13 files changed, 245 insertions, 19 deletions
diff --git a/.dispatch/transport-contract.reference.md b/.dispatch/transport-contract.reference.md
index 047f050..182279a 100644
--- a/.dispatch/transport-contract.reference.md
+++ b/.dispatch/transport-contract.reference.md
@@ -27,6 +27,14 @@
 > `PUT /settings/vision` ← `SetVisionSettingsRequest` (partial: `imageLimit?` non-negative int, 0 = disable
 > compaction; `compactionModel?` `<key>/<model>` or null = auto). See `backend-handoff.md` §2j.
 >
+> **2026-06-26 update (image storage — NO type change, behavior only):** persisted `ImageChunk.url`s are now
+> compact relative HTTP paths (`/images/<conversationId>/<uuid>.png`) served by the new
+> `GET /images/:conversationId/:imageId` endpoint (raw image bytes + correct Content-Type) — NOT base64 data
+> URLs (images are stored on disk under tmp, not in the SQLite store). `ChatRequest.images` (`ImageInput.url`)
+> is UNCHANGED — clients still send data URLs; the backend saves them to tmp and returns compact paths in
+> the persisted chunks. A client resolves a relative `url` against its API base (`resolveImageUrl`); the
+> optimistic echo's data URL and any absolute URL pass through. See `backend-handoff.md` §2j.
+>
 > **2026-06-25 delta (SSH handoff #2 — ADDITIVE to `[email protected]`, NO version bump):** adds the
 > computer HTTP API types: `ComputerListResponse` (`GET /computers`), `ComputerResponse` (`GET /computers/:alias`),
 > `ComputerStatusResponse` (`GET /computers/:alias/status`), `TestComputerResponse` (`POST /computers/:alias/test`),
diff --git a/.dispatch/wire.reference.md b/.dispatch/wire.reference.md
index c40fe81..75adac5 100644
--- a/.dispatch/wire.reference.md
+++ b/.dispatch/wire.reference.md
@@ -14,6 +14,15 @@
 > — the orchestrator's vision handoff transcribes each to a text description (persisted as a separate
 > `text` chunk in the SAME user message). See `backend-handoff.md` §2j.
 >
+> **2026-06-26 update (image storage — NO type change, behavior only):** `ImageChunk.url` for PERSISTED
+> chunks is now a compact relative HTTP path (`/images/<conversationId>/<uuid>.png`) served by the backend's
+> new `GET /images/:conversationId/:imageId` endpoint (raw bytes + correct Content-Type), NOT a base64 data
+> URL — images are stored on disk under tmp, not in the SQLite conversation store (keeps payloads small).
+> `ImageInput.url` (what a client SENDS on `ChatRequest.images`) is UNCHANGED — still a data URL or
+> `http(s)://` URL; the backend saves it to tmp and returns the compact path in the persisted chunk. A client
+> resolves a relative `url` against its API base (`resolveImageUrl`); a data URL (the optimistic echo) or an
+> absolute URL passes through unchanged. See `backend-handoff.md` §2j.
+>
 > **2026-06-23 delta (workspaces handoff — package bumped `0.11.0` → `0.12.0`, ADDITIVE):** adds
 > `Workspace` + `WorkspaceEntry` (a list entry with a conversation count) and a required
 > `workspaceId: string` on `ConversationMeta` (`"default"` for legacy/unspecified conversations). A
@@ -156,12 +165,17 @@ export interface SystemChunk {
 /**
  * An image attached to a message (e.g. a user-pasted screenshot or pasted
  * photo). Carries a `url` that is EITHER a base64 data URL
- * (`data:image/png;base64,…`) OR an `http(s)://` URL. Vision-capable models
- * receive it natively (the provider serializes it to its image-content
- * format); non-vision models never see it directly — the orchestrator's
- * **vision handoff** transcribes it to a text description (via a
- * vision-capable model) and feeds that text instead, so a text-only model can
- * still reason about the image's contents.
