Select and parse results** | `JSONEachRow` reads, `JSON` with metadata, picking a select format | `reference/select-formats.md` | | **Parameterize queries** | Binding values, special characters / escaping, "SQL injection?", `{name: Type}` syntax | `reference/query-parameters.md` | | **Sessions & temporary tables** | `session_id`, `CREATE TEMPORARY TABLE`, per-session `SET` commands | `reference/sessions.md` | | **Modern data types** | `Dynamic`, `Variant`, `JSON` (object), `Time`, `Time64`, `QBit` (vector search) | `reference/data-types.md` | | **Custom JSON parse/stringify** | Plug in `JSONBig` / `safe-stable-stringify` / a `BigInt`-aware serializer | `reference/custom-json.md` | --- ## Conventions used in answers - Always show `import { createClient } from '@clickhouse/client'` (Node, never Web). - Always `await client.close()` at the end of self-contained snippets; in long-running services, close on graceful shutdown. - For inserts, prefer `format: 'JSONEachRow'` and `values: [...]` unless the user's scenario requires otherwise. - For selects, prefer `await (await client.query({...})).json()` for small / medium result sets; for bigger results suggest streaming. - When showing parameter binding, use ClickHouse's native `{name: Type}` syntax — never `$1`, `?`, or `:name`. - For DDL inside a cluster or behind a load balancer, set `clickhouse_settings: { wait_end_of_query: 1 }` on the `command()` call so the server only acknowledges after the change is applied. See https://clickhouse.com/docs/en/interfaces/http/#response-buffering. --- ## Out of scope This skill covers day-to-day coding against `@clickhouse/client` (Node). The following topics are intentionally **not** covered here: - **Errors, hangs, type mismatches, proxy pathname surprises, log silence, socket hang-ups, `ECONNRESET`** → use the `clickhouse-js-node-troubleshooting` skill. - **Streaming, Parquet, file streams, server-side bulk moves, progress streaming, async-insert throughput tuning** — see [`examples/node/performance/`](https://github.com/ClickHouse/clickhouse-js/tree/main/examples/node/performance). - **TLS, RBAC / read-only users, deeper SQL-injection guidance** — see [`examples/node/security/`](https://github.com/ClickHouse/clickhouse-js/tree/main/examples/node/security). - **`CREATE TABLE` patterns, deployment-shaped connection strings, replication / sharding choices** — see [`examples/node/schema-and-deployments/`](https://github.com/ClickHouse/clickhouse-js/tree/main/examples/node/schema-and-deployments). - **Browser, Web Worker, Next.js Edge, Cloudflare Workers** — use `@clickhouse/client-web` and see [`examples/web/`](https://github.com/ClickHouse/clickhouse-js/tree/main/examples/web). --- ## Still Stuck? - [`examples/node/coding/`](https://github.com/ClickHouse/clickhouse-js/tree/main/examples/node/coding) — the runnable corpus this skill is built on. - [ClickHouse JS client docs](https://clickhouse.com/docs/integrations/javascript) - [ClickHouse supported formats](https://clickhouse.com/docs/interfaces/formats) - [ClickHouse data types](https://clickhouse.com/docs/sql-reference/data-types) ## Dónde encaja - Categoría: [Bases de datos](https://skillsagentes.com/categorias/bases-de-datos.md) — Diseño de esquemas, migraciones y optimización de consultas. - Creador: [ClickHouse](https://skillsagentes.com/creators/clickhouse.md) — 11 skills en el directorio - [Todas las skills](https://skillsagentes.com/skills.md) - [Ranking de instalaciones](https://skillsagentes.com/ranking.md) ## Otras skills del mismo repositorio - [Clickhouse Js Node Rowbinary](https://skillsagentes.com/skills/clickhouse/agent-skills/clickhouse-js-node-rowbinary.md): Generate TypeScript/JavaScript code that reads/decodes AND writes/encodes ClickHouse RowBinary streams for the ClickHouse HTTP server. Use this skill whenever a user wants to parse or produce `RowBinary`, `RowBinaryWithNames`, or `RowBinaryWithNamesAndTypes`. Node.js only, doesn't cover browsers. - [Infra Postgres](https://skillsagentes.com/skills/clickhouse/agent-skills/infra-postgres.md): Sets up and manages Postgres using the clickhousectl CLI — runs a local Docker-backed Postgres for development, and creates and operates managed ClickHouse Cloud Postgres services (connections, TLS, runtime config, read replicas, failover, point-in-time restore). Use when the user wants a Postgres or PostgreSQL database for their application, a local Postgres dev environment, psql access, or a managed/production Postgres in ClickHouse Cloud, or mentions moving a local Postgres to production. - [Infra Clickhouse](https://skillsagentes.com/skills/clickhouse/agent-skills/infra-clickhouse.md): Sets up and manages ClickHouse using the