fix: resolve biome lint errors and simplify README quickstart

Fix all biome lint errors (formatting, import sorting, noNonNullAssertion,
useTemplate, noDelete, useNumberNamespace) and trim the Quickstart for
Agents section to a one-liner install command.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: jiunbae

README.md

@@ -19,27 +19,11 @@ A context-aware **MCP server** for [Claude Code](https://claude.ai/claude-code)
 
 ## Quickstart for Agents
 
-<div><img src="https://quickstart-for-agents.vercel.app/api/header.svg?theme=claude-code&title=Install+and+configure+context-compress&mascot=thinking&lang=MCP" width="100%" /></div>
-
 ```
-Install context-compress — a context-aware MCP server that compresses tool output
-for Claude Code. It keeps raw data in sandboxed subprocesses so only concise
-summaries enter the context window. Supports 11 languages (JS, TS, Python, Shell,
-Ruby, Go, Rust, PHP, Perl, R, Elixir) with FTS5 search and smart truncation.
-
-Steps:
-1. Run: npm install -g context-compress
-2. Run: claude mcp add context-compress -- node $(which context-compress)
-3. Run: context-compress doctor   # verify runtimes, hooks, FTS5
-4. Optionally create .context-compress.json with:
-   { "passthroughEnvVars": ["GH_TOKEN"], "debug": false }
-
-After setup, the PreToolUse hook auto-redirects data-fetching tools through
-the sandbox. Use execute() instead of Bash for large outputs, execute_file()
-instead of Read for large files, and fetch_and_index() instead of WebFetch.
+npm install -g context-compress && claude mcp add context-compress -- node $(which context-compress)
 ```
 
-<div><img src="https://quickstart-for-agents.vercel.app/api/footer.svg?theme=claude-code&tokens=4.2k&model=Opus+4.6&project=context-compress" width="100%" /></div>
+MCP server that compresses tool output for Claude Code — raw data stays in sandboxed subprocesses, only concise summaries enter your context window.
 
 ---
 

src/cli/doctor.ts

@@ -1,19 +1,17 @@
-import { accessSync, constants, readFileSync } from "node:fs";
-import { dirname, resolve } from "node:path";
+import { constants, accessSync, readFileSync } from "node:fs";
 import { homedir } from "node:os";
+import { dirname, resolve } from "node:path";
 import { fileURLToPath } from "node:url";
 import Database from "better-sqlite3";
-import { SubprocessExecutor } from "../executor.js";
 import { loadConfig } from "../config.js";
+import { SubprocessExecutor } from "../executor.js";
 import { detectRuntimes, getRuntimeSummary, hasBun } from "../runtime/index.js";
 
 const __dirname = dirname(fileURLToPath(import.meta.url));
 
 function getVersion(): string {
 	try {
-		const pkg = JSON.parse(
-			readFileSync(resolve(__dirname, "..", "..", "package.json"), "utf-8"),
-		);
+		const pkg = JSON.parse(readFileSync(resolve(__dirname, "..", "..", "package.json"), "utf-8"));
 		return pkg.version ?? "unknown";
 	} catch {
 		return "unknown";
@@ -80,7 +78,9 @@ export async function doctor(): Promise<number> {
 	const settings = readSettings();
 	if (settings) {
 		const hooks = settings.hooks as Record<string, unknown[]> | undefined;
-		const preToolUse = hooks?.PreToolUse as Array<{ hooks?: Array<{ command?: string }> }> | undefined;
+		const preToolUse = hooks?.PreToolUse as
+			| Array<{ hooks?: Array<{ command?: string }> }>
+			| undefined;
 		if (preToolUse?.some((e) => e.hooks?.some((h) => h.command?.includes("pretooluse.mjs")))) {
 			console.log("  [PASS] PreToolUse hook configured");
 		} else {
@@ -105,9 +105,11 @@ export async function doctor(): Promise<number> {
 		const db = new Database(":memory:");
 		db.exec("CREATE VIRTUAL TABLE fts_test USING fts5(content)");
 		db.exec("INSERT INTO fts_test(content) VALUES ('hello world')");
-		const row = db.prepare("SELECT * FROM fts_test WHERE fts_test MATCH 'hello'").get() as {
-			content: string;
-		} | undefined;
+		const row = db.prepare("SELECT * FROM fts_test WHERE fts_test MATCH 'hello'").get() as
+			| {
+					content: string;
+			  }
+			| undefined;
 		db.close();
 		if (row?.content === "hello world") {
 			console.log("  [PASS] FTS5 / better-sqlite3 works");

