People searching for “AI API proxy” have usually hit the same wall: the provider's console opens fine in a browser, yet requests from the SDK time out now and then, come back 403, or trigger a one-off human check. Browsers and APIs do not ask the same things of a network — whether the egress IP stays fixed, whether the route holds up under concurrency and timeouts, and whether DNS and split routing send requests the wrong way decide whether calls keep running over months. Below, each of the three is broken down with a way to verify it yourself, followed by a pre-launch checklist.
How API calls differ from browser traffic
Start with the differences and the later choices have something to stand on. Browser traffic is mostly short requests with a cache in front, and a user who can hit refresh when something fails. API calls are mostly long-lived connections and streamed responses; failures come back as status codes, and the code usually runs in scripts, scheduled jobs or CI where nobody is watching a screen.
| Dimension | Browser | API calls |
|---|---|---|
| Connection pattern | Mostly short requests; static assets can be cached | Mostly long-lived connections and streaming; an interrupted connection starts over |
| Failure mode | A spinner on the page; the user can refresh | A 4xx / 5xx response, or a stream truncated mid-output |
| Network sensitivity | First-paint load speed | Egress IP stability, packet loss, client timeout settings |
| Concurrency profile | A few concurrent requests per user | Batch jobs, multiple processes, several services calling at once |
| Where to look first | Browser network panel | Status codes and latency distribution in request logs |
So “pages open fast” cannot be the only metric when choosing a route. Three things are worth checking, and the order below is the one to follow: egress first, stability second, resolution and split routing last.
Egress IP: a fixed address and its location are the first gate
Most AI platforms run risk checks on accounts, and one input is how often the egress IP changes. An account that hops between regions within a short window tends to trigger step-up verification or a temporary limit; an egress that stays in one region over time keeps the call history coherent and makes logs easier to line up when something breaks.
What a fixed egress means for developers
- Whitelists stay maintainable: many teams keep IP allowlists in cloud security groups or their own gateway, and every egress change means re-adding the address. A fixed egress removes that rework.
- Risk checks stay calmer: keeping the login region and the calling region the same passes platform checks more reliably than three regions in one day.
- Logs stay comparable: when something breaks you can tell whether the route changed or the code changed — mixing the two is the most expensive way to debug.
How to confirm your egress
The simplest check runs on the target machine itself; whatever address comes back is that machine's current egress IP:
curl -sS https://ifconfig.me; echoTo see the location and the resolution result at the same time, use the site's IP lookup page and query once before and once after switching routes, then compare whether both land in the same region. When a team shares one API key, agree on nodes in a single region so the egress does not wander across the map.
A subscription URL is the same thing as an account credential. Do not paste it into a repository, CI logs or a chat group; if it leaks, reset the subscription in the dashboard and import it into the client again.
Concurrency and timeouts: choosing a route for long-lived connections
The second difficulty with API calls is concurrency. Modern clients and servers mostly speak HTTP/2, which lets many requests share one TCP connection and skips repeated handshakes. On a clean route that is an advantage; on a lossy route it becomes a burden, because streams on one connection wait for each other — the higher the concurrency, the more everything slows down together.
Split the timeout into two stages
- Connect timeout: keep it in the range of a few seconds. Past that, switch routes and retry rather than waiting indefinitely.
- Read timeout: set it generously for streaming endpoints, because the model returns content piece by piece and a short read timeout turns normal output into a failure.
Use status codes to tell whose problem it is
429: a rate or quota limit on the account side. Back off on retry; switching routes does nothing.401/403: credentials or a regional restriction. Check the key and the egress region before suspecting the route.502/504: a link or upstream fault. These are the ones worth re-testing on another route.
One more thing easy to miss with streaming: when a connection is cut mid-stream, the client may receive half the content without any error. Check whether the end marker arrived; if it did not, retry as a failure instead of writing half a result into the database.
Treating 429 as a route problem is the most common misdiagnosis: swapping nodes and protocols for an hour leaves the quota exactly where it was. Read the status code first, then decide whether the route needs touching.
DNS resolution and split routing
The third item is the least visible and the most frequent cause of “it connects, but the API is still slow”. A DNS leak means resolution requests skip the tunnel and go to a resolver on the local network: results can be poisoned, domains can resolve to a far-away node, and the sites you visit are exposed on the local link.
Keep resolution inside the tunnel
Mainstream clients offer remote resolution or encrypted DNS; with either enabled, domains resolve on the egress side and the answer matches the egress region. To verify, query the same domain and see whether the returned address fits the egress region — if the answer lands on a local carrier node, resolution is almost certainly outside the tunnel.
