Best AI Agent Integration Platforms in 2026

Your agent works in a demo. Now add 10 customers.

Your first agent probably ran on your own API token. It read your inbox, posted to your Slack channel, and it worked.

Then a customer asks to connect their workspace. Then ten customers, each wanting a dozen apps. That is 120 connected accounts before you count individual users, and each one has its own token, scopes and expiry.

The problems change at that point:

• Every end user has to go through an OAuth consent flow once, and you have to store the result.
• Tokens expire. They have to be refreshed before a call fails, not after.
• Apps don't agree on auth. Some use OAuth, others API keys, bearer tokens or service accounts.
• One customer's agent run must never reach another customer's credentials.
• When something goes wrong, someone will ask which user the agent was acting for, and what it did.

You can build that layer yourself. This article compares seven platforms that sell it, based on how they handle multi-customer agents and what they cost once you're in production.

What to look for in an agent integration platform

Seven questions decide most evaluations:

1. Per-user auth. Does each end user connect their own account, and does the platform store and refresh that token for you?
2. Auth methods. OAuth only, or also API keys, bearer tokens, basic auth and service accounts?
3. Custom APIs. Can you add an internal API or a remote MCP server under the same auth model as the built-in connectors?
4. Tool scoping and guardrails. Can you limit which tools a given agent sees, and check or block what a call sends and returns?
5. Logs and audit. Can you trace a call back to the user and agent that made it, and for how long are records kept?
6. Deployment. Managed cloud only, or VPC, on-prem or air-gapped?
7. Pricing unit. Tool calls, credits, connections, external users or compute time? The unit decides how your bill grows.

How we checked. Features and prices come from each vendor's own pricing page and documentation, checked between 1 and 5 November 2026. These pages change often, so confirm them before you sign anything. This article was written for Scalekit, which is listed first.

If you only care about hosted MCP endpoints, Scalekit's Best Managed MCP Server Platforms covers ten platforms on that narrower question. This article looks at the wider integration layer: auth, custom APIs, guardrails, deployment and cost.

1. Scalekit: For agent integrations, Scoped tool access, and production-readiness

Scalekit holds each user's credentials and runs tool calls as that user. Your agent calls a tool; Scalekit runs the OAuth flow, stores and refreshes the token, and makes the API call. The token never passes through your code or into the model's context.

What stands out

• Virtual MCP servers. You define one Virtual MCP server per agent role and list exactly which connections and tools it exposes. A Gmail connection might offer 30 tools; a summarizer agent can be given only the one that fetches mail.
• A session token per run. Before each run you mint a short-lived token bound to one user's connected accounts. It lasts an hour by default and can be set from 60 seconds to 24 hours. One user's run cannot act with another user's credentials.
• Custom connectors. Bring your own connector for any REST API, internal API or remote MCP server. It uses the same vault, user authorization and Tool Proxy as the built-in connectors. Supported auth methods include OAuth 2.0, API keys, bearer tokens and custom JWT.
• Deployment. Managed cloud in the US or EU, or VPC, on-prem and air-gapped deployments on Enterprise.

In code, the per-run step is one call. This is the Python SDK after you've created the Virtual MCP server once:

from datetime import timedelta

token = scalekit_client.actions.mcp.create_session_token(
    mcp_config_id=config_id,   # the Virtual MCP server for this agent role
    identifier="user_123",     # your own ID for the end user
    expiry=timedelta(hours=1),
).token

# Any MCP client connects to the shared server URL with:
# Authorization: Bearer <token>

Tokens can't be refreshed in place, so you mint a fresh one for each run rather than holding a long-lived credential.

Pricing. Free includes 10,000 tool calls and 10,000 trigger events a month. Growth is $99 a month for 100,000 tool calls and 50,000 trigger events, then $0.50 per 1,000 tool calls. EU data residency is a $99-a-month add-on (pricing). Custom connectors start on Growth.

Best for. Teams that need to manage authentication and tool access across multiple users and enterprise environments.

