diff --git a/packages/producer/README.md b/packages/producer/README.md
index 8e5bc6f48..c77691732 100644
--- a/packages/producer/README.md
+++ b/packages/producer/README.md
@@ -106,6 +106,38 @@ This is not chroma keying. There is no green/blue background to remove and no "k
 
 Don't paint a fullscreen background in your HTML. The default body background is overridden to transparent automatically — any `body { background: ... }`, `#root { background: ... }`, or `[data-composition-id] { background: ... }` rule is force-overridden during alpha rendering. Backgrounds on inner elements (cards, scenes, components) are kept.
 
+## Distributed rendering
+
+For renders too large for a single machine, the producer ships a public set of distributed-render primitives. They are pure functions over local file paths — networking and orchestration live in adapter packages (Temporal, AWS Lambda + Step Functions, Cloud Run Jobs, K8s Jobs).
+
+```typescript
+import { plan, renderChunk, assemble } from "@hyperframes/producer/distributed";
+
+// Controller-side: produce a self-contained planDir + content-addressed planHash.
+const planResult = await plan(
+  projectDir,
+  { fps: 30, width: 1920, height: 1080, format: "mp4" },
+  "/tmp/plan",
+);
+
+// Worker-side: render one chunk. Byte-identical retries on the same
+// `(planDir, chunkIndex)` — Temporal / Step Functions retry policies are safe
+// to point at this.
+const chunk = await renderChunk("/tmp/plan", 0, "/tmp/chunks/0.mp4");
+
+// Controller-side: stitch chunks into the final deliverable.
+await assemble(
+  "/tmp/plan",
+  ["/tmp/chunks/0.mp4", "/tmp/chunks/1.mp4"],
+  "/tmp/plan/audio.aac",
+  "/tmp/output.mp4",
+);
+```
+
+The three activity functions plus their result types are also re-exported from `@hyperframes/producer` so callers that pin the main package don't need a separate subpath import. Supported formats: `mp4` SDR, `mov` ProRes 4444, and `png-sequence`. webm and HDR mp4 trip a typed `FormatNotSupportedInDistributedError` — use the in-process renderer (`executeRenderJob`) for those.
+
+See [`DISTRIBUTED-RENDERING-PLAN.md`](../../DISTRIBUTED-RENDERING-PLAN.md) for the full architecture.
+
 ## How it works
 
 1. **Serve** — spins up a local file server for the HTML composition
diff --git a/packages/producer/build.mjs b/packages/producer/build.mjs
index 7b205f140..b2f4d4fb8 100644
--- a/packages/producer/build.mjs
+++ b/packages/producer/build.mjs
@@ -93,6 +93,23 @@ await Promise.all([
     entryPoints: ["src/services/shaderTransitionWorker.ts"],
     outfile: "dist/services/shaderTransitionWorker.js",
   }),
+  // `@hyperframes/producer/distributed` subpath — the public distributed
+  // render primitives (plan / renderChunk / assemble). Bundled as a
+  // separate entry so adopters that don't need the in-process renderer
+  // (Lambda chunk workers, CDK constructs, thin orchestrators) can import
+  // only this surface and skip the rest of the producer's dependency tree.
+  build({
+    bundle: true,
+    platform: "node",
+    target: "node22",
+    format: "esm",
+    external: ["puppeteer", "esbuild", "postcss"],
+    plugins: [workspaceAliasPlugin],
+    minify: false,
+    sourcemap: true,
+    entryPoints: ["src/distributed.ts"],
+    outfile: "dist/distributed.js",
+  }),
 ]);
 
 // Copy core runtime artifacts so the producer can find them at dist/
diff --git a/packages/producer/package.json b/packages/producer/package.json
index abf019f44..b93b35ebe 100644
--- a/packages/producer/package.json
+++ b/packages/producer/package.json
@@ -20,6 +20,10 @@
     },
     "./server": {
       "import": "./dist/public-server.js"
+    },
+    "./distributed": {
+      "import": "./dist/distributed.js",
+      "types": "./dist/distributed.d.ts"
     }
   },
   "publishConfig": {
diff --git a/packages/producer/src/distributed.ts b/packages/producer/src/distributed.ts
new file mode 100644
index 000000000..8a402187d
--- /dev/null
+++ b/packages/producer/src/distributed.ts
@@ -0,0 +1,78 @@
+/**
+ * `@hyperframes/producer/distributed` — the distributed render primitives.
