API changelog

In short

This page lists changes to the Clikso API, newest first. Most changes only add things. When a change can affect code that already works, it says so.

October 2026

short_code can now be up to 30 characters on every plan. It was 20. This only allows more.
On Starter and up, short_code can contain /, like acme/launch. See Choose your own slug for the rules.
On Free, a short_code with / gets 402 UPGRADE_REQUIRED. If a workspace moves to Free, its nested links keep working, and you can still update them.

Every account has one default workspace that's free forever, and each extra workspace needs its own paid plan. A new extra workspace waits for its first payment; an extra workspace is paused when its paid plan ends.
Two new errors, both 402: WORKSPACE_PAYMENT_REQUIRED and WORKSPACE_PAUSED. See Errors. Reads and click analytics keep working on a paused workspace, and its short links keep redirecting.
Get workspace details adds workspaces[].access_state (null for a normal workspace, awaiting_payment or paused) and workspaces[].is_default (true when the workspace is its owner's default). This only adds fields.

Clikso runs an MCP server at https://app.clik.so/mcp. Claude, ChatGPT, Gemini, Cursor, VS Code and other AI apps can use it. See Use Clikso from AI apps.
AI apps sign in with OAuth, so they never need an API key. They follow the same plan limits as API keys.
Nothing changed for API keys. Your integrations keep working as they are.

Can affect working code. On Update a link, null now clears geo_targeting, device_targeting, ab_testing, og_preview and qr_metadata. Before, null left them as they were. Leave a field out to keep it.
Create and update now check four fields. title can be up to 60 characters, description up to 250, and expired_redirect_url up to 2,048. expires_at must be a date. A bad value gets 422 VALIDATION_ERROR with details.field, not a 500.
Check a slug now says why a slug cannot be used. reason is invalid_format or reserved, with a message to show. It is still a 200, and a taken slug is still a plain available: false.
Get a tag and Update a tag return the real link_count, not 0.
With a key, Get bootstrap returns subscription.subscription_id as null, and pending invitations come without a token.

These docs went live at clik.so/docs, with an API reference for every endpoint a key can call.
Each page has examples in nine languages and a Markdown copy.

API keys now work on every plan, including Free.
A Free workspace can hold 3 keys. Keys you already have keep working, even above that number.

Three new endpoints: click summary, clicks over time and raw clicks.
They have their own quota per workspace, per minute and per UTC day. On Free that is 5 a minute and 100 a day. See Limits.
The AI analytics chat stays in the dashboard. It is not part of the API.

Can affect working code. Fields that need a paid plan now return 402 UPGRADE_REQUIRED when a key sets them on a plan without the feature.
Starter and up: passwords, tracking pixels and custom social previews.
Pro and up: country rules, device rules and A/B tests.
Creating a folder or tag past your plan's count also returns 402.
On an update, sending a value the link already has, or clearing a field, always works.

Can affect working code. GET /links/{id}/password no longer accepts API keys. It returns 403 API_KEY_NOT_ALLOWED.
Links still show has_password, and you can still set or clear a password.

Can affect working code. The per-key limit now depends on the plan: 30 requests a minute on Free, 100 on Starter, 300 on Pro and 500 on Business.
Over the limit you get 429 RATE_LIMITED with a Retry-After header.

Each plan now has a limit on how many keys a workspace can hold. It only applies when you create a key.
Revoked keys do not count toward it.

Responses only ever gain fields. Your code should ignore fields it does not know.
Error codes are stable. New codes may be added; existing ones keep their meaning.
The full contract is the API reference.