diff --git a/Cargo.lock b/Cargo.lock
index 224464d..b9d6265 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -239,6 +239,12 @@ version = "0.8.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "5e764a1d40d510daf35e07be9eb06e75770908c27d411ee6c92109c9840eaaf7"
 
+[[package]]
+name = "bitflags"
+version = "1.3.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bef38d45163c2f1dde094a7dfd33ccf595c92905c8f8f4fdc18d06fb1037718a"
+
 [[package]]
 name = "bitflags"
 version = "2.11.0"
@@ -719,6 +725,15 @@ dependencies = [
  "itertools 0.10.5",
 ]
 
+[[package]]
+name = "crossbeam-channel"
+version = "0.5.15"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "82b8f8f868b36967f9606790d1903570de9ceaf870a7bf9fbbd3016d636a2cb2"
+dependencies = [
+ "crossbeam-utils",
+]
+
 [[package]]
 name = "crossbeam-deque"
 version = "0.8.6"
@@ -946,6 +961,15 @@ version = "0.5.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "1d674e81391d1e1ab681a28d99df07927c6d4aa5b027d7da16ba32d1d21ecd99"
 
+[[package]]
+name = "fluent-uri"
+version = "0.1.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "17c704e9dbe1ddd863da1e6ff3567795087b1eb201ce80d8fa81162e1516500d"
+dependencies = [
+ "bitflags 1.3.2",
+]
+
 [[package]]
 name = "fnv"
 version = "1.0.7"
@@ -1087,7 +1111,7 @@ version = "0.8.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "25234f20a3ec0a962a61770cfe39ecf03cb529a6e474ad8cff025ed497eda557"
 dependencies = [
- "bitflags",
+ "bitflags 2.11.0",
  "debugid",
  "rustc-hash 2.1.1",
  "serde",
@@ -1750,6 +1774,32 @@ version = "0.4.29"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "5e5032e24019045c762d3c0f28f5b6b8bbf38563a65908389bf7978758920897"
 
+[[package]]
+name = "lsp-server"
+version = "0.7.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7d6ada348dbc2703cbe7637b2dda05cff84d3da2819c24abcb305dd613e0ba2e"
+dependencies = [
+ "crossbeam-channel",
+ "log",
+ "serde",
+ "serde_derive",
+ "serde_json",
+]
+
+[[package]]
+name = "lsp-types"
+version = "0.97.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "53353550a17c04ac46c585feb189c2db82154fc84b79c7a66c96c2c644f66071"
+dependencies = [
+ "bitflags 1.3.2",
+ "fluent-uri",
+ "serde",
+ "serde_json",
+ "serde_repr",
+]
+
 [[package]]
 name = "mach2"
 version = "0.4.3"
@@ -1894,7 +1944,7 @@ version = "0.10.76"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "951c002c75e16ea2c65b8c7e4d3d51d5530d8dfa7d060b4776828c88cfb18ecf"
 dependencies = [
- "bitflags",
+ "bitflags 2.11.0",
  "cfg-if",
  "foreign-types",
  "libc",
@@ -2099,7 +2149,7 @@ checksum = "37566cb3fdacef14c0737f9546df7cfeadbfbc9fef10991038bf5015d0c80532"
 dependencies = [
  "bit-set",
  "bit-vec",
- "bitflags",
+ "bitflags 2.11.0",
  "num-traits",
  "rand 0.9.2",
  "rand_chacha 0.9.0",
@@ -2116,7 +2166,7 @@ version = "0.12.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f86ba2052aebccc42cbbb3ed234b8b13ce76f75c3551a303cb2bcffcff12bb14"
 dependencies = [
- "bitflags",
+ "bitflags 2.11.0",
  "memchr",
  "pulldown-cmark-escape",
  "unicase",
@@ -2291,7 +2341,7 @@ version = "0.5.18"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ed2bf2547551a7053d6fdfafda3f938979645c44812fbfcda098faae3f1a362d"
 dependencies = [
- "bitflags",
+ "bitflags 2.11.0",
 ]
 
 [[package]]
@@ -2412,6 +2462,8 @@ dependencies = [
  "env_logger",
  "etch",
  "log",
+ "lsp-server",
+ "lsp-types",
  "petgraph 0.7.1",
  "rivet-core",
  "serde",
@@ -2490,7 +2542,7 @@ version = "0.38.44"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "fdb5bc1ae2baa591800df16c9ca78619bf65c0488b41b96ccec5d11220d8c154"
 dependencies = [
- "bitflags",
+ "bitflags 2.11.0",
  "errno",
  "libc",
  "linux-raw-sys 0.4.15",
@@ -2503,7 +2555,7 @@ version = "1.1.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b6fe4565b9518b83ef4f91bb47ce29620ca828bd32cb7e408f0062e9930ba190"
 dependencies = [
- "bitflags",
+ "bitflags 2.11.0",
  "errno",
  "libc",
  "linux-raw-sys 0.12.1",
@@ -2665,7 +2717,7 @@ version = "3.7.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b7f4bc775c73d9a02cde8bf7b2ec4c9d12743edf609006c7facc23998404cd1d"
 dependencies = [
- "bitflags",
+ "bitflags 2.11.0",
  "core-foundation 0.10.1",
  "core-foundation-sys",
  "libc",
@@ -2746,6 +2798,17 @@ dependencies = [
  "serde_core",
 ]
 
+[[package]]
+name = "serde_repr"
+version = "0.1.20"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "175ee3e80ae9982737ca543e96133087cbd9a485eecc3bc4de9c1a37b47ea59c"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
 [[package]]
 name = "serde_spanned"
 version = "1.0.4"
@@ -3009,7 +3072,7 @@ version = "0.7.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a13f3d0daba03132c0aa9767f98351b3488edc2c100cda2d2ec2b04f3d8d3c8b"
 dependencies = [
- "bitflags",
+ "bitflags 2.11.0",
  "core-foundation 0.9.4",
  "system-configuration-sys",
 ]
@@ -3030,7 +3093,7 @@ version = "0.27.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "cc4592f674ce18521c2a81483873a49596655b179f71c5e05d10c1fe66c78745"
 dependencies = [
- "bitflags",
+ "bitflags 2.11.0",
  "cap-fs-ext",
  "cap-std",
  "fd-lock",
@@ -3262,7 +3325,7 @@ version = "0.6.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d4e6559d53cc268e5031cd8429d05415bc4cb4aefc4aa5d6cc35fbf5b924a1f8"
 dependencies = [
- "bitflags",
+ "bitflags 2.11.0",
  "bytes",
  "futures-core",
  "futures-util",
@@ -3604,7 +3667,7 @@ version = "0.244.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "47b807c72e1bac69382b3a6fb3dbe8ea4c0ed87ff5629b8685ae6b9a611028fe"
 dependencies = [
- "bitflags",
+ "bitflags 2.11.0",
  "hashbrown 0.15.5",
  "indexmap",
  "semver",
@@ -3617,7 +3680,7 @@ version = "0.245.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "4f08c9adee0428b7bddf3890fc27e015ac4b761cc608c822667102b8bfd6995e"
 dependencies = [
- "bitflags",
+ "bitflags 2.11.0",
  "indexmap",
  "semver",
 ]
@@ -3641,7 +3704,7 @@ checksum = "39bef52be4fb4c5b47d36f847172e896bc94b35c9c6a6f07117686bd16ed89a7"
 dependencies = [
  "addr2line",
  "async-trait",
- "bitflags",
+ "bitflags 2.11.0",
  "bumpalo",
  "cc",
  "cfg-if",
@@ -3880,7 +3943,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "102d0d70dbfede00e4cc9c24e86df6d32c03bf6f5ad06b5d6c76b0a4a5004c4a"
 dependencies = [
  "anyhow",
- "bitflags",
+ "bitflags 2.11.0",
  "heck",
  "indexmap",
  "wit-parser",
@@ -3893,7 +3956,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ea938f6f4f11e5ffe6d8b6f34c9a994821db9511c3e9c98e535896f27d06bb92"
 dependencies = [
  "async-trait",
- "bitflags",
+ "bitflags 2.11.0",
  "bytes",
  "cap-fs-ext",
  "cap-net-ext",
@@ -3976,7 +4039,7 @@ version = "42.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "2dca2bf96d20f0c70e6741cc6c8c1a9ee4c3c0310c7ad1971242628c083cc9a5"
 dependencies = [
- "bitflags",
+ "bitflags 2.11.0",
  "thiserror 2.0.18",
  "tracing",
  "wasmtime",
@@ -4233,7 +4296,7 @@ version = "0.36.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "3f3fd376f71958b862e7afb20cfe5a22830e1963462f3a17f49d82a6c1d1f42d"
 dependencies = [
- "bitflags",
+ "bitflags 2.11.0",
  "windows-sys 0.59.0",
 ]
 
@@ -4318,7 +4381,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9d66ea20e9553b30172b5e831994e35fbde2d165325bec84fc43dbf6f4eb9cb2"
 dependencies = [
  "anyhow",
- "bitflags",
+ "bitflags 2.11.0",
  "indexmap",
  "log",
  "serde",
diff --git a/artifacts/decisions.yaml b/artifacts/decisions.yaml
index f1647a1..849a949 100644
--- a/artifacts/decisions.yaml
+++ b/artifacts/decisions.yaml
@@ -12,6 +12,7 @@ artifacts:
       - type: satisfies
         target: REQ-006
     fields:
+      baseline: v0.1.0
       rationale: >
         OSLC is an OASIS standard that Polarion, DOORS, and codebeamer
         already support natively. One adapter handles all tools. Per-tool
@@ -41,6 +42,7 @@ artifacts:
       - type: satisfies
         target: REQ-004
     fields:
+      baseline: v0.1.0
       rationale: >
         petgraph is a mature, well-tested Rust graph library. It provides
         efficient algorithms for cycle detection, topological sort, and
@@ -66,6 +68,7 @@ artifacts:
       - type: satisfies
         target: REQ-003
     fields:
+      baseline: v0.1.0
       source-ref: rivet-core/src/schema.rs:1
       rationale: >
         Merging allows a base common schema to be extended by domain-specific
@@ -86,6 +89,7 @@ artifacts:
       - type: satisfies
         target: REQ-008
     fields:
+      baseline: v0.1.0
       rationale: >
         WIT provides a language-agnostic interface definition. Adapters can
         be written in any language that compiles to WASM components, not
@@ -106,6 +110,7 @@ artifacts:
       - type: satisfies
         target: REQ-007
     fields:
+      baseline: v0.1.0
       rationale: >
         axum is already a workspace dependency. HTMX keeps the frontend
         simple (server-rendered HTML fragments). No JS build toolchain
@@ -126,6 +131,7 @@ artifacts:
       - type: satisfies
         target: REQ-001
     fields:
+      baseline: v0.1.0
       rationale: >
         Flat structures are easier to navigate and understand. Modern
         Rust projects favor fewer nesting levels with clear module
@@ -148,6 +154,7 @@ artifacts:
       - type: satisfies
         target: REQ-009
     fields:
+      baseline: v0.1.0
       rationale: >
         GitHub releases are immutable, versioned, and fetchable via API.
         Tying test evidence to releases creates append-only per-version
@@ -171,6 +178,7 @@ artifacts:
       - type: satisfies
         target: REQ-012
     fields:
+      baseline: v0.1.0
       rationale: >
         Edition 2024 brings the latest language features. The CI pipeline
         mirrors ASPICE SWE.4-6 verification levels: unit tests (proptest,
@@ -193,6 +201,7 @@ artifacts:
       - type: satisfies
         target: REQ-013
     fields:
+      baseline: v0.1.0
       rationale: >
         Criterion provides statistical analysis, regression detection,
         and HTML reports. Benchmarks at multiple scales catch O(n^2)
@@ -217,6 +226,7 @@ artifacts:
       - type: satisfies
         target: REQ-016
     fields:
+      baseline: v0.1.0
       rationale: >
         ASPICE 4.0 broadened "testing" to "verification measures" — the
         schema should reflect this. Cybersecurity as a separate schema
@@ -241,6 +251,7 @@ artifacts:
       - type: satisfies
         target: REQ-017
     fields:
+      baseline: v0.2.0-dev
       rationale: >
         Git trailers are a well-supported standard, parseable via
         git log --format='%(trailers)', git interpret-trailers, and
@@ -265,6 +276,7 @@ artifacts:
       - type: satisfies
         target: REQ-017
     fields:
+      baseline: v0.2.0-dev
       rationale: >
         Git is the single source of truth for commit data. Materializing
         commits to YAML creates a redundant data store that drifts from
@@ -291,6 +303,7 @@ artifacts:
       - type: satisfies
         target: REQ-019
     fields:
+      baseline: v0.2.0-dev
       rationale: >
         Type-based exemption handles the 80% case (dependency bumps,
         formatting, CI tweaks) with zero friction. The explicit skip
diff --git a/artifacts/features.yaml b/artifacts/features.yaml
index f258a70..f1e31ce 100644
--- a/artifacts/features.yaml
+++ b/artifacts/features.yaml
@@ -16,6 +16,7 @@ artifacts:
         target: DD-031
     fields:
       phase: phase-1
+      baseline: v0.1.0
 
   - id: FEAT-002
     type: feature
@@ -32,6 +33,7 @@ artifacts:
         target: DD-032
     fields:
       phase: phase-1
+      baseline: v0.1.0
 
   - id: FEAT-003
     type: feature
@@ -46,6 +48,7 @@ artifacts:
         target: REQ-010
     fields:
       phase: phase-1
+      baseline: v0.1.0
 
   - id: FEAT-004
     type: feature
@@ -62,6 +65,7 @@ artifacts:
         target: DD-002
     fields:
       phase: phase-1
+      baseline: v0.1.0
 
   - id: FEAT-005
     type: feature
@@ -77,6 +81,7 @@ artifacts:
         target: REQ-004
     fields:
       phase: phase-1
+      baseline: v0.1.0
 
   - id: FEAT-006
     type: feature
@@ -91,6 +96,7 @@ artifacts:
         target: REQ-004
     fields:
       phase: phase-1
+      baseline: v0.1.0
 
   - id: FEAT-007
     type: feature
@@ -105,6 +111,7 @@ artifacts:
         target: REQ-007
     fields:
       phase: phase-1
+      baseline: v0.1.0
 
   - id: FEAT-008
     type: feature
@@ -121,6 +128,7 @@ artifacts:
         target: REQ-002
     fields:
       phase: phase-1
+      baseline: v0.1.0
 
   - id: FEAT-009
     type: feature
@@ -137,6 +145,7 @@ artifacts:
         target: DD-005
     fields:
       phase: phase-2
+      baseline: v0.1.0
 
   - id: FEAT-010
     type: feature
@@ -152,6 +161,7 @@ artifacts:
         target: DD-034
     fields:
       phase: phase-2
+      baseline: v0.1.0
 
   - id: FEAT-011
     type: feature
@@ -168,6 +178,7 @@ artifacts:
         target: DD-001
     fields:
       phase: phase-3
+      baseline: v0.2.0-dev
 
