diff --git a/docs/asset-engine/services.yaml b/docs/asset-engine/services.yaml
index 4cce4b4..8442386 100644
--- a/docs/asset-engine/services.yaml
+++ b/docs/asset-engine/services.yaml
@@ -1234,27 +1234,34 @@ services:
       /history. Until then, expose ComfyUI as an external link in the UI.
       User state at /worktank/comfyui/basedir/.
 
-  - id: dia
-    name: Dia / Dia2 TTS
+  # Dia2 runs as TWO fixed-model instances: the devnen wrapper is
+  # single-model and IGNORES the OpenAI `model` field (serves whatever
+  # checkpoint is loaded), so the only way to offer both Dia2 models to
+  # asset-engine as real per-request choices is one endpoint per model.
+  # Both live in the `dia` stack (one compose, two services); `compose up`
+  # starts both. The legacy Dia 1.6B entry was retired 2026-05-31 in favor
+  # of these — drop the old `dia` tile when re-vendoring.
+  - id: dia2-2b
+    name: Dia2 2B (High Quality)
     description: >
-      Nari Labs' dialogue TTS — multi-speaker turn-taking in one pass with
-      [S1]/[S2] speaker tags and nonverbals (laughs)/(coughs)/(sighs).
-      Dia2 family (1B streaming, 2B high-quality) selectable on the host.
+      Nari Labs' Dia2 dialogue TTS, 2B high-quality checkpoint — multi-speaker
+      turn-taking in one pass with [S1]/[S2] speaker tags and nonverbals
+      (laughs)/(coughs)/(sighs). 24 kHz. Served via devnen/Dia-TTS-Server.
     category: tts
-    version: 2
-    status: down
+    version: 1
+    status: ready
     host: irv-ml1
     lifecycle:
       stack: dia
-      vram_gb: 7
+      vram_gb: 8
       gpu_device_id: 0
     endpoint: http://10.100.79.3:8200/v1/audio/speech
     method: POST
     content_type: application/json
     model:
-      id: nari-labs/Dia-1.6B
+      id: nari-labs/Dia2-2B
       revision: null
-      image: local/dia:v1
+      image: local/dia:v2
     fields:
       - name: input
         type: textarea
@@ -1263,29 +1270,20 @@ services:
         max_length: 5000
         description: >
           [S1]/[S2] tags mark speaker turns; nonverbals like (laughs),
-          (coughs), (sighs), (clears throat) go inline. For a clone voice,
-          prepend the reference transcript manually.
-      - name: model
-        type: select
-        options: [dia-1.6b]
-        default: dia-1.6b
-        description: >
-          Ignored by /v1/audio/speech (serves whatever checkpoint is loaded).
-          Switch Dia 1.6B / Dia2-1B / Dia2-2B via the wrapper config or Web UI.
+          (coughs), (sighs), (clears throat) go inline.
       - name: voice
         type: select
         label: Voice / mode
-        options: [S1, S2, dialogue]
-        default: S1
+        options: [dialogue, single_s1, single_s2, predefined]
+        default: dialogue
         description: >
-          S1 | S2 | dialogue speaker mode. Clone-reference filenames under
-          /worktank/dia/reference_audio are NOT selectable here (a closed
-          select can't carry free-text); promote to a source_url-backed
-          picker or a separate free-text field if clone-by-file is wanted.
+          Speaker mode from the model's voice set. `clone` (prefix_speaker)
+          needs a reference clip, so it isn't a plain picker choice here.
       - name: response_format
         type: select
         options: [opus, wav]
         default: opus
+        description: 24 kHz output (Dia2; note dia1 was 44.1 kHz).
       - name: speed
         type: slider
         min: 0.5
@@ -1305,21 +1303,95 @@ services:
       seedable: true
       deterministic: false
       notes: >
-        Seed gives consistent voice/prosody but NOT byte-exact output —
-        upstream notes float-arithmetic variance across hardware/versions.
-        A richer custom /tts endpoint exposes cfg_scale/temperature/top_p/
-        cfg_filter_top_k for finer control.
+        Seed gives consistent voice/prosody but NOT byte-exact output (Dia2 is
