ClickHouse chat agent

import { chat } from "@trigger.dev/sdk/ai";
import { anthropic } from "@ai-sdk/anthropic";
import { stepCountIs, streamText } from "ai";

export const clickhouseAgent = chat.agent({
  id: "clickhouse-agent",
  idleTimeoutInSeconds: 300,
  tools: { listTables, describeTable, runQuery },
  run: async ({ messages, tools, signal }) => {
    return streamText({
      // Spread chat.toStreamTextOptions() FIRST — it wires up
      // prepareStep (compaction, steering, background injection),
      // the system prompt set via chat.prompt(), and telemetry.
      ...chat.toStreamTextOptions(),
      model: anthropic("claude-opus-4-8"),
      system: SYSTEM_PROMPT,
      messages,
      tools,
      stopWhen: stepCountIs(15),
      abortSignal: signal,
    });
  },
});

const READ_ONLY_STATEMENTS = /^\s*(select|with|show|describe|desc|explain|exists)\b/i;

const runQuery = tool({
  description:
    "Run a read-only SQL query against ClickHouse and get the results as JSON rows.",
  inputSchema: z.object({
    query: z.string().describe("The ClickHouse SQL query to run"),
  }),
  execute: async ({ query }) => {
    if (!READ_ONLY_STATEMENTS.test(query)) {
      return { error: "Only read-only statements are allowed." };
    }
    try {
      const result = await getClickHouse().query({
        query,
        format: "JSONEachRow",
        clickhouse_settings: {
          // readonly=2: reads only (no writes/DDL), but per-query settings
          // like the limits below are still allowed.
          readonly: "2",
          max_result_rows: "1000",
          result_overflow_mode: "break",
          max_execution_time: 30,
        },
      });
      const rows = await result.json();
      return { rowCount: rows.length, rows };
    } catch (error) {
      // Return ClickHouse errors to the model so it can fix the query and retry.
      return { error: error instanceof Error ? error.message : String(error) };
    }
  },
});

import { createClient } from "@clickhouse/client";

const clickhouse = createClient({ url: process.env.CLICKHOUSE_URL });