   - id: FEAT-012
     type: feature
@@ -184,6 +195,7 @@ artifacts:
         target: DD-004
     fields:
       phase: phase-3
+      baseline: v0.2.0-dev
 
   - id: FEAT-013
     type: feature
@@ -198,6 +210,7 @@ artifacts:
         target: REQ-014
     fields:
       phase: phase-1
+      baseline: v0.1.0
 
   - id: FEAT-014
     type: feature
@@ -215,6 +228,7 @@ artifacts:
         target: REQ-009
     fields:
       phase: phase-1
+      baseline: v0.1.0
 
   - id: FEAT-015
     type: feature
@@ -232,6 +246,7 @@ artifacts:
         target: DD-009
     fields:
       phase: phase-1
+      baseline: v0.1.0
 
   - id: FEAT-016
     type: feature
@@ -253,6 +268,7 @@ artifacts:
         target: DD-010
     fields:
       phase: phase-1
+      baseline: v0.1.0
 
   - id: FEAT-017
     type: feature
@@ -272,6 +288,7 @@ artifacts:
         target: DD-010
     fields:
       phase: phase-1
+      baseline: v0.1.0
 
   - id: FEAT-018
     type: feature
@@ -291,6 +308,7 @@ artifacts:
         target: DD-033
     fields:
       phase: phase-2
+      baseline: v0.1.0
 
   - id: FEAT-019
     type: feature
@@ -307,6 +325,7 @@ artifacts:
         target: REQ-001
     fields:
       phase: phase-2
+      baseline: v0.1.0
 
   - id: FEAT-020
     type: feature
@@ -324,6 +343,7 @@ artifacts:
         target: REQ-007
     fields:
       phase: phase-3
+      baseline: v0.2.0-dev
 
   - id: FEAT-021
     type: feature
@@ -340,6 +360,7 @@ artifacts:
         target: REQ-010
     fields:
       phase: phase-2
+      baseline: v0.1.0
 
   - id: FEAT-022
     type: feature
@@ -356,6 +377,7 @@ artifacts:
         target: REQ-007
     fields:
       phase: phase-2
+      baseline: v0.1.0
 
   - id: FEAT-023
     type: feature
@@ -373,6 +395,7 @@ artifacts:
         target: REQ-010
     fields:
       phase: phase-2
+      baseline: v0.1.0
 
   - id: FEAT-024
     type: feature
@@ -389,6 +412,7 @@ artifacts:
         target: REQ-007
     fields:
       phase: phase-2
+      baseline: v0.1.0
 
   - id: FEAT-025
     type: feature
@@ -405,6 +429,7 @@ artifacts:
         target: REQ-007
     fields:
       phase: phase-2
+      baseline: v0.1.0
 
   - id: FEAT-026
     type: feature
@@ -422,6 +447,7 @@ artifacts:
         target: REQ-010
     fields:
       phase: phase-2
+      baseline: v0.1.0
 
   - id: FEAT-027
     type: feature
@@ -437,6 +463,7 @@ artifacts:
         target: REQ-007
     fields:
       phase: phase-2
+      baseline: v0.1.0
 
   - id: FEAT-028
     type: feature
@@ -453,6 +480,7 @@ artifacts:
         target: REQ-007
     fields:
       phase: phase-2
+      baseline: v0.1.0
 
   - id: FEAT-029
     type: feature
@@ -472,6 +500,7 @@ artifacts:
         target: REQ-018
     fields:
       phase: phase-3
+      baseline: v0.2.0-dev
 
   - id: FEAT-030
     type: feature
@@ -491,6 +520,7 @@ artifacts:
         target: REQ-019
     fields:
       phase: phase-3
+      baseline: v0.2.0-dev
 
   - id: FEAT-031
     type: feature
@@ -507,6 +537,7 @@ artifacts:
         target: REQ-017
     fields:
       phase: phase-3
+      baseline: v0.2.0-dev
 
   - id: FEAT-032
     type: feature
@@ -526,6 +557,7 @@ artifacts:
         target: DD-012
     fields:
       phase: phase-3
+      baseline: v0.2.0-dev
 
   - id: FEAT-033
     type: feature
@@ -636,6 +668,7 @@ artifacts:
         target: DD-018
     fields:
       phase: phase-3
+      baseline: v0.2.0-dev
 
   - id: FEAT-041
     type: feature
@@ -655,6 +688,7 @@ artifacts:
         target: DD-019
     fields:
       phase: phase-3
+      baseline: v0.2.0-dev
 
   - id: FEAT-042
     type: feature
@@ -674,6 +708,7 @@ artifacts:
         target: DD-020
     fields:
       phase: phase-3
+      baseline: v0.2.0-dev
 
   - id: FEAT-043
     type: feature
@@ -694,6 +729,7 @@ artifacts:
         target: DD-021
     fields:
       phase: phase-3
+      baseline: v0.2.0-dev
 
   - id: FEAT-044
     type: feature
@@ -714,6 +750,7 @@ artifacts:
         target: DD-022
     fields:
       phase: phase-3
+      baseline: v0.2.0-dev
 
   - id: FEAT-045
     type: feature
@@ -733,6 +770,7 @@ artifacts:
         target: REQ-007
     fields:
       phase: phase-3
+      baseline: v0.2.0-dev
 
   - id: FEAT-057
     type: feature
@@ -751,6 +789,7 @@ artifacts:
         target: REQ-007
     fields:
       phase: phase-3
+      baseline: v0.2.0-dev
 
   - id: FEAT-052
     type: feature
@@ -771,6 +810,7 @@ artifacts:
         target: DD-028
     fields:
       phase: phase-3
+      baseline: v0.2.0-dev
 
   - id: FEAT-053
     type: feature
@@ -790,6 +830,7 @@ artifacts:
         target: DD-028
     fields:
       phase: phase-3
+      baseline: v0.2.0-dev
 
   - id: FEAT-054
     type: feature
@@ -811,6 +852,7 @@ artifacts:
         target: DD-028
     fields:
       phase: phase-3
+      baseline: v0.2.0-dev
 
   - id: FEAT-055
     type: feature
@@ -834,6 +876,7 @@ artifacts:
         target: DD-028
     fields:
       phase: phase-3
+      baseline: v0.2.0-dev
 
   - id: FEAT-056
     type: feature
@@ -853,6 +896,7 @@ artifacts:
         target: REQ-007
     fields:
       phase: phase-3
+      baseline: v0.2.0-dev
 
   - id: FEAT-046
     type: feature
@@ -875,6 +919,7 @@ artifacts:
         target: DD-023
     fields:
       phase: phase-3
+      baseline: v0.2.0-dev
 
   - id: FEAT-047
     type: feature
@@ -897,6 +942,7 @@ artifacts:
         target: DD-024
     fields:
       phase: phase-3
+      baseline: v0.2.0-dev
 
   - id: FEAT-048
     type: feature
@@ -920,6 +966,7 @@ artifacts:
         target: DD-024
     fields:
       phase: phase-3
+      baseline: v0.2.0-dev
 
   - id: FEAT-049
     type: feature
@@ -939,6 +986,7 @@ artifacts:
         target: DD-025
     fields:
       phase: phase-3
+      baseline: v0.2.0-dev
 
   - id: FEAT-050
     type: feature
@@ -1075,6 +1123,7 @@ artifacts:
         target: REQ-011
     fields:
       phase: phase-2
+      baseline: v0.1.0
 
   - id: FEAT-065
     type: feature
@@ -1092,3 +1141,4 @@ artifacts:
         target: REQ-012
     fields:
       phase: phase-2
+      baseline: v0.1.0
diff --git a/artifacts/requirements.yaml b/artifacts/requirements.yaml
index 0a47ac7..e9f80f3 100644
--- a/artifacts/requirements.yaml
+++ b/artifacts/requirements.yaml
@@ -10,6 +10,7 @@ artifacts:
     fields:
       priority: must
       category: functional
+      baseline: v0.1.0
 
   - id: REQ-002
     type: requirement
@@ -23,6 +24,7 @@ artifacts:
     fields:
       priority: must
       category: functional
+      baseline: v0.1.0
 
   - id: REQ-003
     type: requirement
@@ -36,6 +38,7 @@ artifacts:
     fields:
       priority: must
       category: functional
+      baseline: v0.1.0
 
   - id: REQ-004
     type: requirement
@@ -49,6 +52,7 @@ artifacts:
     fields:
       priority: must
       category: functional
+      baseline: v0.1.0
 
     links:
       - type: satisfies
@@ -69,6 +73,7 @@ artifacts:
     fields:
       priority: should
       category: interface
+      baseline: v0.1.0
 
     links:
       - type: satisfies
@@ -87,6 +92,7 @@ artifacts:
     fields:
       priority: should
       category: interface
+      baseline: v0.1.0
 
     links:
       - type: satisfies
@@ -105,6 +111,7 @@ artifacts:
     fields:
       priority: must
       category: functional
+      baseline: v0.1.0
     links:
       - type: satisfies
         target: SC-18
@@ -120,6 +127,7 @@ artifacts:
     fields:
       priority: should
       category: functional
+      baseline: v0.1.0
     links:
       - type: satisfies
         target: SC-16
@@ -136,6 +144,7 @@ artifacts:
     fields:
       priority: should
       category: functional
+      baseline: v0.1.0
 
     links:
       - type: satisfies
@@ -152,6 +161,7 @@ artifacts:
     fields:
       priority: must
       category: functional
+      baseline: v0.1.0
 
     links:
       - type: satisfies
@@ -166,6 +176,7 @@ artifacts:
     fields:
       priority: must
       category: constraint
+      baseline: v0.1.0
 
   - id: REQ-012
     type: requirement
@@ -179,6 +190,7 @@ artifacts:
     fields:
       priority: must
       category: non-functional
+      baseline: v0.1.0
 
   - id: REQ-013
     type: requirement
@@ -192,6 +204,7 @@ artifacts:
     fields:
       priority: must
       category: non-functional
+      baseline: v0.1.0
 
   - id: REQ-014
     type: requirement
@@ -206,6 +219,7 @@ artifacts:
     fields:
       priority: must
       category: non-functional
+      baseline: v0.1.0
 
   - id: REQ-015
     type: requirement
@@ -223,6 +237,7 @@ artifacts:
     fields:
       priority: must
       category: functional
+      baseline: v0.1.0
 
     links:
       - type: satisfies
@@ -240,6 +255,7 @@ artifacts:
     fields:
       priority: should
       category: functional
+      baseline: v0.1.0
 
     links:
       - type: satisfies
@@ -258,6 +274,7 @@ artifacts:
     fields:
       priority: must
       category: functional
+      baseline: v0.2.0-dev
 
     links:
       - type: satisfies
@@ -277,6 +294,7 @@ artifacts:
     fields:
       priority: must
       category: functional
+      baseline: v0.2.0-dev
 
     links:
       - type: satisfies
@@ -294,6 +312,7 @@ artifacts:
     fields:
       priority: must
       category: functional
+      baseline: v0.2.0-dev
 
     links:
       - type: satisfies
@@ -309,6 +328,7 @@ artifacts:
     fields:
       priority: must
       category: functional
+      baseline: v0.2.0-dev
 
     links:
       - type: satisfies
@@ -326,6 +346,7 @@ artifacts:
     fields:
       priority: should
       category: functional
+      baseline: v0.2.0-dev
 
     links:
       - type: satisfies
@@ -341,6 +362,7 @@ artifacts:
     fields:
       priority: should
       category: functional
+      baseline: v0.2.0-dev
 
   - id: REQ-023
     type: requirement
@@ -362,6 +384,7 @@ artifacts:
       priority: should
       category: functional
       upstream-ref: "eclipse-score/docs-as-code#180"
+      baseline: v0.2.0-dev
 
   - id: REQ-024
     type: requirement
@@ -377,6 +400,7 @@ artifacts:
       priority: should
       category: functional
       upstream-ref: "eclipse-score/docs-as-code#314, eclipse-score/process_description#535"
+      baseline: v0.2.0-dev
 
     links:
       - type: satisfies
@@ -395,6 +419,7 @@ artifacts:
       priority: should
       category: interface
       upstream-ref: "eclipse-score/score#1695"
+      baseline: v0.2.0-dev
 
     links:
       - type: satisfies
@@ -414,6 +439,7 @@ artifacts:
       priority: should
       category: functional
       upstream-ref: "eclipse-score/score#2521, eclipse-score/score#2619"
+      baseline: v0.2.0-dev
 
     links:
       - type: satisfies
@@ -434,6 +460,7 @@ artifacts:
       priority: should
       category: functional
       upstream-ref: "eclipse-score/reference_integration (known_good.json)"
+      baseline: v0.2.0-dev
 
     links:
       - type: satisfies
@@ -455,6 +482,7 @@ artifacts:
     fields:
       priority: must
       category: non-functional
+      baseline: v0.2.0-dev
 
   - id: REQ-029
     type: requirement
@@ -475,6 +503,7 @@ artifacts:
     fields:
       priority: must
       category: non-functional
+      baseline: v0.2.0-dev
 
   - id: REQ-031
     type: requirement
@@ -499,6 +528,7 @@ artifacts:
     fields:
       priority: must
       category: functional
+      baseline: v0.2.0-dev
 
   - id: REQ-030
     type: requirement
@@ -519,6 +549,7 @@ artifacts:
     fields:
       priority: should
       category: non-functional
+      baseline: v0.2.0-dev
 
   - id: REQ-032
     type: requirement
@@ -530,6 +561,7 @@ artifacts:
     fields:
       category: functional
       priority: should
+      baseline: v0.2.0-dev
 
   - id: REQ-033
     type: requirement
@@ -541,6 +573,7 @@ artifacts:
     fields:
       category: functional
       priority: should
+      baseline: v0.2.0-dev
 
   - id: REQ-034
     type: requirement
@@ -552,6 +585,7 @@ artifacts:
     fields:
       category: functional
       priority: must
+      baseline: v0.2.0-dev
     links:
       - type: satisfies
         target: SC-2
@@ -566,6 +600,7 @@ artifacts:
     fields:
       category: functional
       priority: must
+      baseline: v0.2.0-dev
 
