Your first Claude Opus 5.5 run: three lines and away
Picture the stopwatch before your first lap. You want Claude Opus 5.5 answering your prompts, and you want to get there without a maze of settings, billing tiers or account juggling. SwiftRelay is built for exactly that kind of clean first run: copy three lines, point your client at the API host, and start working.
SwiftRelay is a pay-per-token API relay. That plain phrase matters. You top up a balance, and each call deducts only what it used. There is no monthly fee and nothing to subscribe to, so you can try the service, watch the usage list fill in and decide how far you want to go. No long contract sits between you and your first answer.
The setup itself is refreshingly short. In Claude Code, you set the base URL, set your token and launch the client:
01 export ANTHROPIC_BASE_URL=https://api.fastapirelay.com 02 export ANTHROPIC_AUTH_TOKEN=<your swft_ key>
claude
That is the whole pit-stop ritual for the API side. The token is the swft_ key you get from your SwiftRelay dashboard. Once those three lines are in place, Claude Opus 5.5 is reachable from the client and ready for your first prompt.
And the first prompt does not need to be complicated. Ask it to summarise a paragraph, rewrite a rough note or outline a small plan. The point of the first run is not to stress-test anything. It is to confirm that the route is open, the balance is live and the answer comes back.
Which client speaks to Claude models
Here is one rule worth learning before you start, because it saves the kind of detour that eats an afternoon. Claude models answer through the official Claude Code or Claude Desktop client, version 2.1.285 or later. Claude Opus 5.5 is one of those models, so one of those two clients is the right home for it.
Claude Desktop follows the same idea. Install or update it to version 2.1.285 or later, point it at the SwiftRelay API host, and supply your swft_ key as the auth token. The configuration lines shown above are the same in spirit: a base URL, a token and a working client.
SwiftRelay also lists usage per call, showing the tokens involved and the cost of that call. That is genuinely useful on a first run, because it turns the abstract idea of "pay per token" into a concrete line in the dashboard. You see what went in, what came out and what it cost, and you can adjust your habits from there.
One more practical note for newcomers: SwiftRelay supports up to 20 live API keys per account. You do not need all of them on day one. One key for one project is plenty to get rolling, and you can add more later if a second project earns its own lane.
What Claude Opus 5.5 costs on SwiftRelay
Now for the numbers, because good value only means something when you can see the arithmetic. The current prices per 1M tokens on the SwiftRelay pricing page for Claude Opus 5.5, model id claude-opus-5-5, are input $1.53, output $7.27 and cache read $0.0694.
Read those as three different meters. Input tokens are the material you send. Output tokens are the reply you get back. Cache reads are the cheaper path for material SwiftRelay can reuse. Because billing follows actual usage, a short question and a long document do not cost the same, and a quiet day does not cost anything at all.
Here is an example, purely for illustration. Say a single call sends 10,000 input tokens and receives 2,000 output tokens. The input portion is $0.0153 and the output portion is $0.01454, for a total of $0.02984. Now say a heavier call sends 100,000 input tokens and receives 20,000 output tokens: $0.153 plus $0.1454, or $0.2984. These are examples, not quotes, and they use the prices listed above.
For comparison within the same pricing page, Claude Haiku 4.5 is listed at $0.3542 input, $1.69 output and $0.0278 cache read, while Claude Sonnet 5.5 is listed at $0.9792 input, $4.89 output and $0.0861 cache read. Different models, different meters, one clear list. That transparency is the point: you can pick the model that suits the job and watch the cost per call in the usage list.
Signing up, topping up and getting your first credit
Starting with SwiftRelay takes minutes rather than paperwork. Create your account, open the dashboard and take a look around before you spend anything. Your sign-up gift credit is $0.22, which is enough to send a few real prompts and see the whole loop in action: balance, call, usage list, deduction.
When you want more runway, the top-up options are $1.39, $6.94, $13.89, $27.78, $69.44 and $138.89. Pick the size that matches how much you actually expect to use. A small top-up keeps the commitment light for a first session; a larger one means fewer interrupts later. Either way, there is no subscription to cancel and no recurring charge waiting in the background.
The refund rule is straightforward as well. Unused credit can be refunded within 11 days of a top-up, minus what was used and the payment fee. If your plans change after a top-up and you have not spent the credit, the path back is short and the terms are stated plainly.
Inviting others works in your favour too. You receive 14% of each top-up made by someone you invited, and 3% from the people they invite in turn. Those rewards can be withdrawn once you reach the $4.86 minimum, or moved into your balance to keep your calls running. If you share SwiftRelay with a colleague who is about to make their own first run, the balance can start working for you before your next top-up.
Your first day on SwiftRelay, step by step
Let us sketch a first day as an example, so the sequence feels familiar before you start. You sign up and see the $0.22 gift credit sitting in your account. You copy your swft_ key. You open a terminal, paste the three configuration lines, and run claude. You ask a small question to confirm the connection.
Then you check the usage list. One call, tokens shown, cost shown. You top up $1.39 to give yourself room for a longer working session, and you run a few more prompts with Claude Opus 5.5, using the pricing page as your guide for how much input and output you are asking for.
Later, if a second project needs its own key, you create another live key in the dashboard, up to the 20 per account that SwiftRelay allows. If anything looks off, you open Messages in the dashboard and ask there. Support runs through Messages with a login required, so keep your account handy when you write. There is no support email to hunt for, which means the answer and the conversation stay in the same place as your balance and your usage.
By the end of that example day, you have not signed up for a package. You have topped up a balance, spent only what you used and can point to a list of calls with their token counts and costs. That is the whole SwiftRelay model in miniature.
One clean lap, then sign up
SwiftRelay takes the friction out of the first run: three lines of configuration, a per-token balance instead of a subscription, transparent prices for Claude Opus 5.5 and a dashboard that shows you exactly what each call cost. The stopwatch is already running, so start your first lap now and sign up for SwiftRelay today.