What Apex is
Apex routes the current Niyra conversation through Claude Opus 4 / Fable 5 — Anthropic's top tier model. It's roughly 5-10x the cost of Sonnet, slower, and significantly better at complex reasoning.
Prerequisites
- Alpha access — Apex is gated to early users today. Email hi@niyra.ai for access.
- BYOK Anthropic key — Apex is BYOK-only. Set up BYOK first.
Turning it on
Per-conversation. From the chat surface:
- Open a chat
- Click the model selector (next to your input)
- Pick "Apex (Fable 5)"
- The orb's color shifts to indicate Apex mode
The whole thread runs on Apex until you turn it off.
When to use Apex
- Deep research — synthesizing many sources into a clean argument
- Complex planning — long horizon, many constraints, real trade-offs
- Subtle reasoning — legal-adjacent work, financial analysis, edge cases
- High-stakes drafting — investor letters, board memos, strategic docs
For daily email triage, scheduling, summaries — Sonnet is the right tool. Apex is overkill.
What it costs
Runs on your Anthropic vendor budget (BYOK). Typical message costs $0.05-$0.25 depending on context size. A complex research session might run $1-$3.
The conversation shows the running cost so you can decide when to stop.
Limits
- No failover — if your vendor quota runs out, the conversation pauses until you top up.
- Voice mode isn't supported with Apex (yet).
- Some tools (especially Composio integrations) still run on Sonnet for cost reasons — only the reasoning step is Apex.
Troubleshooting
- "Apex unavailable" — Either you don't have alpha access (email hi@niyra.ai) or your BYOK key isn't set.
- Cost higher than expected — Apex context windows are larger; long conversations with memories injected can grow fast. Start fresh chats for new topics.