Sourcemaps are missing, causing tooling errors

[samsternatmiter]

The final line of the main @openrouter/sdk/esm/index.js file points to a sourcemap:

$ tail node_modules/@openrouter/sdk/esm/index.js

export { extractUnsupportedContent, getUnsupportedContentSummary, hasUnsupportedContent, } from './lib/stream-transformers.js';
// Tool creation helpers
export { tool } from './lib/tool.js';
export { hasExecuteFunction, isGeneratorTool, isRegularExecuteTool, isToolPreliminaryResultEvent, ToolType, } from './lib/tool-types.js';
// Turn context helpers
export { buildTurnContext, normalizeInputToArray } from './lib/turn-context.js';
// Real-time tool event broadcasting
export { ToolEventBroadcaster } from './lib/tool-event-broadcaster.js';
export * from './sdk/sdk.js';
//# sourceMappingURL=index.js.map

However that file does not actually exist:

$ ls node_modules/@openrouter/sdk/esm/
core.d.ts	funcs		index.d.ts	lib		sdk
core.js		hooks		index.js	models		types

This causes some tools, like swc, to throw an error:

Could you either ship the sourcemaps with the npm package or just remove the sourcemap declaration?

[686f6c61]

Hi @samsternatmiter,

A small minus sign in .npmignore causing havoc in builds. I've investigated the issue and found the root cause.

Root Cause

TypeScript is correctly generating source maps during build (tsconfig.json has "sourceMap": true), which adds //# sourceMappingURL=index.js.map references to all generated .js files. However, the .npmignore file is explicitly excluding these .map files with the pattern /**/*.map.

This creates an inconsistent state where JavaScript files reference source maps that don't exist in the published package, causing SWC and other build tools to fail when processing the SDK.

Reproduction

I created a minimal test case:

npm install @openrouter/sdk@0.3.15 @swc/core
npx swc node_modules/@openrouter/sdk/esm/index.js -o output.js

This produces exactly the error you reported:

ERROR failed to read input source map: failed to find input source map file "index.js.map"

Investigation

I verified how other major AI SDKs handle this:

• OpenAI SDK: Includes 844 .map files in the published package
• Anthropic SDK: Includes 296 .map files in the published package

Both include the source map reference comments and ship the corresponding .map files.

Proposed Solution

Update .npmignore to include source maps:

- /**/*.map
+ !/**/*.map

This would align with the pattern already used for other generated files (.js, .ts, .json).

Impact:

• Package size would increase from 244.5 kB to 404.1 kB
• Would add 652 source map files
• Would enable proper debugging of the SDK in production environments
• Would resolve all SWC compilation errors

I verified this fix works by installing a local package with source maps included and running the same SWC compilation that previously failed. It now compiles successfully.

The alternative would be to completely disable source map generation ("sourceMap": false in tsconfig.json), but this would hurt developer experience and goes against industry standards.

@mattapperson, does this approach make sense to include in the next SDK generation?