Runtime & Package Compatibility

@deuz-sdk/core supports Node.js 22 and newer and ships matching ESM, CommonJS, and declaration files for every public subpath. The core and /edge entries are also browser-bundleable: they depend on Web APIs (fetch, Web Streams, TextEncoder, TextDecoder, and WebCrypto), not Node built-ins.

What changed in 2.4

engines is still node >= 22, every 2.3 subpath is still exported, the package still has no runtime dependencies, and no peer is added or changed. Every 2.4 feature is off until you configure it. What is new in 2.4 has the features, the behaviour changes and the upgrade notes.

New subpaths. Four are edge-safe and five are Node-only. The release gate bundles each edge-safe one for the browser and checks that each Node-only one fails that boundary. Edge & Runtimes lists what each holds.

Existing subpaths. /agent, /chat, /ui, /schedule (and so /edge) and /workspace gain edge-safe 2.4 surface. /ops/sqlite, /ops/postgres, /stores/sqlite, /stores/postgres and /stores/redis gain Node-only 2.4 stores: V3 run stores, conditional chat stores with their transcript indexes, and durable stream stores (the only 2.4 store on Redis, which needs Redis 7 or later like the other Redis stores).

Databases shared with 2.3. Every 2.4 store keeps its data in new tables with a schema version table of its own, and no existing schema version moves, so a 2.3 process keeps opening a database that 2.4 wrote. See Sharing a database with 2.3 processes.

React. @deuz-sdk/react 2.4.0 keeps its @deuz-sdk/core: ^2.0.0 peer range and react: ^18.0.0 || ^19.0.0. Chat snapshots work with any core 2.x: the hook applies stored message ids itself next to a 2.3 core. Replay by message id, messageIds in request bodies and the automatic resume of a dropped read wait until a 2.4 route announces them through the capability handshake. The frozen @deuz-sdk/core/react hook is deprecated in favour of @deuz-sdk/react and will be removed in 3.0; its behaviour is unchanged, and a development build logs one console warning per page.

Backends in CI. The integration job runs the 2.4 PostgreSQL and Redis stores against Postgres 16 and Redis 7, next to the 2.3 ones; the SQLite stores run in every check run. Without those servers, the PostgreSQL stores run against PGlite and the Redis stream store against ioredis-mock, so the check runs stay offline. The pgvector path of the versioned PostgreSQL store was checked only against an emulated vector type in PGlite. A Docker job runs the Docker runner's tests against the Docker Engine of GitHub's ubuntu runner (DEUZ_TEST_DOCKER=1); they were also run locally against Docker Desktop on Windows 11.

What changed in 2.3

engines is still node >= 22, every 2.2 subpath is still exported, and the package still has no runtime dependencies.

New subpaths. Five are edge-safe and four are Node-only. The release gate bundles each edge-safe one for the browser, and checks that each Node-only one fails that boundary. Edge & Runtimes lists what every Node-only subpath needs.

Optional peers. Every peer is still declared optional, so a package manager installs none of them for you.

• @modelcontextprotocol/client ^2.3.1 (new) is the SDK of MCP 2026-07-28. With sdk: 'auto', the default, the MCP client runs on it when it can be imported and on @modelcontextprotocol/sdk (2025-11-25) otherwise, so either one is enough for a client.
• @modelcontextprotocol/server ^2.3.1 (new) serves /mcp/server and /mcp/server/stdio.
• Both MCP 2026-07-28 packages declare Node 20 or later and bring Zod 4 as their own dependency.
• redis accepts ^6.0.0 too (^4.6.0 || ^5.0.0 || ^6.0.0), and now also backs /ops/redis and /swarm/redis. The Redis ops, budget and swarm stores need Redis 7 or later.

React 18 in CI. Both React bindings declare react: ^18.0.0 || ^19.0.0, as before, but until 2.3 CI installed only React 19. A CI job now puts one React 18 under the whole repository and runs the typecheck of both packages, the @deuz-sdk/react tests and the frozen hook's tests on it. @deuz-sdk/react keeps its @deuz-sdk/core: ^2.0.0 peer range and imports nothing a 2.2 core lacks, but the 2.3 wire fields reach useChat through core's applyUIPart, so they need @deuz-sdk/core 2.3.

Redis and Postgres in CI. A CI job runs the Redis ops, runs, budget and swarm stores against Redis 7, and the Postgres stores against Postgres 16, including concurrent writers. These tests read DEUZ_TEST_REDIS_URL or DEUZ_TEST_POSTGRES_URL and skip without them, so the check runs stay offline.

Custom provider base URLs

The SDK never guesses a /v1 prefix for a custom baseURL. An adapter appends only its wire route:

const gateway = createOpenAIResponses({
  apiKey: process.env.GATEWAY_KEY!,
  baseURL: 'https://gateway.example',
});

// POST https://gateway.example/responses
await generateText({
  model: gateway('gpt-5.5'),
  messages: [{ role: 'user', content: 'hello' }],
});

If your gateway exposes https://gateway.example/v1/responses, pass baseURL: 'https://gateway.example/v1'. Trailing slashes are normalized and the prefix is preserved exactly once.

Local gates

Run npm run verify:runtime after npm run build to exercise browser/edge consumer bundles. npm run verify:package validates the packed file list, all export targets, both module formats, publint, and declaration resolution.

See Edge & Runtimes for deployment examples and Node-only subpaths.