+ * (`data:image/png;base64,…`) OR an `http(s)://` URL OR — for PERSISTED chunks
+ * (history/replay) — a compact relative HTTP path (`/images/<conversationId>/
+ * <uuid>.png`) served by the backend's `GET /images/:conversationId/:imageId`
+ * endpoint (images are stored on disk under tmp, NOT in the conversation store,
+ * to keep SQLite payloads small). A client resolves a relative path against its
+ * API base URL; a data URL (the optimistic echo / a pasted image) or an
+ * absolute URL is rendered as-is. Vision-capable models receive it natively
+ * (the provider serializes it to its image-content format); non-vision models
+ * never see it directly — the orchestrator's **vision handoff** transcribes it
+ * to a text description (via a vision-capable model) and feeds that text
+ * instead, so a text-only model can still reason about the image's contents.
  *
  * When a transcription was performed, it is persisted as a separate `text`
  * chunk alongside the `image` chunk in the SAME user message, so the
@@ -170,7 +184,7 @@ export interface SystemChunk {
  */
 export interface ImageChunk {
 	readonly type: "image";
-	/** Image source: a base64 data URL (`data:image/…;base64,…`) or an `http(s)://` URL. */
+	/** Image source: a base64 data URL (`data:image/…;base64,…`), an `http(s)://` URL, or a compact relative path (`/images/<conv>/<uuid>.png`) for persisted chunks. */
 	readonly url: string;
 	/**
 	 * Optional MIME type of the image (e.g. `"image/png"`). Inferred from the
diff --git a/GLOSSARY.md b/GLOSSARY.md
index 3973fe1..14b81d1 100644
--- a/GLOSSARY.md
+++ b/GLOSSARY.md
@@ -26,7 +26,7 @@
 | **steering** | A user message injected into an in-flight turn at the tool-result boundary (drawn from the **message queue**): the model sees it alongside the tool results and may adjust course. Emitted on the chat stream as a `steering` `AgentEvent` (`TurnSteeringEvent`); the queue surface clears on drain (move, don't duplicate). If the turn ends with a non-empty queue (no tool call fired), the queue carries into a NEW turn as its opening prompt (no `steering` event). `[email protected]`. | mid-turn injection, course correction, interruption |
 | **computer** | A remote SSH target discovered from the system's `~/.ssh/config` — a read-only VIEW, NOT an editable entity (no CRUD store; to add one the user edits `~/.ssh/config`). Backend-canonical (`[email protected]`, additive). On the wire as `Computer` (`{ alias, hostName, port, user, identityFile, knownHost }`) + `ComputerEntry extends Computer` (adds `usageCount`, for `GET /computers`). `alias` IS the **computerId** — the string persisted per-conversation / per-workspace (the computer analog of `cwd`). Resolution is SERVER-owned (never re-implement): per-conversation `computerId` → `workspace.defaultComputerId` → `null`/local. USER-facing only: a tool-execution target forwarded to tools, NEVER part of the model prompt (does not affect prompt caching); the agent never sees it. HTTP API (`GET /computers`, `GET`/`PUT /conversations/:id/computer`, `PUT /workspaces/:id/default-computer`, `GET /computers/:alias/status`, `POST /computers/:alias/test`) consumed in handoff #2. | ssh host, remote host, server, connection target |
 | **computerId** | The string id of a **computer** — an SSH config `Host` alias users select. Persisted per-conversation and per-workspace (the computer analog of `cwd`/`workspaceId`). `null` means local (no SSH; today's behavior). On `Workspace` as the REQUIRED `defaultComputerId: string \| null` (null = local / no SSH; the computer analog of `defaultCwd`); per-conversation persistence via `GET`/`PUT`/`DELETE /conversations/:id/computer`. `chat.send` need not send it (resolved server-side from the persisted per-conversation value in the MVP). | ssh alias, host id, remote id |
