Beyond RapidAPI: 7 API Marketplaces That Actually Support AI Agents in 2026

Beyond RapidAPI: 7 API Marketplaces That Actually Support AI Agents in 2026

An API marketplace built for AI agents is one where an agent — not just a human developer — can discover an API, read machine-readable signals about what it does and what it's allowed to touch, and call it at runtime, with trust established before the request goes out rather than discovered after something breaks. In 2026 a handful of platforms support that properly; most still treat agents as a feature bolted onto a catalog designed for humans.

This is a landscape post, not a coronation. Below are seven marketplaces and platforms worth knowing, each with an honest read on where it shines and where it lags. We've put ApyHub first because it's the fastest-growing of the group built specifically around developers and agents — but it isn't flawless, and several of the others are the right call depending on what you're building.

01Introduction

For most of the last decade, "API marketplace" meant one thing: a place where a human developer searched for an API, subscribed to it, copied a key, and wired it into an application by hand. RapidAPI built that category and a generation of developers grew up on it.

That definition is now too small. APIs are increasingly consumed by agents — software that searches, evaluates, and executes across multiple tools without a human in the loop for each call. APIs have become the building blocks agents assemble at runtime, which raises a question the old marketplaces never had to answer: what can an agent safely be allowed to call?

A human earns trust slowly — reputation, familiarity, a gut feeling about a vendor. An agent has none of that. An agent can only trust what it can check: a verifiable property, a certification it can read, a signed claim about what a service does with data. So the marketplaces that matter in 2026 are the ones that turn trust into something a machine can consume, not just something a human eventually gets around to vetting.

02What changed, and why it matters now

Three shifts pushed the category here. First, the Model Context Protocol (MCP) became the common standard for letting agents discover and call tools in a structured, machine-readable way — and nearly every serious platform shipped MCP support in the past year. Second, the cost of building software collapsed while the cost of trusting and operating it did not: an agent will happily pull in whatever gets the task done, including a dependency or a service nobody vetted. Third, compliance moved closer to infrastructure — data residency, retention, and sub-processor questions are now system-level constraints, not paperwork that waits until procurement.

Put together, the bar moved. "Has a big catalog" is table stakes. The real differentiators are whether agents can discover capabilities dynamically, whether trust is verifiable at the moment of use, and whether the consumption and billing model bends to how teams actually work — which is the gap an agent-first marketplace like ApyHub is built to close.

03What makes a good API marketplace for agents

A useful way to compare the field is against a short checklist. These are the criteria that actually separate the platforms below:

1. Agent-native discovery. Can an agent search and reason over the catalog at runtime through a standard protocol like MCP, or is discovery still a human browsing a web page and copying a key?
2. Verifiable trust, checked at call time. Does each API carry machine-readable signals — data handling, residency, retention, standards alignment — that an agent (or a procurement reviewer) can read before the call, rather than trust assumed and audited later, if ever?
3. A consumption model that fits a portfolio. Modern teams use many APIs whose usage ebbs and flows. Does the billing model pool across the catalog, or is every API its own subscription, quota, and renewal cycle?
4. Low friction on both sides. How fast can a developer call something — and how fast can a provider publish? A marketplace is only as good as its supply, and gated three-month publishing pipelines starve supply.
5. Honest operational fit. Does it suit a solo developer grabbing a utility in ten minutes, a product team wiring deep integrations, or a regulated enterprise governing agents at scale? These are different jobs, and no single platform wins all three.

Each criterion is really a question about trust: trust that an agent can find the right building block, trust that the block is safe to use, trust that the bill won't surprise you, and trust that the thing you publish reaches real customers.

04The comparison

1. ApyHub — the agent-first catalog with trust built into every endpoint

ApyHub is a curated, MCP-native API marketplace where developers and AI agents discover, compose, and execute APIs as building blocks. It runs on a single subscription to the whole catalog — currently 1,000+ endpoints across 200+ APIs — priced in "atoms," a unit small enough to bill a tiny lookup and expressive enough to price a heavy compute or inference call honestly. The headroom you buy against one API is spendable against any other.