+ *
+ * See `DISTRIBUTED-RENDERING-PLAN.md` for the full architecture. The three
+ * activities (`plan` → `renderChunk` × N → `assemble`) are pure functions
+ * over local file paths; networking + orchestration live in adapters.
+ *
+ * Adopters (AWS Lambda, Cloud Run Jobs, Temporal, K8s Jobs, plain SSH):
+ *
+ * ```ts
+ * import {
+ *   plan,
+ *   renderChunk,
+ *   assemble,
+ * } from "@hyperframes/producer/distributed";
+ *
+ * // Controller-side: produce a self-contained planDir + content-addressed planHash.
+ * const planResult = await plan(projectDir, config, planDir);
+ *
+ * // Worker-side: render one chunk. Byte-identical retries on the same
+ * // (planDir, chunkIndex) — Temporal / Step Functions retry policies are
+ * // safe to point at this.
+ * const chunk = await renderChunk(planDir, chunkIndex, outputChunkPath);
+ *
+ * // Controller-side: stitch chunks into the final deliverable.
+ * await assemble(planDir, chunkPaths, audioPath, outputPath);
+ * ```
+ *
+ * No networking, no AWS SDK, no Temporal SDK — those live in adapter
+ * packages. This module is library code only.
+ */
+
+// ── Plan (Activity A) ───────────────────────────────────────────────────────
+export {
+  // Functions
+  buildChunkSlices,
+  measurePlanDirBytes,
+  plan,
+  rejectUnsupportedDistributedFormat,
+  resolveChunkPlan,
+  // Types
+  type DistributedRenderConfig,
+  type PlanResult,
+  // Constants
+  DEFAULT_CHUNK_SIZE,
+  DEFAULT_MAX_PARALLEL_CHUNKS,
+  PLAN_DIR_SIZE_LIMIT_BYTES,
+  // Error codes + classes
+  FORMAT_NOT_SUPPORTED_IN_DISTRIBUTED,
+  FormatNotSupportedInDistributedError,
+  PLAN_TOO_LARGE,
+  PlanTooLargeError,
+} from "./services/distributed/plan.js";
+
+// ── RenderChunk (Activity B) ────────────────────────────────────────────────
+export {
+  applyRuntimeEnvSnapshot,
+  readWebGlVendorInfoFromCanvas,
+  renderChunk,
+  // Types
+  type ChunkResult,
+  // Error codes + classes
+  FFMPEG_VERSION_MISMATCH,
+  PLAN_HASH_MISMATCH,
+  RenderChunkValidationError,
+} from "./services/distributed/renderChunk.js";
+
+// ── Assemble (Activity C) ───────────────────────────────────────────────────
+export { assemble, type AssembleResult } from "./services/distributed/assemble.js";
+
+// ── Plan-time shared types from `freezePlan` ───────────────────────────────
+// Re-exported so adopters that deserialize a planDir's `meta/encoder.json`
+// or `meta/chunks.json` see the same shapes the producer wrote them as.
+export type {
+  ChunkSliceJson,
+  CompositionMetadataJson,
+  LockedRenderConfig,
+} from "./services/render/stages/freezePlan.js";
diff --git a/packages/producer/src/index.ts b/packages/producer/src/index.ts
index 91eb8cb82..692931e86 100644
--- a/packages/producer/src/index.ts
+++ b/packages/producer/src/index.ts
@@ -75,3 +75,18 @@ export {
   runHyperframeLint,
   type PreparedHyperframeLintInput,
 } from "./services/hyperframeLint.js";
+
+// ── Distributed render primitives ───────────────────────────────────────────
+// The full surface lives at `@hyperframes/producer/distributed`; we
+// additionally re-export the three activity functions + their result
+// types here so callers that pin `@hyperframes/producer` don't need a
+// separate subpath import.
+export {
+  assemble,
+  plan,
+  renderChunk,
+  type AssembleResult,
+  type ChunkResult,
+  type DistributedRenderConfig,
+  type PlanResult,
+} from "./distributed.js";
diff --git a/packages/producer/src/services/distributed/publicExports.test.ts b/packages/producer/src/services/distributed/publicExports.test.ts
new file mode 100644
index 000000000..08ea9d350
--- /dev/null
+++ b/packages/producer/src/services/distributed/publicExports.test.ts
@@ -0,0 +1,79 @@
+/**
+ * Unit tests for the public-export surface of the distributed primitives.
+ *
+ * Two import paths must work for adopters:
+ *
+ *   1. `import { plan, renderChunk, assemble } from "@hyperframes/producer"`
+ *      — the canonical package entry. Includes the three activity functions
+ *      and their result types.
+ *
+ *   2. `import { plan, renderChunk, assemble } from "@hyperframes/producer/distributed"`
+ *      — the focused subpath, suitable for Lambda chunk-runner images that
+ *      don't pull in the in-process renderer's transitive deps.
+ *
+ * These tests are surface-only: they assert the symbols exist and have the
+ * expected shapes. The functional behaviour is covered by `plan.test.ts` /
+ * `renderChunk.test.ts` / `assemble.test.ts`.
+ *
+ * We import via the workspace-relative `../../distributed.js` /
+ * `../../index.js` paths rather than `"@hyperframes/producer"` because the
+ * package resolver inside the workspace points back at `src/index.ts` —
+ * either form exercises the same surface.
+ */
+
+import { describe, expect, it } from "bun:test";
+import * as distributedSubpath from "../../distributed.js";
+import * as producerIndex from "../../index.js";
+
+describe("@hyperframes/producer/distributed (subpath)", () => {
+  it("exports the three activity functions", () => {
+    expect(typeof distributedSubpath.plan).toBe("function");
+    expect(typeof distributedSubpath.renderChunk).toBe("function");
+    expect(typeof distributedSubpath.assemble).toBe("function");
+  });
+
+  it("exports the chunking helpers + constants", () => {
+    expect(typeof distributedSubpath.resolveChunkPlan).toBe("function");
+    expect(typeof distributedSubpath.buildChunkSlices).toBe("function");
+    expect(typeof distributedSubpath.measurePlanDirBytes).toBe("function");
+    expect(distributedSubpath.DEFAULT_CHUNK_SIZE).toBe(240);
+    expect(distributedSubpath.DEFAULT_MAX_PARALLEL_CHUNKS).toBe(16);
+    expect(distributedSubpath.PLAN_DIR_SIZE_LIMIT_BYTES).toBe(2 * 1024 * 1024 * 1024);
+  });
+
+  it("exports the non-retryable error codes + classes", () => {
+    expect(distributedSubpath.PLAN_TOO_LARGE).toBe("PLAN_TOO_LARGE");
+    expect(distributedSubpath.FORMAT_NOT_SUPPORTED_IN_DISTRIBUTED).toBe(
+      "FORMAT_NOT_SUPPORTED_IN_DISTRIBUTED",
+    );
+    expect(distributedSubpath.FFMPEG_VERSION_MISMATCH).toBe("FFMPEG_VERSION_MISMATCH");
+    expect(distributedSubpath.PLAN_HASH_MISMATCH).toBe("PLAN_HASH_MISMATCH");
+
+    expect(typeof distributedSubpath.PlanTooLargeError).toBe("function");
+    expect(typeof distributedSubpath.FormatNotSupportedInDistributedError).toBe("function");
+    expect(typeof distributedSubpath.RenderChunkValidationError).toBe("function");
+  });
+
+  it("exports the input-validation helpers", () => {
+    expect(typeof distributedSubpath.rejectUnsupportedDistributedFormat).toBe("function");
+    expect(typeof distributedSubpath.applyRuntimeEnvSnapshot).toBe("function");
+    expect(typeof distributedSubpath.readWebGlVendorInfoFromCanvas).toBe("function");
+  });
+});
+
+describe("@hyperframes/producer (main entry)", () => {
+  it("re-exports the three activity functions", () => {
+    expect(typeof producerIndex.plan).toBe("function");
+    expect(typeof producerIndex.renderChunk).toBe("function");
+    expect(typeof producerIndex.assemble).toBe("function");
+  });
+
+  it("preserves the existing in-process exports (executeRenderJob unchanged)", () => {
+    // The distributed primitives must NOT break the in-process surface;
+    // spot-check the load-bearing exports the in-process callers rely on.
+    expect(typeof producerIndex.executeRenderJob).toBe("function");
+    expect(typeof producerIndex.createRenderJob).toBe("function");
+    expect(typeof producerIndex.createCaptureSession).toBe("function");
+    expect(typeof producerIndex.createFileServer).toBe("function");
+  });
+});