-| **image chunk** | An `ImageChunk` (`{ type: "image", url, mimeType? }`) — a NEW `Chunk` variant for an image attached to a message (a user-pasted screenshot/photo). `url` is a base64 data URL (`data:image/…;base64,…`) OR an `http(s)://` URL. Backend-canonical (`[email protected]`, additive). A user message may be multi-chunk (`[text, image, image, …]` in order). On the wire as `ImageChunk` (persisted) + `ImageInput` (what `ChatRequest.images` carries; the orchestrator converts each into an `ImageChunk`). | picture, photo attachment, screenshot chunk |
+| **image chunk** | An `ImageChunk` (`{ type: "image", url, mimeType? }`) — a `Chunk` variant for an image attached to a message (a user-pasted screenshot/photo). `url` is a base64 data URL (`data:image/…;base64,…`), an `http(s)://` URL, or — for PERSISTED chunks — a compact relative HTTP path (`/images/<conversationId>/<uuid>.png`) served by `GET /images/:conversationId/:imageId` (images are stored on disk under tmp, not in the SQLite store). Backend-canonical (`[email protected]`, additive). A user message may be multi-chunk (`[text, image, image, …]` in order). On the wire as `ImageChunk` (persisted) + `ImageInput` (what `ChatRequest.images` carries — still a data URL; the orchestrator saves it to tmp and returns the compact path). A client resolves a relative `url` against its API base (`resolveImageUrl`); a data URL (the optimistic echo) or absolute URL passes through. | picture, photo attachment, screenshot chunk |
 | **vision** (capability) | Whether a model can natively accept image input (multimodal). On the wire as `ModelMetadata.vision?: boolean` (`GET /models` `modelInfo[name].vision`). `true` (e.g. any `kimi/*` model) → image chunks are passed through to the provider natively. Absent/`false` (e.g. `umans/glm-5.2`) → the server's **vision handoff** gives the model a numbered placeholder + the `consult_vision` tool. The FE shows a vision badge in the model picker; it does NOT decide handoff (server-owned). | multimodal, image support |
 | **vision handoff** | The server-owned mechanism by which a NON-vision model still reasons about a pasted image. A non-vision model gets a NUMBERED PLACEHOLDER text chunk alongside the persisted `image` chunk, then calls the `consult_vision` tool (which opens a NEW conversation tab with a vision-capable model, attaches the image + question, and returns the vision model's answer). The persisted user message keeps the original `image` chunk (the FE renders it) AND the placeholder text. When a vision-capable model has more than `imageLimit` images in history, image **compaction** transcribes the oldest to `[Compacted image]: <description>` text chunks (the `image` chunk stays for rendering). All these are regular `text` chunks — the FE renders them as-is. Distinct from a vision-capable model, which receives the image natively. | image transcription, vision relay |
 | **consult_vision** | A tool available to all models that defers image analysis to a vision-capable model: it opens a NEW conversation tab (with a vision model, e.g. Kimi), attaches the image (by `imageIds` from a pasted placeholder, or by `path` from disk) + a `question`, and returns the conversation id + the vision model's answer (suggesting the dispatch CLI for follow-ups). Replaces the former `read_image` tool. Rendered generically like any tool call/result (by `toolName`). | read_image (former), vision tool |
diff --git a/backend-handoff.md b/backend-handoff.md
index 9338a5a..5a476be 100644
--- a/backend-handoff.md
+++ b/backend-handoff.md
@@ -5,12 +5,11 @@
 > **From:** dispatch-web orchestrator · **To:** `../backend` orchestrator · **Courier:** the user.
 > `lsp` does NOT span the repos (AGENTS.md § Backend seam) — every cross-repo ask flows through here.