The part that sets ApyHub apart is trust. It's the only marketplace in this list where certification is built into the catalog itself: every endpoint ships with machine-readable certification covering data handling, retention, and standards alignment (GDPR, SOC 2, ISO 27001), and every endpoint is MCP-ready by default — so an agent can discover a capability, read what it does and what it does with data, and decide whether to call it, all in the same structured flow. That's the difference between an agent trusting a vibe and an agent trusting a verifiable property.

At the protocol level, discovery and execution look like ordinary MCP tool calls — the agent searches the catalog, then calls the chosen capability (the values below are illustrative of the shape, not a fixed schema):

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "apyhub.catalog.search",
    "arguments": {
      "query": "convert PDF to Word",
      "constraints": { "data_residency": "EU", "max_atoms_per_call": 50 }
    }
  }
}

{
  "jsonrpc": "2.0",
  "id": 1,
  "result": {
    "matches": [
      {
        "endpoint": "document/convert/pdf-to-word",
        "atoms_per_call": "scales with payload size",
        "mcp_ready": true,
        "certification": { "gdpr": "aligned", "soc2": "aligned", "iso_27001": "aligned" }
      }
    ]
  }
}

Publishing is the other side of the same coin: it's self-service and AI-assisted — point ApyHub at an endpoint, its system drafts the spec, docs, and validation, and a provider reviews and ships in roughly ten minutes for a simple API. More supply, vetted, reaches the 65,000+ developer workspaces already on the platform. (Note: ApyHub's own materials cite both 65,000+ and 50,000+ developer figures across sources; the 65,000+ workspaces figure is the most recent.)

Where it shines:

• One subscription, one usage pool, one bill across the entire catalog — no per-API quota whack-a-mole.
• Atoms price by the actual work an API does (payload size, compute), not a flat request count.
• MCP-ready and machine-readable certification on every endpoint, so trust is checkable at call time by humans and agents alike.
• Ten-minute, AI-assisted self-service publishing — the fastest path from endpoint to a paying audience in this list.

Where it can go further:

• The catalog is the fastest-growing in this list but still younger than RapidAPI's historical breadth — long-tail coverage keeps expanding as more providers publish.
• Enterprise-grade SLAs and formal procurement tooling are maturing quickly toward what large-organization buyers expect.

Explore the catalog →

2. Postman API Network — the directory most developers already live in

Postman's API Network is where a huge share of the world's developers already work, and it now runs an official, vetted directory of first-party MCP servers — Atlassian (Rovo), AWS, GitHub, Linear, Supabase, plus verified publishers like Stripe, PayPal, and Notion. It also offers an MCP Generator that turns a public API from the network into an MCP server.

Where it shines:

• Enormous existing developer base and best-in-class tooling for building, testing, and documenting APIs.
• A curated, first-party MCP server directory that's genuinely useful for discovering and testing agent tools.
• The MCP Generator lowers the effort of making an existing API agent-callable.

Where it lags:

• It's primarily a tooling and discovery layer, not a unified-billing consumption marketplace — you still manage each API's own keys, plans, and billing.
• The MCP catalog leans toward exploration and testing rather than a single metered pool you consume and pay for in one place.

3. Kong Konnect — enterprise governance for the agentic era

Kong launched its MCP Registry inside Kong Konnect in tech preview on February 2, 2026, positioning Konnect as an enterprise system of record for MCP servers and AI-native tools. Because it ties each MCP server to its underlying API dependencies, ownership, and "blast radius," and pairs it with an AI Gateway that now governs LLM, MCP, and agent-to-agent traffic, it's aimed squarely at enterprises moving agents from pilot to production.

Where it shines:

• Deep, enterprise-grade governance: registers, discovers, and governs MCP servers with consistent security, ownership, and policy.
• Links agent tools to the real APIs beneath them, plus cost governance and metering across the AI data path.
• Strong fit for organizations that already run Kong for mission-critical API management.

Where it lags:

• It governs your own and internal APIs and tools at scale; it isn't a public catalog of ready-made third-party utility APIs you subscribe to and call.
• Heavier to adopt and operate — overkill for a solo developer who just wants a working API in ten minutes.

