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API change intelligenceEst. 2026

apisloth

“Move slow and don’t break things.”— the apisloth doctrine

An oil painting of a sloth resting on a branch
The service

The API changed. Your code is the last to know.

apisloth watches the APIs you build on. When a contract changes, it updates the code it affects and opens a pull request: verified, reviewable, and waiting before your build ever breaks.

Connect your first API
$ apisloth watch api.stripe.com/openapi.json
→ snapshot stored · sha 4f2a1c
! breaking: plan → price_id · 3 repos
⟳ implementing · verifying
✓ pull request opened · verified T3
Watches
OpenAPI specs + docs
Delivers
Verified pull requests
Proof
Tier T0 – T3, always stated
The problem

A field gets renamed at 3 a.m. Your integration is already wrong.

You didn’t change anything. The provider did. And nothing in your stack is watching the one thing that broke.

01

No warning

Providers ship breaking changes on their schedule, not yours. The first signal is usually a 400 in production.

02

Surprise migration

Every change becomes unplanned work: read the changelog, find the call sites, patch, test, and ship, all under deadline.

03

It never stops

Every API you add is one more contract that can move. The surface area you have to watch only grows.

Live demo · try it

Flip a version. Watch the PR write itself.

This is the real apisloth pipeline. Ship a breaking v2 of the Payments API and watch the fix land: detection, code edit, verification, pull request.

payments-api / openapi.jsonstable
Ship version
Current contractin sync
Charge:
  amount: integer
  currency: string
Subscription:
  plan: string
GET /charges
  page, per_page
apislothwatching

No changes. apisloth is watching the contract and your repository is in sync.

↑ flip to v2 to ship a breaking change

How it works · 4 stages

A quiet loop for a noisy dependency.

  1. 01Observe

    Watch the contract

    apisloth snapshots the specs and docs your repositories depend on, around the clock.

  2. 02Isolate

    Find what changed

    A structured diff separates real breaking changes from noise: endpoints, schemas, requirements.

  3. 03Implement

    Fix the right code

    An agent gets the old spec, the new spec, and your repo, then edits the call sites that broke.

  4. 04Prove

    Open a verified PR

    The change is built, tested, and contract-checked. The pull request states how far it got.

Verification · no silent skips

Proof has a name.

Every pull request states exactly how far verification got. When automation can’t run, apisloth says so and leaves a manual path. It never pretends.

T0

Manual handoff

Nothing runnable. The PR is flagged unverified with a concrete test checklist.

T1

Build proof

The detected build, typecheck, or lint command passes with the change in place.

T2

Repository proof

Your repository’s own test suite passes against the implementation.

T3

Contract proof

Tests are re-run against a mock server synthesized from the new specification.

The next change is already scheduled

Let it become a pull request, not a fire drill.

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An oil painting of a sloth hanging from a branch