 
-_Last updated: 2026-06-26 (§2j UPDATED — consult_vision tool + vision settings API: `read_image` is REPLACED by
-`consult_vision` (non-vision models now get numbered placeholder text chunks, not auto-transcriptions); NEW global
-`GET`/`PUT /settings/vision` (`VisionSettingsResponse`/`SetVisionSettingsRequest` — `imageLimit` + `compactionModel`);
-image compaction transcribes old images to `[Compacted image]: …` text chunks (all regular text — render as-is). New
-`vision` feature library + "Vision" sidebar view (imageLimit input + compactionModel dropdown of vision-capable models +
-"Auto"). typecheck 0/0, 948 tests green (+47), biome clean, build OK. §2i unchanged.)_
+_Last updated: 2026-06-26 (§2j UPDATED — Image storage: persisted `ImageChunk.url`s are now compact relative HTTP
+paths (`/images/<conv>/<uuid>.png`) served by `GET /images/:conversationId/:imageId` (images stored on disk under tmp,
+not SQLite). FE resolves relative urls against the API base via a new pure `resolveImageUrl` helper; the optimistic
+echo's data URL passes through unchanged; `ChatRequest.images` (send) is unchanged. typecheck 0/0, 959 tests green
+(+11), biome clean, build OK. §2i unchanged.)_
 **FE is current on `[email protected]` / `[email protected]` / `[email protected]`.** Open asks: **CR-9**
 (`system:os` should detect WSL + include Linux distro — backend behavior change, no contract bump). The SSH-divergence
 (§2d) is RESOLVED.
@@ -854,6 +853,48 @@ reload; set compactionModel to a vision model → confirm the dropdown reflects
 non-vision model → confirm the `[Image N attached — call consult_vision…]` placeholder renders (not an
 auto-transcription); trigger a `consult_vision` tool call → confirm it renders like a tool.
 
+### 2j-update-2. Image storage (tmp, not SQLite) → **CONSUMED ✅ (backend updated; FE built + verified)**
+
+A follow-up to §2j. The backend no longer persists images as base64 data URLs in the conversation store —
+they are saved to a tmp directory and served via HTTP. The `ImageChunk.url` field's FORMAT changed (the
+TYPE is unchanged — still `string`); `GET /images/:conversationId/:imageId` is a new endpoint serving raw
+bytes + the correct Content-Type. **NO wire/transport-contract type change** (behavior only); re-mirrored
+the delta notes in `.dispatch/wire.reference.md` + `.dispatch/transport-contract.reference.md`.
+
+**What changed (backend):**
+- **BEFORE:** `ImageChunk.url` was a base64 data URL (`data:image/png;base64,…`).
+- **NOW:** `ImageChunk.url` for PERSISTED chunks (history/replay) is a compact relative HTTP path
+  (`/images/<conversationId>/<uuid>.png`), served by `GET /images/:conversationId/:imageId` (raw image
+  bytes + Content-Type). Images live on disk under tmp, NOT in the SQLite conversation store (keeps
+  payloads small).
+- **`ChatRequest.images` (`ImageInput.url`) is UNCHANGED** — the FE still sends data URLs; the backend
+  saves them to tmp and returns compact paths in the persisted chunks.
+- **Optimistic echo:** the FE's provisional echo still uses the data URL it sent (immediate render);
+  when the persisted chunk arrives (via `loadSince`/`syncTail`/event stream), it carries the compact path
+  and the FE switches to rendering via the HTTP endpoint.
+- The vision settings API, `consult_vision`, and image compaction are UNCHANGED (compaction resolves
+  compact URLs internally).
+
+**FE (DONE + verified):**
+- **New pure helper `resolveImageUrl(url, apiBase)`** (`core/chunks/image-url.ts`, +8 tests, exported from
+  `core/chunks` + re-exported from `features/chat`): a `data:` URL or an `http(s)://` URL passes through
+  unchanged; a relative path (`/images/…`) is prepended with the API base (no double slash; an empty base
+  yields a root-relative path a browser resolves against its origin). Pure — zero DOM/Svelte.
+- **`ChatView.svelte`:** new `apiBaseUrl` prop (default `""`); the `<img src>` now uses
+  `resolveImageUrl(rendered.chunk.url, apiBaseUrl)`. The optimistic echo's data URL + any absolute URL
+  pass through; persisted relative paths resolve against the base. +3 ChatView tests (relative-path
+  resolution, data-URL pass-through with a base set, root-relative when no base).