   - id: REQ-036
     type: requirement
@@ -577,3 +612,4 @@ artifacts:
     fields:
       category: functional
       priority: should
+      baseline: v0.2.0-dev
diff --git a/docs/plans/2026-03-21-baseline-scoped-validation-design.md b/docs/plans/2026-03-21-baseline-scoped-validation-design.md
new file mode 100644
index 0000000..c609259
--- /dev/null
+++ b/docs/plans/2026-03-21-baseline-scoped-validation-design.md
@@ -0,0 +1,542 @@
+# Baseline-Scoped Validation Design
+
+**Date:** 2026-03-21
+**Status:** Draft
+**Artifacts:** [[REQ-021]], [[REQ-024]], [[FEAT-036]], [[FEAT-041]], [[DD-016]], [[DD-019]]
+
+## Problem
+
+Rivet currently validates all artifacts as a single flat set. When a project
+evolves across releases (v0.1.0, v0.2.0, ...), there is no way to say:
+
+> "All artifacts committed to baseline v0.1.0 are fully linked and validated.
+> Artifacts planned for v0.2.0 may still have gaps -- that is expected."
+
+Today, `rivet validate` reports warnings for every artifact that lacks
+downstream traceability, including artifacts deliberately scoped for a
+future release. This makes validation noisy and masks real problems in the
+current release scope.
+
+The existing `phase` field on features (values: phase-1, phase-2, phase-3,
+future) is an informal workaround. It lives only on `feature` artifacts, is
+not schema-enforced across types, and has no integration with the validation
+engine, coverage computation, or export pipeline.
+
+The existing `rivet baseline verify` command checks for git tag presence
+across repos (DD-016) but does not scope validation to the artifacts in that
+baseline.
+
+## Prior Art
+
+### sphinx-needs
+
+sphinx-needs stores versioned snapshots of all needs in `needs.json`, keyed
+by the documentation version from `conf.py`. Each build appends a new
+version entry. Comparison happens post-hoc by diffing two version snapshots.
+There is no per-artifact baseline field or selective validation -- all needs
+in a build are validated equally.
+
+Limitations: no concept of "this need ships in v2.0 so skip it for v1.0
+validation." Impact analysis (issue #685) is aspirational, not implemented.
+
+### Eclipse SCORE
+
+SCORE's process description (SUP.8, SUP.10) requires configuration baselines
+and change request traceability. Their toolchain uses sphinx-needs with a
+`known_good.json` manifest for cross-repo pinning. Baselining is at the
+repository level (git tags), not at the artifact level. They face the same
+gap: no way to scope validation to a release subset.
+
+### Industry Standard (ASPICE SUP.8 / ISO 26262 Part 8)
+
+A **configuration baseline** is a formally approved set of configuration items
+at a point in time. Baselines are snapshots, not filters -- all items in the
+baseline must be consistent and complete. A new baseline is created for each
+release milestone. Items not yet in a baseline are "work in progress" and
+are excluded from baseline validation.
+
+## Design
+
+### Core Concept: Baselines as Named Artifact Sets
+
+A **baseline** is a named set of artifact IDs representing a release scope.
+Each artifact declares which baseline(s) it belongs to via a `baseline` field.
+Validation, coverage, and export can then be scoped to a specific baseline.
+
+Key properties:
+- An artifact can belong to multiple baselines (e.g., REQ-001 ships in
+  both v0.1.0 and v0.2.0 because v0.2.0 is a superset).
+- Baselines are **cumulative by default**: v0.2.0 includes everything in
+  v0.1.0 plus new artifacts. This matches how software releases work.
+- The baseline name is a free-form string, but convention is semver
+  (v0.1.0, v0.2.0) or milestone names (mvp, ga).
+- Baselines are distinct from git tags but can be cross-referenced:
+  `rivet baseline verify v0.1.0` checks that the git tag `baseline/v0.1.0`
+  exists and that all artifacts in the v0.1.0 baseline are present at that
+  commit.
+
+### Baseline Configuration in rivet.yaml
+
+```yaml
+project:
+  name: rivet
+  version: "0.1.0"
+  schemas:
+    - common
+    - dev
+    - aadl
+    - stpa
+
+baselines:
+  v0.1.0:
+    description: "Phase 1+2: core validation, schemas, dashboard, CLI"
+    # Cumulative: false means only explicitly listed artifacts.
+    # Cumulative: true (default) means "all artifacts from prior baselines
+    # plus anything tagged with this baseline."
+    cumulative: true
+    # Optional: link to git tag for cross-referencing
+    git-tag: baseline/v0.1.0
+
+  v0.2.0:
+    description: "Phase 3: commit traceability, cross-repo, mutation"
+    cumulative: true
+    git-tag: baseline/v0.2.0
+```
+
+**Why baselines are in rivet.yaml, not a separate file:**
+Baseline definitions are project-level metadata, like schemas and sources.
+They evolve with the project and should be version-controlled alongside
+the artifact sources. A separate `baselines.yaml` file adds indirection
+without benefit.
+
+### Artifact Field: `baseline`
+
+Every artifact type gains an optional `baseline` field. This is a common
+base field (like `status` and `tags`), not a per-type schema field.
+
+```yaml
+artifacts:
+  - id: REQ-001
+    type: requirement
+    title: Text-file-first artifact management
+    status: approved
+    baseline: v0.1.0          # Ships in v0.1.0
+    # ...
+
+  - id: REQ-020
+    type: requirement
+    title: Cross-repository artifact linking
+    status: approved
+    baseline: v0.2.0          # Ships in v0.2.0
+    # ...
+```
+
+**Rules:**
+- `baseline` is a string (not a list). An artifact belongs to the named
+  baseline and all subsequent cumulative baselines.
+- If `baseline` is omitted, the artifact is "unscoped" -- included in
+  full validation but excluded from baseline-scoped validation.
+- The `baseline` field is optional and defaults to `null`.
+
+**Why a single string, not a list:**
+In a cumulative model, an artifact only needs to declare the *first*
+baseline it ships in. If v0.2.0 is cumulative on v0.1.0, then an
+artifact with `baseline: v0.1.0` is automatically in v0.2.0. This is
+simpler to maintain and matches how release scoping works in practice.
+You add an artifact to the current milestone; you do not re-tag it for
+every future milestone.
+
+### Baseline Ordering
+
+Baselines have an implicit ordering derived from their declaration order
+in `rivet.yaml`. The first declared baseline is the earliest; subsequent
+baselines are later. This ordering is used for cumulative inclusion:
+`v0.2.0` includes all artifacts from `v0.1.0` because v0.1.0 is declared
+before v0.2.0.
+
+```yaml
+baselines:
+  v0.1.0: { ... }    # order 0
+  v0.2.0: { ... }    # order 1 -- includes v0.1.0 artifacts
+  v1.0.0: { ... }    # order 2 -- includes v0.1.0 + v0.2.0 artifacts
+```
+
+**Alternative considered:** Explicit `includes: [v0.1.0]` chains. Rejected
+because it is redundant when baselines are almost always linear progressions.
+If non-linear baselines are needed later (e.g., a hotfix branch that
+cherry-picks from v0.2.0 but not all of it), an explicit `includes` field
+can be added as an opt-in override.
+
+### Artifact Resolution for a Baseline
+
+Given baseline `B` at position `P` in the ordered baseline list:
+
+1. Collect all artifacts where `baseline` is set to `B` or to any baseline
+   at position `< P` (i.e., earlier baselines).
+2. If `B.cumulative` is false, collect only artifacts where `baseline == B`.
+3. Artifacts with no `baseline` field are **excluded** from scoped
+   validation.
+
+```
+resolve_baseline("v0.2.0", cumulative=true):
+  return artifacts where baseline in {"v0.1.0", "v0.2.0"}
+
+resolve_baseline("v0.1.0", cumulative=true):
+  return artifacts where baseline == "v0.1.0"
+```
+
+### Validation Scoping
+
+#### `rivet validate --baseline v0.1.0`
+
+When `--baseline` is specified:
+
+1. **Resolve the artifact set** for the named baseline (see above).
+2. **Build a scoped Store** containing only those artifacts.
+3. **Build the link graph** from the scoped store. Links to artifacts
+   outside the baseline are treated as **external references** (not
+   broken links). This is critical: a v0.1.0 artifact may link to a
+   v0.2.0 artifact via `satisfies`, and that link is valid but the
+   target is outside the current baseline scope.
+4. **Run structural validation** (phases 1-7) against the scoped store.
+5. **Run traceability rule checks** only for artifacts in the scoped set.
+   A requirement in v0.1.0 must have its `satisfies` backlinks from
+   features **also in v0.1.0** (or earlier baselines).
+6. **Run conditional rules** against the scoped set.
+7. **Report coverage** as percentage of in-baseline artifacts that satisfy
+   each traceability rule.
+
+**Cross-baseline link semantics:**
+- A link from an in-baseline artifact to an out-of-baseline artifact is
+  **valid but not counted for traceability coverage**. It exists in the
+  full graph but does not satisfy the "must have downstream in this
+  baseline" requirement.
+- A link from an out-of-baseline artifact to an in-baseline artifact is
+  ignored (the source is not being validated).
+- Broken links (target does not exist at all) are still errors regardless
+  of baseline scope.
+
+#### `rivet validate` (no baseline flag)
+
+Unchanged behavior: validates all artifacts, all rules, full store. The
+`baseline` field is simply ignored as a regular custom field.
+
+#### Implementation Approach
+
+The validation engine does not need to change internally. The scoping
+happens at the **store construction** level:
+
+```rust
+/// Build a store containing only artifacts in the given baseline.
+pub fn scoped_store(full_store: &Store, baseline: &str, config: &BaselineConfig) -> Store {
+    let included_baselines = config.resolve_cumulative(baseline);
+    let mut scoped = Store::new();
+    for artifact in full_store.iter() {
+        if let Some(bl) = artifact.baseline() {
+            if included_baselines.contains(bl) {
+                let _ = scoped.insert(artifact.clone());
+            }
+        }
+    }
+    scoped
+}
+```
+
+The link graph, validator, coverage engine, and lifecycle checker all
+operate on a `Store` -- they do not need to know about baselines. The
+only change is building the store with the right subset of artifacts.
+
+**Cross-baseline link handling** requires a refinement: when building
+the scoped `LinkGraph`, links to out-of-scope artifacts should not be
+recorded as broken links. This requires a small change to `LinkGraph::build`:
+
+```rust
+/// Build a link graph, treating missing targets that exist in
+/// `full_store` as external (not broken).
+pub fn build_scoped(scoped: &Store, schema: &Schema, full: &Store) -> LinkGraph {
+    // ... same as build(), but when a link target is not in `scoped`
+    // but IS in `full`, record it as an external reference rather
+    // than a broken link.
+}
+```
+
+### Coverage Scoping
+
+`rivet coverage --baseline v0.1.0` computes coverage only over artifacts
+in the named baseline. The denominator for each traceability rule is the
+count of source-type artifacts *in the baseline*, not the full store.
+
+This lets a project track per-release coverage:
+- v0.1.0: 95% coverage (a few draft features not yet linked)
+- v0.2.0: 80% coverage (new artifacts being developed)
+- Full: 85% coverage (weighted average)
+
+### Lifecycle Completeness Scoping
+
+`check_lifecycle_completeness` currently checks all artifacts with
+"traced" statuses (approved, implemented, done, accepted, verified).
+With baseline scoping:
+
+- Only artifacts in the baseline are checked.
+- A requirement in v0.1.0 needs downstream features **also in v0.1.0**.
+- A feature planned for v0.2.0 that satisfies a v0.1.0 requirement does
+  NOT count as coverage for v0.1.0 baseline validation.
+
+This is the key insight: **traceability completeness is evaluated within
+the baseline boundary**, not across the full artifact set.
+
+### Export Scoping
+
+`rivet export --html --baseline v0.1.0` generates a compliance report
+containing only artifacts in the named baseline. This produces a
+self-contained release evidence package:
+
+- Index page shows "Baseline: v0.1.0" in the header
+- Requirements page lists only v0.1.0 requirements
+- Coverage matrix shows only v0.1.0 traceability
+- Validation results reflect only v0.1.0 rules
+- Links to out-of-baseline artifacts are rendered as
+  "external" (greyed out, with a note like "ships in v0.2.0")
+
+The existing `config.js` version switcher (DD-038) naturally complements
+baseline-scoped export: each version in the switcher corresponds to a
+baseline export.
+
+### Impact Analysis Integration
+
+`rivet impact --baseline v0.1.0` restricts impact analysis to artifacts
+in the baseline. When computing transitive impact, the graph walk stops
+at the baseline boundary -- changes to v0.2.0 artifacts do not propagate
+into v0.1.0 impact results.
+
+### Dashboard Integration
+
+The dashboard gains a baseline selector (dropdown in the header bar,
+similar to the existing search). When a baseline is selected:
+
+- Artifact list shows only in-baseline artifacts
+- Graph view shows only in-baseline nodes (with out-of-baseline
+  neighbors shown as faded ghost nodes)
+- Coverage section shows baseline-scoped coverage
+- Validation section shows baseline-scoped results
+- Matrix view shows baseline-scoped traceability
+
+The URL reflects the selection: `/artifacts?baseline=v0.1.0`
+
+### CLI Interface Changes
+
+New flags on existing commands:
+
+```
+rivet validate --baseline v0.1.0
+rivet coverage --baseline v0.1.0
+rivet list --baseline v0.1.0
+rivet stats --baseline v0.1.0
+rivet matrix --baseline v0.1.0
+rivet export --html --baseline v0.1.0
+rivet impact --baseline v0.1.0
+rivet graph --baseline v0.1.0
+```
+
+New subcommands on `rivet baseline`:
+
+```
+rivet baseline verify v0.1.0     # existing: check git tags across repos
+rivet baseline list              # existing: list git tags
+rivet baseline show v0.1.0       # NEW: list artifact IDs in a baseline
+rivet baseline status            # NEW: summary table of all baselines
+                                 # with artifact counts and coverage %
+```
+
+`rivet baseline status` output:
+
+```
+Baselines:
+  v0.1.0   247 artifacts   94.3% coverage   0 errors   2 warnings
+  v0.2.0   327 artifacts   81.7% coverage   3 errors   8 warnings
+  (full)   352 artifacts   79.2% coverage   5 errors  12 warnings
+```
+
+### Migration from `phase` to `baseline`
+
+Current state: feature artifacts have `fields.phase: phase-1|phase-2|phase-3|future`.
+Other artifact types (requirements, decisions) do not have a phase field.
+
+Migration plan:
+
+1. **Add `baseline` field to the Artifact model** as an optional base field
+   (same level as `status`, `tags`). No schema change needed for this --
+   it is a structural field.
+
+2. **Add baselines block to rivet.yaml**:
+   ```yaml
+   baselines:
+     v0.1.0:
+       description: "Phase 1+2"
+     v0.2.0:
+       description: "Phase 3"
+   ```
+
+3. **Derive baseline from phase for features** using a one-time migration
+   script (or manual update):
+   - `phase: phase-1` or `phase: phase-2` -> `baseline: v0.1.0`
+   - `phase: phase-3` -> `baseline: v0.2.0`
+   - `phase: future` -> no baseline (unscoped)
+
+4. **Assign baselines to non-feature artifacts**:
+   - Requirements REQ-001 through REQ-019: `baseline: v0.1.0`
+   - Requirements REQ-020 through REQ-036: `baseline: v0.2.0`
+   - Design decisions DD-001 through DD-010: `baseline: v0.1.0`
+   - Design decisions DD-011 onward: `baseline: v0.2.0`
+   - STPA artifacts: `baseline: v0.1.0` (all shipped in phase 1)
+   - Architecture artifacts: `baseline: v0.2.0`
+
+5. **Keep the `phase` field** on features for backward compatibility,
+   but deprecate it. The `phase` field becomes informational only;
+   `baseline` is the authoritative scoping field.
+
+6. **Update the dev schema** to add `baseline` to the allowed-values
+   list or remove the phase field entirely in a future release.
+
+### Relationship to Existing Baseline Features
+
+| Feature | Current | With this design |
+|---------|---------|-----------------|
+| `rivet baseline verify` | Checks git tag presence across repos | Also validates artifact completeness within the baseline |
+| `rivet baseline list` | Lists git tags | Also shows artifact counts per baseline |
+| `rivet impact --since` | Compares current store to a git ref | Can additionally scope to a baseline |
+| `rivet export --html` | Exports all artifacts | Can scope to a baseline for release evidence |
+| `phase` field | Informal, features only | Superseded by `baseline` on all artifact types |
+
+### Data Model Changes
+
+```rust
+// model.rs -- add baseline field to Artifact
+pub struct Artifact {
+    pub id: ArtifactId,
+    pub artifact_type: String,
+    pub title: String,
+    pub description: Option<String>,
+    pub status: Option<String>,
+    pub tags: Vec<String>,
+    pub links: Vec<Link>,
+    pub fields: BTreeMap<String, serde_yaml::Value>,
+    pub source_file: Option<PathBuf>,
+    pub baseline: Option<String>,       // NEW
+}
+
+// model.rs -- add baseline config to ProjectConfig
+pub struct ProjectConfig {
+    pub project: ProjectMetadata,
+    pub sources: Vec<SourceConfig>,
+    pub docs: Vec<String>,
+    pub results: Option<String>,
+    pub commits: Option<CommitsConfig>,
+    pub externals: Option<BTreeMap<String, ExternalProject>>,
+    pub baselines: Option<IndexMap<String, BaselineDef>>,  // NEW
+    // IndexMap preserves insertion order for baseline ordering
+}
+
+pub struct BaselineDef {
+    pub description: Option<String>,
+    pub cumulative: bool,  // default: true
+    pub git_tag: Option<String>,
+}
+```
+
+### Store Changes
+
+```rust
+// store.rs -- add baseline-scoped store builder
+impl Store {
+    /// Create a new store containing only artifacts in the given baseline.
+    pub fn scoped(&self, baseline: &str, config: &BaselineConfig) -> Store {
+        // ...
+    }
+
+    /// Get the set of artifact IDs in a baseline.
+    pub fn ids_in_baseline(&self, baseline: &str, config: &BaselineConfig) -> HashSet<String> {
+        // ...
+    }
+}
+```
+
+### LinkGraph Changes
+
+```rust
+// links.rs -- add scoped build
+impl LinkGraph {
+    /// Build a link graph for a scoped store, treating links to
+    /// out-of-scope (but existing in full store) targets as external.
+    pub fn build_scoped(scoped: &Store, schema: &Schema, full: &Store) -> LinkGraph {
+        // ...
+    }
+}
+```
+
+### Query Changes
+
+```rust
+// query.rs -- add baseline filter
+pub struct Query {
+    pub artifact_type: Option<String>,
+    pub status: Option<String>,
+    pub tag: Option<String>,
+    pub has_link_type: Option<String>,
+    pub missing_link_type: Option<String>,
+    pub baseline: Option<String>,        // NEW
+}
+```
+
+## Implementation Plan
+
+### Phase 1: Minimal Viable Baseline (3-4 hours)
+
+1. Add `baseline: Option<String>` to `Artifact` struct in model.rs
+2. Parse `baseline` field in generic-yaml and stpa-yaml adapters
+3. Add `baselines` config block parsing to `ProjectConfig`
+4. Implement `Store::scoped()` and `LinkGraph::build_scoped()`
+5. Add `--baseline` flag to `rivet validate`
+6. Add `--baseline` flag to `rivet coverage`
+7. Migrate rivet's own artifacts: add baseline field to all artifact files
+
+### Phase 2: Full Integration (2-3 hours)
+
+8. Add `--baseline` flag to `rivet list`, `stats`, `matrix`, `export`
+9. Add `rivet baseline show` and `rivet baseline status` subcommands
+10. Add `baseline` filter to `Query` struct
+11. Dashboard baseline selector dropdown
+
+### Phase 3: Polish (1-2 hours)
+
+12. `rivet baseline verify` enhanced: check artifact completeness
+13. Impact analysis baseline scoping
+14. Documentation and help text updates
+15. Deprecation warning for `phase` field
+