Order split rules from specific to broad
Split routing exists to send only the traffic that needs the route through it, keeping intranet, local services and LAN addresses direct. Order the rules from specific to broad and finish with a catch-all:
rules:
- DOMAIN-SUFFIX,openai.com,PROXY
- DOMAIN-SUFFIX,anthropic.com,PROXY
- IP-CIDR,10.0.0.0/8,DIRECT
- IP-CIDR,192.168.0.0/16,DIRECT
- GEOIP,CN,DIRECT
- MATCH,PROXYThe typical symptom of a wrong rule is an intranet endpoint that suddenly refuses to connect, or a local debug service taking a detour through the proxy. After editing rules, run one internal request and one external API call; only when both work is the configuration done.
Protocol differences: TCP-based and QUIC-based
Shadowsocks, VMess, Trojan and VLESS mostly ride on TCP (VLESS often runs with XTLS / Reality), while Hysteria2 and TUIC are built on QUIC and use UDP. On a lossy network the QUIC family recovers faster and long connections are less likely to stall; if the network in question restricts UDP, fall back to the TCP family. One subscription usually carries several routes, so switch according to the current network instead of betting on a single protocol.
Route types: IEPL dedicated, relay and direct
Understanding route types is more useful than comparing node counts. The three differ mainly in how the cross-border leg is handled, and that changes what they do for API calls:
| Route type | Outbound path | Impact on API calls | Best for |
|---|---|---|---|
| IEPL dedicated | A carrier dedicated channel that skips the public international gateway | Less jitter and packet loss; steadier long connections and streaming | Production workloads, long batch jobs |
| Relay | Traffic enters a relay node before the cross-border leg | Relay bandwidth at peak hours can make latency fluctuate | Day-to-day development, debugging, non-critical jobs |
| Direct | Traffic leaves through the public international gateway | Lowest cost, and the most exposed to congestion at that gateway | Light queries, backup route |
The three are not mutually exclusive. A common setup uses a relay from the development machine, a dedicated line for batch jobs and production services, and direct as a fallback. The site's Servers list labels each entry by route type, so you can pick against the regions you use most.
Pre-launch checklist
Everything above, compressed into one list. Walk through it before launch and most of the rework disappears.
- ✅ The egress IP stays in one region long term, and the team agrees on which
- ✅ Long connections hold through the evening peak and streams finish without breaking
- ✅ The client supports HTTP/2 and connection reuse, with adjustable timeout values
- ✅ Resolution happens inside the tunnel and split rules match domains exactly
- ✅ The subscription URL lives only in controlled environments and can be reset if it leaks
- ❌ Judging API availability by “pages open fast” alone
- ❌ Running batch jobs with a production key on free public nodes
- ❌ Committing the subscription link to a repository or printing it in CI logs
Conclusion: the criteria for picking an AI API route are not node counts but three things — whether the egress is fixed, whether long connections hold at peak hours, and whether DNS and split routing stay under control. All three can be verified yourself, so there is no need to rely on someone else's review.
From subscription link to first request
To turn the selection into practice, work through the steps below in order.
- Measure a baseline: run one request from the target machine on a direct connection and record the status code and latency as your reference sample.
- Estimate traffic: multiply daily request count by average usage to get monthly volume, then compare plans — ¥9.9/month includes 60GB, ¥18/month includes 250GB, ¥28/month includes 500GB, and data resets monthly on your activation date. If usage is spiky, start with a data pack (use it up at your own pace, it never expires).
- Get the subscription: signing up needs only a username and password, no email address; once logged in, copy the subscription URL from the dashboard, import it into the client and update the rules.
- Re-test: run the same command again, compare status code and latency, and confirm the egress IP and resolution results match expectations.
- Push concurrency: run a round of concurrent requests from a script, watch for 429 / 502 / 504, handle each status code separately, and give the client exponential backoff.
- Freeze the configuration: put route, timeout and retry parameters into your deployment config so a new machine is configured the same way — no more “works on my laptop, not on the server”.
# 1) Check the egress IP
curl -sS https://ifconfig.me; echo
# 2) Compare status code and latency (run once before and after switching routes)
curl -sS -o /dev/null -w 'code=%{http_code} total=%{time_total}s\n' https://api.openai.com/v1/models
# 3) Check domain resolution (on Windows, use nslookup instead)
dig +short api.openai.comA no-questions-asked refund can be requested within 7 days of the first payment, and the number of devices online at once is unlimited. Verify the egress and stability at small cost first, then decide on long-term use — steadier than betting everything up front.
A fuller client import walkthrough is in Guides, the route and region list is on the Servers page, and plan and data pack details are on the Pricing page. Read the three together and they cover everything from choosing a route to going live.