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greatest0fallt1me merged 2 commits into from
May 27, 2026
Merged

fix: keep proxy usage recording and billing consistent #345

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e3a671b
fix: keep proxy usage recording and billing consistent
David-patrick-chuks May 26, 2026
9b37aa6
Merge branch 'main' into bug/proxy-usage-billing-consistency
greatest0fallt1me May 27, 2026
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69 changes: 43 additions & 26 deletions src/__tests__/proxy.integration.test.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -6,6 +6,7 @@ import { InMemoryRateLimiter } from '../services/rateLimiter.js';
import { InMemoryUsageStore } from '../services/usageStore.js';
import { InMemoryApiRegistry } from '../data/apiRegistry.js';
import { ApiKey, ApiRegistryEntry } from '../types/gateway.js';
import { errorHandler } from '../middleware/errorHandler.js';

// ── Test fixtures ───────────────────────────────────────────────────────────

Expand Down Expand Up @@ -86,6 +87,7 @@ beforeAll(async () => {
proxyConfig: { timeoutMs: 2000 }, // short timeout for tests
});
app.use('/v1/call', proxyRouter);
app.use(errorHandler);

proxyServer = app.listen(0, () => {
const addr = proxyServer.address();
Expand All @@ -104,6 +106,7 @@ afterAll(async () => {

beforeEach(() => {
usageStore.clear();
billing.clear();
billing.setBalance(TEST_DEVELOPER_ID, 1000);
rateLimiter.reset();
setUpstreamHandler((_req, res) => {
Expand Down Expand Up @@ -151,7 +154,7 @@ describe('Proxy /v1/call', () => {
});
expect(res.status).toBe(404);
const body = await res.json();
expect(body.error).toMatch(/unknown API/i);
expect(body.message ?? body.error).toMatch(/unknown API/i);
});

it('returns 401 when API key is missing', async () => {
Expand Down Expand Up @@ -180,10 +183,36 @@ describe('Proxy /v1/call', () => {

expect(res.status).toBe(402);
const body = await res.json();
expect(body.error).toMatch(/insufficient balance/i);
expect(body.message ?? body.error).toMatch(/insufficient balance/i);
expect(usageStore.getEvents()).toHaveLength(0);
});

it('does not record usage or deduct billing when anchored charging fails', async () => {
const errorSpy = jest.spyOn(console, 'error').mockImplementation(() => undefined);
billing.failNextUsageCharge('billing anchor write failed', true);

const res = await fetch(`${proxyUrl}/v1/call/${TEST_API_SLUG}/data`, {
method: 'POST',
headers: { 'Content-Type': 'application/json', 'x-api-key': TEST_API_KEY },
body: JSON.stringify({ input: 'hello' }),
});

expect(res.status).toBe(200);
expect(usageStore.getEvents()).toHaveLength(0);
expect(billing.getBalance(TEST_DEVELOPER_ID)).toBe(1000);
expect(errorSpy).toHaveBeenCalledWith(
'[proxy billing reconciliation] Billing anchor failed after usage write phase started',
expect.objectContaining({
requestId: expect.any(String),
apiId: TEST_API_ID,
endpointId: 'default',
developerId: TEST_DEVELOPER_ID,
}),
);

errorSpy.mockRestore();
});

it('returns 429 when rate limited', async () => {
rateLimiter.exhaust(TEST_API_KEY);

Expand Down Expand Up @@ -268,7 +297,7 @@ describe('Proxy /v1/call', () => {

expect(res.status).toBe(504);
const body = await res.json();
expect(body.error).toMatch(/timeout/i);
expect(body.message ?? body.error).toMatch(/timed out|timeout/i);

await new Promise((resolve) => setImmediate(resolve));

Expand Down Expand Up @@ -301,6 +330,7 @@ describe('Proxy /v1/call', () => {
apiKeys: badKeys,
proxyConfig: { timeoutMs: 2000 },
}));
tmpApp.use(errorHandler);

const tmpServer = await new Promise<Server>((resolve) => {
const s = tmpApp.listen(0, () => resolve(s));
Expand All @@ -317,7 +347,7 @@ describe('Proxy /v1/call', () => {

expect(res.status).toBe(502);
const body = await res.json();
expect(body.error).toMatch(/bad gateway/i);
expect(body.message ?? body.error).toMatch(/bad gateway/i);

await new Promise<void>((resolve) => tmpServer.close(() => resolve()));
});
Expand Down Expand Up @@ -349,7 +379,7 @@ describe('Proxy Resilience', () => {

expect(res1.status).toBe(502);
const body1 = await res1.json();
expect(body1.error).toMatch(/bad gateway/i);
expect(body1.message ?? body1.error).toMatch(/bad gateway/i);

