The CTX API connects your website, app or internal systems directly to the CTX marketplace. See live listings, price a purchase down to the last fee, and buy credits with a single call.
The API gives partners direct, programmatic access to the marketplace, without anyone having to visit the CTX website.
Live listings
A real-time snapshot of the credits on offer on CTX. Each listing carries its project details, vintage, standard, quantity and price, and shows whether the price is negotiable.
Cost calculator
Ask for a price on any purchase and get a full breakdown, ready to show a buyer: the unit price, the CTX transaction fee, the registry fee and the total, in both the traded currency and the buyer's invoice currency.
Trading
Place a real purchase against a live listing with a single API call. The trade is processed end to end on the CTX platform, and the retirement certificate is issued in the name of the API account holder.
Automate quarterly retirements against a net-zero target, or show the live CTX catalogue inside a sustainability dashboard.
Offer carbon credits at checkout under your own brand, with customers choosing from live listings.
Use live offer data to build client quotes, price histories or market indices.
Keys, listing rules, approved web addresses and usage are all managed from your side, through the CTX member area.
An API account is a CTX account of its own, with the same checks as any other.
Apply for a Corporate API account, using an email address that isn't already linked to a CTX account. Our sales team can point you to the right form.
The same KYC and AML checks as any CTX account. Documents you have already given us are accepted if they were issued in the last 12 months.
Once the account is open, you receive the technical documentation and a test environment that mirrors a live account.
With your application processed, payment received and documents in, the account can go live straight away.
API members buy credits at wholesale and can set their own price on their own site. Once your account is open, CTX extends a line of credit so your customers' purchases complete in real time. It is a pre-approved spending buffer, not a loan, and carries no interest.
Yes. Once your account is approved, you get a test account that mirrors a live one, so you can build and demonstrate your integration before going live.
After your account is opened. The documentation sets out the technical details and authentication requirements.
The certificate is always issued in the name of the CTX API account holder.
Yes. API members buy at wholesale and are free to set their own prices on their own websites.
The API runs on a separate Corporate API account, opened with a different email address from your existing CTX account. KYC documents you have already provided can be reused if they were issued within the last 12 months.
Get started
Tell our sales team what you want to build, and we'll take you through the account, the documentation and the test environment.