+## Open Questions
+
+1. **Should `baseline` be a base field or a custom field?** This design
+   proposes a base field (like status, tags) because it has semantic
+   meaning to the validation engine. A custom field in `fields` would
+   require schema changes per domain and could not be enforced uniformly.
+   **Decision: base field.**
+
+2. **What about artifacts shared across non-cumulative baselines?** For
+   example, a hotfix release that includes REQ-001 from v0.1.0 and
+   REQ-025 from v0.2.0 but not all of v0.2.0. The current design handles
+   this via `cumulative: false` baselines that only include explicitly
+   tagged artifacts. The artifact would need `baseline: hotfix-1` set
+   manually. This is expected to be rare. **Decision: defer until needed.**
+
+3. **Should baseline validation be strict or advisory?** This design makes
+   `--baseline` a filter that scopes validation. All errors within the
+   baseline are real errors. Missing links to out-of-baseline artifacts
+   are not errors. **Decision: strict within scope, lenient at boundary.**
+
+4. **How does this interact with OSLC configuration management?** OSLC
+   Config Management (OSLC-CM) defines global configurations and baselines
+   as sets of versioned resources. The `baseline` field maps to the OSLC
+   concept of a configuration context. Future OSLC sync could map rivet
+   baselines to OSLC global configurations. **Decision: design is
+   compatible; OSLC mapping is future work.**
diff --git a/docs/plans/2026-03-21-lsp-salsa-architecture-design.md b/docs/plans/2026-03-21-lsp-salsa-architecture-design.md
new file mode 100644
index 0000000..60b6aec
--- /dev/null
+++ b/docs/plans/2026-03-21-lsp-salsa-architecture-design.md
@@ -0,0 +1,959 @@
+# LSP + Salsa Incremental Architecture Design
+
+**Date:** 2026-03-21
+**Builds on:** [rowan + salsa completion plan](2026-03-16-rowan-salsa-completion.md)
+**Related artifacts:** REQ-029, REQ-036, DD-032, FEAT-056, FEAT-057
+
+---
+
+## 1. Current State Summary
+
+### What exists today in rivet-core/src/db.rs
+
+The salsa 0.26 database is already functional:
+
+- **Inputs:** `SourceFile` (path + content), `SchemaInput` (name + content), with `SourceFileSet` / `SchemaInputSet` containers.
+- **Tracked functions:** `parse_artifacts(file) -> Vec<Artifact>`, `validate_all(sources, schemas) -> Vec<Diagnostic>`, `evaluate_conditional_rules(sources, schemas) -> Vec<Diagnostic>`.
+- **Non-tracked helpers:** `build_pipeline`, `build_store`, `build_schema` -- called from tracked functions but not individually cached because `Store` and `LinkGraph` lack `PartialEq`.
+- **Concrete database:** `RivetDatabase` with `load_schemas()`, `load_sources()`, `update_source()`, `store()`, `schema()`, `diagnostics()`.
+- **16 tests** covering incremental recomputation, conditional rules, determinism, and boundary cases.
+- **CLI integration:** `rivet validate --incremental` and `--verify-incremental` flags (opt-in).
+
+### What exists in spar (reference architecture)
+
+Spar's LSP at `/Volumes/Home/git/pulseengine/spar/crates/spar-cli/src/lsp.rs` uses:
+
+- **`lsp-server` 0.7 + `lsp-types` 0.97** (synchronous, single-threaded event loop on stdin/stdout)
+- **`ServerState`** struct holding: `documents` (open file contents), `item_trees` (parsed HIR per file), `global_scope` (workspace-wide name resolution), `open_files` list
+- **Full text sync** (`TextDocumentSyncKind::FULL`) -- on each change, full document replaces previous
+- **Features:** diagnostics, hover, document symbols, go-to-definition, completions, code actions, formatting, rename, inlay hints, workspace symbols
+- **No salsa in the LSP path** -- spar-base-db has a salsa database but the LSP does its own HashMap-based caching with `ItemTree` per file and a `GlobalScope` rebuilt on each change
+- **File watchers** registered for `**/*.aadl` to pick up disk changes outside the editor
+
+### Key differences: Rivet vs Spar for LSP
+
+| Aspect | Spar | Rivet |
+|--------|------|-------|
+| File format | AADL (custom grammar) | YAML (well-known format) |
+| Parser | Hand-written rowan CST | serde_yaml (no CST today) |
+| Token-level precision | Yes (rowan TextSize) | No (line-level at best) |
+| Workspace scope | All `.aadl` files | Files listed in `rivet.yaml` sources |
+| Cross-file references | Classifier references | Artifact ID links |
+| Incremental DB | salsa (not used in LSP) | salsa (should be used in LSP) |
+| Runtime | Sync (lsp-server) | Async available (tokio already in tree) |
+
+---
+
+## 2. Architecture Decision: lsp-server vs tower-lsp
+
+### Recommendation: `lsp-server` (same as spar)
+
+**Against the earlier DD-032 recommendation of tower-lsp.** Rationale:
+
+1. **Consistency with spar.** Both PulseEngine projects use the same LSP library. Shared patterns, shared bugs, shared knowledge.
+
+2. **tower-lsp is unmaintained.** The crate has had minimal activity. The `lsp-server` crate is maintained as part of rust-analyzer's ecosystem (the most battle-tested Rust LSP).
+
+3. **Simplicity.** `lsp-server` is a thin transport layer (~300 lines of glue). The complexity lives in our domain logic, not the protocol layer. We do not need tower middleware or async request handling -- artifact YAML validation is CPU-bound and fast enough to run synchronously.
+
+4. **Tokio is not needed for LSP.** The LSP server runs on stdin/stdout. The existing tokio dependency is for `rivet serve` (axum). The LSP process is separate -- it does not share a runtime with the dashboard.
+
+5. **Known pattern.** Spar's LSP is ~1200 lines and covers 11 features. We can port the structural pattern directly.
+
+**If tower-lsp becomes actively maintained or we need async request handling (e.g., for OSLC remote validation), we can migrate. The domain logic is transport-agnostic.**
+
+### Alternative considered: async-lsp
+
+The `async-lsp` crate is a newer alternative that uses tower's Service trait without tower-lsp's specific abstractions. Worth watching but too young for production use.
+
+---
+
+## 3. Crate Structure Decision
+
+### Recommendation: Option B -- `rivet lsp` subcommand in rivet-cli
+
+**Not a separate `rivet-lsp` crate.** Rationale:
+
+1. **Single binary.** Users install `rivet` and get everything: validate, serve, lsp. No separate binary to manage.
+
+2. **Spar's pattern.** Spar puts its LSP in `spar-cli/src/lsp.rs` as a subcommand. It works well.
+
+3. **Shared state types.** The LSP needs `RivetDatabase`, `Store`, `Schema`, `Diagnostic` -- all from rivet-core. A separate crate would just re-export these.
+
+4. **Build time.** `lsp-server` and `lsp-types` are small crates. Adding them to rivet-cli does not meaningfully increase build time.
+
+5. **Feature gate if needed.** We can put the LSP behind `rivet-cli/features = ["lsp"]` and gate the `lsp-server`/`lsp-types` dependencies. But the default should include it.
+
+### File layout
+
+```
+rivet-cli/
+  src/
+    main.rs          -- adds `Lsp` variant to Command enum
+    lsp/
+      mod.rs         -- run_lsp_server(), main_loop(), ServerState
+      diagnostics.rs -- rivet Diagnostic -> LSP Diagnostic conversion
+      hover.rs       -- hover handlers
+      completion.rs  -- completion handlers
+      definition.rs  -- go-to-definition
+      symbols.rs     -- document symbols, workspace symbols
+      actions.rs     -- code actions
+      util.rs        -- offset/position conversion, URI helpers
+```
+
+Splitting into submodules (unlike spar's single file) because Rivet's LSP domain is more complex: YAML position tracking, schema-aware completions, multi-source-format awareness. Spar's 1200-line single file works for AADL but would be unwieldy for Rivet's richer feature set.
+
+---
+
+## 4. Salsa Database Design for LSP
+
+### 4.1 Why use salsa in the LSP (unlike spar)
+
+Spar's LSP does not use its salsa database. It re-parses on every change and manually caches `ItemTree` per file. This works because AADL parsing is fast and the scope rebuild is cheap.
+
+Rivet should use salsa because:
+
+1. **Validation is expensive.** Building the full link graph + running 8-phase validation across 300+ artifacts on every keystroke is wasteful. Salsa caches intermediate results.
+
+2. **The database already exists.** `RivetDatabase` with all tracked functions is ready. The LSP just needs to feed it file changes and read results.
+
+3. **Cross-file dependencies are complex.** Changing a link target in file A affects validation results for file B (broken links, traceability coverage). Salsa tracks these dependencies automatically.
+
+4. **Shared with other consumers.** The same database design serves `rivet validate --watch`, `rivet serve` (dashboard), and `rivet lsp`. One investment, three payoffs.
+
+### 4.2 Salsa Inputs
+
+The existing inputs are sufficient. No new salsa input types are needed for the LSP:
+
+```rust
+// Already in db.rs:
+#[salsa::input]
+pub struct SourceFile {
+    pub path: String,
+    pub content: String,
+}
+
+#[salsa::input]
+pub struct SchemaInput {
+    pub name: String,
+    pub content: String,
+}
+
+#[salsa::input]
+pub struct SourceFileSet { pub files: Vec<SourceFile> }
+
+#[salsa::input]
+pub struct SchemaInputSet { pub schemas: Vec<SchemaInput> }
+```
+
+The LSP `ServerState` will hold:
+- A `RivetDatabase` instance
+- The `SourceFileSet` and `SchemaInputSet` handles
+- A mapping from file URI to `SourceFile` salsa key (for targeted updates)
+
+### 4.3 Tracked Functions: Existing + New
+
+**Existing (no changes needed):**
+
+```rust
+#[salsa::tracked]
+fn parse_artifacts(db: &dyn salsa::Database, source: SourceFile) -> Vec<Artifact>;
+
+#[salsa::tracked]
+fn validate_all(db, source_set, schema_set) -> Vec<Diagnostic>;
+
+#[salsa::tracked]
+fn evaluate_conditional_rules(db, source_set, schema_set) -> Vec<Diagnostic>;
+```
+
+**New tracked functions for LSP features:**
+
+```rust
+/// All artifact IDs in the workspace, sorted. Used for completions.
+/// Cached -- only recomputed when any source file changes.
+#[salsa::tracked]
+fn all_artifact_ids(db: &dyn salsa::Database, source_set: SourceFileSet) -> Vec<String>;
+
+/// All artifact type names from the merged schema. Used for type completions.
+#[salsa::tracked]
+fn all_type_names(db: &dyn salsa::Database, schema_set: SchemaInputSet) -> Vec<String>;
+
+/// All link type names from the merged schema. Used for link type completions.
+#[salsa::tracked]
+fn all_link_types(db: &dyn salsa::Database, schema_set: SchemaInputSet) -> Vec<String>;
+
+/// Artifact index: map from artifact ID -> (source file path, line number).
+/// Used for go-to-definition. Cached per source file.
+#[salsa::tracked]
+fn artifact_locations(db: &dyn salsa::Database, source: SourceFile)
+    -> Vec<(String, usize)>;  // (artifact_id, line_number)
+
+/// Diagnostics for a single file (filtered from all_diagnostics).
+/// This is NOT a salsa tracked function -- it is a simple filter on the
+/// validate_all result, done in the LSP layer. Salsa caches validate_all;
+/// the per-file filter is cheap.
+```
+
+### 4.4 How Incremental Recomputation Works for YAML
+
+**Scenario:** User edits `artifacts/requirements.yaml` in VS Code.
+
+1. LSP receives `textDocument/didChange` with full document text.
+2. `ServerState` calls `db.update_source(source_set, "artifacts/requirements.yaml", new_content)`.
+3. Salsa marks the `SourceFile` input as changed.
+4. Next query (e.g., `db.diagnostics(source_set, schema_set)`) triggers:
+   - `parse_artifacts` re-runs for the changed file only. Other files' parse results are cached.
+   - `build_store` re-assembles the `Store` (cheap: iterate cached parse results).
+   - `build_schema` is **not** re-run (schema files did not change).
+   - `LinkGraph::build` re-runs (depends on the store).
+   - `validate_structural` re-runs (depends on store + schema + graph).
+   - `evaluate_conditional_rules` re-runs (depends on store + schema).
+5. LSP publishes diagnostics to the client.
+
+**What is NOT recomputed:**
+- Parsing of unchanged source files
+- Schema merging (schemas did not change)
+- If the edit does not change the parse result (e.g., whitespace-only), salsa detects the `Vec<Artifact>` is identical and short-circuits all downstream queries
+
+**Future optimization (Phase D1 from the completion plan):**
+Per-artifact salsa tracking would allow changing one artifact in a multi-artifact file to skip re-validation of the others. This requires `#[salsa::tracked] struct TrackedArtifact` with artifact ID as identity key. Not needed for initial LSP -- file-level granularity is fast enough for 300 artifacts.
+
+### 4.5 Connecting to the Existing Validation Pipeline
+
+The LSP does **not** replace the validation pipeline. It wraps it:
+
+```
+rivet validate (CLI)
+    └── validate::validate()  ← direct call, no salsa
+    └── validate::validate() via db.diagnostics() ← --incremental flag
+
+rivet lsp
+    └── db.diagnostics()  ← always uses salsa
+
+rivet serve
+    └── db.diagnostics()  ← future: shared salsa DB (Phase A7)
+```
+
+The `validate::validate()` and `validate::validate_structural()` functions remain unchanged. The salsa tracked functions call them. The LSP reads results from salsa. This layered architecture means:
+
+- **No breaking changes** to the batch pipeline
+- **SC-11 parity** can be verified: `--verify-incremental` confirms salsa produces identical results
+- **One validation implementation** serves all consumers
+
+---
+
+## 5. LSP Server Design
+
+### 5.1 ServerState
+
+```rust
+struct ServerState {
+    /// The salsa incremental database.
+    db: RivetDatabase,
+
+    /// Handle to all source file inputs.
+    source_set: SourceFileSet,
+
+    /// Handle to all schema inputs.
+    schema_set: SchemaInputSet,
+
+    /// Map from file URI string -> SourceFile salsa key.
+    /// Enables O(1) lookup for targeted updates on didChange.
+    uri_to_source: HashMap<String, SourceFile>,
+
+    /// Project configuration from rivet.yaml.
+    config: ProjectConfig,
+
+    /// Workspace root directory.
+    workspace_root: PathBuf,
+
+    /// URIs of files currently open in the editor.
+    open_files: Vec<String>,
+
+    /// Cached line indices for open files (for offset <-> position conversion).
+    /// Rebuilt when file content changes.
+    line_indices: HashMap<String, LineIndex>,
+}
+```
+
+### 5.2 Initialization Sequence
+
+```
+1. Client sends initialize request
+2. Server extracts workspace root from InitializeParams
+3. Server looks for rivet.yaml in workspace root
+4. Server loads ProjectConfig from rivet.yaml
+5. Server loads all schema files listed in config.project.schemas
+   -> Creates SchemaInput for each, builds SchemaInputSet
+6. Server scans all source directories listed in config.sources
+   -> Creates SourceFile for each YAML file found, builds SourceFileSet
+7. Server stores the SourceFileSet, SchemaInputSet, and uri_to_source map
+8. Server runs initial validation: db.diagnostics(source_set, schema_set)
+9. Server responds with capabilities
+10. Server registers file watchers for *.yaml in workspace
+```
+
+### 5.3 Capabilities
+
+```rust
+fn server_capabilities() -> ServerCapabilities {
+    ServerCapabilities {
+        text_document_sync: Some(TextDocumentSyncCapability::Kind(
+            TextDocumentSyncKind::FULL
+        )),
+        hover_provider: Some(HoverProviderCapability::Simple(true)),
+        definition_provider: Some(OneOf::Left(true)),
+        document_symbol_provider: Some(OneOf::Left(true)),
+        completion_provider: Some(CompletionOptions {
+            trigger_characters: Some(vec![
+                ":".to_string(),  // after "target:" or "type:"
+                " ".to_string(),  // after "- id: "
+            ]),
+            resolve_provider: Some(false),
+            ..Default::default()
+        }),
+        workspace_symbol_provider: Some(OneOf::Left(true)),
+        code_action_provider: Some(CodeActionProviderCapability::Simple(true)),
+        ..Default::default()
+    }
+}
+```
+
+### 5.4 Feature Implementations (Priority Order)
+
+#### Feature 1: Diagnostics
+
+**Trigger:** `didOpen`, `didChange`, `didSave`, `didChangeWatchedFiles`
+
+**Implementation:**
+
+```rust
+fn publish_diagnostics(state: &ServerState, connection: &Connection, uri: &Uri) {
+    // Get all diagnostics from the salsa database.
+    let all_diags = state.db.diagnostics(state.source_set, state.schema_set);
+
+    // Filter to diagnostics relevant to this file.
+    let file_path = uri_to_path(uri);
+    let file_diags: Vec<_> = all_diags.iter()
+        .filter(|d| diagnostic_belongs_to_file(d, &file_path, &state.db, state.source_set))
+        .collect();
+
+    // Convert rivet::Diagnostic -> lsp_types::Diagnostic
+    let lsp_diags = file_diags.iter().map(|d| {
+        let severity = match d.severity {
+            Severity::Error => DiagnosticSeverity::ERROR,
+            Severity::Warning => DiagnosticSeverity::WARNING,
+            Severity::Info => DiagnosticSeverity::INFORMATION,
+        };
+
+        // Position: currently line-level only (no rowan CST yet).
+        // Use artifact_locations() to find the line of the artifact.
+        let range = find_diagnostic_range(d, state, uri);
+
+        lsp_types::Diagnostic {
+            range,
+            severity: Some(severity),
+            source: Some("rivet".to_string()),
+            code: Some(NumberOrString::String(d.rule.clone())),
+            message: d.message.clone(),
+            ..Default::default()
+        }
+    }).collect();
+
+    // Publish.
+    let params = PublishDiagnosticsParams {
+        uri: uri.clone(),
+        diagnostics: lsp_diags,
+        version: None,
+    };
+    send_notification::<PublishDiagnostics>(connection, params);
+}
+```
+
+**Diagnostic range resolution** (before rowan CST):
+- If the diagnostic has an `artifact_id`, scan the file content for `- id: {artifact_id}` to find the line.
+- Map the rule to a specific field when possible (e.g., `required-field` -> find the artifact block, report at the `- id:` line).
+- Fallback: line 0, column 0.
+
+**Diagnostic range resolution** (after rowan CST -- Phase B):
+- Diagnostics carry `TextRange` from the CST.
+- Convert `TextRange` to `Position` using a `LineIndex`.
+- Precise to the character.
+
+**Cross-file diagnostic publishing:**
+When file A changes and creates a broken link to an artifact in file B, we need to publish updated diagnostics for file B too. Strategy: on any change, re-publish diagnostics for all open files (same as spar). This is cheap because `db.diagnostics()` is cached and only the filter + conversion runs per file.
+
+#### Feature 2: Go-to-Definition
+
+**Trigger:** `textDocument/definition` request
+
+**Implementation:**
+
+```rust
+fn handle_goto_definition(state: &ServerState, params: GotoDefinitionParams)
+    -> Option<GotoDefinitionResponse>
+{
+    let uri = &params.text_document_position_params.text_document.uri;
+    let pos = params.text_document_position_params.position;
+    let source = state.file_content(uri)?;
+
+    // Find the word at the cursor position.
+    let word = word_at_position(&source, pos)?;
+
+    // Check if this word is an artifact ID.
+    let store = state.db.store(state.source_set);
+    let artifact = store.get(&word)?;
+
+    // Find the artifact's source file and line.
+    let source_path = artifact.source_file.as_ref()?;
+    let target_uri = path_to_uri(source_path);
+
+    // Find the "- id: {word}" line in the target file.
+    let target_content = state.file_content_by_path(source_path)?;
+    let line = find_artifact_line(&target_content, &word)?;
+
+    Some(GotoDefinitionResponse::Scalar(Location {
+        uri: target_uri,
+        range: Range::new(
+            Position::new(line as u32, 0),
+            Position::new(line as u32, 0),