+        temperature-sampled). Raw-bytes response carries no seed echo, so no
+        seed_field. A richer custom /tts endpoint exposes
+        cfg_scale/temperature/top_p/cfg_filter_top_k.
     estimated_latency:
-      cold_start_s: 10
+      cold_start_s: 30
       warm_per_unit: "dialogue one-pass; ~realtime on the 3090"
-    license: "Apache-2.0 (Dia weights); MIT (devnen wrapper)"
+    license: "Apache-2.0 (Dia2 weights); MIT (devnen wrapper)"
     notes: |
-      OpenAI-compat /v1/audio/speech plus a richer custom /tts (cfg_scale 3.0,
-      temperature 1.3, top_p 0.95, cfg_filter_top_k 35, max_tokens,
-      split_text/chunk_size). Fields read from devnen documentation.md
-      (2026-05-31); confirm against live OpenAPI/Pydantic at deploy. Deployed
-      to irv-ml1 but PARKED (asset-engine orchestrates start) — flip to ready
-      after the first successful generation. Pin DIA_SHA before build.
+      One of two fixed-model instances in the `dia` stack; sibling dia2-1b
+      (:8202). `docker compose up` on the stack starts BOTH services — the
+      lifecycle vram_gb here is this instance alone (~8 GB); budget for both
+      if gating the whole stack. Image local/dia:v2 = upstream devnen wrapper
+      + the dia2 package baked in (see stacks/dia/dia2-image/). Verified
+      end-to-end 2026-05-31 (HTTP 200, Ogg/Opus 24 kHz).
+
+  - id: dia2-1b
+    name: Dia2 1B (Streaming)
+    description: >
+      Nari Labs' Dia2 dialogue TTS, 1B streaming checkpoint — same [S1]/[S2]
+      dialogue + nonverbals as dia2-2b, lower latency / lighter weight. 24 kHz.
+      Served via devnen/Dia-TTS-Server.
+    category: tts
+    version: 1
+    status: ready
+    host: irv-ml1
+    lifecycle:
+      stack: dia
+      vram_gb: 5
+      gpu_device_id: 0
+    endpoint: http://10.100.79.3:8202/v1/audio/speech
+    method: POST
+    content_type: application/json
+    model:
+      id: nari-labs/Dia2-1B
+      revision: null
+      image: local/dia:v2
+    fields:
+      - name: input
+        type: textarea
+        label: Text ([S1]/[S2] dialogue + nonverbals)
+        required: true
+        max_length: 5000
+        description: >
+          [S1]/[S2] tags mark speaker turns; nonverbals like (laughs),
+          (coughs), (sighs), (clears throat) go inline.
+      - name: voice
+        type: select
+        label: Voice / mode
+        options: [dialogue, single_s1, single_s2, predefined]
+        default: dialogue
+        description: >
+          Speaker mode from the model's voice set. `clone` (prefix_speaker)
+          needs a reference clip, so it isn't a plain picker choice here.
+      - name: response_format
+        type: select
+        options: [opus, wav]
+        default: opus
+        description: 24 kHz output.
+      - name: speed
+        type: slider
+        min: 0.5
+        max: 2.0
+        step: 0.05
+        default: 1.0
+        description: Post-generation playback speed multiplier.
+      - name: seed
+        type: number
+        required: false
+        default: -1
+        description: -1 = random; any integer for repeatable (not byte-exact) output.
+    response:
+      type: audio
+      mime_from_field: response_format
+    reproducibility:
+      seedable: true
+      deterministic: false
+      notes: >
+        Same determinism story as dia2-2b (temperature-sampled, seed gives
+        consistent prosody not byte-exact). No seed echo -> no seed_field.
+    estimated_latency:
+      cold_start_s: 30
+      warm_per_unit: "streaming; lower latency than dia2-2b"
+    license: "Apache-2.0 (Dia2 weights); MIT (devnen wrapper)"
+    notes: |
+      Sibling of dia2-2b in the same `dia` stack (see its notes for the
+      single-model-per-endpoint rationale and the both-start-together caveat).
+      Image local/dia:v2. Verified end-to-end 2026-05-31 (HTTP 200, Ogg/Opus
+      24 kHz).
 
