IT tools with an API

CheckmateIT Operations & Sysadmin

Checkmate tracks service availability, response times and server health from a self-hosted installation.

Checkout.comBusiness Software

Checkout.com provides payment APIs and hosted components for building merchant checkout flows.

ChronosphereMonitoring & Observability

Chronosphere provides metrics, logs and traces observability for cloud-native and Kubernetes environments with cardinality/cost controls. Palo Alto Networks completed its acquisition of Chronosphere in 2026.

CircleCICI/CD

CircleCI runs repository-defined pipelines that organize workflows, jobs and steps.

ClerkIdentity & Access Management

Clerk provides pre-built authentication UI, session management and user management for developers, via SDKs for React, Next.js and other frameworks, with a free Hobby tier and paid Pro/Business plans.

ClickUpProject Management

ClickUp is an all-in-one work platform combining task/project management, docs, chat and dashboards, with a public REST API available on all plans including the free tier.

CloudflareCDN & Edge

Cloudflare provides authoritative DNS, reverse-proxy services, CDN caching, web application firewall controls, and edge application tools.

CohereAI Platforms & Generative AI

Cohere provides text generation, embedding and rerank models via API for enterprise use, alongside North (an AI workplace platform) and Compass (enterprise search), with free trial keys and usage-based production pricing.

Contrast SecurityApplication Security

Contrast Security, founded by OWASP co-creator Jeff Williams, instruments applications with in-app sensors: Contrast Assess (IAST) and Scan (SAST) find vulnerabilities, Contrast SCA flags risky dependencies, and its ADR/RASP layer detects and blocks attacks in production.

CoralogixAnalytics & BI

Coralogix provides log, metrics and APM observability built on a streaming analytics architecture that avoids traditional indexed hot storage, with a 14-day free trial and usage-based pricing.

CrewAIAI Platforms & Generative AI

CrewAI is an MIT-licensed open-source Python framework for orchestrating multi-agent AI workflows; CrewAI Enterprise adds a hosted runtime with a free Basic tier and custom-priced governance features.

CrowdStrikeEndpoint Security

CrowdStrike Falcon unifies endpoint protection (EDR/XDR), identity threat detection and cloud security under one lightweight agent, sold in tiers from Falcon Go to Complete.

CyclicDeveloper Tools

Cyclic, a serverless Node.js hosting platform, appears to be discontinued: as of September 2026 its domain returns a broken TLS certificate rather than a working site.

DagsterData Engineering

Dagster is an open-source Python orchestrator built around software-defined assets. Its creator, Dagster Labs (formerly Elementl), was acquired by Prefect in 2026; the open-source project keeps its license and Dagster+ continues unchanged for existing customers.

Dash0Monitoring & Observability

Dash0 is an OpenTelemetry-native observability platform priced on ingestion and storage volume, with a 14-day full-featured free trial and no permanent free tier.

DatabricksData Warehousing & Lakehouse

Databricks combines data engineering, SQL analytics and machine learning on a lakehouse platform.

DatadogMonitoring & Observability

Datadog collects infrastructure metrics, logs, traces, and other signals so teams can investigate services and configure alerts.

DeepInfraAI Platforms & Generative AI

DeepInfra provides pay-as-you-go, serverless GPU inference APIs for 100+ open-source AI models covering text generation, text-to-speech, text-to-image and embeddings, without customers managing their own GPU infrastructure.

Deta SpaceDeveloper Tools

Deta Space, a free personal-cloud app hosting platform, appears to be discontinued: as of September 2026 its website and docs return server errors and are no longer reachable.

Dev.toTutorials & Learning

Dev.to, built on the open-source Forem platform, is a free community where developers publish articles, discuss technology and build public profiles.

DifyAI Platforms & Generative AI

Dify (by LangGenius) is an open-source platform for building LLM apps with a visual workflow builder, RAG pipeline and agent tools; self-host the Community Edition free or use Dify Cloud on a freemium plan.

DigitalOceanCloud Providers & Hosting

DigitalOcean provides Linux virtual machines, managed Kubernetes, and application deployment services for teams building and operating web applications.

DirectusDeveloper Tools

Directus wraps an existing SQL database with an instant REST/GraphQL API and a customizable admin app, without migrating data into a proprietary format.

DockerContainers & Kubernetes

Docker provides tools to build container images, run isolated containers, define multi-service applications with Compose, and distribute images through registries.