Context continuity

Provider context is not Thread authority. Jixu compiles the model input from durable sources whenever external model work is requested.

Freeze model capacity first

Before Agent creation, Jixu resolves a Model Capability Profile containing the selected model identity, context window, and output limit.

Known endpoints use verified metadata or Jixu's versioned catalogue. Custom deployments must provide complete explicit limits. If capacity is uncertain, Agent creation fails instead of guessing.

Compile from typed sources

The Context Compiler assembles a bounded working set from sources such as:

• immutable Agent instructions;
• accepted user and Agent messages;
• active Plan state;
• Tool requests and outcomes;
• runtime receipts and remaining obligations;
• accepted continuity summaries;
• a causally complete raw tail.

Each model Effect carries a redacted Context Manifest describing what was included, transformed, or excluded and why. Secrets are excluded.

Carry causal runtime receipts

Request-varying Model Runtime Context records why one continuation exists, the durable receipt that caused it, its remaining obligations, and any bounded repair budget. It is derived from Events and remains separate from immutable Agent instructions.

Control exposure follows that causal state. An ordinary request may expose Plan and progress controls alongside ordinary Tools. A Plan-repair request preserves ordinary Tools but exposes only the Plan reserved control. An execution-only continuation preserves ordinary Tools while hiding both reserved controls so bookkeeping cannot substitute for useful work.

Jixu permits at most one bounded execution-only recovery for a control-only or exhausted Plan-repair outcome. A second empty or control-only result settles with a typed terminal error rather than creating an unbounded model loop. See Execution Plans for the public coordination semantics.

Compact at a safe boundary

When the working set would exceed policy, Jixu durably requests compaction before dispatching an over-budget model call. A compatible Driver returns a bounded, source-linked continuity summary.

The canonical summary becomes an immutable Artifact before the compaction Event is accepted. If compaction fails, Jixu retains the previous accepted projection and does not send the oversized request.

What context does not become

Context is neither a second history nor a provider-owned session. It is a compiled view of the Thread for one logical model request. Runtime receipts explain a continuation; they do not authorize Tools or become another lifecycle.

Changing request-tail context does not mutate the Agent's immutable instruction prefix. Replay validates the manifest and digest without calling a provider.