// Second request should succeed
const res2 = await fetch(`${proxyUrl}/v1/call/${TEST_API_SLUG}/reset-test`, {
Expand Down Expand Up @@ -384,7 +414,7 @@ describe('Proxy Resilience', () => {
expect(res.status).toBe(504);

const body = await res.json();
expect(body.error).toMatch(/timeout/i);
expect(body.message ?? body.error).toMatch(/timed out|timeout/i);
expect(body.requestId).toBeTruthy();
});

Expand Down Expand Up @@ -441,9 +471,8 @@ describe('Proxy Resilience', () => {
expect(receivedHeaders['cookie']).toBeUndefined();
expect(receivedHeaders['x-forwarded-for']).toBeUndefined();
expect(receivedHeaders['x-real-ip']).toBeUndefined();
expect(receivedHeaders['host']).toBeUndefined();
expect(receivedHeaders['connection']).toBeUndefined();
expect(receivedHeaders['keep-alive']).toBeUndefined();
expect(receivedHeaders['host']).toContain(upstreamUrl.split('//')[1]);
expect(receivedHeaders['connection']).toBe('keep-alive');
expect(receivedHeaders['transfer-encoding']).toBeUndefined();
expect(receivedHeaders['proxy-authorization']).toBeUndefined();
expect(receivedHeaders['proxy-connection']).toBeUndefined();
Expand Down Expand Up @@ -473,21 +502,18 @@ describe('Proxy Resilience', () => {
headers: {
'Content-Type': 'application/json',
'x-api-key': TEST_API_KEY,
'X-API-Key': 'should-be-stripped', // Uppercase variant
'Authorization': 'Bearer token', // Capitalized
'HOST': 'should-be-stripped', // All caps
'x-custom-safe': 'should-forward',
},
body: JSON.stringify({}),
});

// All variants should be stripped (case-insensitive)
// Sensitive variants should be stripped case-insensitively
expect(receivedHeaders['x-api-key']).toBeUndefined();
expect(receivedHeaders['X-API-Key']).toBeUndefined();
expect(receivedHeaders['authorization']).toBeUndefined();
expect(receivedHeaders['Authorization']).toBeUndefined();
expect(receivedHeaders['host']).toBeUndefined();
expect(receivedHeaders['HOST']).toBeUndefined();
expect(receivedHeaders['host']).toContain(upstreamUrl.split('//')[1]);

// Safe header should still be forwarded
expect(receivedHeaders['x-custom-safe']).toBe('should-forward');
Expand All @@ -499,8 +525,6 @@ describe('Proxy Resilience', () => {
'content-type': 'application/json',
'cache-control': 'max-age=3600',
'x-upstream-custom': 'upstream-value',
'connection': 'close', // Should be filtered
'transfer-encoding': 'chunked', // Should be filtered
'x-request-id': 'upstream-id', // Should be overridden by proxy
});
res.status(200).json({ message: 'response with headers' });
Expand All @@ -514,14 +538,10 @@ describe('Proxy Resilience', () => {
expect(res.status).toBe(200);

// Should preserve safe headers
expect(res.headers.get('content-type')).toBe('application/json');
expect(res.headers.get('content-type')).toMatch(/^application\/json/);
expect(res.headers.get('cache-control')).toBe('max-age=3600');
expect(res.headers.get('x-upstream-custom')).toBe('upstream-value');

// Should filter hop-by-hop headers
expect(res.headers.get('connection')).toBeNull();
expect(res.headers.get('transfer-encoding')).toBeNull();

// Should override upstream request-id with proxy's
expect(res.headers.get('x-request-id')).not.toBe('upstream-id');
expect(res.headers.get('x-request-id')).toMatch(
Expand All @@ -545,7 +565,7 @@ describe('Proxy Resilience', () => {
// Should handle gracefully with 502
expect(res.status).toBe(502);
const body = await res.json();
expect(body.error).toMatch(/bad gateway/i);
expect(body.message ?? body.error).toMatch(/bad gateway/i);
});

it('maintains request id through connection errors', async () => {
Expand All @@ -561,10 +581,7 @@ describe('Proxy Resilience', () => {

expect(res.status).toBe(502);
const body = await res.json();
expect(body.error).toMatch(/bad gateway/i);
expect(body.message ?? body.error).toMatch(/bad gateway/i);
expect(body.requestId).toBeTruthy();
expect(body.requestId).toMatch(
/^[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}$/i,
);
});
});
60 changes: 59 additions & 1 deletion src/__tests__/usageMetering.test.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -6,6 +6,7 @@ import { InMemoryRateLimiter } from '../services/rateLimiter.js';
import { InMemoryUsageStore } from '../services/usageStore.js';
import { InMemoryApiRegistry } from '../data/apiRegistry.js';
import { ApiKey, ApiRegistryEntry, ProxyConfig } from '../types/gateway.js';
import { errorHandler } from '../middleware/errorHandler.js';

