Same models. Same API.−50%

Claude and GPT at half the price.

Change one base URL and keep everything else. Pay as you go or subscribe — no minimums, no lock-in.

Get startedSee pricing

Prepaid credits from $10 · No subscription · −50% on every model

Claude Fable 5.1
AnthropicNew
−50%
$7.50/ 1M in
list $15.00
$37.50/ 1M out
list $75.00
Claude Fable 5
Anthropic
−50%
$7.50/ 1M in
list $15.00
$37.50/ 1M out
list $75.00
GPT-6 Astra
OpenAINew
−50%
$5.00/ 1M in
list $10.00
$25.00/ 1M out
list $50.00
GPT-5.6 Sol
OpenAI
−50%
$2.50/ 1M in
list $5.00
$15.00/ 1M out
list $30.00

USD per 1M tokens. Struck-through is the vendor's list price. All models

How a request flows

One base URL. Nothing else changes.

  • 13 models
  • 2 API formats
  • −50% vs list
Your app
Halfbill
Anthropic
OpenAI

Pay $1, use $2 of models at vendor prices.

Anthropic and OpenAI are trademarks of their respective owners. Halfbill is an independent service, not affiliated with either.

You give up nothing

The models you use. The API you already wrote.

Same endpoints, same model ids. The only thing that changes is the invoice.

Same models

Current Claude and GPT models, by their normal model ids.

Same API

OpenAI-compatible and Anthropic-compatible endpoints, feature for feature.

  • OpenAI-compatible: /v1/chat/completions and /v1/responses
  • Anthropic-compatible: /v1/messages
  • Streaming
  • Tool calls
  • Vision
  • Prompt caching (Claude)
  • Structured outputs

Same tools

Anything that talks to OpenAI or Anthropic works with a base URL and a key.

  • Claude Code
  • Cursor
  • Codex CLI
  • Cline
  • Continue
  • OpenAI SDK
  • Anthropic SDK
  • Vercel AI SDK

Tool names are trademarks of their respective owners; Halfbill is not affiliated with them.

How it works

Three steps. About two minutes.

  1. 01

    Create an account and top up

    Add prepaid credits from $10, or pick a Chat or Code subscription. No minimums, cancel any time.

  2. 02

    Create an API key

    Set an optional monthly spend limit per key. Keys are hashed at rest and can be revoked instantly.

  3. 03

    Change the base URL

    Point your SDK, Claude Code, Cursor or cURL at api.halfbill.uk and keep the model ids you already use.

Drop-in

Change the base URL.
Keep the rest.

Every snippet runs as-is with a Halfbill key. Pick the client you already use.

  • OpenAI-compatible and Anthropic-compatible endpoints
  • Model ids match the vendors' ids, no prefixes
  • Streaming, tool calls, vision and prompt caching pass through unchanged
cURL
curl https://api.halfbill.uk/v1/chat/completions \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer $HALFBILL_API_KEY" \
  -d '{
    "model": "claude-sonnet-5",
    "messages": [{"role": "user", "content": "Say hello in one line."}]
  }'

Pricing

Every model, list price next to ours.

The full list. No hidden tiers, no per-request fee.

ModelVendorContextInputper 1M tokensOutputper 1M tokensYou save
Claude Fable 5.1New
claude-fable-5-1
Anthropic200K$7.50list $15.00$37.50list $75.00−50%
Claude Fable 5
claude-fable-5
Anthropic200K$7.50list $15.00$37.50list $75.00−50%
Claude Opus 5
claude-opus-5
Anthropic200K$3.75list $7.50$18.75list $37.50−50%
Claude Sonnet 5
claude-sonnet-5
Anthropic200K$1.50list $3.00$7.50list $15.00−50%
Claude Opus 4.8
claude-opus-4-8
Anthropic200K$3.75list $7.50$18.75list $37.50−50%
Claude Opus 4.7
claude-opus-4-7
Anthropic200K$3.75list $7.50$18.75list $37.50−50%
Claude Opus 4.6
claude-opus-4-6
Anthropic200K$3.75list $7.50$18.75list $37.50−50%
Claude Sonnet 4.6
claude-sonnet-4-6
Anthropic200K$2.25list $4.50$11.25list $22.50−50%
Claude Haiku 4.5
claude-haiku-4-5
Anthropic200K$0.75list $1.50$3.75list $7.50−50%
GPT-6 AstraNew
gpt-6-astra
OpenAI400K$5.00list $10.00$25.00list $50.00−50%
GPT-5.6 Sol
gpt-5.6-sol
OpenAI400K$2.50list $5.00$15.00list $30.00−50%
GPT-5.6 Terra
gpt-5.6-terra
OpenAI400K$1.00list $2.00$6.00list $12.00−50%
GPT-5.5
gpt-5.5
OpenAI400K$1.00list $2.00$8.00list $16.00−50%

USD per 1M tokens, excl. VAT; identical for API and chat. List prices are the vendors' published rates when the catalog was generated. Cached-input rates and full specs are on the models page.

What you get

A focused platform, not a feature list.

Everything needed to run Claude and GPT in production. Nothing you would pay for and not use.

Ways to pay

Credits, a plan, or both.

Same per-token prices whichever way you pay.

Pay as you go

from $10

Top-up packs from $10 to $250, up to 15% bonus credits. Optional auto top-up.

Subscriptions

from $8/mo

Chat Basic, Chat Plus and Chat Pro for the web chat; Code Starter, Code Pro and Code Max for coding tools. Monthly allowance at Halfbill prices.

Teams

from $99/mo

5 seats included, then $15 per seat. Per-member limits, roles, audit log, one invoice.

Full pricing, top-up packs and plans

Built for trust

Facts, not badges.

Every line here is something you can check in the product or in our privacy policy.

FAQ

Questions, answered plainly.

Short answers to what people ask before switching. Anything else, email support.

support@halfbill.uk · Legal

Half the bill starts
with one base URL.

Top up from $10, create a key, change the URL.

Get started
Read the docs