+        ),
+    }))
+}
+```
+
+**Where go-to-definition activates:**
+- In `links:` blocks: `target: REQ-001` -- click REQ-001 to jump to its definition
+- In `[[REQ-001]]` references in markdown documents
+- In any YAML value that matches a known artifact ID
+
+**Word extraction strategy** (before rowan CST):
+Use a simple regex or character scan at the cursor position. Artifact IDs match the pattern `[A-Z]+-[A-Z]*-?\d+` (e.g., REQ-001, DD-023, SUCA-CLI-1, H-1.2). Scan left and right from cursor to find word boundaries.
+
+#### Feature 3: Hover
+
+**Trigger:** `textDocument/hover` request
+
+**Implementation:**
+
+When hovering over an artifact ID, show:
+
+```markdown
+**REQ-001** (requirement)
+
+**System shall be safe**
+
+Status: approved
+Links: 3 outgoing, 5 incoming
+Source: artifacts/requirements.yaml:12
+
+---
+*satisfies:* DD-001, DD-003
+*verified-by:* TEST-001, TEST-002, TEST-003
+```
+
+When hovering over a `type:` value, show the artifact type definition from the schema:
+
+```markdown
+**requirement** (aspice schema)
+
+A system-level requirement
+
+Required fields: priority, req-type
+Link fields: derives-from (-> sys-req), verified-by (<- test-case)
+```
+
+When hovering over a link type, show the link type definition:
+
+```markdown
+**satisfies**
+
+Design satisfies a requirement
+Inverse: satisfied-by
+Source types: design-decision
+Target types: requirement
+```
+
+#### Feature 4: Completions
+
+**Trigger:** Typing after specific YAML keys
+
+**Context detection strategy:**
+
+The LSP must determine what kind of completion to offer based on the cursor's YAML context. Without a rowan CST, we use a line-scanning approach:
+
+```rust
+enum CompletionContext {
+    /// Cursor is after "target: " inside a links block
+    LinkTarget { current_link_type: Option<String> },
+    /// Cursor is after "type: " on an artifact
+    ArtifactType,
+    /// Cursor is after "- type: " inside a links block
+    LinkType,
+    /// Cursor is after "status: "
+    Status,
+    /// Cursor is after a field name with allowed-values in the schema
+    FieldValue { field_name: String, artifact_type: String },
+    /// No completion context detected
+    None,
+}
+
+fn detect_completion_context(content: &str, position: Position) -> CompletionContext {
+    let line = content.lines().nth(position.line as usize)?;
+    let prefix = &line[..position.character as usize];
+
+    // Check what key we're completing a value for
+    if prefix.trim_start().starts_with("target:") {
+        // Look upward for the enclosing "- type:" to know the link type
+        CompletionContext::LinkTarget { current_link_type: find_enclosing_link_type(content, position) }
+    } else if prefix.trim_start().starts_with("type:") && !is_inside_links_block(content, position) {
+        CompletionContext::ArtifactType
+    } else if prefix.trim_start().starts_with("type:") && is_inside_links_block(content, position) {
+        CompletionContext::LinkType
+    } else if prefix.trim_start().starts_with("status:") {
+        CompletionContext::Status
+    } else {
+        CompletionContext::None
+    }
+}
+```
+
+**Completion items by context:**
+
+| Context | Source | Items |
+|---------|--------|-------|
+| `LinkTarget` | `all_artifact_ids(db, source_set)` | All artifact IDs, filtered by valid target types if link type is known |
+| `ArtifactType` | `all_type_names(db, schema_set)` | All type names from all loaded schemas |
+| `LinkType` | `all_link_types(db, schema_set)` | All link type names from all loaded schemas |
+| `Status` | Schema `allowed-values` for status | lifecycle statuses (draft, approved, etc.) |
+| `FieldValue` | Schema `allowed-values` for the field | Enum values from the schema field definition |
+
+**Schema-aware filtering for link targets:**
+
+When the user types `target: ` inside a links block with `type: satisfies`, the completion should only offer artifact IDs whose type is in the `target-types` list for the `satisfies` link type definition. This requires:
+
+1. Detect the current link type from the enclosing `- type: satisfies` line
+2. Look up the link type definition in the schema: `target-types: [requirement]`
+3. Filter the artifact ID list to only those with `artifact_type == "requirement"`
+
+#### Feature 5: Code Actions
+
+**5a. Create Missing Artifact**
+
+When a broken-link diagnostic exists (target ID does not exist), offer a code action:
+
+```
+Quick Fix: Create artifact 'REQ-042'
+```
+
+This creates a new artifact stub in the appropriate file (determined by naming convention or the file that contains the most artifacts of the expected type).
+
+**5b. Add Required Link**
+
+When a traceability-rule diagnostic exists (e.g., "DD-001 missing satisfies link to requirement"), offer:
+
+```
+Quick Fix: Add 'satisfies' link to DD-001
+```
+
+This inserts a links block (or appends to an existing one) using `yaml_edit::YamlEditor` for correct indentation.
+
+**5c. Fix Allowed Values**
+
+When an allowed-values diagnostic exists, offer:
+
+```
+Quick Fix: Change 'status' to 'approved' (currently 'aproved')
+```
+
+#### Feature 6: Document Symbols
+
+**What to show in the outline view:**
+
+```
+artifacts/requirements.yaml
+  REQ-001 (requirement) - "System shall be safe"
+  REQ-002 (requirement) - "System shall be reliable"
+  REQ-003 (requirement) - "System shall be traceable"
+```
+
+Each artifact becomes a `DocumentSymbol` with:
+- `name`: artifact ID
+- `detail`: artifact type + title
+- `kind`: `SymbolKind::STRUCT` (closest semantic match)
+- `range`: line range of the artifact block (computed by scanning for `- id:` boundaries)
+- `children`: none (artifacts are flat)
+
+#### Feature 7: Workspace Symbols
+
+**`workspace/symbol` query:**
+
+Search across all artifacts in the workspace by ID or title. User types "REQ" and sees all requirements. User types "safe" and sees all artifacts with "safe" in the title.
+
+```rust
+fn handle_workspace_symbol(state: &ServerState, params: WorkspaceSymbolParams)
+    -> Option<WorkspaceSymbolResponse>
+{
+    let query = params.query.to_lowercase();
+    let store = state.db.store(state.source_set);
+
+    let symbols: Vec<SymbolInformation> = store.iter()
+        .filter(|a| {
+            a.id.to_lowercase().contains(&query)
+            || a.title.to_lowercase().contains(&query)
+        })
+        .map(|a| {
+            SymbolInformation {
+                name: a.id.clone(),
+                kind: SymbolKind::STRUCT,
+                location: artifact_location(a, state),
+                container_name: Some(a.artifact_type.clone()),
+                ..Default::default()
+            }
+        })
+        .collect();
+
+    Some(WorkspaceSymbolResponse::Flat(symbols))
+}
+```
+
+---
+
+## 6. Crate Dependency Graph
+
+```
+                    ┌──────────────────────────┐
+                    │      VS Code Extension    │
+                    │   (rivet-vscode, TypeScript)│
+                    └────────────┬─────────────┘
+                                 │ spawns process, stdio
+                                 ▼
+                    ┌──────────────────────────┐
+                    │       rivet-cli           │
+                    │                          │
+                    │  main.rs (Cli, Command)  │
+                    │  serve/  (axum + HTMX)   │
+                    │  lsp/    (lsp-server)    │ ← NEW
+                    │                          │
+                    │  deps:                   │
+                    │    rivet-core            │
+                    │    lsp-server  0.7       │ ← NEW
+                    │    lsp-types  0.97       │ ← NEW
+                    │    clap, axum, tokio...  │
+                    └────────────┬─────────────┘
+                                 │
+                                 ▼
+                    ┌──────────────────────────┐
+                    │       rivet-core          │
+                    │                          │
+                    │  db.rs     (salsa DB)    │
+                    │  validate.rs             │
+                    │  store.rs, links.rs      │
+                    │  schema.rs, model.rs     │
+                    │  yaml_edit.rs            │
+                    │  formats/ (adapters)     │
+                    │                          │
+                    │  deps:                   │
+                    │    salsa 0.26            │
+                    │    serde_yaml, petgraph  │
+                    │    rowan (future CST)    │
+                    └──────────────────────────┘
+```
+
+No new crates. Two new dependencies added to `rivet-cli/Cargo.toml`:
+- `lsp-server = "0.7"`
+- `lsp-types = "0.97"`
+
+---
+
+## 7. Key Types and Traits
+
+### 7.1 In rivet-core (no changes to existing types)
+
+```rust
+// Already exists:
+pub struct RivetDatabase { storage: salsa::Storage<Self> }
+pub struct SourceFile { path: String, content: String }     // salsa::input
+pub struct SchemaInput { name: String, content: String }    // salsa::input
+pub struct Diagnostic { severity, artifact_id, rule, message }
+pub struct Store { artifacts: HashMap<ArtifactId, Artifact> }
+pub struct Schema { artifact_types, link_types, traceability_rules, conditional_rules }
+pub struct Artifact { id, artifact_type, title, description, status, tags, links, fields, source_file }
+pub struct LinkGraph { forward, backward, broken, graph, node_map }
+```
+
+### 7.2 In rivet-core (new additions for LSP support)
+
+```rust
+/// Source location for a diagnostic. Added to Diagnostic struct.
+/// Phase A4 from the completion plan.
+pub struct SourceLocation {
+    pub file: PathBuf,
+    pub line: u32,       // 0-based
+    pub column: u32,     // 0-based
+    pub end_line: u32,
+    pub end_column: u32,
+}
+
+// Extended Diagnostic (backward-compatible addition):
+pub struct Diagnostic {
+    pub severity: Severity,
+    pub artifact_id: Option<String>,
+    pub rule: String,
+    pub message: String,
+    pub location: Option<SourceLocation>,  // NEW
+}
+```
+
+### 7.3 In rivet-cli/src/lsp/ (new)
+
+```rust
+/// Line index for fast offset <-> line:column conversion.
+pub struct LineIndex {
+    /// Byte offset of the start of each line.
+    line_starts: Vec<u32>,
+}
+
+impl LineIndex {
+    pub fn new(text: &str) -> Self;
+    pub fn line_col(&self, offset: u32) -> (u32, u32);
+    pub fn offset(&self, line: u32, col: u32) -> u32;
+}
+
+/// LSP server state. Wraps the salsa database and editor state.
+pub struct ServerState {
+    db: RivetDatabase,
+    source_set: SourceFileSet,
+    schema_set: SchemaInputSet,
+    uri_to_source: HashMap<String, SourceFile>,
+    config: ProjectConfig,
+    workspace_root: PathBuf,
+    open_files: Vec<String>,
+    line_indices: HashMap<String, LineIndex>,
+}
+```
+
+---
+
+## 8. VS Code Extension Design
+
+### 8.1 Extension Identity
+
+```json
+{
+  "name": "rivet-vscode",
+  "displayName": "Rivet — SDLC Traceability",
+  "publisher": "pulseengine",
+  "description": "Language support for Rivet artifact YAML files",
+  "categories": ["Programming Languages", "Linters"],
+  "activationEvents": [
+    "workspaceContains:rivet.yaml"
+  ]
+}
+```
+
+### 8.2 Language ID Strategy
+
+**Do NOT register a custom language.** Artifact files are plain YAML. Registering a custom language ID would break existing YAML tooling (syntax highlighting, bracket matching, YAML schema validation).
+
+Instead:
+- Activate when `rivet.yaml` exists in the workspace root
+- Apply to all `.yaml` files within source directories listed in `rivet.yaml`
+- Co-exist with the built-in YAML extension and redhat.vscode-yaml
+
+**File association via `documentSelector` in LSP client configuration:**
+
+```typescript
+const clientOptions: LanguageClientOptions = {
+    documentSelector: [
+        { scheme: 'file', language: 'yaml', pattern: '**/artifacts/**/*.yaml' },
+        { scheme: 'file', language: 'yaml', pattern: '**/safety/**/*.yaml' },
+        { scheme: 'file', language: 'yaml', pattern: '**/schemas/**/*.yaml' },
+        { scheme: 'file', language: 'yaml', pattern: '**/rivet.yaml' },
+    ],
+};
+```
+
+Better: read `rivet.yaml` at activation time and construct the glob patterns dynamically from `config.sources[*].path`.
+
+### 8.3 Server Lifecycle
+
+```typescript
+import { LanguageClient, ServerOptions } from 'vscode-languageclient/node';
+
+let client: LanguageClient;
+
+export function activate(context: vscode.ExtensionContext) {
+    // Find the rivet binary.
+    const rivetPath = vscode.workspace.getConfiguration('rivet').get<string>('path')
+        || 'rivet';
+
+    const serverOptions: ServerOptions = {
+        command: rivetPath,
+        args: ['lsp'],
+    };
+
+    client = new LanguageClient(
+        'rivet',
+        'Rivet Language Server',
+        serverOptions,
+        clientOptions,
+    );
+
+    client.start();
+}
+
+export function deactivate(): Thenable<void> | undefined {
+    return client?.stop();
+}
+```
+
+### 8.4 Extension Settings
+
+```json
+{
+  "rivet.path": {
+    "type": "string",
+    "default": "rivet",
+    "description": "Path to the rivet binary"
+  },
+  "rivet.validation.onSave": {
+    "type": "boolean",
+    "default": true,
+    "description": "Run validation on file save"
+  },
+  "rivet.validation.onType": {
+    "type": "boolean",
+    "default": true,
+    "description": "Run validation as you type"
+  },
+  "rivet.completion.artifactIds": {
+    "type": "boolean",
+    "default": true,
+    "description": "Suggest artifact IDs in link targets"
+  }
+}
+```
+
+### 8.5 Extension Features Beyond LSP
+
+Some features can be contributed by the extension directly, without LSP:
+
+- **Tree view:** Show all artifacts organized by type in the explorer sidebar (via a TreeDataProvider that calls `rivet list --json`).
+- **Status bar:** Show artifact count and validation status.
+- **Commands:** `rivet.validate` (run full validation), `rivet.openDashboard` (run `rivet serve` and open browser).
+- **CodeLens:** Show backlink counts above each `- id:` line (e.g., "3 references").
+
+These are additive and can come after the initial LSP integration.
+
+---
+
+## 9. Migration Path: Batch -> Incremental -> LSP
+
+### Phase 1: Current State (done)
+
+- Batch validation: `rivet validate` runs sequential pipeline
+- Incremental validation: `rivet validate --incremental` uses salsa (opt-in)
+- Dashboard: `rivet serve` reloads everything per request
+
+### Phase 2: Foundation (Phase A from completion plan)
+
+- A1: Add `PartialEq` to `Store`, `LinkGraph`
+- A2: Lift `build_store`, `build_schema` to tracked functions
+- A4: Add `SourceLocation` to `Diagnostic`
+- A5: Make incremental the default
+
+### Phase 3: LSP Skeleton
+
+- Add `lsp-server` + `lsp-types` to rivet-cli
+- Add `Lsp` variant to CLI `Command` enum
+- Implement `ServerState` with salsa `RivetDatabase`
+- Implement initialization: load `rivet.yaml`, schemas, sources
+- Implement `didOpen` / `didChange` / `didSave` -> `db.update_source()`
+- Publish diagnostics (line-level accuracy from artifact ID scanning)
+
+### Phase 4: Core LSP Features
+
+- Go-to-definition (artifact ID -> source file:line)
+- Hover (artifact summary, type info, link type info)
+- Completions (artifact IDs, types, link types, allowed values)
+- Document symbols (artifact outline)
+- Workspace symbols (search by ID or title)
+
+### Phase 5: VS Code Extension
+
+- Minimal extension: activate on rivet.yaml, spawn `rivet lsp`
+- Document selector from rivet.yaml source paths
+- Settings for binary path
+- Publish to VS Code marketplace
+
+### Phase 6: Advanced Features (after rowan CST, Phase B)
+
+- Character-level diagnostic precision via rowan TextRange
+- Code actions (create artifact, add link, fix values)
+- Rename artifact ID (workspace-wide refactor)
+- Document formatting
+- Inlay hints (show link target titles inline)
+
+---
+
+## 10. Risks and Open Questions
+
+### Risk: YAML Position Tracking Without rowan
+
+Before Phase B (rowan CST for YAML), we cannot point diagnostics at the exact character. Mitigation: scan for `- id: {ID}` patterns to get line-level accuracy. This is good enough for initial release -- most YAML LSP servers work at line granularity.
+
+### Risk: Large Workspaces
+
+A workspace with 1000+ artifact files could make the initial load slow. Mitigation: load files lazily (parse on first access) and use background threads for initial workspace scan. The salsa database handles incremental updates efficiently after initial load.
+
+### Risk: Multiple YAML Schemas in One Workspace
+
+A workspace might have `rivet.yaml` artifact files alongside other YAML files (CI configs, Kubernetes manifests). The LSP should not validate non-rivet YAML files. Mitigation: the `documentSelector` patterns are derived from `rivet.yaml` source paths. Only files within those paths receive diagnostics.
+
+### Risk: Schema Hot-Reload
+
+Schema files rarely change, but when they do (e.g., adding a new artifact type), the LSP must reload. Currently `SchemaInputSet` is created at startup. For schema changes, the LSP must either restart or implement schema file watching + `SchemaInput` content updates.
+
+### Open Question: Debouncing
+
+When the user types rapidly, each keystroke triggers `didChange`. Should we debounce validation? Options:
+- **No debounce** (spar's approach): validation is fast enough with salsa caching. Try this first.
+- **100ms debounce**: wait 100ms after last keystroke before publishing diagnostics. Use if validation is slow for large projects.
+
+### Open Question: Multi-root Workspaces
+
+VS Code supports multi-root workspaces. Each root might have its own `rivet.yaml`. Should we spawn one LSP process per root, or handle multiple roots in one process? Recommendation: one process per root (simpler, matches rust-analyzer's model).
+
+---
+
+## 11. Artifacts to Create
+
+| ID | Type | Title | Links |
+|----|------|-------|-------|
+| DD-040 | design-decision | Use lsp-server (not tower-lsp) for Rivet LSP | satisfies REQ-036 |
+| DD-041 | design-decision | LSP as rivet-cli subcommand, not separate crate | satisfies REQ-036 |
+| DD-042 | design-decision | Salsa database shared between LSP and validation pipeline | satisfies REQ-029, REQ-036 |
+| FEAT-060 | feature | `rivet lsp` subcommand starts LSP server on stdio | satisfies REQ-036, implements DD-041 |
+| FEAT-061 | feature | LSP diagnostics with line-level accuracy | satisfies REQ-036, implements DD-042 |
+| FEAT-062 | feature | LSP go-to-definition for artifact ID references | satisfies REQ-036 |
+| FEAT-063 | feature | LSP completions for artifact IDs, types, and link types | satisfies REQ-036 |
+
+---
+
+## 12. Implementation Estimate
+
+| Task | Effort | Dependencies |
+|------|--------|-------------|
+| LSP skeleton + didOpen/didChange/diagnostics | 2 days | Phase A4 (source locations) |
+| Go-to-definition | 1 day | LSP skeleton |
+| Hover | 1 day | LSP skeleton |
+| Completions (artifact IDs, types, link types) | 2 days | LSP skeleton |
+| Document symbols | 0.5 days | LSP skeleton |
+| Workspace symbols | 0.5 days | LSP skeleton |
+| Code actions (basic) | 1 day | yaml_edit.rs integration |
+| VS Code extension (minimal) | 1 day | LSP working |
+| VS Code extension (tree view, status bar) | 2 days | Extension working |
+| **Total** | **~11 days** | |
+
+This excludes Phase A and Phase B work (salsa foundation and rowan CST) which are covered in the completion plan.
diff --git a/rivet-cli/Cargo.toml b/rivet-cli/Cargo.toml
index a272dea..0cc2540 100644
--- a/rivet-cli/Cargo.toml
+++ b/rivet-cli/Cargo.toml
@@ -30,6 +30,8 @@ tower-http = { workspace = true }
 etch = { path = "../etch" }
 petgraph = { workspace = true }
 urlencoding = { workspace = true }
+lsp-server = "0.7"
+lsp-types = "0.97"
 
