API Features

Browse the network by technical capability — authentication methods, protocols, delivery mechanisms, deployment models, compliance certifications, and agent-native surfaces. Providers describe features as free text in apis.yml — nearly 14,900 distinct strings — so APIs.io maps them onto a canonical vocabulary. Each feature below lists every provider that offers it, ranked by API Evangelist rating.

Webhooks

Outbound HTTP callbacks pushed on events.

265 providers · 6475 APIs

REST API

Resource-oriented HTTP API over standard verbs.

197 providers · 5155 APIs

Client SDKs

Official libraries in multiple languages.

190 providers · 3411 APIs

OAuth 2.0

Delegated authorization via OAuth 2.0 flows.

169 providers · 4672 APIs

Server-Sent Events & Streaming Responses

Incrementally streamed HTTP responses.

137 providers · 2803 APIs

Open Source

Source code published under an open license.

124 providers · 1639 APIs

Workflow Automation

Multi-step, event-triggered orchestration.

121 providers · 2403 APIs

MCP Server

Model Context Protocol server for AI agents.

107 providers · 1864 APIs

Observability & Monitoring

Metrics, traces, and logs for API usage.

96 providers · 1518 APIs

Bearer Tokens & JWT

Signed bearer tokens and JWTs for stateless authentication.

94 providers · 2477 APIs

Self-Hosting

Run the software in your own infrastructure.

91 providers · 1564 APIs

Single Sign-On

Enterprise SSO via SAML or OIDC identity providers.

83 providers · 3729 APIs

API Key Authentication

Simple key-based authentication for server-to-server calls.

81 providers · 1343 APIs

Rate Limiting

Documented request quotas and throttling behavior.

80 providers · 2291 APIs

Multi-Tenancy

Isolated tenants, workspaces, or organizations.

65 providers · 1673 APIs

Containers & Kubernetes

Container images and Kubernetes-native deployment.

64 providers · 4624 APIs

OpenAPI Specification

A machine-readable OpenAPI/Swagger contract.

60 providers · 993 APIs

Role-Based Access Control

Roles and permissions governing who can call what.

54 providers · 1029 APIs

Sandbox Environment

A safe test environment with fake data.

53 providers · 1558 APIs

Audit Logs

Immutable record of who did what, when.

52 providers · 1270 APIs

Multi-Region Deployment

Regional endpoints and cross-region replication.

52 providers · 1639 APIs

Plugin & Extension Architecture

Extend the platform with custom plugins.

52 providers · 1587 APIs

Internationalization

Multi-language and multi-currency support.

51 providers · 1033 APIs

Filtering & Querying

Server-side filters, sorting, and field selection.

47 providers · 706 APIs

No-Code / Low-Code Builder

Visual configuration without writing code.

47 providers · 868 APIs

Event Streaming

Durable event logs and stream consumption.

46 providers · 3059 APIs

Batch & Bulk Operations

Submit or retrieve many records in one call.

44 providers · 1161 APIs

File Upload & Object Storage

Binary upload, storage, and retrieval.

44 providers · 4713 APIs

API Gateway

Managed ingress with routing, auth, and policy.

43 providers · 2957 APIs

High Availability

Redundant, fault-tolerant architecture.

43 providers · 475 APIs

Auto Scaling

Capacity that grows and shrinks with load.

42 providers · 876 APIs

Prebuilt Connectors

A library of ready integrations to other systems.

41 providers · 586 APIs

WebSockets

Persistent bidirectional connections for live data.

41 providers · 612 APIs

API Versioning

Explicit versions with a stated compatibility policy.

40 providers · 435 APIs

Pagination

Cursor or offset paging through large result sets.

40 providers · 579 APIs

API Discovery & Catalog

A machine-readable index of available APIs.

38 providers · 839 APIs

SOC 2

Independently audited SOC 2 controls.

38 providers · 692 APIs

Caching & Conditional Requests

ETags, cache headers, and conditional GETs.

34 providers · 986 APIs

Edge Computing & CDN

Execution and caching at points of presence.

34 providers · 4278 APIs

GraphQL API

Single-endpoint query language with client-shaped responses.

34 providers · 1352 APIs

Agent Skills

Packaged skills and instructions for AI agents.

33 providers · 644 APIs

Developer Portal

A self-service hub for keys, docs, and apps.

33 providers · 408 APIs

Encryption at Rest & in Transit

TLS on the wire, encrypted storage, and key control.

33 providers · 405 APIs

Full-Text Search

Indexed text search across the provider's corpus.

33 providers · 691 APIs

Scheduled Jobs & Cron

Recurring, time-triggered execution.

31 providers · 378 APIs

SCIM User Provisioning

Automated user and group provisioning via SCIM.

30 providers · 726 APIs

Data Export

Full export of your data out of the platform.

27 providers · 424 APIs

Multiple Output Formats

JSON, XML, CSV, and other selectable representations.

27 providers · 191 APIs

API Governance

Linting, standards, and design rules enforced automatically.