+- **Store + wiring:** `httpBase` (the resolved HTTP API base) is now exposed as a getter on `AppStore`;
+  `App.svelte` passes `apiBaseUrl={store.httpBase}` to `ChatView` AND to the heartbeat `RunModal` (its
+  `ChatView` also renders image chunks — added an `apiBaseUrl` prop there, threaded from `App.svelte`).
+
+**Verification:** `svelte-check` 0/0; vitest **959/959** (run TWICE — no cross-test pollution; +11 since the
+prior commit: 8 `resolveImageUrl`, 3 ChatView resolution), biome clean, `vite build` succeeds.
+**Live probe NOT run** (backend not reachable headless). To confirm end-to-end: paste an image with a
+vision model, send, confirm the image renders immediately (data-URL echo) AND continues to render after
+the turn seals (the persisted compact-path `/images/…` resolved against `httpBase`); reload the
+conversation → confirm the persisted image renders from the `/images/…` endpoint (not a data URL).
+
 ---
 
 ## 3. Likely NEXT backend asks (heads-up, not yet requested)
diff --git a/src/app/App.svelte b/src/app/App.svelte
index f41d7ba..7d70f67 100644
--- a/src/app/App.svelte
+++ b/src/app/App.svelte
@@ -516,6 +516,7 @@
 							onShowEarlier={handleShowEarlier}
 							thinkingKeyBase={store.activeChat.thinkingKeyBase}
 							providerRetry={store.activeChat.providerRetry}
+							apiBaseUrl={store.httpBase}
 						/>
 					{/key}
 				</div>
@@ -610,6 +611,7 @@
 			closeChat={closeRunChat}
 			stopRun={stopHeartbeatRun}
 			onClose={() => (heartbeatRun = null)}
+			apiBaseUrl={store.httpBase}
 		/>
 	{/key}
 {/if}
diff --git a/src/app/store.svelte.ts b/src/app/store.svelte.ts
index 554d5e0..8353820 100644
--- a/src/app/store.svelte.ts
+++ b/src/app/store.svelte.ts
@@ -157,6 +157,12 @@ export interface AppStore {
   readonly activeConversationId: string | null;
   /** The workspace currently in view (URL slug); tabs are filtered to it. */
   readonly activeWorkspaceId: string;
+  /**
+   * The resolved HTTP API base URL (e.g. `http://localhost:24203`). Used to
+   * resolve relative image URLs served by the backend (`/images/…`) into
+   * absolute URLs for `<img src>`.
+   */
+  readonly httpBase: string;
   readonly activeChat: ChatStore;
   readonly models: readonly string[];
   /** Per-model metadata (contextWindow, etc.) from `GET /models`. */
@@ -1127,6 +1133,9 @@ export function createAppStore(opts?: CreateAppStoreOptions): AppStore {
     get activeWorkspaceId(): string {
       return activeWorkspaceId;
     },
+    get httpBase(): string {
+      return httpBase;
+    },
     setActiveWorkspace(workspaceId: string): void {
       activeWorkspaceId = workspaceId;
       // Reset to a fresh draft scoped to the new workspace so a new chat is
diff --git a/src/core/chunks/image-url.test.ts b/src/core/chunks/image-url.test.ts
new file mode 100644
index 0000000..8a79c09
--- /dev/null
+++ b/src/core/chunks/image-url.test.ts
@@ -0,0 +1,46 @@
+import { describe, expect, it } from "vitest";
+import { resolveImageUrl } from "./image-url";
+
+const BASE = "http://localhost:24203";
+
+describe("resolveImageUrl", () => {
+  it("returns a data URL as-is (the optimistic echo / a pasted image)", () => {
+    const dataUrl = "data:image/png;base64,iVBORw0KGgo=";
+    expect(resolveImageUrl(dataUrl, BASE)).toBe(dataUrl);
+  });
+
+  it("returns an absolute http URL as-is", () => {
+    const abs = "https://example.com/img.png";
+    expect(resolveImageUrl(abs, BASE)).toBe(abs);
+  });
+
+  it("prepends the api base to a relative /images/ path", () => {
+    expect(resolveImageUrl("/images/conv-123/abc-456.png", BASE)).toBe(
+      "http://localhost:24203/images/conv-123/abc-456.png",
+    );
+  });
+
+  it("does not double the slash when the base has a trailing slash", () => {
+    expect(resolveImageUrl("/images/c/x.png", "http://localhost:24203/")).toBe(
+      "http://localhost:24203/images/c/x.png",
+    );
+  });
+
+  it("adds a leading slash to a path-relative url without one", () => {
+    expect(resolveImageUrl("images/c/x.png", BASE)).toBe("http://localhost:24203/images/c/x.png");
+  });
+
+  it("returns the relative path as-is when apiBase is empty (root-relative)", () => {
+    // A browser resolves a root-relative `/images/…` against the document origin.