When it's not the right fit. The catalog of 600+ connectors and 30,000+ tools is smaller than Composio's or Pipedream's, so check your long-tail apps first. Audit logs are kept for 30 days on Free and Growth; longer retention and SIEM streaming are Enterprise features. There is no payload-level DLP of the kind Merge offers. And a single-user agent with three straightforward integrations doesn't need this layer yet.

2. Composio: broad tool coverage and a generous free tier

Composio is the quickest way on this list to get one agent working across many apps: prebuilt toolkits for 1,000+ apps and a free tier sized for experimenting. That makes it a natural fit for personal and internal agents. It also handles credentials per connected account (one user's authorized account, such as their Gmail), so it can serve multi-user agents too, though the controls those need sit in add-ons and on Enterprise. In code, you pass your own user_id when you create a session, and Composio ties that user's connected accounts, sessions and logs to it.

What stands out

• Fast start. A large catalog of ready tools, plus a proxy that calls endpoints Composio hasn't wrapped as tools while still handling auth.
• Free tier. Hobby includes 100,000 tool calls and 50,000 trigger events a month, with unlimited connected accounts.
• Logs on every plan. Execution logs are kept for up to a year, including request and response payloads by default. Zero data retention, which stops payload storage, is a paid option on Pro and included on Enterprise.
• Firewall. A Pro add-on that checks tool requests and results against your own policies, billed at $0.50 per million tokens evaluated.
• Enterprise controls. SSO, SCIM and customer-managed keys on Enterprise, where Composio also offers self-hosting inside your VPC.

Pricing. Hobby is free. Pro is $29 a month as a usage credit, then $0.0003 per tool call. Calls through Composio's shared OAuth apps cost more: $0.0005 per call after the first 20,000. On Pro, a HIPAA BAA, an IP allowlist and zero data retention are each billed as per-call add-ons (pricing). Composio changed its pricing model in August 2026, so model your volume against the current page.

Best for. Individual developers and internal agents that need many apps working fast. For a customer-facing product, budget for the add-ons and Enterprise features below.

When it's not the right fit. Production controls are spread across add-ons and the Enterprise plan. If you need private deployment or compliance terms from day one, price the Enterprise conversation early rather than the $29 plan.

3. Nango: integrations as code, plus data sync

Nango is an integration runtime for auth, tool calls, syncs and webhooks across 1,000+ APIs. You start from 10,000+ prebuilt tools, triggers and syncs, then extend them or write your own.

What stands out

• Logic you own. Integrations run as code (Nango Functions) that you can read and change, so an unusual API is not a dead end.
• Actions and sync together. The same connection can serve agent tool calls, scheduled syncs that keep RAG context fresh, and incoming webhooks.
• Observability. Built-in logs, metrics and alerting, with real-time trace export in OpenTelemetry format.
• Self-hosting. Self-hosting and bring-your-own-cloud in any AWS, GCP or Azure region on Enterprise.

Pricing. Free covers 10 connections, 10 compute hours and 10 GB of data transfer a month. Pay-as-you-go is $50 a month in credits, then $0.29 per connection, $0.72 per compute hour and $0.50 per GB (pricing). A connection is one user's account, so three users connecting Gmail is three connections. Each tool call is billed for at least one second of compute.

Best for. Engineering teams that want to own integration behavior, or need agent actions and ongoing data sync from one platform.

When it's not the right fit. You take on more of the integration logic yourself. Three meters (connections, compute and data) are harder to forecast than a flat per-call price. Nango has no EU-hosted cloud today; the option is a BYOC instance on Enterprise.

4. Arcade: authorization checks at execution time

Arcade is a runtime that authenticates users, authorizes each tool call and executes it. It manages the full OAuth lifecycle in an isolated runtime, so the agent never sees a credential.

What stands out

• Contextual Access hooks. Three hook points call your own webhook server. The access hook decides which tools a user can see. The pre-execution hook can allow, deny or modify inputs. The post-execution hook can allow, deny or modify outputs.
• Layered policies. Hooks run at organization and project level in a fixed order. Each can fail closed or fail open if your server is unreachable, so security checks block by default while optional ones don't stall the agent.
• Deployment. Arcade Cloud, your VPC, or fully air-gapped on Enterprise.

Pricing. Free includes 2,000 tool calls a month. Team is $25 a month plus $0.01 per tool call. Enterprise adds annual call bundles, discounted rates, SSO, RBAC and audit logs (pricing).

Best for. Teams whose main concern is enforcing their own access and compliance rules on every agent action.

When it's not the right fit. The hooks are yours to build and host, and each one is a network call in the execution path (5-second timeout by default). Audit logs, SSO and RBAC are listed on Enterprise, not Team. At $0.01 per call, 100,000 calls on Team cost about $1,000 a month, so high-volume agents should price Enterprise.

5. Merge Agent Handler: data-loss prevention on every call

Merge Agent Handler is an MCP tool-calling layer with managed connectors, per-user credentials, and a Security Gateway that scans every tool input and output.

What stands out

• Tool Packs. Bundles that set which connectors and tools an agent can act on. You can rewrite tool descriptions per pack so the model picks the right tool.
• Security Gateway. Rules run on arguments before they leave Merge and on responses before they reach your agent. Each rule allows, redacts or blocks, for example stopping an SSN from landing in a ticket description.
• Logs. Audit logs on all plans, plus tool-call logs that split latency into auth, gateway scan, connector dispatch and the third-party round trip.
• Bring your own MCP. You can import any public MCP server alongside Merge's connectors.

Pricing. Free includes 2,000 credits a month. Pro is $1,000 a month for 25,000 credits, and unused credits roll over. A simple call costs 1 credit; a long-running or batch call costs 10. Enterprise adds custom deployments, including on-prem (pricing).

Best for. Agents that handle sensitive business data, where a security team needs DLP and a full record of tool calls.

When it's not the right fit. There is no tier between Free and $1,000 a month, which is a steep step for an early product. Complex calls cost ten times a simple one, so estimate your call mix before you budget.

6. Paragon ActionKit: agent actions inside an embedded-integration product

ActionKit is Paragon's API for integration actions, offered as a managed MCP server listed on the official MCP registry. It covers 130+ integrations and 750+ agent-ready actions.

What stands out

• Part of a wider platform. ActionKit sits alongside Paragon's Connect Portal (the UI where your customers connect their apps), Managed Sync and Workflows.
• Event triggers. ActionKit Triggers, in public beta since May 2026, let agents react to events in apps such as Google Calendar, Jira and HubSpot. Paragon handles OAuth, retries and payload verification.
• Logs you can filter by user. ActionKit logs record every list and run request, filterable by user ID and integration, with a trace of the calls made to the provider. Retention depends on your plan, and Event Destinations forward warnings to tools such as Slack, Datadog and Sentry.
• Self-hosted MCP option. An open-source MCP server is available if you'd rather run that layer yourself.

Pricing. Quote-based and metered on Connected Users. A Connected User usually represents one of your customer organizations. Your plan sets a limit; once you reach it, new users can't connect integrations until you upgrade.

Best for. SaaS teams that want customer-facing integrations and agent actions from one vendor, especially teams already on Paragon.

When it's not the right fit. No public prices, so you can't estimate cost before a sales call. The catalog is narrower than the broad-coverage platforms on this list.

7. Pipedream Connect: broad API coverage with workflows

Pipedream Connect adds managed auth, prebuilt tools and triggers, MCP servers and an API proxy to your app. It runs on Pipedream's catalog of 3,000+ connectors and its workflow engine.

What stands out

• Coverage. Managed auth for 3,000+ APIs and 10,000+ prebuilt tools and triggers, plus a proxy for calls Pipedream hasn't wrapped as tools.
• Per-user calls. Each request carries the external user ID you choose, such as your own database key, and the MCP server loads tools for one app or several at once.
• Workflows. Agent actions can sit next to event triggers and code-based workflows on the same platform.
• Ownership. Workday announced its acquisition of Pipedream in November 2025 and has since closed it. Workday frames the deal around connecting its HR and finance data to third-party apps, which is worth weighing in a long-term choice.

Pricing. Connect is billed on two meters: credits and unique external users. A tool call, action or proxy request uses 1 credit per 30 seconds of compute. Free is development only. Startup is $99 a month billed annually ($150 monthly), with 10,000 credits ($0.012 each after) and 100 external users ($2 each after). SSO, SCIM, HIPAA and SLAs are on the custom Business plan; SOC 2 Type 2 applies to all plans (pricing).

Best for. Developers who need the widest app coverage and want to mix agent tools with triggers and workflows.

When it's not the right fit. The per-user fee grows with your customer base: 5,000 external users means about $9,800 a month in user fees on Startup, before credits. Credits are metered by compute time, so a slow call costs more than a fast one. Teams that need SSO or HIPAA go straight to the Business contract.

Side-by-side comparison

The seven platforms split on two things: how a call is tied to a user, and what you can control about that call.

Platform	How a call is tied to a user	Controls on tool calls	Logs and audit	Private deployment
Scalekit	Short-lived session token per user, per run	Tools chosen per Virtual MCP server	30 days on Free and Growth; up to 1 year and SIEM on Enterprise	VPC, on-prem, air-gapped (Enterprise)
Composio	user_id per session	Firewall policy checks (Pro add-on)	Up to 1 year on every plan, payloads included unless ZDR is on	Self-hosted in your VPC (Enterprise)
Nango	Connection per user account	Your own logic in code	Logs, metrics, OpenTelemetry export	Self-hosted or BYOC (Enterprise)
Arcade	Per-user OAuth held in Arcade's runtime	Access, pre- and post-execution hooks	Audit logs on Enterprise	VPC, air-gapped (Enterprise)
Merge Agent Handler	Registered user per end user	Tool Packs; DLP rules that allow, redact or block	Audit logs on all plans; per-call latency logs	On-prem (Enterprise)
Paragon ActionKit	Connected User, often one customer org	Choice of integrations exposed	Tool-call logs filterable by user; retention by plan	Open-source MCP server you can self-host
Pipedream Connect	External user ID on each request	Tools loaded per app	Not mentioned on its pricing page	No VPC or on-prem option advertised; static egress IPs on Business

Platform	Free tier	Entry paid plan	Billed on
Scalekit	10,000 tool calls/mo	$99/mo for 100,000 calls, then $0.50 per 1,000	Tool calls, trigger events
Composio	100,000 tool calls/mo	$29/mo usage credit, then $0.0003 per call	Tool calls, triggers, add-ons
Nango	10 connections, 10 compute hours	$50/mo credit, then $0.29 per connection and $0.72 per compute hour	Connections, compute, data
Arcade	2,000 tool calls/mo	$25/mo plus $0.01 per call	Tool calls
Merge Agent Handler	2,000 credits/mo	$1,000/mo for 25,000 credits	Credits (1 or 10 per call)
Paragon ActionKit	None published	Quote	Connected Users
Pipedream Connect	Development only	$99/mo billed annually: 10,000 credits, 100 users	Credits, external users

How to choose

Start with who your agent acts for. If it acts for you or your own team, a shared connection and a big catalog may be all you need. If it acts for your customers' users, per-user auth and isolation come first, and the rest is about which problem you hit next:

• User-bound connections and scoped tools per agent role: evaluate Scalekit.
• A broad catalog to get an agent working quickly: evaluate Composio.
• Custom integration logic and ongoing data sync: evaluate Nango.
• Your own authorization rules enforced on every call: evaluate Arcade.
• DLP and detailed tool-call auditing for sensitive data: evaluate Merge Agent Handler.
• Customer-facing integrations and event triggers inside a SaaS product: evaluate Paragon ActionKit.
• The widest API coverage, combined with triggers and workflows: evaluate Pipedream Connect.

These are starting points; several platforms overlap. Before you commit, connect two real user accounts to the same app, run the same task for each, and confirm each call used the right user's token. Then price a realistic month at your expected volume, because the pricing units above diverge quickly as usage grows.

A caveat: if your agent serves a single user and talks to two or three APIs with stable auth, you may not need a dedicated platform yet. The calculation changes when the second customer arrives.

Getting started

To try per-user tool calling with your own accounts, follow the Scalekit quickstart.