clickhousectl CLI — installs and runs a local ClickHouse server for development, and creates managed ClickHouse Cloud services for production (authentication, service creation, schema migration, application connection). Use when the user wants to build an application with ClickHouse, set up a local ClickHouse dev environment, create tables and start querying, deploy ClickHouse to production or ClickHouse Cloud, or migrate from a local setup to the cloud. - [Clickstack Otel Collector](https://skillsagentes.com/skills/clickhouse/agent-skills/clickstack-otel-collector.md): Use when a user wants to wire an OpenTelemetry collector into a Managed ClickStack service on ClickHouse Cloud, either by deploying a new local collector (Docker run or Docker Compose) or by configuring their own existing collector, then send rich synthetic telemetry and verify it is visible in ClickStack. - [Clickhouse Js Node Troubleshooting](https://skillsagentes.com/skills/clickhouse/agent-skills/clickhouse-js-node-troubleshooting.md): Troubleshoot and resolve common issues with the ClickHouse Node.js client (@clickhouse/client). Use this skill whenever a user reports errors, unexpected behavior, or configuration questions involving the Node.js client specifically — including socket hang-up errors, Keep-Alive problems, stream handling issues, data type mismatches, read-only user restrictions, proxy/TLS setup problems, or long-running query timeouts. Trigger even when the user hasn't precisely named the issue; vague symptoms like "my inserts keep failing" or "connection drops randomly" in a Node.js context are strong signals to use this skill. Do NOT use for browser/Web client issues. ## Skills relacionadas - [Chdb Datastore](https://skillsagentes.com/skills/clickhouse/agent-skills/chdb-datastore.md): Use when the user has tabular data (pandas DataFrame, parquet, csv, Arrow, json) and wants to filter, group, aggregate, join, or speed up slow pandas. Provides chDB DataStore — same pandas API, ClickHouse engine underneath. Also handles reading from S3, MySQL, PostgreSQL, MongoDB, ClickHouse Cloud, Iceberg, Delta Lake as DataFrames and joining across sources. TRIGGER when: user mentions DataFrame, parquet, csv, "fast pandas", "speed up pandas", or cross-source DataFrame joins; user imports `chdb.datastore` or `from datastore import DataStore`. SKIP this skill for raw SQL syntax (use chdb-sql instead), ClickHouse server administration, or non-Python DataStore API work. - [Chdb Sql](https://skillsagentes.com/skills/clickhouse/agent-skills/chdb-sql.md): Use when the user wants to run SQL — especially analytical SQL — on local files (parquet/csv/json), URLs, S3 paths, or remote databases (Postgres, MySQL, MongoDB, ClickHouse Cloud, Iceberg, Delta Lake) without setting up a server. Provides chDB — embedded ClickHouse SQL in Python with 1000+ functions, Session for stateful multi-step pipelines, parametrized queries, and cross-source joins via `s3()`, `mysql()`, `postgresql()`, `iceberg()`, `deltaLake()`, `remoteSecure()` table functions. TRIGGER when: user wants SQL on parquet/csv/files or across remote analytical sources; uses ClickHouse SQL features (window functions, windowFunnel, geoToH3, JSON path ops, Session, parametrized queries); imports `chdb` or calls `chdb.query()`. SKIP this skill for pandas-style DataFrame method-chaining (use chdb-datastore instead) or ClickHouse server administration. - [Clickhouse Architecture Advisor](https://skillsagentes.com/skills/clickhouse/agent-skills/clickhouse-architecture-advisor.md): MUST USE when designing ClickHouse architectures, selecting between ingestion or modeling patterns, or translating best practices into workload-specific system designs. Complements clickhouse-best-practices with decision frameworks and explicit provenance labels. - [Clickhouse Best Practices](https://skillsagentes.com/skills/clickhouse/agent-skills/clickhouse-best-practices.md): MUST USE when reviewing ClickHouse schemas, queries, or configurations. Contains 31 rules that MUST be checked before providing recommendations. Always read relevant rule files and cite specific rules in responses. - [Clickhouse Js Node Rowbinary](https://skillsagentes.com/skills/clickhouse/agent-skills/clickhouse-js-node-rowbinary.md): Generate TypeScript/JavaScript code that reads/decodes AND writes/encodes ClickHouse RowBinary streams for the ClickHouse HTTP server. Use this skill whenever a user wants to parse or produce `RowBinary`, `RowBinaryWithNames`, or `RowBinaryWithNamesAndTypes`. Node.js only, doesn't cover browsers. --- Skills Agentes · [Índice de páginas en markdown](https://skillsagentes.com/sitemap.md) · [Inicio](https://skillsagentes.com/index.md)