diff --git a/LICENSE b/LICENSE
index 22f1f1d..d8ec8cc 100644
--- a/LICENSE
+++ b/LICENSE
@@ -1,21 +1,13 @@
-MIT License
+Pay It Forward License (PIF)
 
-Copyright (c) 2026 spacedevin
+Copyright (c) 2026-present spacedevin
 
-Permission is hereby granted, free of charge, to any person obtaining a copy
-of this software and associated documentation files (the "Software"), to deal
-in the Software without restriction, including without limitation the rights
-to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-copies of the Software, and to permit persons to whom the Software is
-furnished to do so, subject to the following conditions:
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
 
-The above copyright notice and this permission notice shall be included in all
-copies or substantial portions of the Software.
+The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
 
-THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
-SOFTWARE.
+This license includes a perpetual, worldwide, non-exclusive, royalty-free, irrevocable (except as stated below) grant for patent claims necessarily infringed by the use of the Software or any contributions submitted to it; terminating automatically when an entity initiates patent litigation (including a cross-claim or counterclaim) alleging that the Software or any portion thereof infringes a patent.
+
+The software is provided "as is," without warranty of any kind, express or implied, including but not limited to the warranties of merchantability, fitness for a particular purpose, and non-infringement. In no event shall the authors or copyright holders be liable for any claim, damages, or other liability, whether in an action of contract, tort, or otherwise, arising from, out of, or in connection with the software or the use or other dealings in the software.
+
+Recipients of the Software should pay it forward by contributing to the open-source community through actions including but not limited to providing code, documentation, tutorials, guides, support, feedback, or promoting open-source projects through advocacy or related efforts that advance innovation and community growth.
diff --git a/README.md b/README.md
index 74ef965..d9a989b 100644
--- a/README.md
+++ b/README.md
@@ -89,4 +89,6 @@ any restricted host (via a profile). It is what makes drift a test failure rathe
 
 Branch % is lower (~60%) because the Tish→JS emit adds many `?? null` / typeof guards that are defensive noise, not language logic. Line coverage is the gate in CI.
 
-MIT
+## License
+
+Pay It Forward (PIF) — see [LICENSE](LICENSE). Same license as [tish](https://github.com/tishlang/tish).
diff --git a/package.json b/package.json
index 10d2834..ac4b0df 100644
--- a/package.json
+++ b/package.json
@@ -3,7 +3,7 @@
   "version": "0.1.0",
   "type": "module",
   "description": ".deck language only \u2014 tokenize, parse, format, registries, highlight classify",
-  "license": "MIT",
+  "license": "PIF",
   "author": "spacedevin",
   "repository": {
     "type": "git",
diff --git a/scripts/build-rust.mjs b/scripts/build-rust.mjs
index 2332817..0fdc575 100644
--- a/scripts/build-rust.mjs
+++ b/scripts/build-rust.mjs
@@ -55,6 +55,80 @@ fs.appendFileSync(
   "\n// ── Typed facade (hand-written; see the deck repo's rust/facade.rs) ───────────\npub mod facade;\npub use facade::{parse, BarSelector, BodyRow, Clip, DeckProgram, Directive, GenBlock, Params, ParseError, Track};\n"
 )
 