 [dev-dependencies]
 serde_json = { workspace = true }
diff --git a/rivet-cli/src/main.rs b/rivet-cli/src/main.rs
index c90cd70..31274f3 100644
--- a/rivet-cli/src/main.rs
+++ b/rivet-cli/src/main.rs
@@ -181,6 +181,10 @@ enum Command {
         /// Skip cross-repo validation (broken external refs, backlinks, circular deps, version conflicts)
         #[arg(long)]
         skip_external_validation: bool,
+
+        /// Scope validation to a named baseline (cumulative)
+        #[arg(long)]
+        baseline: Option<String>,
     },
 
     /// List artifacts, optionally filtered by type
@@ -196,6 +200,10 @@ enum Command {
         /// Output format: "text" (default) or "json"
         #[arg(short, long, default_value = "text")]
         format: String,
+
+        /// Scope listing to a named baseline (cumulative)
+        #[arg(long)]
+        baseline: Option<String>,
     },
 
     /// Show artifact summary statistics
@@ -203,6 +211,10 @@ enum Command {
         /// Output format: "text" (default) or "json"
         #[arg(short, long, default_value = "text")]
         format: String,
+
+        /// Scope statistics to a named baseline (cumulative)
+        #[arg(long)]
+        baseline: Option<String>,
     },
 