src/cli/setup.ts

@@ -23,16 +23,7 @@ export async function setup(): Promise<void> {
 	}
 
 	// Step 3: Missing optional runtimes
-	const all = [
-		"python",
-		"ruby",
-		"go",
-		"rust",
-		"php",
-		"perl",
-		"r",
-		"elixir",
-	] as const;
+	const all = ["python", "ruby", "go", "rust", "php", "perl", "r", "elixir"] as const;
 	const missing = all.filter((lang) => !runtimes.has(lang));
 	if (missing.length > 0) {
 		console.log(`  Optional runtimes not found: ${missing.join(", ")}`);

src/cli/uninstall.ts

@@ -17,14 +17,17 @@ export async function uninstall(): Promise<void> {
 			const before = hooks.PreToolUse.length;
 			hooks.PreToolUse = (hooks.PreToolUse as Array<Record<string, unknown>>).filter((entry) => {
 				const entryHooks = entry.hooks as Array<{ command?: string }> | undefined;
-				return !entryHooks?.some((h) => h.command?.includes("context-compress") || h.command?.includes("pretooluse.mjs"));
+				return !entryHooks?.some(
+					(h) => h.command?.includes("context-compress") || h.command?.includes("pretooluse.mjs"),
+				);
 			});
 			if (hooks.PreToolUse.length === 0) {
+				// biome-ignore lint/performance/noDelete: removing key from JSON object
 				delete hooks.PreToolUse;
 			}
 			if (hooks.PreToolUse === undefined || hooks.PreToolUse.length < before) {
 				settings.hooks = hooks;
-				writeFileSync(settingsPath, JSON.stringify(settings, null, 2) + "\n", "utf-8");
+				writeFileSync(settingsPath, `${JSON.stringify(settings, null, 2)}\n`, "utf-8");
 				changes.push("Removed PreToolUse hooks from settings.json");
 			}
 		}
@@ -39,8 +42,8 @@ export async function uninstall(): Promise<void> {
 		const settings = JSON.parse(readFileSync(mcpPath, "utf-8"));
 		const mcpServers = settings.mcpServers as Record<string, unknown> | undefined;
 		if (mcpServers && "context-compress" in mcpServers) {
-			delete mcpServers["context-compress"];
-			writeFileSync(mcpPath, JSON.stringify(settings, null, 2) + "\n", "utf-8");
+			mcpServers["context-compress"] = undefined;
+			writeFileSync(mcpPath, `${JSON.stringify(settings, null, 2)}\n`, "utf-8");
 			changes.push("Removed context-compress MCP server from settings");
 		}
 	} catch {
@@ -54,8 +57,8 @@ export async function uninstall(): Promise<void> {
 		const mcp = JSON.parse(readFileSync(mcpJson, "utf-8"));
 		const servers = mcp.mcpServers as Record<string, unknown> | undefined;
 		if (servers && "context-compress" in servers) {
-			delete servers["context-compress"];
-			writeFileSync(mcpJson, JSON.stringify(mcp, null, 2) + "\n", "utf-8");
+			servers["context-compress"] = undefined;
+			writeFileSync(mcpJson, `${JSON.stringify(mcp, null, 2)}\n`, "utf-8");
 			changes.push("Removed context-compress from .mcp.json");
 		}
 	} catch {
@@ -97,7 +100,5 @@ export async function uninstall(): Promise<void> {
 		console.log("  Nothing to clean up.");
 	}
 
-	console.log(
-		"\n  Uninstall complete. Restart Claude Code to apply changes.\n",
-	);
+	console.log("\n  Uninstall complete. Restart Claude Code to apply changes.\n");
 }

src/config.ts

@@ -76,8 +76,7 @@ function loadEnvConfig(): Partial<Config> {
 		partial.debug = true;
 	}
 	if (process.env.CONTEXT_COMPRESS_PASSTHROUGH_ENV) {
-		partial.passthroughEnvVars = process.env.CONTEXT_COMPRESS_PASSTHROUGH_ENV
-			.split(",")
+		partial.passthroughEnvVars = process.env.CONTEXT_COMPRESS_PASSTHROUGH_ENV.split(",")
 			.map((s) => s.trim())
 			.filter(Boolean);
 	}

src/executor.ts

@@ -44,7 +44,7 @@ function buildEnv(config: Config): Record<string, string> {
 	// Copy safe base variables
 	for (const key of SAFE_ENV_KEYS) {
 		if (process.env[key]) {
-			env[key] = process.env[key]!;
+			env[key] = process.env[key] as string;
 		}
 	}
 