+    expect(resolveImageUrl("/images/c/x.png", "")).toBe("/images/c/x.png");
+  });
+
+  it("handles a relative path with an empty apiBase (path-relative without slash)", () => {
+    expect(resolveImageUrl("images/c/x.png", "")).toBe("/images/c/x.png");
+  });
+
+  it("returns a data URL as-is even with an empty apiBase", () => {
+    const dataUrl = "data:image/jpeg;base64,AAAA";
+    expect(resolveImageUrl(dataUrl, "")).toBe(dataUrl);
+  });
+});
diff --git a/src/core/chunks/image-url.ts b/src/core/chunks/image-url.ts
new file mode 100644
index 0000000..e5ec756
--- /dev/null
+++ b/src/core/chunks/image-url.ts
@@ -0,0 +1,35 @@
+/**
+ * Resolve an `ImageChunk.url` into a renderable `<img src>` value.
+ *
+ * Persisted image chunks now carry a COMPACT HTTP path
+ * (`/images/<conversationId>/<uuid>.png`) served by the backend — NOT a base64
+ * data URL (images are stored on disk under tmp, not in the conversation store,
+ * to keep SQLite payloads small). The optimistic echo (what the FE just sent in
+ * `ChatRequest.images`) still carries a data URL, and a chunk could also carry
+ * an absolute `http(s)://` URL, so the resolution is format-aware:
+ *
+ * - `data:` URL  → returned as-is (the optimistic echo / a pasted data URL).
+ * - `http(s)://` → returned as-is (an absolute URL already).
+ * - anything else (a relative path like `/images/…`) → `apiBase` is prepended
+ *   (with no double slash). An empty `apiBase` leaves a root-relative path,
+ *   which a browser resolves against the document origin.
+ *
+ * Pure: input → output, zero DOM, zero Svelte.
+ *
+ * @param url      The chunk's `url` (data URL, absolute, or relative path).
+ * @param apiBase  The HTTP API base URL (e.g. `http://localhost:24203`).
+ */
+export function resolveImageUrl(url: string, apiBase: string): string {
+  if (url.startsWith("data:") || url.startsWith("http://") || url.startsWith("https://")) {
+    return url;
+  }
+  // A relative path (e.g. `/images/…`) — normalize to a leading slash and
+  // prepend the api base. With an empty base this yields a root-relative path
+  // (a browser resolves `/images/…` against the document origin).
+  const path = url.startsWith("/") ? url : `/${url}`;
+  if (apiBase.length === 0) return path;
+  // Join without a double slash: strip a trailing slash from the base, then
+  // append the (leading-slash) path verbatim.