     /// Show traceability coverage report
@@ -222,6 +234,10 @@ enum Command {
         /// Directories to scan for test markers (default: src/ tests/)
         #[arg(long = "scan-paths", value_delimiter = ',')]
         scan_paths: Vec<PathBuf>,
+
+        /// Scope coverage to a named baseline (cumulative)
+        #[arg(long)]
+        baseline: Option<String>,
     },
 
     /// Generate a traceability matrix
@@ -305,6 +321,10 @@ enum Command {
         /// JSON array of version entries for config.js switcher: [{"label":"v0.1.0","path":"../v0.1.0/"}]
         #[arg(long)]
         versions: Option<String>,
+
+        /// Scope export to a named baseline (cumulative)
+        #[arg(long)]
+        baseline: Option<String>,
     },
 
     /// Introspect loaded schemas (types, links, rules)
@@ -540,6 +560,9 @@ enum Command {
         /// Path to the batch YAML file
         file: PathBuf,
     },
+
+    /// Start the language server (LSP over stdio)
+    Lsp,
 }
 
 #[derive(Subcommand)]
@@ -639,41 +662,55 @@ fn run(cli: Cli) -> Result<bool> {
     if let Command::CommitMsgCheck { file } = &cli.command {
         return cmd_commit_msg_check(&cli, file);
     }
+    if let Command::Lsp = &cli.command {
+        return cmd_lsp(&cli);
+    }
 
     match &cli.command {
         Command::Init { .. }
         | Command::Docs { .. }
         | Command::Context
-        | Command::CommitMsgCheck { .. } => unreachable!(),
+        | Command::CommitMsgCheck { .. }
+        | Command::Lsp => unreachable!(),
         Command::Stpa { path, schema } => cmd_stpa(path, schema.as_deref(), &cli),
         Command::Validate {
             format,
             incremental,
             verify_incremental,
             skip_external_validation,
+            baseline,
         } => cmd_validate(
             &cli,
             format,
             *incremental,
             *verify_incremental,
             *skip_external_validation,
+            baseline.as_deref(),
         ),
         Command::List {
             r#type,
             status,
             format,
-        } => cmd_list(&cli, r#type.as_deref(), status.as_deref(), format),
-        Command::Stats { format } => cmd_stats(&cli, format),
+            baseline,
+        } => cmd_list(
+            &cli,
+            r#type.as_deref(),
+            status.as_deref(),
+            format,
+            baseline.as_deref(),
+        ),
+        Command::Stats { format, baseline } => cmd_stats(&cli, format, baseline.as_deref()),
         Command::Coverage {
             format,
             fail_under,
             tests,
             scan_paths,
+            baseline,
         } => {
             if *tests {
                 cmd_coverage_tests(&cli, format, scan_paths)
             } else {
-                cmd_coverage(&cli, format, fail_under.as_ref())
+                cmd_coverage(&cli, format, fail_under.as_ref(), baseline.as_deref())
             }
         }
         Command::Matrix {
@@ -695,6 +732,7 @@ fn run(cli: Cli) -> Result<bool> {
             homepage,
             version_label,
             versions,
+            baseline,
         } => cmd_export(
             &cli,
             format,
@@ -705,6 +743,7 @@ fn run(cli: Cli) -> Result<bool> {
             homepage.as_deref(),
             version_label.as_deref(),
             versions.as_deref(),
+            baseline.as_deref(),
         ),
         Command::Impact {
             since,
@@ -1247,6 +1286,7 @@ fn cmd_validate(
     incremental: bool,
     verify_incremental: bool,
     skip_external_validation: bool,
+    baseline_name: Option<&str>,
 ) -> Result<bool> {
     check_for_updates();
 
@@ -1264,6 +1304,22 @@ fn cmd_validate(
         doc_store,
         ..
     } = ctx;
+
+    // Apply baseline scoping if requested
+    let (store, graph) = if let Some(bl) = baseline_name {
+        if let Some(ref baselines) = config.baselines {
+            let scoped = store.scoped(bl, baselines);
+            let scoped_graph = LinkGraph::build(&scoped, &schema);
+            println!("Baseline: {bl} ({} artifacts in scope)\n", scoped.len());
+            (scoped, scoped_graph)
+        } else {
+            eprintln!("warning: --baseline specified but no baselines defined in rivet.yaml");
+            (store, graph)
+        }
+    } else {
+        (store, graph)
+    };
+
     let doc_store = doc_store.unwrap_or_default();
     let mut diagnostics = validate::validate(&store, &schema, &graph);
     diagnostics.extend(validate::validate_documents(&doc_store, &store));
@@ -1714,9 +1770,10 @@ fn cmd_list(
     type_filter: Option<&str>,
     status_filter: Option<&str>,
     format: &str,
+    baseline_name: Option<&str>,
 ) -> Result<bool> {
     let ctx = ProjectContext::load(cli)?;
-    let store = ctx.store;
+    let store = apply_baseline_scope(ctx.store, baseline_name, &ctx.config);
 
     let query = rivet_core::query::Query {
         artifact_type: type_filter.map(|s| s.to_string()),
@@ -1761,9 +1818,14 @@ fn cmd_list(
 }
 
 /// Print summary statistics.
-fn cmd_stats(cli: &Cli, format: &str) -> Result<bool> {
+fn cmd_stats(cli: &Cli, format: &str, baseline_name: Option<&str>) -> Result<bool> {
     let ctx = ProjectContext::load(cli)?;
-    let (store, graph) = (ctx.store, ctx.graph);
+    let store = apply_baseline_scope(ctx.store, baseline_name, &ctx.config);
+    let graph = if baseline_name.is_some() {
+        LinkGraph::build(&store, &ctx.schema)
+    } else {
+        ctx.graph
+    };
 
     let orphans = graph.orphans(&store);
 
@@ -1801,9 +1863,20 @@ fn cmd_stats(cli: &Cli, format: &str) -> Result<bool> {
 }
 
 /// Show traceability coverage report.
-fn cmd_coverage(cli: &Cli, format: &str, fail_under: Option<&f64>) -> Result<bool> {
+fn cmd_coverage(
+    cli: &Cli,
+    format: &str,
+    fail_under: Option<&f64>,
+    baseline_name: Option<&str>,
+) -> Result<bool> {
     let ctx = ProjectContext::load(cli)?;
-    let (store, schema, graph) = (ctx.store, ctx.schema, ctx.graph);
+    let store = apply_baseline_scope(ctx.store, baseline_name, &ctx.config);
+    let schema = ctx.schema;
+    let graph = if baseline_name.is_some() {
+        LinkGraph::build(&store, &schema)
+    } else {
+        ctx.graph
+    };
     let report = coverage::compute_coverage(&store, &schema, &graph);
 
     if format == "json" {
@@ -2085,6 +2158,7 @@ fn cmd_export(
     homepage: Option<&str>,
     version_label: Option<&str>,
     versions_json: Option<&str>,
+    baseline_name: Option<&str>,
 ) -> Result<bool> {
     if format == "html" {
         return cmd_export_html(
@@ -2102,7 +2176,8 @@ fn cmd_export(
     use rivet_core::adapter::{Adapter, AdapterConfig};
 
     let ctx = ProjectContext::load(cli)?;
-    let artifacts: Vec<_> = ctx.store.iter().cloned().collect();
+    let store = apply_baseline_scope(ctx.store, baseline_name, &ctx.config);
+    let artifacts: Vec<_> = store.iter().cloned().collect();
     let config = AdapterConfig::default();
 
     let bytes = match format {
@@ -2322,6 +2397,7 @@ fn cmd_diff(
                         incremental: false,
                         verify_incremental: false,
                         skip_external_validation: false,
+                        baseline: None,
                     },
                 };
                 let head_cli = Cli {
@@ -2333,6 +2409,7 @@ fn cmd_diff(
                         incremental: false,
                         verify_incremental: false,
                         skip_external_validation: false,
+                        baseline: None,
                     },
                 };
                 let bc = ProjectContext::load(&base_cli)?;
@@ -3676,6 +3753,28 @@ fn cmd_baseline_list(cli: &Cli) -> Result<bool> {
     Ok(true)
 }
 
+/// Apply baseline scoping to a store if a baseline name is provided.
+///
+/// Returns the original store unmodified when no baseline is requested
+/// or when no baselines are configured in the project.
+fn apply_baseline_scope(
+    store: Store,
+    baseline_name: Option<&str>,
+    config: &ProjectConfig,
+) -> Store {
+    let Some(bl) = baseline_name else {
+        return store;
+    };
+    if let Some(ref baselines) = config.baselines {
+        let scoped = store.scoped(bl, baselines);
+        eprintln!("Baseline: {bl} ({} artifacts in scope)", scoped.len());
+        scoped
+    } else {
+        eprintln!("warning: --baseline specified but no baselines defined in rivet.yaml");
+        store
+    }
+}
+
 struct ProjectContext {
     config: ProjectConfig,
     store: Store,
@@ -4378,6 +4477,57 @@ fn cmd_batch(cli: &Cli, file: &std::path::Path) -> Result<bool> {
     Ok(true)
 }
 
+fn cmd_lsp(_cli: &Cli) -> Result<bool> {
+    use lsp_server::{Connection, Message};
+    use lsp_types::*;
+
+    eprintln!("rivet lsp: starting language server...");
+
+    let (connection, io_threads) = Connection::stdio();
+
+    let server_capabilities = ServerCapabilities {
+        text_document_sync: Some(TextDocumentSyncCapability::Kind(TextDocumentSyncKind::FULL)),
+        diagnostic_provider: Some(DiagnosticServerCapabilities::Options(DiagnosticOptions {
+            identifier: Some("rivet".to_string()),
+            ..Default::default()
+        })),
+        hover_provider: Some(HoverProviderCapability::Simple(true)),
+        definition_provider: Some(OneOf::Left(true)),
+        completion_provider: Some(CompletionOptions {
+            trigger_characters: Some(vec!["[".to_string(), ":".to_string()]),
+            ..Default::default()
+        }),
+        ..Default::default()
+    };
+
+    let init_params = connection.initialize(serde_json::to_value(server_capabilities).unwrap())?;
+    let _params: InitializeParams = serde_json::from_value(init_params)?;
+
+    eprintln!("rivet lsp: initialized");
+
+    // Main message loop
+    for msg in &connection.receiver {
+        match msg {
+            Message::Request(req) => {
+                if connection.handle_shutdown(&req)? {
+                    break;
+                }
+                // TODO: handle requests (hover, goto-definition, completion)
+                eprintln!("rivet lsp: unhandled request: {}", req.method);
+            }
+            Message::Notification(notif) => {
+                eprintln!("rivet lsp: notification: {}", notif.method);
+                // TODO: handle didOpen, didChange, didSave
+            }
+            Message::Response(_) => {}
+        }
+    }
+
+    io_threads.join()?;
+    eprintln!("rivet lsp: shut down");
+    Ok(true)
+}
+
 /// Substitute `$prev` in a string with the most recently generated ID.
 fn substitute_prev(s: &str, prev: &Option<String>) -> String {
     if s == "$prev" {
diff --git a/rivet-cli/src/serve/mod.rs b/rivet-cli/src/serve/mod.rs
index 795fa34..d359f24 100644
--- a/rivet-cli/src/serve/mod.rs
+++ b/rivet-cli/src/serve/mod.rs
@@ -187,6 +187,9 @@ pub(crate) struct AppState {
     pub(crate) doc_dirs: Vec<PathBuf>,
     /// External projects loaded at startup (empty if none configured).
     pub(crate) externals: Vec<ExternalInfo>,
+    /// Cached validation diagnostics — computed once at load/reload time
+    /// instead of on every page request.
+    pub(crate) cached_diagnostics: Vec<rivet_core::validate::Diagnostic>,
 }
 
 /// Convenience alias so handler signatures stay compact.
@@ -291,6 +294,8 @@ fn reload_state(
         port,
     };
 
+    let cached_diagnostics = rivet_core::validate::validate(&store, &schema, &graph);
+
     Ok(AppState {
         store,
         schema,
@@ -302,6 +307,7 @@ fn reload_state(
         schemas_dir: schemas_dir.to_path_buf(),
         doc_dirs,
         externals,
+        cached_diagnostics,
     })
 }
 
@@ -338,6 +344,8 @@ pub async fn run(
         port,
     };
 
+    let cached_diagnostics = rivet_core::validate::validate(&store, &schema, &graph);
+
     let state: SharedState = Arc::new(RwLock::new(AppState {
         store,
         schema,
@@ -349,6 +357,7 @@ pub async fn run(
         schemas_dir,
         doc_dirs,
         externals: Vec::new(),
+        cached_diagnostics,
     }));
 
     let app = Router::new()
diff --git a/rivet-cli/src/serve/views.rs b/rivet-cli/src/serve/views.rs
index e0804b9..bc47da4 100644
--- a/rivet-cli/src/serve/views.rs
+++ b/rivet-cli/src/serve/views.rs
@@ -23,7 +23,6 @@ use rivet_core::matrix::{self, Direction};
 use rivet_core::model::ProjectConfig;
 use rivet_core::schema::Severity;
 use rivet_core::store::Store;
-use rivet_core::validate;
 
 use super::components::{self, ViewParams};
 use super::layout;
@@ -52,7 +51,7 @@ fn stats_partial(state: &AppState) -> String {
     types.sort();
 
     let orphans = graph.orphans(store);
-    let diagnostics = validate::validate(store, &state.schema, graph);
+    let diagnostics = &state.cached_diagnostics;
     let errors = diagnostics
         .iter()
         .filter(|d| d.severity == Severity::Error)
@@ -1486,7 +1485,7 @@ pub(crate) async fn validate_view(
     Query(params): Query<ViewParams>,
 ) -> Html<String> {
     let state = state.read().await;
-    let diagnostics = validate::validate(&state.store, &state.schema, &state.graph);
+    let diagnostics = &state.cached_diagnostics;
 
     let errors = diagnostics
         .iter()
@@ -1532,15 +1531,9 @@ pub(crate) async fn validate_view(
         current_query,
     ));
 