@@ -57,7 +57,7 @@ function buildEnv(config: Config): Record<string, string> {
 	// Opt-in passthrough (security fix: default is empty)
 	for (const key of config.passthroughEnvVars) {
 		if (process.env[key]) {
-			env[key] = process.env[key]!;
+			env[key] = process.env[key] as string;
 		}
 	}
 
@@ -297,7 +297,7 @@ export class SubprocessExecutor {
 				// Extract network bytes from JS/TS stderr marker
 				const netMatch = stderr.match(/__CM_NET__:(\d+)/);
 				if (netMatch) {
-					networkBytes = parseInt(netMatch[1], 10);
+					networkBytes = Number.parseInt(netMatch[1], 10);
 					stderr = stderr.replace(/__CM_NET__:\d+\n?/, "");
 				}
 
@@ -341,7 +341,8 @@ export class SubprocessExecutor {
  * Wrap JS/TS code with fetch interceptor for network tracking.
  */
 function wrapWithNetworkTracking(code: string): string {
-	const preamble = `let __cm_net=0;const __cm_f=globalThis.fetch;if(__cm_f){globalThis.fetch=async(...a)=>{const r=await __cm_f(...a);try{const cl=r.clone();const b=await cl.arrayBuffer();__cm_net+=b.byteLength}catch{}return r};}`;
+	const preamble =
+		"let __cm_net=0;const __cm_f=globalThis.fetch;if(__cm_f){globalThis.fetch=async(...a)=>{const r=await __cm_f(...a);try{const cl=r.clone();const b=await cl.arrayBuffer();__cm_net+=b.byteLength}catch{}return r};}";
 	const epilogue = `\nprocess.stderr.write('__CM_NET__:'+__cm_net+'\\n');`;
 
 	// Wrap in async IIFE

src/runtime/languages/rust.ts

@@ -26,10 +26,7 @@ export const rustPlugin: LanguagePlugin = {
 		const escaped = JSON.stringify(filePath);
 		const preamble = `use std::fs;\nlet file_content_path = ${escaped};\nlet file_content = fs::read_to_string(file_content_path).unwrap();\n`;
 		if (code.includes("fn main")) {
-			return code.replace(
-				/fn main\s*\(\s*\)\s*\{/,
-				`fn main() {\n${preamble}`,
-			);
+			return code.replace(/fn main\s*\(\s*\)\s*\{/, `fn main() {\n${preamble}`);
 		}
 		return `fn main() {\n${preamble}${code}\n}`;
 	},

src/server.ts

@@ -13,8 +13,17 @@ import { ContentStore, cleanupStaleDbs } from "./store.js";
 import type { Language } from "./types.js";
 
 const LANGUAGES: [Language, ...Language[]] = [
-	"javascript", "typescript", "python", "shell", "ruby",
-	"go", "rust", "php", "perl", "r", "elixir",
+	"javascript",
+	"typescript",
+	"python",
+	"shell",
+	"ruby",
+	"go",
+	"rust",
+	"php",
+	"perl",
+	"r",
+	"elixir",
 ];
 
 function getVersion(): string {
@@ -61,8 +70,17 @@ export async function createServer(config: Config) {
 PREFER THIS OVER BASH for: API calls (gh, curl, aws), test runners (npm test, pytest), git queries (git log, git diff), data processing, and ANY CLI command that may produce large output. Bash should only be used for file mutations, git writes, and navigation.`,
 		{
 			language: z.enum(LANGUAGES).describe("Runtime language"),
-			code: z.string().describe("Source code to execute. Use console.log (JS/TS), print (Python/Ruby/Perl/R), echo (Shell), echo (PHP), fmt.Println (Go), or IO.puts (Elixir) to output a summary to context."),
-			intent: z.string().optional().describe("What you're looking for in the output. When provided and output is large (>5KB), indexes output into knowledge base and returns section titles + previews — not full content. Use search(queries: [...]) to retrieve specific sections."),
+			code: z
+				.string()
+				.describe(
+					"Source code to execute. Use console.log (JS/TS), print (Python/Ruby/Perl/R), echo (Shell), echo (PHP), fmt.Println (Go), or IO.puts (Elixir) to output a summary to context.",
+				),
+			intent: z
+				.string()
+				.optional()
+				.describe(
+					"What you're looking for in the output. When provided and output is large (>5KB), indexes output into knowledge base and returns section titles + previews — not full content. Use search(queries: [...]) to retrieve specific sections.",
+				),
 			timeout: z.number().default(30000).describe("Max execution time in ms"),
 		},
 		async ({ language, code, intent, timeout }) => {
@@ -93,7 +111,7 @@ PREFER THIS OVER BASH for: API calls (gh, curl, aws), test runners (npm test, py
 				if (terms.length > 0) {
 					filtered += `\nSearchable terms: ${terms.join(", ")}\n`;
 				}
-				filtered += `\nUse search(queries: [...]) to retrieve full content of any section.`;
+				filtered += "\nUse search(queries: [...]) to retrieve full content of any section.";
 				output = filtered;
 			}
 
@@ -112,7 +130,11 @@ PREFER THIS OVER BASH for: API calls (gh, curl, aws), test runners (npm test, py
 		{
 			path: z.string().describe("Absolute file path or relative to project root"),
 			language: z.enum(LANGUAGES).describe("Runtime language"),
-			code: z.string().describe("Code to process FILE_CONTENT. Print summary via console.log/print/echo/IO.puts."),
+			code: z
+				.string()
+				.describe(
+					"Code to process FILE_CONTENT. Print summary via console.log/print/echo/IO.puts.",
+				),
 			intent: z.string().optional().describe("What you're looking for in the output."),
 			timeout: z.number().default(30000).describe("Max execution time in ms"),
 		},
@@ -147,7 +169,7 @@ PREFER THIS OVER BASH for: API calls (gh, curl, aws), test runners (npm test, py
 				if (terms.length > 0) {
 					filtered += `\nSearchable terms: ${terms.join(", ")}\n`;
 				}
-				filtered += `\nUse search(queries: [...]) to retrieve full content of any section.`;
+				filtered += "\nUse search(queries: [...]) to retrieve full content of any section.";
 				output = filtered;
 			}
 
@@ -162,10 +184,16 @@ PREFER THIS OVER BASH for: API calls (gh, curl, aws), test runners (npm test, py
 
 	server.tool(
 		"index",
-		'Index documentation or knowledge content into a searchable BM25 knowledge base. Chunks markdown by headings (keeping code blocks intact) and stores in ephemeral FTS5 database. The full content does NOT stay in context — only a brief summary is returned.\n\nWHEN TO USE:\n- Documentation (API docs, framework guides, code examples)\n- README files, migration guides, changelog entries\n- Any content with code examples you may need to reference precisely\n\nAfter indexing, use \'search\' to retrieve specific sections on-demand.',
+		"Index documentation or knowledge content into a searchable BM25 knowledge base. Chunks markdown by headings (keeping code blocks intact) and stores in ephemeral FTS5 database. The full content does NOT stay in context — only a brief summary is returned.\n\nWHEN TO USE:\n- Documentation (API docs, framework guides, code examples)\n- README files, migration guides, changelog entries\n- Any content with code examples you may need to reference precisely\n\nAfter indexing, use 'search' to retrieve specific sections on-demand.",
 		{
-			content: z.string().optional().describe("Raw text/markdown to index. Provide this OR path, not both."),
-			path: z.string().optional().describe("File path to read and index (content never enters context)."),
+			content: z
+				.string()
+				.optional()
+				.describe("Raw text/markdown to index. Provide this OR path, not both."),
+			path: z
+				.string()
+				.optional()
+				.describe("File path to read and index (content never enters context)."),
 			source: z.string().optional().describe("Label for the indexed content"),
 		},
 		async ({ content, path: filePath, source }) => {
@@ -198,10 +226,15 @@ PREFER THIS OVER BASH for: API calls (gh, curl, aws), test runners (npm test, py
 
