Responses
default deepseek-v4-flash-responses
USE CASE
If a provider drops, the stream continues.
Failover is an ordered list on the runtime, not a rewrite of the UI. The same session.send, the same event types, the next model in line.
Anthropic
next deepseek-v4-flash-anthropic
failover_ids
ordered list on the runtime
The challenge of provider lock-in
Swap a provider and teams rewrite the stream parser, the tool-call dialect, and the UI status. Failover becomes a second client path. The visitor sees a restart. Sveda keeps session.send and the same event types. The catalog walks an ordered list.
A parser per protocol
Responses in one module, Anthropic in another, a third for the UI. Failover means picking a different frontend.
Retry in the page
The host catches a 5xx and calls send again. Tokens already streamed are lost. Chat state forks.
Keys in the widget
Model URLs and secrets leak into the client so the browser can “choose a backup.” The runtime should own the chain.
How Sveda solves it
Primary is DeepSeek V4 Flash on the Responses protocol. Builtin failover is the same model on the Anthropic path. Custom Responses or Anthropic URLs join the catalog. failover_ids is an ordered list. The client still calls session.send. Events do not change.
Ordered catalog
The runtime builds a stream chain from the primary plus failover_ids. Duplicates are skipped. Unknown ids are skipped.
- Default id: deepseek-v4-flash-responses
- Builtin failover_ids: deepseek-v4-flash-anthropic
- deepseek-v4-pro is in the catalog for heavier work
- SVEDA_FAILOVER overrides the ordered list
- SVEDA_DEFAULT_MODEL can move the primary
Custom endpoints
The catalog takes custom Responses or Anthropic URLs. You are not locked to one vendor hostname.
- Protocol is Responses or Anthropic — not a third dialect
- Custom entries speak those URLs from settings
- Same tool-call path on the runtime
- Swap a provider in the catalog, not in the UI
- Keys stay on sveda-server
Same client, same events
The host does not learn a failover API. session.send is the turn. The SSE event list does not restart as a new product.
- Client still calls session.send
- Accept is still application/vnd.sveda.stream+json
- message.start, text.delta, tool.call, message.end stay the names
- Frontend tools keep the same registry
- No second widget for the backup model
FAILOVER PATH
Primary, then the next id in line.
The default chain is Flash Responses, then Flash Anthropic. That is the same DeepSeek V4 Flash model on two protocols — not a marketing “99.9% uptime” claim, and not a rewrite of the client. If the primary cannot stream, the runtime walks the next id.
Put more ids on failover_ids when you add custom endpoints. The chain is ordered. The UI does not pick the backup.
The models page and the models docs list catalog ids and SVEDA_FAILOVER.
FAILOVER PATH ordered
- deepseek-v4-flash-responses primary
- deepseek-v4-flash-anthropic failover
- deepseek-v4-pro catalog
Client still session.send. Event names unchanged.
CLIENT unchanged
await session.send(text)
Accept: application/vnd.sveda.stream+json
message.start
text.delta
tool.call → tool.result
message.end
provider walk runtime
SAME WIRE
Do not rewrite the stream to change a model.
The host may pass model or provider on a turn. Failover is still the ordered list on the runtime. The JS client does not grow a backup send() or a second Accept header. Custom endpoints are catalog rows, not a new protocol for the page.
This is developer infrastructure: a catalog, a chain, a stream. Not a SaaS chatbot with a status badge and a fabricated conversion lift.
Pair with the stream protocol and stream docs. The copilot path is still session.send on the host you already have.
Related
Product copilot
Same session.send. Failover does not change the attach path.
Code agent
Index tools stay in the catalog while the model list walks.
Host MCP
HTTP tools stay attached across the failover chain.
Models
DeepSeek catalog, custom URLs, ordered failover_ids.
Stream protocol
Event names stay put when the provider changes.
Models docs
Catalog ids, protocols, SVEDA_FAILOVER.
Stream protocol docs
SSE framing and the closed event list.
JS client docs
session.send is still the turn after a failover.
Change the catalog. Keep session.send.
Flash Responses, then Flash Anthropic, then your failover_ids. The stream events do not get a new name.