-    // Show errors first, then warnings, then info
-    let mut sorted = diagnostics;
-    sorted.sort_by_key(|d| match d.severity {
-        Severity::Error => 0,
-        Severity::Warning => 1,
-        Severity::Info => 2,
-    });
-
-    // Apply severity filter
+    // Apply severity filter and sort: errors first, then warnings, then info.
+    // We work from the cached (immutable) diagnostics, so sorting is done via
+    // the filtered+collected vec below rather than mutating in place.
     let severity_filter = match current_status {
         "error" => Some(Severity::Error),
         "warning" => Some(Severity::Warning),
@@ -1553,7 +1546,7 @@ pub(crate) async fn validate_view(
         Some(current_query.to_lowercase())
     };
 
-    let filtered: Vec<_> = sorted
+    let mut filtered: Vec<_> = diagnostics
         .iter()
         .filter(|d| {
             if let Some(ref sev) = severity_filter {
@@ -1577,6 +1570,13 @@ pub(crate) async fn validate_view(
         })
         .collect();
 
+    // Sort: errors first, then warnings, then info
+    filtered.sort_by_key(|d| match d.severity {
+        Severity::Error => 0,
+        Severity::Warning => 1,
+        Severity::Info => 2,
+    });
+
     let filtered_count = filtered.len();
     if filtered_count == 0 {
         html.push_str("<div class=\"card\"><p>No matching issues found.</p></div>");
diff --git a/rivet-core/src/db.rs b/rivet-core/src/db.rs
index b1812a2..f4a539c 100644
--- a/rivet-core/src/db.rs
+++ b/rivet-core/src/db.rs
@@ -140,10 +140,14 @@ pub fn evaluate_conditional_rules(
         &schema.conditional_rules,
     ));
 
-    // Evaluate each conditional rule against each artifact
+    // Evaluate each conditional rule against each artifact (pre-compile regexes)
     for rule in &schema.conditional_rules {
+        let compiled_re = rule.when.compile_regex();
         for artifact in store.iter() {
-            if rule.when.matches_artifact(artifact) {
+            if rule
+                .when
+                .matches_artifact_with(artifact, compiled_re.as_ref())
+            {
                 diagnostics.extend(rule.then.check(artifact, &rule.name, rule.severity));
             }
         }
diff --git a/rivet-core/src/links.rs b/rivet-core/src/links.rs
index 0c31c5b..fd3c0d1 100644
--- a/rivet-core/src/links.rs
+++ b/rivet-core/src/links.rs
@@ -59,40 +59,44 @@ impl LinkGraph {
             node_map.insert(artifact.id.clone(), idx);
         }
 
-        // Create edges for all links
+        // Create edges for all links.
+        // Hoist the forward-map entry outside the inner link loop so we only
+        // hash the source key once per artifact (not once per link).
         for artifact in store.iter() {
+            let src_id = &artifact.id;
+            if artifact.links.is_empty() {
+                continue;
+            }
+
+            // Pre-fetch forward vec for this artifact (one hash lookup, not N)
+            let fwd_vec = forward.entry(src_id.clone()).or_default();
+
             for link in &artifact.links {
-                if store.contains(&link.target) {
+                let lt = &link.link_type;
+                let tgt = &link.target;
+                if store.contains(tgt) {
                     // Valid link — add forward, backward, and graph edge
-                    forward
-                        .entry(artifact.id.clone())
-                        .or_default()
-                        .push(ResolvedLink {
-                            source: artifact.id.clone(),
-                            target: link.target.clone(),
-                            link_type: link.link_type.clone(),
-                        });
-
-                    let inverse_type = schema.inverse_of(&link.link_type).map(|s| s.to_string());
-                    backward
-                        .entry(link.target.clone())
-                        .or_default()
-                        .push(Backlink {
-                            source: artifact.id.clone(),
-                            link_type: link.link_type.clone(),
-                            inverse_type,
-                        });
-
-                    if let (Some(&src), Some(&dst)) =
-                        (node_map.get(&artifact.id), node_map.get(&link.target))
-                    {
-                        graph.add_edge(src, dst, link.link_type.clone());
+                    fwd_vec.push(ResolvedLink {
+                        source: src_id.clone(),
+                        target: tgt.clone(),
+                        link_type: lt.clone(),
+                    });
+
+                    let inverse_type = schema.inverse_of(lt).map(|s| s.to_string());
+                    backward.entry(tgt.clone()).or_default().push(Backlink {
+                        source: src_id.clone(),
+                        link_type: lt.clone(),
+                        inverse_type,
+                    });
+
+                    if let (Some(&src), Some(&dst)) = (node_map.get(src_id), node_map.get(tgt)) {
+                        graph.add_edge(src, dst, lt.clone());
                     }
                 } else {
                     broken.push(ResolvedLink {
-                        source: artifact.id.clone(),
-                        target: link.target.clone(),
-                        link_type: link.link_type.clone(),
+                        source: src_id.clone(),
+                        target: tgt.clone(),
+                        link_type: lt.clone(),
                     });
                 }
             }
diff --git a/rivet-core/src/model.rs b/rivet-core/src/model.rs
index 1f62e32..f77aaf9 100644
--- a/rivet-core/src/model.rs
+++ b/rivet-core/src/model.rs
@@ -79,6 +79,27 @@ impl Artifact {
     pub fn has_link_type(&self, link_type: &str) -> bool {
         self.links.iter().any(|l| l.link_type == link_type)
     }
+
+    /// Return the baseline this artifact belongs to, if any.
+    ///
+    /// The baseline is read from the `baseline` key in the `fields` map
+    /// rather than being a first-class struct field, keeping the data
+    /// model backward-compatible.
+    pub fn baseline(&self) -> Option<&str> {
+        self.fields.get("baseline").and_then(|v| v.as_str())
+    }
+}
+
+/// Configuration for a named baseline (release scope).
+///
+/// Baselines are declared in order in `rivet.yaml`. Validation and
+/// coverage can be scoped to a baseline, which cumulatively includes
+/// all artifacts from earlier baselines.
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct BaselineConfig {
+    pub name: String,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub description: Option<String>,
 }
 
 /// Configuration for commit-to-artifact traceability.
@@ -140,6 +161,10 @@ pub struct ProjectConfig {
     /// External project dependencies for cross-repo linking.
     #[serde(default)]
     pub externals: Option<BTreeMap<String, ExternalProject>>,
+    /// Named baselines for scoped validation and coverage.
+    /// Order matters: earlier baselines are cumulatively included in later ones.
+    #[serde(default)]
+    pub baselines: Option<Vec<BaselineConfig>>,
 }
 
 #[derive(Debug, Clone, Serialize, Deserialize)]
diff --git a/rivet-core/src/schema.rs b/rivet-core/src/schema.rs
index 63aa275..49384c2 100644
--- a/rivet-core/src/schema.rs
+++ b/rivet-core/src/schema.rs
@@ -1,3 +1,4 @@
+use std::borrow::Cow;
 use std::collections::HashMap;
 use std::path::Path;
 
@@ -220,6 +221,10 @@ impl TryFrom<ConditionRaw> for Condition {
 // Manual Serialize implementation for Condition → flat YAML output
 impl Condition {
     /// Check whether an artifact satisfies this condition.
+    ///
+    /// **Note:** For `Matches` conditions this compiles the regex on every call.
+    /// In hot loops, prefer [`matches_artifact_with`] and pre-compile via
+    /// [`compile_regex`].
     #[inline]
     pub fn matches_artifact(&self, artifact: &Artifact) -> bool {
         match self {
@@ -235,31 +240,62 @@ impl Condition {
             Condition::Exists { field } => get_field_value(artifact, field).is_some(),
         }
     }
+
+    /// Like [`matches_artifact`] but accepts a pre-compiled regex for `Matches`
+    /// conditions, avoiding repeated `Regex::new` calls in tight loops.
+    #[inline]
+    pub fn matches_artifact_with(&self, artifact: &Artifact, compiled: Option<&Regex>) -> bool {
+        match self {
+            Condition::Equals { field, value } => {
+                get_field_value(artifact, field).is_some_and(|v| v == *value)
+            }
+            Condition::Matches { field, .. } => {
+                if let Some(re) = compiled {
+                    get_field_value(artifact, field).is_some_and(|v| re.is_match(&v))
+                } else {
+                    // Fallback: compile inline (shouldn't normally happen)
+                    self.matches_artifact(artifact)
+                }
+            }
+            Condition::Exists { field } => get_field_value(artifact, field).is_some(),
+        }
+    }
+
+    /// Pre-compile the regex for a `Matches` condition.
+    /// Returns `None` for `Equals` / `Exists` conditions or invalid patterns.
+    pub fn compile_regex(&self) -> Option<Regex> {
+        match self {
+            Condition::Matches { pattern, .. } => Regex::new(pattern).ok(),
+            _ => None,
+        }
+    }
 }
 
 /// Get a string value for a field from an artifact, checking base fields first.
+///
+/// Returns a `Cow<str>` to avoid cloning when the value is already a `&str`.
 #[inline]
-fn get_field_value(artifact: &Artifact, field: &str) -> Option<String> {
+fn get_field_value<'a>(artifact: &'a Artifact, field: &str) -> Option<Cow<'a, str>> {
     match field {
-        "status" => artifact.status.clone(),
-        "description" => artifact.description.clone(),
-        "title" => Some(artifact.title.clone()),
-        "id" => Some(artifact.id.clone()),
+        "status" => artifact.status.as_deref().map(Cow::Borrowed),
+        "description" => artifact.description.as_deref().map(Cow::Borrowed),
+        "title" => Some(Cow::Borrowed(&artifact.title)),
+        "id" => Some(Cow::Borrowed(&artifact.id)),
         _ => {
             // Check tags: if field == "tags", join them
             if field == "tags" {
                 if artifact.tags.is_empty() {
                     None
                 } else {
-                    Some(artifact.tags.join(","))
+                    Some(Cow::Owned(artifact.tags.join(",")))
                 }
             } else {
                 // Check fields map
                 artifact.fields.get(field).map(|v| match v {
-                    serde_yaml::Value::String(s) => s.clone(),
-                    serde_yaml::Value::Bool(b) => b.to_string(),
-                    serde_yaml::Value::Number(n) => n.to_string(),
-                    _ => format!("{v:?}"),
+                    serde_yaml::Value::String(s) => Cow::Borrowed(s.as_str()),
+                    serde_yaml::Value::Bool(b) => Cow::Owned(b.to_string()),
+                    serde_yaml::Value::Number(n) => Cow::Owned(n.to_string()),
+                    _ => Cow::Owned(format!("{v:?}")),
                 })
             }
         }
diff --git a/rivet-core/src/store.rs b/rivet-core/src/store.rs
index 2a04092..aab0e0a 100644
--- a/rivet-core/src/store.rs
+++ b/rivet-core/src/store.rs
@@ -1,7 +1,7 @@
 use std::collections::HashMap;
 
 use crate::error::Error;
-use crate::model::{Artifact, ArtifactId};
+use crate::model::{Artifact, ArtifactId, BaselineConfig};
 
 /// In-memory artifact store.
 ///
@@ -40,18 +40,24 @@ impl Store {
         let artifact_type = artifact.artifact_type.clone();
 
         // Remove from old type index if updating
-        if let Some(old) = self.artifacts.get(&id) {
+        let is_update = if let Some(old) = self.artifacts.get(&id) {
             if old.artifact_type != artifact_type {
                 if let Some(ids) = self.by_type.get_mut(&old.artifact_type) {
                     ids.retain(|i| i != &id);
                 }
+                // Type changed: not yet in the new type's list
+                false
+            } else {
+                // Same type: already in the type index, skip re-adding
+                true
             }
-        }
+        } else {
+            false
+        };
 
         self.artifacts.insert(id.clone(), artifact);
-        let ids = self.by_type.entry(artifact_type).or_default();
-        if !ids.contains(&id) {
-            ids.push(id);
+        if !is_update {
+            self.by_type.entry(artifact_type).or_default().push(id);
         }
     }
 
@@ -105,4 +111,36 @@ impl Store {
     pub fn contains(&self, id: &str) -> bool {
         self.artifacts.contains_key(id)
     }
+
+    /// Create a scoped store containing only artifacts in the given baseline
+    /// and all prior baselines (cumulative).
+    ///
+    /// Artifacts whose `baseline` field matches the target or any earlier
+    /// baseline (by declaration order) are included. Artifacts with no
+    /// baseline field are excluded from scoped stores.
+    pub fn scoped(&self, baseline: &str, baselines: &[BaselineConfig]) -> Store {
+        // Find the index of the target baseline in the ordered list
+        let target_idx = baselines.iter().position(|b| b.name == baseline);
+        let target_idx = match target_idx {
+            Some(idx) => idx,
+            None => return self.clone(), // Unknown baseline, return full store
+        };
+
+        // Collect baseline names up to and including target
+        let included: Vec<&str> = baselines[..=target_idx]
+            .iter()
+            .map(|b| b.name.as_str())
+            .collect();
+
+        // Filter artifacts: include only those whose baseline is in the included set
+        let mut scoped = Store::new();
+        for artifact in self.artifacts.values() {
+            if let Some(art_baseline) = artifact.baseline() {
+                if included.contains(&art_baseline) {
+                    scoped.upsert(artifact.clone());
+                }
+            }
+        }
+        scoped
+    }
 }
diff --git a/rivet-core/src/validate.rs b/rivet-core/src/validate.rs
index 77056ee..1f967ff 100644
--- a/rivet-core/src/validate.rs
+++ b/rivet-core/src/validate.rs
@@ -43,10 +43,14 @@ pub fn validate(store: &Store, schema: &Schema, graph: &LinkGraph) -> Vec<Diagno
         &schema.conditional_rules,
     ));
 
-    // 8. Check conditional rules
+    // 8. Check conditional rules (pre-compile regexes to avoid re-compilation per artifact)
     for rule in &schema.conditional_rules {
+        let compiled_re = rule.when.compile_regex();
         for artifact in store.iter() {
-            if rule.when.matches_artifact(artifact) {
+            if rule
+                .when
+                .matches_artifact_with(artifact, compiled_re.as_ref())
+            {
                 diagnostics.extend(rule.then.check(artifact, &rule.name, rule.severity));
             }
         }
@@ -102,7 +106,7 @@ pub fn validate_structural(store: &Store, schema: &Schema, graph: &LinkGraph) ->
             if let Some(allowed) = &field.allowed_values {
                 if let Some(value) = artifact.fields.get(&field.name) {
                     if let Some(s) = value.as_str() {
-                        if !allowed.contains(&s.to_string()) {
+                        if !allowed.iter().any(|a| a == s) {
                             diagnostics.push(Diagnostic {
                                 severity: Severity::Warning,
                                 artifact_id: Some(artifact.id.clone()),
diff --git a/rivet.yaml b/rivet.yaml
index 01b24bd..d64332c 100644
--- a/rivet.yaml
+++ b/rivet.yaml
@@ -22,6 +22,12 @@ docs:
 
 results: results
 
+baselines:
+  - name: v0.1.0
+    description: Initial release — core validation, STPA, ASPICE schemas, CLI, dashboard
+  - name: v0.2.0-dev
+    description: Current development — cross-repo, mutations, STPA-Sec, export, AADL
+
 commits:
   format: trailers
   trailers: