Runtime
The execution core — every request becomes a run with a plan, a ceiling, and a trace.
The runtime is the part of Y0 that earns the word 'cognitive'. Every request — a one-line prompt from the CLI, a webhook-triggered workflow, an agent chasing invoices — is normalized into the same unit of work: a run. A run gets a plan composed by the reasoning layer, a hard max_steps ceiling, scoped access to the context graph, and a trace that records everything that happens. That uniformity is the whole trick. Because there is exactly one execution shape, there is exactly one place to enforce scopes, one place to meter cost, one place to attach approval gates, and one trace format your tooling ever needs to parse. The runtime schedules across the y0-fast and y0-deep profiles automatically when you set model to 'auto', keeping interactive requests under 200 ms to first token while routing genuinely hard steps to deliberate computation. Failures are designed to be boring: runs halt at their ceiling instead of looping, partial work is preserved in the trace, and idempotency keys make retries safe. The runtime is regionally pinned — a run started in your project's region executes and stores its trace there, full stop.
[ 01 ]Key features
One unit of work
Prompts, workflows, and agent actions all execute as runs — one shape to secure, meter, debug, and bill.
Enforced step ceilings
max_steps is a wall, not a suggestion. Runaway plans halt with partial work preserved rather than billing you for a loop.
Profile routing
model: auto routes each step between y0-fast and y0-deep, so latency-sensitive work stays interactive and hard steps get deliberate compute.
Replayable traces
Every run emits a trace that renders identically forever — the plan, each context fetch with its scope, each step, the result.
[ 02 ][ run lifecycle ]
POST /v1/runs → plan composed 2 steps, 96 ms → context fetched calendar (scope calendar:read) → step 1/2 collect_deadlines → step 2/2 draft_brief → result 612 ms total ✓ trace stored — replayable, region-pinned
Keep exploring