005-coupling-gate

The coupling gate: join the two views and refuse drift

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The PR-time coupling gate (spec-spine.md guardrail 2): cross-reference every changed code path against the authority graph and refuse the merge when code drifts from the spec that owns it. A pure function of (config, registry, index, diff, waiver); the CLI parses `git diff --no-color -U0 --no-renames base...head` (quotepath off, end-of-options) into a typed DiffInput so git stays out of core. Matches a diff hunk to its owning unit at file, section, and symbol granularity; is amends-aware with the FR-005 strict-expansion guard; transfers authority across supersedes; honors PR-body waivers and an additive bypass list. Establishes the couple engine and the `spec-spine couple` subcommand.

Read the full pinned specification ↗

Relationships

depends on

depended on by

amended by

Claimed units

establishes

{
  "kind": "file",
  "path": "crates/spec-spine-core/src/couple.rs"
}

establishes

{
  "kind": "file",
  "path": "crates/spec-spine-core/src/dep_only.rs"
}

establishes

{
  "kind": "file",
  "path": "crates/spec-spine-cli/src/cmd_couple.rs"
}

establishes

{
  "kind": "file",
  "path": "crates/spec-spine-core/tests/couple.rs"
}

establishes

{
  "kind": "file",
  "path": "crates/spec-spine-cli/tests/couple.rs"
}

extends

{
  "nature": "additive",
  "spec": "001-compile-registry",
  "unit": {
    "kind": "file",
    "path": "crates/spec-spine-core/src/lib.rs"
  }
}

extends

{
  "nature": "additive",
  "spec": "001-compile-registry",
  "unit": {
    "kind": "file",
    "path": "crates/spec-spine-cli/src/main.rs"
  }
}

Source headings

005: The coupling gate
1. Purpose
2. Territory
3. Behavior
3.1 The boundary: git stays out of core
3.2 Owner derivation: three granularities
3.3 Amends-awareness and the strict-expansion guard (FR-005)
3.4 Supersedes: authority transfer
3.5 Clearance, waivers, and bypass
3.6 Granularity reconciliation (the crate-spec vs file-establishes question)
3.7 Exit codes
3.8 Determinism
4. Out of scope

Frozen anchors

No frozen anchors declared.