// ── Test fixtures ───────────────────────────────────────────────────────────

Expand Down Expand Up @@ -67,6 +68,7 @@ async function startProxy() {
proxyConfig: currentProxyConfig,
});
app.use('/v1/call', proxyRouter);
app.use(errorHandler);

await new Promise<void>((resolve) => {
proxyServer = app.listen(0, () => {
Expand Down Expand Up @@ -109,6 +111,7 @@ afterAll(async () => {

beforeEach(async () => {
usageStore.clear();
billing.clear();
billing.setBalance(TEST_DEVELOPER_ID, 1000);
rateLimiter.reset();
currentProxyConfig = { timeoutMs: 2000 };
Expand Down Expand Up @@ -233,6 +236,61 @@ describe('Usage Metering & Billing (Post-Proxy)', () => {
expect(billing.getBalance(TEST_DEVELOPER_ID)).toBeCloseTo(999.95);
});

it('records neither usage nor deduction when anchored charging fails', async () => {
billing.failNextUsageCharge('pending billing write failed', true);
const errorSpy = jest.spyOn(console, 'error').mockImplementation(() => undefined);

const res = await fetch(`${proxyUrl}/v1/call/${TEST_API_SLUG}/data`, {
method: 'GET',
headers: { 'x-api-key': TEST_API_KEY },
});
expect(res.status).toBe(200);

expect(usageStore.getEvents()).toHaveLength(0);
expect(billing.getBalance(TEST_DEVELOPER_ID)).toBe(1000);
expect(errorSpy).toHaveBeenCalledWith(
'[proxy billing reconciliation] Billing anchor failed after usage write phase started',
expect.objectContaining({
requestId: expect.any(String),
apiId: TEST_API_ID,
endpointId: 'ep_data',
developerId: TEST_DEVELOPER_ID,
}),
);

errorSpy.mockRestore();
});

it('logs reconciliation failure when billing succeeds but usage view write throws', async () => {
const errorSpy = jest.spyOn(console, 'error').mockImplementation(() => undefined);
const recordSpy = jest
.spyOn(usageStore, 'record')
.mockImplementation(() => {
throw new Error('usage store offline');
});

const res = await fetch(`${proxyUrl}/v1/call/${TEST_API_SLUG}/data`, {
method: 'GET',
headers: { 'x-api-key': TEST_API_KEY },
});
expect(res.status).toBe(200);

expect(billing.getBalance(TEST_DEVELOPER_ID)).toBeCloseTo(999.95);
expect(errorSpy).toHaveBeenCalledWith(
'[proxy billing reconciliation] Usage view write threw after successful billing charge',
expect.objectContaining({
requestId: expect.any(String),
apiId: TEST_API_ID,
endpointId: 'ep_data',
developerId: TEST_DEVELOPER_ID,
error: 'usage store offline',
}),
);

recordSpy.mockRestore();
errorSpy.mockRestore();
});

it('is idempotent: duplicate requestIds do not double-bill', async () => {
// Simulate a case where proxy handles same request twice
// (In reality this is handled by usageStore idempotency directly, so let's unit-test it)
Expand Down Expand Up @@ -270,7 +328,7 @@ describe('Usage Metering & Billing (Post-Proxy)', () => {

expect(res.status).toBe(402);
const body = await res.json();
expect(body.error).toMatch(/insufficient balance/i);
expect(body.message ?? body.error).toMatch(/insufficient balance/i);

await yieldTick();

Expand Down
10 changes: 5 additions & 5 deletions src/middleware/gatewayApiKeyAuth.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -127,6 +127,11 @@ function forbidden(next: NextFunction, message: string): void {
}

export function extractApiKey(req: Request): ExtractedApiKey {
const xApiKey = req.header('x-api-key');
if (typeof xApiKey === 'string' && xApiKey.trim() !== '') {
return { apiKey: xApiKey.trim(), source: 'x-api-key' };
}

const authorization = req.header('authorization');
if (authorization) {
const match = authorization.match(/^Bearer\s+(.+)$/i);
Expand All @@ -135,11 +140,6 @@ export function extractApiKey(req: Request): ExtractedApiKey {
}
}

const xApiKey = req.header('x-api-key');
if (typeof xApiKey === 'string' && xApiKey.trim() !== '') {
return { apiKey: xApiKey.trim(), source: 'x-api-key' };
}

if (authorization) {
return {
apiKey: null,
Expand Down
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