# AgentsKit Chat 0.2.0

`0.2.0` is the trusted-backend release for ecosystem dogfooding. It keeps the
same framework-neutral chat definition and seven native renderers from `0.1.0`
while adding a production boundary for requests that cannot be answered by a
host's deterministic artifact.

## What changed

- The browser sends only a runtime-validated Ask request and resumable session
  cursor. Authentication determines the trusted site, corpus, and persona.
- Exact facts stay local through the deterministic answer plane. Only a
  validated escalation may reach the backend.
- Hosts inject AgentsKit RAG retrieval and model generation. Local and
  federated sources use the same grounded citation contract.
- CAS persistence prevents concurrent turns and cursor rollback. Deadlines,
  cancellation, rate limits, safe diagnostics, and request IDs are mandatory.
- Metrics include latency, event counts, retrieval, persistence, token usage,
  and cost without prompts, answers, source content, subjects, or session IDs.
- The shared Ask adapter recognizes valid NDJSON even when an intermediary
  incorrectly labels it as `text/plain`; ordinary text keeps its safe fallback.

## Upgrade

Keep the fixed package group on one minor line:

```json
{
  "dependencies": {
    "@agentskit/chat": "^0.2.0",
    "@agentskit/chat-protocol": "^0.2.0",
    "@agentskit/chat-react": "^0.2.0",
    "@agentskit/chat-server": "^0.2.0"
  }
}
```

Existing `0.1.x` chat definitions remain source-compatible. Upgrade the fixed
package graph together and follow the
[0.2 migration guide](./migration-to-0.2.md).

See the [backend guide](../backend.md),
[Ask protocol](../protocol/ask-service.md), and
[ADR-0026](../architecture/adrs/0026-trusted-ask-backend-vertical.md) for integration
and security details.

## Evidence

The release gate builds and clean-installs all 12 packages, exercises all seven
renderers, runs browser and terminal E2E, validates Doc Bridge output, and
verifies the immutable tarball checksums before publication.