Migrating to 0.8

0.8 makes RPC schemas validator-neutral and validated at runtime, upgrades the MCP adapter to @modelcontextprotocol/sdk v2, and lands the agent-native MCP surface (ctx.agent, tool providers, and the devframe connect connector). This page covers the changes between 0.7.x and 0.8 — see the v0.8.0 release notes for the full changelog.

RPC schemas are Standard Schema and validated at runtime

args and returns on defineRpcFunction are now typed against Standard Schema rather than valibot's GenericSchema. Any Standard-Schema-compliant validator works — valibot, zod, arktype — so existing valibot schemas keep compiling and inferring types unchanged.

Two things change in practice:

Devframe no longer bundles a validator. valibot was dropped from devframe's runtime dependencies, so author your schemas with whichever validator you prefer and install it yourself:

npm install valibot # or: zod / arktype

If your app already pulls in zod (the JSON-render integration and the MCP server both use it), prefer zod for your RPC schemas and reuse the dependency. For first-party code that wants zero dependencies, devframe ships a minimal built-in builder at devframe/utils/simple-schema:

// Bring your own validator …
import { defineRpcFunction } from 'devframe'
import * as v from 'valibot'

export const rename = defineRpcFunction({
  name: 'devframes:plugin:terminals:rename',
  type: 'action',
  args: [v.object({ id: v.string(), title: v.string() })],
  returns: v.void(),
  setup: ctx => ({ handler: ({ id, title }) => { /* … */ } }),
})

// … or use the built-in zero-dep builder
import { defineRpcFunction } from 'devframe'
import { s } from 'devframe/utils/simple-schema'

export const rename = defineRpcFunction({
  name: 'devframes:plugin:terminals:rename',
  type: 'action',
  args: [s.object({ id: s.string(), title: s.string() })],
  returns: s.void(),
  setup: ctx => ({ handler: ({ id, title }) => { /* … */ } }),
})

Declared schemas are now enforced. Each argument is validated against its schema at the boundary before the handler runs, and the resolved return value is validated on the way out; a mismatch is rejected with a coded diagnostic instead of reaching (or leaving) the handler. Payloads are guarded, not rewritten — extra object fields the schema doesn't mention still reach the handler. Audit any schema that was previously more of a type hint than a contract, since inputs that used to slip through now throw.

See RPC for the full reference.

MCP adapter upgraded to @modelcontextprotocol/sdk v2

The MCP adapter now targets the v2 SDK, which ships as scoped @modelcontextprotocol/server and @modelcontextprotocol/client packages. Swap the peer dependency when you ship MCP support:

0.7.x	0.8
@modelcontextprotocol/sdk@^1	@modelcontextprotocol/server@^2

npm uninstall @modelcontextprotocol/sdk
npm install @modelcontextprotocol/server

@modelcontextprotocol/server remains an optional peer dependency, pulled in only through devframe/adapters/mcp. The devframe connect connector (below) additionally uses @modelcontextprotocol/client — install it too if you drive agents through the connector.

If you imported SDK types directly, the deep @modelcontextprotocol/sdk/... subpaths are now flat entries on the scoped packages (e.g. @modelcontextprotocol/sdk/server/stdio.js → @modelcontextprotocol/server/stdio). See MCP for the adapter reference.

Agent-native MCP surface

0.8 adds the agent host on ctx.agent — registerTool, registerToolProvider, and registerResource — plus an instance registry and the devframe connect MCP connector shipped in the devframe bin. These are additive; existing agent-flagged RPCs keep working and are projected to MCP as before.

One type sharpens: an RPC handler (and its dump) now returns Thenable<returns> — the returns schema describes the resolved value and the runtime always awaits the handler. Synchronous handlers are unaffected; an async handler whose declared returns was the unwrapped value now type-checks correctly rather than needing the promise spelled into the schema.

See Agent-Native for the tool/resource surface and MCP → devframe connect for the connector.