+  const base = apiBase.endsWith("/") ? apiBase.slice(0, -1) : apiBase;
+  return `${base}${path}`;
+}
diff --git a/src/core/chunks/index.ts b/src/core/chunks/index.ts
index eea2303..bdd6ce4 100644
--- a/src/core/chunks/index.ts
+++ b/src/core/chunks/index.ts
@@ -1,5 +1,6 @@
 export type { RenderGroup, ToolBatchEntry } from "./groups";
 export { groupRenderedChunks } from "./groups";
+export { resolveImageUrl } from "./image-url";
 export {
   appendUserMessage,
   applyHistory,
diff --git a/src/features/chat/index.ts b/src/features/chat/index.ts
index 8694691..773cb91 100644
--- a/src/features/chat/index.ts
+++ b/src/features/chat/index.ts
@@ -4,7 +4,7 @@ export type {
   RenderGroup,
   ToolBatchEntry,
 } from "../../core/chunks";
-export { groupRenderedChunks, viewProviderRetry } from "../../core/chunks";
+export { groupRenderedChunks, resolveImageUrl, viewProviderRetry } from "../../core/chunks";
 export type { TurnMetricsEntry } from "../../core/metrics";
 export { isVisionModel } from "./model-select";
 export type { ChatTransport, HistorySync, HistoryWindow, MetricsSync } from "./ports";
diff --git a/src/features/chat/ui.test.ts b/src/features/chat/ui.test.ts
index b0aa6f0..5f8067d 100644
--- a/src/features/chat/ui.test.ts
+++ b/src/features/chat/ui.test.ts
@@ -628,6 +628,58 @@ describe("ChatView", () => {
     expect(img?.getAttribute("loading")).toBe("lazy");
   });
 
+  it("resolves a persisted image chunk's relative url against apiBaseUrl", () => {
+    // Persisted image chunks now carry a compact relative path (`/images/…`)
+    // served by the backend — prepend the API base to render them.
+    const chunks: RenderedChunk[] = [
+      {
+        seq: 1,
+        role: "user",
+        chunk: { type: "image", url: "/images/conv-123/abc-456.png", mimeType: "image/png" },
+        provisional: false,
+      },
+    ];
+
+    const { container } = render(ChatView, {
+      props: { chunks, apiBaseUrl: "http://localhost:24203" },
+    });
+
+    expect(container.querySelector("img")?.getAttribute("src")).toBe(
+      "http://localhost:24203/images/conv-123/abc-456.png",
+    );
+  });
+
+  it("passes a data URL through unchanged even with apiBaseUrl set (optimistic echo)", () => {
+    // The optimistic echo (what the FE just sent) is still a data URL; it must
+    // NOT be mangled by the base-URL prepend.
+    const dataUrl = "data:image/png;base64,iVBOR=";
+    const chunks: RenderedChunk[] = [
+      { seq: null, role: "user", chunk: { type: "image", url: dataUrl }, provisional: true },
+    ];
+
+    const { container } = render(ChatView, {
+      props: { chunks, apiBaseUrl: "http://localhost:24203" },
+    });
+
+    expect(container.querySelector("img")?.getAttribute("src")).toBe(dataUrl);
+  });
+
+  it("leaves a relative image url root-relative when apiBaseUrl is absent", () => {
+    // No apiBaseUrl → a browser resolves `/images/…` against the document origin.
+    const chunks: RenderedChunk[] = [
+      {
+        seq: 1,
+        role: "user",
+        chunk: { type: "image", url: "/images/conv-1/x.png" },
+        provisional: false,
+      },
+    ];
+
+    const { container } = render(ChatView, { props: { chunks } });
+
+    expect(container.querySelector("img")?.getAttribute("src")).toBe("/images/conv-1/x.png");
+  });
+
   it("renders a multi-chunk user message [text, image] and a transcription text", () => {
     // A non-vision model: the server persists the original image chunk AND a
     // transcription text chunk in the SAME user message — render both.