4. Nango — a different tool for a different job

Nango is worth including precisely because it isn't a consumption marketplace — it's an integration-engineering platform, solving a different problem than the others on this list. Rather than subscribing to ready-priced APIs you call, you use Nango to build and run your own integrations in code across 800+ APIs, with an AI builder that generates TypeScript from natural-language descriptions and a native MCP server that exposes those integrations to agents. If your need is "give my product deep, custom, two-way integrations and let agents call them," that's Nango's lane; if your need is "discover and consume vetted utility APIs through one bill," that's a marketplace like ApyHub.

Where it fits:

• Teams who want full, code-first control over integration logic — readable code they review and version, not a black box.
• Building deep, custom, or two-way integrations that a normalized catalog wouldn't cover.
• Exposing those custom integrations to agents through a native MCP server.

Where it doesn't:

• It's an integrations platform, not a metered catalog of sellable, ready-priced APIs — there's nothing to "subscribe to and call" out of the box.
• Code-first means you implement and maintain the mapping logic per API, so the maintenance burden shifts to you rather than disappearing.
• More engineering setup and a steeper learning curve than a point-and-subscribe marketplace.

5. Merge — governed agent access for the enterprise

Merge made its name as a unified API across 220+ connectors in categories like HRIS, ATS, CRM, accounting, and ticketing, with normalized data models and serious compliance credentials (SOC 2 Type II, ISO 27001, HIPAA, GDPR). Its Agent Handler product (launched October 2025) adds a governed layer for agent tool calls — scoped per-user auth, DLP and PII scanning before data reaches the model, tool-packs, and full audit trails. Customers include Perplexity and other AI-native names.

Where it shines:

• A genuinely strong governance and audit story for agents operating in regulated environments — every tool call inspected, scoped, and logged.
• Deep, well-maintained connectors in core enterprise categories, with normalized data models that simplify multi-system logic.
• Battle-tested enterprise compliance, not marketing-deck compliance.

Where it lags:

• Pre-built tool calls only — you can't author custom tools, and roughly 110–220 connectors is category depth, not broad utility-API breadth.
• Per-linked-account pricing compounds quickly in multi-tenant agent products with many customers.
• Normalized models aren't configurable per tenant, which chafes when enterprise customers heavily customize their data.

6. APILayer — simple, self-service, first-party

APILayer is a clean, self-service marketplace built around focused first-party APIs — currency conversion, IP geolocation, weather, and similar utilities — with predictable per-API plans and easy onboarding. Its AI and MCP focus is emerging rather than central.

Where it shines:

• Genuinely simple: pick an API, subscribe, get going, with well-documented first-party services.
• Predictable per-API pricing and low onboarding friction for a single, well-scoped need.

Where it lags:

• Separate subscription per API with no pooled headroom across the catalog.
• Request-count pricing that doesn't distinguish a tiny ping from a heavy payload.
• Primarily first-party, so the catalog is narrower, and agent/MCP readiness is still early.

7. Rapid (formerly RapidAPI) — the category's origin, now pointed at telecom

Rapid built the modern API marketplace and once counted millions of developers and tens of thousands of APIs. Nokia acquired its technology assets in late 2024 and is folding it into a Network-as-Code platform aimed at helping telecom operators monetize 5G/4G network APIs. MCP support exists, but the center of gravity has shifted toward telecom.

Where it shines:

• Enormous historical mindshare and breadth of discovery; still a place many developers think of first.
• Backed now by Nokia's scale and a clear strategy for network-API monetization.

Where it lags:

• The active developer base and API count have declined sharply from their peak as the focus pivots to telecom and operators.
• Per-API subscriptions with overage fees, plus a marketplace commission and payment-processing cut. (The exact commission figure is often cited as ~25% plus payment processing; treat the precise number as worth verifying against Rapid's current published terms.)
• General-purpose, agent-first developers are no longer the primary audience.

05At a glance

06Where ApyHub fits

If your work is agent-first — building software where agents discover and call APIs as building blocks, and where you need to trust what those agents reach for — ApyHub is the clearest fit in this list, and it's not close. The single-subscription, atoms-based model means an agent's usage spikes don't blow up a per-API quota, and the built-in certification on every endpoint gives an agent something it can actually check before it acts. No other marketplace here puts a readable trust signal on every endpoint by default. That's the whole point: in an agentic system, trust has to be a verifiable property, or it isn't trust, it's hope.

The others have real strengths in their lanes — Kong for governing internal tools at enterprise scale, Merge for audited access in regulated settings — but for the broad middle of developers and teams who want a trusted catalog of building blocks that both they and their agents can rely on, ApyHub is the one to start with.

Try ApyHub free →

07Conclusion

There's no single winner here, and saying otherwise would be marketing, not analysis. Postman wins on existing reach and tooling; Kong wins on enterprise governance; Merge wins on governed, audited access in regulated settings; APILayer wins on simplicity for one focused need; Rapid carries the history but now points at telecom. Nango isn't really in the same race — it's an integration-engineering platform for teams who want to build their own, which is a different job than consuming a catalog of ready-made APIs. What's genuinely changed is the bar: the marketplaces that matter in 2026 are the ones where agents can discover capabilities dynamically and where trust is verifiable at the moment of use.

ApyHub is the fastest-growing option built for exactly that — developers and agents, a single metered catalog, and trust readable on every endpoint. If APIs are the building blocks of agentic software, the platform that lets you trust each block before you snap it in is the one worth starting with.

Browse the catalog →

08FAQ

What is an API marketplace for AI agents? It's a platform where an AI agent — not just a human — can discover an API, read machine-readable information about what it does and what it does with data, and call it at runtime. The key difference from a traditional marketplace is that trust and discovery are structured for a machine, usually through MCP.

Which API marketplace is best for AI agents in 2026? It depends on what you're building. For an agent-first catalog with trust built into every endpoint, ApyHub is the strongest general-purpose fit; for enterprise governance at scale, Kong Konnect; for governed, audited access in regulated environments, Merge. Nango isn't really a marketplace — it's for teams who want to build their own integrations in code.

What is MCP and why does it matter for API marketplaces? MCP (Model Context Protocol) is a standard that lets agents connect to tools and data in a structured, machine-readable way. It matters because it turns a static catalog into something an agent can actively search, reason about, and call — discovery and execution become part of the same flow rather than a human copying a key.

Is RapidAPI still a good choice? It depends on your goal. Rapid still has broad historical reach, but after Nokia's acquisition its focus has shifted toward telecom and network-API monetization, and its general-purpose developer base has declined. For agent-first, general-purpose work, the newer platforms in this list are usually a better fit.

How does ApyHub's pricing work? ApyHub uses a single subscription to the whole catalog, priced in "atoms" — a unit small enough to bill a tiny lookup and expressive enough to price a heavy compute or inference call. Headroom you buy is spendable across any API, and there's a free tier with no card required.

What makes ApyHub's APIs trustworthy for agents? Every endpoint ships with machine-readable certification covering data handling, retention, and standards alignment (GDPR, SOC 2, ISO 27001), and is MCP-ready by default. That gives an agent a verifiable property it can check before calling, instead of trust it can only assume.

How is Nango different from a marketplace like ApyHub? They solve different problems. Nango is an integration-engineering platform — you write or AI-generate the integration logic and maintain it yourself. ApyHub is a metered catalog of ready-priced APIs you discover and call, with certification on every endpoint. One is for building custom integrations; the other is for consuming vetted ones.

Can I publish my own API to these marketplaces? On ApyHub, publishing is self-service and AI-assisted — point it at your endpoint and you can be live in roughly ten minutes, reaching the developers and agents already on the platform. Postman lets you promote APIs and MCP servers to its network; Kong and Merge are more about governing connectors than hosting a public third-party catalog.

09About ApyHub

ApyHub is the distribution and consumption layer for APIs: a curated, certified catalog that developers and AI agents use as a trusted operational layer. The catalog spans 200+ APIs and 1,000+ endpoints, available under a single subscription priced in atoms, ApyHub's unified usage unit. Every API ships with machine-readable certification covering GDPR, SOC 2, and ISO 27001 alignment, and every endpoint is MCP-ready by default. ApyHub is headquartered in Amsterdam, with offices in the Netherlands, Greece, and India, and serves 65,000+ monthly developer workspaces . The free tier requires no card. Building an API? Become a provider →