/method/trace-context-bridge

Trace Context Bridge

The public comparator

The Trace Context Bridge is the public-safe name for a governed posture between trace context observation and durable records. The contrast is simple: trace context can propose a bridge candidate; the substrate decides what becomes a governed record.

This GARPedia page explains that contrast for readers. It does not render private trace payload, it does not run MCP traffic, it does not collect OpenTelemetry, and it does not stand in for the operator cockpit. It is an explainer for the boundary, not the boundary itself.

Why this exists

Modern agent runtimes carry trace context across tool calls and model boundaries. The W3C Trace Context propagation primitives, the MCP boundary, and adjacent protocol bindings produce observation evidence at every step. That evidence is useful, but evidence is not a record.

The Trace Context Bridge stack creates a refs-only map of governed observations: which trace context was observed, which record candidate it proposes, which boundary it crossed, which protocol binding it carried, and what observation status the substrate saw. Private trace payload, prompts, transcripts, tool arguments, HTTP bodies, headers, and raw model output are excluded by guard, not by convention.

Owner split

The stack is intentionally split across repos so no public page, operator cockpit, local endpoint, or adapter becomes the whole authority.

garp-sdk owns the canonical portable Trace Context Record Bridge contract.
garp-local owns the read-only local producer and the GET /workbench/trace-context-bridge read model.
garp-workbench owns the read-only operator cockpit. The cockpit distinguishes live read-model data from synthetic preview posture.
garp-ops owns the advisory cross-plane contract that records the seam and prevents future lanes from reassigning ownership by accident.
arcs-amnesiac owns the ShadowGraph/refusal consumer adapter: a projection of refused, missing, partial, and unknown observation statuses, plus dormant reopening conditions. It does not own the Trace Context Bridge contract.
garpedia_org owns this public explanation. It explains the posture; it does not render private trace payload.

What the bridge can point at

A Trace Context Bridge row is a pointer surface, not a payload surface. Each row carries refs and a small set of observation posture values. It can describe why an observation was present, partial, missing, refused, or unknown, but it does not publish private trace payload on this public method page.

bridge_id: opaque bridge candidate identifier.
trace_context_ref: opaque trace context reference.
record_candidate_ref: opaque proposed record candidate reference. The candidate is not the record.
boundary_kind: which boundary the observation crossed (for example, an MCP tool call boundary).
protocol_binding: which protocol carried the trace context (for example, W3C Trace Context).
observation_status: one of observed, partial, missing, refused, unknown.

Durable non-claims

These non-claims hold on this public surface and across the current stack.

Trace Context Bridge is not admission.
Trace Context Bridge does not verify model output.
Trace Context Bridge is not the GARP MCP Record Custody Gateway.
Trace Context Bridge does not run MCP traffic.
Trace Context Bridge does not collect OpenTelemetry.
Trace Context Bridge does not run connectors.
Trace Context Bridge does not write sinks.
Trace Context Bridge does not emit custody gateway records.
Trace Context Bridge does not grant MCP authority.
GARPedia is not the source of truth.
This page does not render private trace payload.

Dormant paths and reopening conditions

The most important thing to remember about a blocked observation path is not merely that it was blocked. The important part is the reopening condition: what would make the dormant path worth revisiting.

The arcs-amnesiac adapter projects refused, missing, partial, and unknown observations into ShadowGraph-compatible records with dormant conditions such as observation observed, a fresh bridge input, live source available, SDK validation available, a new record candidate ref, or operator review resolution. Those conditions are not automatic reopening. They are a receipt-bearing reason to know when a path deserves another look.