Retrofit, don’t rebuild: Agentic overlays for transforming legacy enterprise services
TL;DR
AWS presents agentic overlays as thin adapters on top of existing REST services: they translate A2A messages into REST calls and convert REST responses back into JSON-RPC-style agent responses. The pitch is pragmatic enterprise migration: add A2A support and MCP-compatible tool exposure without rewriting business logic, duplicating code, or running a second agent infrastructure beside existing APIs.
Nauti's Take
This is the more sensible agent story for enterprise teams: do not rebuild everything, make existing services agent-capable in a controlled way. Still, the article carries a fair amount of AWS and architecture PR, and the real friction points are only lightly touched.
An overlay will not fix bad APIs, unclear permission logic, or broken data contracts. It can, however, make migration smaller, easier to measure, and less prone to agent sprawl.
Briefingshow
Most enterprises already have stable REST services and little appetite for a second agent stack with separate auth, observability, and release pipelines. Overlays can be a realistic bridge: existing systems stay authoritative while agents get standardized integration points. The hard part is not the demo, but governance, security, and clean tool boundaries in production.
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