diff --git a/src/features/chat/ui/ChatView.svelte b/src/features/chat/ui/ChatView.svelte
index 8081951..cd69071 100644
--- a/src/features/chat/ui/ChatView.svelte
+++ b/src/features/chat/ui/ChatView.svelte
@@ -1,6 +1,6 @@
 <script lang="ts">
   import type { TurnProviderRetryEvent } from "@dispatch/wire";
-  import { groupRenderedChunks, type RenderedChunk, viewProviderRetry } from "../index";
+  import { groupRenderedChunks, resolveImageUrl, type RenderedChunk, viewProviderRetry } from "../index";
   import {
     interleaveTurnMetrics,
     viewCacheRate,
@@ -24,6 +24,7 @@
     onShowEarlier,
     thinkingKeyBase = 0,
     providerRetry = null,
+    apiBaseUrl = "",
   }: {
     chunks: readonly RenderedChunk[];
     turnMetrics?: readonly TurnMetricsEntry[];
@@ -44,6 +45,14 @@
      * newest attempt + delay, and is cleared when content resumes / turn ends.
      */
     providerRetry?: TurnProviderRetryEvent | null;
+    /**
+     * The HTTP API base URL (e.g. `http://localhost:24203`). Persisted image
+     * chunks carry a compact relative path (`/images/<conv>/<uuid>.png`); this
+     * base is prepended to render them. The optimistic echo's data URL and any
+     * absolute URL pass through unchanged (see `resolveImageUrl`). Defaults to
+     * "" (root-relative — a browser resolves `/images/…` against its origin).
+     */
+    apiBaseUrl?: string;
   } = $props();
 
   // True while a show-earlier page-in is awaited (disables the button).
@@ -96,15 +105,17 @@
 {#snippet chunkRow(rendered: RenderedChunk)}
   {#if rendered.role === "user"}
     <!-- User: a speech bubble, left-aligned. A user message may be multi-chunk
-         ([text, image, image, …]); each chunk renders in its own bubble (the
-         image's url is a base64 data URL or an https URL — render it directly). -->
+         ([text, image, image, …]); each chunk renders in its own bubble. A
+         persisted image chunk's url is a compact relative path (`/images/…`)
+         served by the backend — resolve it against the API base. The
+         optimistic echo's data URL (and any absolute URL) passes through. -->
     <div class="chat chat-start">
       <div class="chat-bubble chat-bubble-primary">
         {#if rendered.chunk.type === "text"}
           <p>{rendered.chunk.text}</p>
         {:else if rendered.chunk.type === "image"}
           <img
-            src={rendered.chunk.url}
+            src={resolveImageUrl(rendered.chunk.url, apiBaseUrl)}
             alt={rendered.chunk.mimeType ?? "pasted image"}
             loading="lazy"
             decoding="async"
diff --git a/src/features/heartbeat/ui/RunModal.svelte b/src/features/heartbeat/ui/RunModal.svelte
index a4ed356..92068ae 100644
--- a/src/features/heartbeat/ui/RunModal.svelte
+++ b/src/features/heartbeat/ui/RunModal.svelte
@@ -11,6 +11,7 @@
 		closeChat,
 		stopRun,
 		onClose,
+		apiBaseUrl = "",
 	}: {
 		/** The run to display (its conversation's chat is shown live). */
 		run: HeartbeatRunView;
@@ -26,6 +27,11 @@
 		/** Stop the heartbeat run (`POST .../runs/:runId/stop`). */
 		stopRun: StopHeartbeatRun;
 		onClose: () => void;
+		/**
+		 * The HTTP API base URL, to resolve persisted image chunk URLs
+		 * (`/images/…`) in the run's transcript. Defaults to "" (root-relative).
+		 */
+		apiBaseUrl?: string;
 	} = $props();
 
 	// Open the live watch ONCE on mount (the modal is keyed per run.id, so a run
@@ -153,6 +159,7 @@
 						onShowEarlier={chat.showEarlier}
 						thinkingKeyBase={chat.thinkingKeyBase}
 						providerRetry={chat.providerRetry}
+						apiBaseUrl={apiBaseUrl}
 					/>
 				{/if}
 			</div>