+
+/// Rust-facing README. Deliberately not the npm one: a Rust consumer needs `parse()` and the typed
+/// rows, not `npm install` and the Tish import path.
+function crateReadme() {
+  return `# deckfile
+
+Parser for the **\`.deck\`** patch language — the Rust target of [@spacedevin/deck][npm].
+
+\`\`\`toml
+[dependencies]
+deckfile = "${CRATE_VERSION}"
+\`\`\`
+
+\`\`\`rust
+let program = deckfile::parse(source);
+
+println!("{:?} bpm", program.bpm);
+for track in &program.tracks {
+    println!("{} ({}) — {} bars", track.name, track.generator_id, track.loop_bars.unwrap_or(1));
+    for row in &track.body {
+        match row {
+            deckfile::BodyRow::Note { midi, start_beat, dur_beats, .. } => { /* … */ }
+            deckfile::BodyRow::Steps { on, .. } => { /* … */ }
+            _ => {}
+        }
+    }
+}
+\`\`\`
+
+\`parse\` never fails: malformed lines land in \`program.errors\`, because a streaming host has to be
+able to parse a partial program.
+
+## Generated — one source, three targets
+
+Everything here except the typed facade is **generated** from the same \`src/index.tish\` that
+produces the npm package, using \`tish build --target rust-lib\`. Rust, JavaScript and Tish consumers
+therefore parse \`.deck\` identically by construction rather than by discipline, and a
+[shared conformance corpus][conf] — the same \`.deck\` inputs with the same expected parses — is run
+against every target on every change.
+
+Don't send patches here; fix the language upstream in [spacedevin/deck][repo].
+
+## Scope
+
+Tokenize · parse to an AST · track/clip body lines as typed rows · format helpers · scale vocabulary ·
+bar selectors · Euclidean fill · highlight classification · host registries.
+
+**Not** included, by design: applying the AST to a project model, emitting \`.deck\` text, audio
+engines, instrument catalogs. Those belong to the host — see [HOST.md][host].
+
+Hosts extend the language through registries rather than forking it:
+\`registerTopLevelStatement\`, \`registerBodyLineDialect\`, \`registerGenBlockDialect\`,
+\`registerGeneratorIdAliases\`, \`registerBuiltinMacros\`.
+
+## Docs
+
+- [Language grammar][grammar] — the canonical \`.deck\` surface
+- [Host integration][host] — boot order and what a host implements
+- [gen_block extensions][ext] — dialect registration
+
+## License
+
+Pay It Forward (PIF) — see LICENSE. Same license as [tish][tish].
+
+[npm]: https://www.npmjs.com/package/@spacedevin/deck
+[repo]: https://github.com/spacedevin/deck
+[conf]: https://github.com/spacedevin/deck/tree/main/conformance
+[grammar]: https://github.com/spacedevin/deck/blob/main/docs/DECK_GRAMMAR.md
+[host]: https://github.com/spacedevin/deck/blob/main/docs/HOST.md
+[ext]: https://github.com/spacedevin/deck/blob/main/docs/DECK_EXTENSION.md
+[tish]: https://github.com/tishlang/tish
+`
+}
+
 // The crate runs the SAME corpus as the JS build — that is the whole point of emitting it from one
 // source. Ship the fixtures inside the crate so `cargo test` works from a published copy too.
 fs.mkdirSync(path.join(out, "tests"), { recursive: true })
@@ -79,11 +153,14 @@ const CRATE_VERSION = process.env.DECKFILE_VERSION ?? pkg.version
 const manifestPath = path.join(out, "Cargo.toml")
 let manifest = fs.readFileSync(manifestPath, "utf8")
 const deps = `[dependencies]\ntishlang_runtime = "${RUNTIME_VERSION}"\n`
+// `license-file`, not `license`: PIF is not an SPDX identifier, so an SPDX field would either be
+// rejected or misreport the terms. Same approach tish itself uses.
 manifest = `[package]
 name = "${CRATE_NAME}"
 version = "${CRATE_VERSION}"
 edition = "2021"
-license = "${pkg.license}"
+license-file = "LICENSE"
+readme = "README.md"
 description = "${pkg.description}"
 repository = "${pkg.repository.url}"
 keywords = ["deck", "tish", "parser", "music"]
@@ -101,5 +178,10 @@ path = "src/lib.rs"
 ${deps}`
 fs.writeFileSync(manifestPath, manifest)
 
+// A published crate needs its own LICENSE and README in the package — crates.io renders the README
+// on the crate page and cannot reach back into the repo for either.
+fs.copyFileSync(path.join(root, "LICENSE"), path.join(out, "LICENSE"))
+fs.writeFileSync(path.join(out, "README.md"), crateReadme())
+
 const pubFns = (fs.readFileSync(libPath, "utf8").match(/^pub fn /gm) ?? []).length
 console.log(`crate: ${CRATE_NAME} v${CRATE_VERSION} — ${pubFns} exported fns + typed facade`)