26 providers · 396 APIs

Infrastructure as Code

Terraform, Pulumi, or declarative configuration.

26 providers · 1397 APIs

Multi-Protocol Support

Several interfaces — REST, GraphQL, gRPC, streaming — on one product.

26 providers · 372 APIs

Private Networking

VPC peering, PrivateLink, and private endpoints.

26 providers · 679 APIs

White-Label & Branding

Rebrand the product as your own.

26 providers · 366 APIs

CI/CD Integration

Hooks into build and deployment pipelines.

24 providers · 556 APIs

Multi-Factor Authentication

Second-factor and step-up authentication support.

24 providers · 555 APIs

Request Signing

HMAC or cryptographically signed requests.

24 providers · 319 APIs

API Documentation

Reference docs, guides, and examples.

23 providers · 141 APIs

Historical Data & Time Series

Deep archives and time-series history, not just current state.

23 providers · 285 APIs

Multi-Cloud Support

Runs on AWS, Azure, GCP, and beyond.

23 providers · 468 APIs

OpenAI-Compatible API

Drop-in compatibility with the OpenAI request shape.

21 providers · 268 APIs

Uptime SLA

A contractual availability commitment.

21 providers · 272 APIs

API Testing Tooling

Built-in contract, integration, and load testing.

20 providers · 298 APIs

Data Governance & Lineage

Cataloging, lineage, and quality controls over data.

20 providers · 376 APIs

Fully Managed Service

Vendor operates the infrastructure for you.

20 providers · 507 APIs

Idempotency

Safe retries without duplicate side effects.

20 providers · 476 APIs

Secrets & Credential Management

Safe storage and rotation of keys and secrets.

20 providers · 192 APIs

Embeddings & Vector Support

Vector embeddings and similarity search.

19 providers · 370 APIs

Real-Time Data

Live, low-latency data rather than delayed snapshots.

19 providers · 173 APIs

Function Calling & Tool Use

Structured tool definitions LLMs can invoke.

18 providers · 249 APIs

HIPAA Compliance

Protected health information handled under HIPAA.

18 providers · 395 APIs

Fine-Grained Authorization

Attribute, resource, or field-level permission control.

17 providers · 169 APIs

Code & SDK Generation

Generate clients, types, or servers from the spec.

16 providers · 209 APIs

DDoS & Abuse Protection

Traffic filtering, WAF, and bot mitigation.

15 providers · 473 APIs

Embeddable UI Components

Drop-in widgets and hosted UI.

15 providers · 275 APIs

gRPC

High-performance binary RPC over HTTP/2.

15 providers · 173 APIs

Status Page & Incident Communication

Public health status, incidents, and history.

15 providers · 235 APIs

GDPR & Privacy Compliance

EU/UK privacy obligations and data-subject rights.

14 providers · 120 APIs

Human-in-the-Loop Controls

Approval gates on automated actions.

14 providers · 186 APIs

ISO 27001

Certified information-security management system.

14 providers · 213 APIs

LLM Inference

Hosted model inference endpoints.

14 providers · 386 APIs

Public / No Authentication

Open endpoints callable without credentials.

14 providers · 111 APIs

Usage Analytics

Per-key and per-endpoint consumption reporting.

14 providers · 140 APIs

Backup & Point-in-Time Recovery

Automated backups and restore to a prior state.

13 providers · 116 APIs

Basic Authentication

HTTP Basic username and password credentials.

13 providers · 296 APIs

Postman Collection

A ready-to-run collection for API exploration.

13 providers · 433 APIs

JSON Responses

JSON as the primary request and response format.

12 providers · 101 APIs

Fine-Tuning & Custom Models

Adapt hosted models to your own data.

11 providers · 97 APIs

MQTT & IoT Protocols

Lightweight pub/sub messaging for devices.

11 providers · 262 APIs

Push Notifications

Mobile and browser push message delivery.

11 providers · 186 APIs

PCI DSS

Cardholder-data handling certified to PCI DSS.

10 providers · 119 APIs

CORS Support

Browser-callable endpoints with CORS headers.

8 providers · 59 APIs

Feature Flags

Toggle behavior without redeploying.

8 providers · 210 APIs

FedRAMP & Government Authorization

Authorized for US public-sector workloads.

6 providers · 181 APIs

Structured Error Handling

Machine-readable, documented error responses.

6 providers · 110 APIs

Command-Line Interface

An official CLI for scripting and automation.

5 providers · 46 APIs

Mutual TLS

Certificate-based client authentication at the transport layer.

5 providers · 106 APIs

SOAP & XML Web Services

WSDL-described SOAP endpoints.

5 providers · 34 APIs

Vulnerability Disclosure & Bug Bounty

A published path for reporting security issues.

5 providers · 24 APIs

Deprecation Policy

Advance notice and sunset windows for changes.

4 providers · 32 APIs

RSS & Atom Feeds

Syndication feeds for content and updates.

4 providers · 28 APIs