 	server.tool(
 		"search",
-		'Search indexed content. Pass ALL search questions as queries array in ONE call.\n\nTIPS: 2-4 specific terms per query. Use \'source\' to scope results.',
+		"Search indexed content. Pass ALL search questions as queries array in ONE call.\n\nTIPS: 2-4 specific terms per query. Use 'source' to scope results.",
 		{
-			queries: z.array(z.string()).describe("Array of search queries. Batch ALL questions in one call."),
-			source: z.string().optional().describe("Filter to a specific indexed source (partial match)."),
+			queries: z
+				.array(z.string())
+				.describe("Array of search queries. Batch ALL questions in one call."),
+			source: z
+				.string()
+				.optional()
+				.describe("Filter to a specific indexed source (partial match)."),
 			limit: z.number().default(3).describe("Results per query (default: 3)"),
 		},
 		async ({ queries, source, limit }) => {
@@ -216,12 +249,14 @@ PREFER THIS OVER BASH for: API calls (gh, curl, aws), test runners (npm test, py
 			const callCount = searchCalls.length;
 
 			if (callCount > config.searchBlockAfter) {
-				const msg = "Too many search calls in quick succession. Use batch_execute instead to run commands and search in one call.";
+				const msg =
+					"Too many search calls in quick succession. Use batch_execute instead to run commands and search in one call.";
 				tracker.trackCall("search", Buffer.byteLength(msg));
 				return { content: [{ type: "text" as const, text: msg }] };
 			}
 
-			const effectiveLimit = callCount > config.searchReduceAfter ? 1 : Math.min(limit, config.searchLimit);
+			const effectiveLimit =
+				callCount > config.searchReduceAfter ? 1 : Math.min(limit, config.searchLimit);
 
 			const allResults: string[] = [];
 			let totalBytes = 0;
@@ -249,7 +284,9 @@ PREFER THIS OVER BASH for: API calls (gh, curl, aws), test runners (npm test, py
 			}
 
 			if (callCount > config.searchReduceAfter) {
-				allResults.push(`\n⚠ Search rate limited (${callCount} calls in ${config.searchWindowMs / 1000}s). Results reduced to 1 per query.`);
+				allResults.push(
+					`\n⚠ Search rate limited (${callCount} calls in ${config.searchWindowMs / 1000}s). Results reduced to 1 per query.`,
+				);
 			}
 
 			const output = allResults.join("\n---\n\n");
@@ -315,11 +352,19 @@ PREFER THIS OVER BASH for: API calls (gh, curl, aws), test runners (npm test, py
 		"batch_execute",
 		"Execute multiple commands in ONE call, auto-index all output, and search with multiple queries. Returns search results directly — no follow-up calls needed.\n\nTHIS IS THE PRIMARY TOOL. Use this instead of multiple execute() calls.\n\nOne batch_execute call replaces 30+ execute calls + 10+ search calls.\nProvide all commands to run and all queries to search — everything happens in one round trip.",
 		{
-			commands: z.array(z.object({
-				label: z.string().describe("Section header for this command's output"),
-				command: z.string().describe("Shell command to execute"),
-			})).describe("Commands to execute as a batch."),
-			queries: z.array(z.string()).describe("Search queries to extract information from indexed output. Use 5-8 comprehensive queries."),
+			commands: z
+				.array(
+					z.object({
+						label: z.string().describe("Section header for this command's output"),
+						command: z.string().describe("Shell command to execute"),
+					}),
+				)
+				.describe("Commands to execute as a batch."),
+			queries: z
+				.array(z.string())
+				.describe(
+					"Search queries to extract information from indexed output. Use 5-8 comprehensive queries.",
+				),
 			timeout: z.number().default(60000).describe("Max execution time in ms (default: 60s)"),
 		},
 		async ({ commands, queries, timeout }) => {

src/snippet.ts

@@ -52,10 +52,7 @@ interface Window {
  * Extract snippet windows around match positions.
  * Returns concatenated windows with ellipsis separators.
  */
-export function extractSnippet(
-	highlighted: string,
-	maxLen: number = DEFAULT_MAX_LEN,
-): string {
+export function extractSnippet(highlighted: string, maxLen: number = DEFAULT_MAX_LEN): string {
 	const positions = positionsFromHighlight(highlighted);
 	const clean = stripMarkers(highlighted);