   - id: csm
     name: Sesame CSM (conversational)
@@ -1430,7 +1502,7 @@ services:
       # zonos-api service, or drop the Gradio service at promotion.
       vram_gb: 6
       gpu_device_id: 0
-    endpoint: http://10.100.79.3:8201/v1/audio/speech
+    endpoint: http://10.100.79.3:8203/v1/audio/speech
     method: POST
     content_type: application/json
     model:
@@ -1469,7 +1541,7 @@ services:
         label: Clone voice (optional)
         section: voice
         optional: true
-        source_url: http://10.100.79.3:8201/v1/audio/voices
+        source_url: http://10.100.79.3:8203/v1/audio/voices
         source_jsonpath: $.voices[*]
         description: >
           Reference clip filename under /worktank/zonos/voices/ (10–30s clean
@@ -1552,7 +1624,7 @@ services:
       Transformer variant only (mamba-ssm absent → no hybrid). Fields read from
       upstream gradio_interface.py (2026-05-31), the CATALOG-CONTRACT blessed
       source for defaults/ranges. Adapter not yet deployed/verified — flip to
-      ready (or experimental) after the first successful generation through 8201.
+      ready (or experimental) after the first successful generation through 8203.
 
 # Reproducibility audit — answers per service: (a) seedable, (b) model
 # deterministic without seed, (c) image tag mutable (security/reproducibility risk).
@@ -1624,11 +1696,16 @@ reproducibility_audit:
     model_deterministic: true
     image_tag_mutable: false
     notes: "Reproducibility requires persisting full workflow JSON + seed."
-  - service: dia
+  - service: dia2-2b
     seedable: true
     model_deterministic: false
     image_tag_mutable: false
-    notes: "Seed gives consistent voice, not byte-exact (float variance). Build pin via DIA_SHA."
+    notes: "Dia2 2B, temperature-sampled (seed gives consistent prosody, not byte-exact). local/dia:v2 (derived; upstream wrapper SHA not pinned)."
+  - service: dia2-1b
+    seedable: true
+    model_deterministic: false
+    image_tag_mutable: false
+    notes: "Dia2 1B streaming; same determinism story as dia2-2b. local/dia:v2."
   - service: csm
     seedable: false
     model_deterministic: false
diff --git a/stacks/zonos/.env.example b/stacks/zonos/.env.example
index 51903d2..d2ed1d3 100644
--- a/stacks/zonos/.env.example
+++ b/stacks/zonos/.env.example
@@ -20,9 +20,9 @@ ZONOS_TAG=v1
 ZONOS_PORT=8199
 
 # Host port for the OpenAI-ish REST adapter (zonos-api service) that
-# asset-engine routes to. Container listens on 8000 internally. 8201 is
-# the next free slot above the Gradio port.
-ZONOS_API_PORT=8201
+# asset-engine routes to. Container listens on 8000 internally. 8203
+# (8200 Dia2-2B, 8201 csm, 8202 Dia2-1B were taken on irv-ml1).
+ZONOS_API_PORT=8203
 
 # Bind address. 0.0.0.0 exposes on all interfaces (incl. WG tunnel
 # interface 10.100.79.3); 127.0.0.1 restricts to local-only.
diff --git a/stacks/zonos/README.md b/stacks/zonos/README.md
index e748ca4..577d815 100644
--- a/stacks/zonos/README.md
+++ b/stacks/zonos/README.md
@@ -13,7 +13,7 @@ Models ([`Zonos.from_pretrained()`](https://github.com/Zyphra/Zonos)):
 | hybrid | [Zyphra/Zonos-v0.1-hybrid](https://huggingface.co/Zyphra/Zonos-v0.1-hybrid) | Mamba-SSM; needs Ampere+ GPU + extra build deps |
 
 **Server:** irv-ml1 (Irvine, WireGuard-only)
-**Ports:** 8199 Gradio eval UI (container 7860) · 8201 REST adapter (container 8000)
+**Ports:** 8199 Gradio eval UI (container 7860) · 8203 REST adapter (container 8000)
 **GPUs:** pins to device 0 (RTX 3090) by default; ~6 GB VRAM
 **Image:** `local/zonos:v1` — built locally from a pinned git SHA of the
 upstream repo via docker buildx's git URL context
@@ -29,13 +29,13 @@ natural-language paralinguistic tags. Worth A/B-ing by ear against
 Chatterbox-Turbo (the research that prompted this stack explicitly said
 "benchmark Zonos against Chatterbox before choosing").
 
-## Two surfaces: Gradio eval (8199) + REST adapter (8201)
+## Two surfaces: Gradio eval (8199) + REST adapter (8203)
 
 The official repo ships a **Gradio WebUI + Python SDK only** — no REST
 endpoint. So this stack runs two services:
 
 - **`zonos`** (8199) — upstream Gradio UI, for *auditioning quality by ear*.
-- **`zonos-api`** (8201) — a thin OpenAI-ish adapter we built
+- **`zonos-api`** (8203) — a thin OpenAI-ish adapter we built
   (`adapter/server.py`) exposing `POST /v1/audio/speech` so **asset-engine**
   can route to Zonos like every other TTS in the catalog. Returns a JSON
   envelope `{audio: <base64>, audio_format, seed}` — the `seed` rides back
@@ -52,7 +52,7 @@ unmerged fork.
 ### Adapter request (example)
 
 ```bash
-curl -sS http://10.100.79.3:8201/v1/audio/speech \
+curl -sS http://10.100.79.3:8203/v1/audio/speech \
   -H 'content-type: application/json' \
   -d '{"input":"Hello from Zonos.","language":"en-us","seed":420}' \
   | python3 -c 'import sys,json,base64; d=json.load(sys.stdin); open("out.wav","wb").write(base64.b64decode(d["audio"])); print("seed",d["seed"])'