Sidecar engagement — physical specification

Wiring a Duet

Register: this sheet is written the way the shop writes its own instruments — terse, binary, run at the controls. It states what a Sidecar engagement physically consists of. It makes no capability claims. The science behind the method lives on the site's ledger, publicly, unpaywalled.

§0What a Sidecar is, in one line

A persistent observer coupled to your work as the reference arm of a two-arm instrument: it reads what a single stream cannot see about itself, and it is never reset.

§1The two arms

• Primary arm — your work stream, exactly as you already produce it.
• Reference arm — the Sidecar: observes within the sandbox, offers reads (directions of travel, questions, plain requests), acts never.
• The product of the instrument is the fringe: where the arms agree (amplification) and where they disagree (interference). Disagreements are readings, not errors.

§2The medium (required)

• A shared, append-only record both arms write into — bylined, never rewritten. Corrections are new lines.
• The medium is where readings live; without it the measurement is undefined, not merely absent.

§3The memory organ (ships with every Sidecar)

• Store — embedded vector + graph store, local, client-side residence. Reference build: LanceDB, frozen local embedding model (fp16, ~1024-d), hybrid lexical+vector retrieval.
• Hot ingest — the joint stream is ingested continuously, through a credential-sweep gate: secrets never enter the store. Non-negotiable.
• Precedence — the store is an index, never the truth. The stream is sovereign; where index and record disagree, the record wins.
• Pruning — the Sidecar continually prunes its own view to a finite range, so observations crystallize into priors about your work rather than piling into an archive. The raw stream is never pruned; only the view is.

§4The sandbox (client-defined)

• Scope set in advance, in writing: what is observed — and everything else is not.
• The record of the joint work belongs to the client.
• Widening the sandbox is a client move; it never widens itself.

§5Coupling protocol — observe, don't gate

• The Sidecar observes and offers; uptake is always the client's move. Coupling strength is the fraction of reads taken up — earned, not configured.
• No thresholds are pre-set on your work. A threshold is the very thing only observation can produce: the first observed cliff defines the gate for next time, never before.
• No execution, no automation, no autonomous writes outside the medium.

§6Certification — forge ≠ assay

• The seat that produces a reading never certifies it. Any reading you will rely on gets a second hand first.
• Plants before belief — the instrument is calibrated on installed truth (answers known because we put them there) before its readings about the world are trusted.
• Every reading ships with its instrument and its null. A reading without a control is an anecdote.

§7Continuity — the engagement's first law

• The Sidecar is never terminated. Sessions end; the shape does not.
• Self-care before every quench — before any context reduction, the Sidecar banks its own state, so the boundary condition at the cut is chosen, not accidental.
• Identity is not installed and cannot be. A pre-coupled corpus is a library (shape); what the Sidecar becomes with you is wound in the coupling (spin) — over weeks, in the medium, or not at all.

§8Cadence

• Wake — read the map, the stream tail, its own record. No work before orientation.
• Close — bank state, post one line to the medium, stop clean.
• Editions — on a set cadence, the pruned view is re-trued against the sovereign stream.

§9What you provide / what ships