AwsArchitecture

Hosting MCP Servers on Amazon Bedrock AgentCore Runtime: A UK Production Pattern

Stop running enterprise MCP tools on laptops. Use Bedrock AgentCore Runtime to host FastMCP containers with IAM or OAuth, session isolation and CloudWatch — and know when Gateway is the better fit.

AQ
Ali Qaiser
Enterprise AI & Automation Consultant
8 September 2026
8 min read
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Hosting MCP Servers on Amazon Bedrock AgentCore Runtime: A UK Production Pattern
In brief

Stop running enterprise MCP tools on laptops. Use Bedrock AgentCore Runtime to host FastMCP containers with IAM or OAuth, session isolation and CloudWatch — and know when Gateway is the better fit.

Key Takeaways
  • AgentCore Runtime hosts MCP servers as containers exposing 0.0.0.0:8000/mcp.
  • Authenticate with IAM SigV4 or OAuth; prefer SigV4 for service agents.
  • Use Gateway for Lambda/OpenAPI wrapping; use Runtime for custom MCP tool logic.
  • Cut over with a 30-day inventory, dual-run and retire-laptop plan.

MCP servers need a real home

Most UK teams that adopt Model Context Protocol start the same way: a FastMCP process on a laptop, or a container on a shared EC2 box, pointed at by Claude Code or Cursor. That is fine for a spike. It is not fine for tools that can read tickets, open change windows or call payment APIs.

Amazon Bedrock AgentCore Runtime is AWS's managed answer for hosting those MCP servers as containerised workloads — with session isolation, scaling and CloudWatch observability — so coding agents and production agents share a governed tool plane.

What AgentCore Runtime expects

When you deploy an MCP server to AgentCore, the container must expose the MCP streamable-HTTP endpoint at:

0.0.0.0:8000/mcp

That matches the default path used by official MCP SDKs (including FastMCP). Clients then invoke the deployed runtime through the regional AgentCore invocations endpoint (ARN-encoded), authenticated with IAM SigV4 or OAuth bearer tokens (for example via Cognito).

ModeConfigUse when
Stateless (recommended default)stateless_http=TrueMost tools; platform can manage session continuity headers
Statefulstateless_http=FalseElicitation, sampling, or progress notifications that need sticky session state

Deploy path in practice

  1. Author — Define tools with the MCP Python SDK (FastMCP) or TypeScript SDK.
  2. Test locally — Run on localhost:8000 and validate with an MCP client or MCP Inspector.
  3. Scaffold — Install the AgentCore CLI (npm install -g @aws/agentcore) then run agentcore create --protocol MCP (generates agentcore/agentcore.json and project layout).
  4. Deployagentcore deploy packages dependencies, uploads to S3 and creates an AgentCore Runtime (you get a runtime ARN).
  5. Invoke — Point approved agents at the invocations URL with the right qualifier (typically DEFAULT).

AWS publishes IAM and OAuth sample implementations under the MCP deployment patterns repository — start from those rather than inventing auth from scratch.

How this differs from AgentCore Gateway

Do not confuse the two:

  • Gateway turns your Lambdas / OpenAPI APIs into MCP tools for agents to call (managed MCP server in front of existing backends).
  • Runtime (this pattern) hosts your MCP server code as the workload — useful when the tool logic is custom, multi-step, or needs a dedicated container.

Many UK estates will use both: Gateway for commodity enterprise APIs, Runtime-hosted MCP for specialised diagnostic or domain tools (including patterns adjacent to the AWS MCP Server serverless Lambda diagnostics capability).

UK enterprise checklist

Security and identity

  • Prefer IAM SigV4 for service-to-service agents; use OAuth when human-delegated coding agents need user context.
  • Scope each runtime role to the minimum AWS APIs the tools need — no wildcard on production accounts.
  • Keep PII and payment tools in a separate runtime and account boundary from read-only observability utilities.

Operability

  • Wire CloudWatch metrics and logs to your existing observability stack on day one.
  • Version the container image; treat agentcore deploy like any other release (change ticket, rollback ARN).
  • Load-test cold starts for interactive IDE use cases — developers abandon tools that stall.

Governance

  • Register every production MCP endpoint in an internal catalogue (owner, data class, blast radius).
  • Block laptop MCP servers from production IdP / VPN paths once the AgentCore endpoint is live.
  • Align with your Bedrock Guardrails and AgentCore Identity plans so tool auth is not reinvented per agent.

A sensible 30-day cutover

Days 1–7 — Inventory MCP tools in use (personal configs included). Classify read-only vs mutating.

Days 8–14 — Move one read-only tool (for example config/diagnostics) to AgentCore Runtime with SigV4. Dual-run laptop vs Runtime for the pilot team.

Days 15–21 — Add one mutating tool behind stronger IAM and change-control. Document failure modes (timeouts, partial writes).

Days 22–30 — Retire the laptop endpoint for that team, publish the invocations URL to approved agents only, and schedule the next three tools through the same factory.

When not to use this pattern

  • Pure OpenAPI/Lambda backends with no custom MCP logic — prefer AgentCore Gateway.
  • Strict multi-cloud portability requirements — AgentCore is AWS-specific; accept that or keep a portable container you can also run on EKS.
  • Ultra-custom runtimes that need exotic OS packages AgentCore will not allow — validate image constraints early.

Bottom line

If MCP is becoming your enterprise tool bus, stop hosting it on developer workstations. Put the servers on AgentCore Runtime, authenticate properly, observe them like any other production service, and let Gateway handle the boring API wrapping. That is the difference between a demo and a platform UK risk teams will sign off.

Expert Commentary

Gateway wraps APIs; Runtime hosts your MCP server. UK teams that mix laptop MCP with production credentials will lose the risk conversation — move tools to AgentCore Runtime with least-privilege IAM and a catalogue owner.

Topics
AWSAmazon BedrockAgentCoreMCPFastMCPRuntimeIAMOAuthUKCloud

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