feat(core): normalize tool and attachment images at settlement

packages/core/src/session.ts

@@ -37,6 +37,7 @@ import { Snapshot } from "./snapshot"
 import { SessionRevert } from "./session/revert"
 import { Session } from "@opencode-ai/schema/session"
 import { FSUtil } from "./fs-util"
+import { Image } from "./image"
 import { Mime } from "./mime"
 import type { EventLog } from "@opencode-ai/schema/event-log"
 import { SkillV2 } from "./skill"
@@ -531,9 +532,13 @@ const layer = Layer.effect(
             // continues from the reverted boundary rather than stale post-boundary history.
             if (session.revert)
               yield* SessionRevert.commit(session).pipe(Effect.provideService(EventV2.Service, events))
-            const prompt = yield* resolvePrompt({ text: input.text, files: input.files, agents: input.agents }).pipe(
-              Effect.provideService(FSUtil.Service, fs),
-            )
+            // Resolved lazily so prompt admission only boots location services when an
+            // image attachment actually needs the resizer.
+            const image = Image.Service.pipe(Effect.provide(locations.get(session.location)))
+            const prompt = yield* resolvePrompt(
+              { text: input.text, files: input.files, agents: input.agents },
+              image,
+            ).pipe(Effect.provideService(FSUtil.Service, fs))
             const messageID = input.id ?? SessionMessage.ID.create()
             const admittedInput = SessionPending.Message.make({
               type: "user",
@@ -859,10 +864,13 @@ function synthesizeTerminalShellInfo(started: ShellSchema.Info): ShellSchema.Inf
   }
 }
 
-const resolvePrompt = Effect.fn("V2Session.resolvePrompt")(function* (input: PromptInput.Prompt) {
+const resolvePrompt = Effect.fn("V2Session.resolvePrompt")(function* (
+  input: PromptInput.Prompt,
+  image: Effect.Effect<Image.Interface>,
+) {
   const fs = yield* FSUtil.Service
   const files = input.files
-    ? yield* Effect.forEach(input.files, (file) => materializeAttachment(fs, file), { concurrency: 8 })
+    ? yield* Effect.forEach(input.files, (file) => materializeAttachment(fs, file, image), { concurrency: 8 })
     : undefined
   return Prompt.make({ text: input.text, agents: input.agents, files })
 })
@@ -872,6 +880,7 @@ const MAX_ATTACHMENT_BYTES = 20 * 1024 * 1024
 const materializeAttachment = Effect.fn("V2Session.materializeAttachment")(function* (
   fs: FSUtil.Interface,
   input: PromptInput.FileAttachment,
+  image: Effect.Effect<Image.Interface>,
 ) {
   const resolved = input.uri.startsWith("data:")
     ? {
@@ -900,16 +909,39 @@ const materializeAttachment = Effect.fn("V2Session.materializeAttachment")(funct
             .join("\n"),
         )
       : resolved.bytes
-  return FileAttachment.create({
-    data: Base64.make(Buffer.from(content).toString("base64")),
+  const normalized = yield* normalizeImageAttachment(
+    input,
+    Base64.make(Buffer.from(content).toString("base64")),
     mime,
+    image,
+  )
+  return FileAttachment.create({
+    data: normalized.data,
+    mime: normalized.mime,
     source: resolved.source,
     name: input.name ?? resolved.name,
     description: input.description,
     mention: input.mention,
   })
 })
 
+const normalizeImageAttachment = Effect.fn("V2Session.normalizeImageAttachment")(function* (
+  input: PromptInput.FileAttachment,
+  data: Base64,
+  mime: string,
+  image: Effect.Effect<Image.Interface>,
+) {
+  if (!mime.startsWith("image/")) return { data, mime }
+  const service = yield* image
+  const label = input.name ?? (input.uri.startsWith("data:") ? "inline attachment" : input.uri)
+  const content = { uri: label, content: data, encoding: "base64" as const, mime }
+  const normalized = yield* service.normalize(label, content).pipe(
+    Effect.catchTag("Image.ResizerUnavailableError", () => Effect.succeed(content)),
+    Effect.mapError((error) => new AttachmentError({ uri: label, message: error.message })),
+  )
+  return { data: Base64.make(normalized.content), mime: normalized.mime }
+})
+
 const readFileAttachment = Effect.fn("V2Session.readFileAttachment")(function* (fs: FSUtil.Interface, uri: string) {
   const url = yield* Effect.try({
     try: () => new URL(uri),

packages/core/src/tool/read.ts

@@ -6,7 +6,6 @@ import { ToolFailure } from "@opencode-ai/ai"
 import { Effect, Schema } from "effect"
 import { FileSystem } from "../filesystem"
 import { FSUtil } from "../fs-util"
-import { Image } from "../image"
 import { Location } from "../location"
 import { LocationMutation } from "../location-mutation"
 import { PermissionV2 } from "../permission"
@@ -35,7 +34,6 @@ export const Plugin = {
   effect: Effect.fn("ReadTool.Plugin")(function* (ctx: PluginContext) {
     const reader = yield* ReadToolFileSystem.Service
     const mutation = yield* LocationMutation.Service
-    const image = yield* Image.Service
     const permission = yield* PermissionV2.Service
     const sessionInstructions = yield* SessionInstructions.Service
     const fs = yield* FSUtil.Service
@@ -50,6 +48,12 @@ export const Plugin = {
               "Read a text file or supported image, page through a large UTF-8 text file by line offset, or list a directory page. Relative paths resolve from the current location; absolute paths inside it are accepted, while external absolute paths require external_directory approval.",
             input: Input,
             output: Output,
+            structured: Schema.toEncoded(Output),
+            // Image base64 reaches the model through content items (normalized generically
+            // at tool settlement); persisting a second copy in structured would store the
+            // original unresized bytes in the message row.
+            toStructuredOutput: ({ output }) =>
+              "encoding" in output && output.encoding === "base64" ? { ...output, content: "" } : output,
             toModelOutput: ({ input, output }) => {
               if (!("encoding" in output) || output.encoding !== "base64" || !SUPPORTED_IMAGE_MIMES.has(output.mime))
                 return []
@@ -117,21 +121,14 @@ export const Plugin = {
                   Effect.catch(() => Effect.void),
                   Effect.catchDefect(() => Effect.void),
                 )
-                if ("encoding" in content && content.encoding === "base64" && SUPPORTED_IMAGE_MIMES.has(content.mime)) {
-                  return yield* image
-                    .normalize(resource, { ...content, encoding: "base64" })
-                    .pipe(Effect.catchTag("Image.ResizerUnavailableError", () => Effect.succeed(content)))
-                }
-                if ("encoding" in content && content.encoding === "base64")
+                if ("encoding" in content && content.encoding === "base64" && !SUPPORTED_IMAGE_MIMES.has(content.mime))
                   return yield* Effect.fail(new ReadToolFileSystem.BinaryFileError({ resource }))
                 return content
               }).pipe(
                 Effect.mapError((error) => {
                   const message =
                     error instanceof ReadToolFileSystem.BinaryFileError ||
-                    error instanceof ReadToolFileSystem.MediaIngestLimitError ||
-                    error instanceof Image.DecodeError ||
-                    error instanceof Image.SizeError
+                    error instanceof ReadToolFileSystem.MediaIngestLimitError
                       ? error.message
                       : `Unable to read ${input.path}`
                   return new ToolFailure({ message, error })

packages/core/src/tool/registry.ts

@@ -3,6 +3,7 @@ export * as ToolRegistry from "./registry"
 import { ToolOutput, type ToolCall, type ToolDefinition, type ToolResultValue } from "@opencode-ai/ai"
 import { Context, Effect, Layer, Scope } from "effect"
 import type { AgentV2 } from "../agent"
+import { Image } from "../image"
 import { PermissionV2 } from "../permission"
 import { SessionMessage } from "../session/message"
 import { SessionSchema } from "../session/schema"
@@ -57,6 +58,40 @@ const registryLayer = Layer.effect(
   Effect.gen(function* () {
     const resources = yield* ToolOutputStore.Service
     const toolHooks = yield* ToolHooks.Service
+    const image = yield* Image.Service
+
+    type NormalizedItem = ToolOutput["content"][number] | "decode" | "size"
+    const normalizeImages = Effect.fn("ToolRegistry.normalizeImages")(function* (content: ToolOutput["content"]) {
+      const normalized = yield* Effect.forEach(content, (item): Effect.Effect<NormalizedItem> => {
+        if (item.type !== "file" || !item.mime.startsWith("image/")) return Effect.succeed(item)
+        // RFC 2397 permits parameters between the mime and ";base64".
+        const base64 = /^data:[^,]*;base64,(.*)$/s.exec(item.uri)?.[1]
+        if (base64 === undefined) return Effect.succeed(item)
+        const resource = item.name ?? `${item.mime} tool output`
+        return image
+          .normalize(resource, { uri: resource, content: base64, encoding: "base64", mime: item.mime })
+          .pipe(
+            Effect.map((result) => ({
+              ...item,
+              uri: `data:${result.mime};base64,${result.content}`,
+              mime: result.mime,
+            })),
+            Effect.catchTag("Image.ResizerUnavailableError", () => Effect.succeed(item)),
+            Effect.catchTag("Image.DecodeError", () => Effect.succeed("decode" as const)),
+            Effect.catchTag("Image.SizeError", () => Effect.succeed("size" as const)),
+          )
+      })
+      const note = (reason: "decode" | "size", text: string) => {
+        const count = normalized.filter((item) => item === reason).length
+        if (count === 0) return []
+        return [{ type: "text" as const, text: `[${count} image${count === 1 ? "" : "s"} omitted: ${text}]` }]
+      }
+      return [
+        ...normalized.filter((item) => typeof item !== "string"),
+        ...note("decode", "could not be decoded."),
+        ...note("size", "could not be resized below the image size limit."),
+      ]
+    })
     type Registration = {
       readonly tool: AnyTool
       readonly name: string
@@ -84,10 +119,11 @@ const registryLayer = Layer.effect(
           agent: input.agent,
           messageID: input.messageID,
           callID: input.call.id,
-          progress: (update) =>
-            input.progress?.({
-              structured: update.structured,
-              content: (update.content ?? []).map((part) =>
+          progress: (update) => {
+            const progress = input.progress
+            if (!progress) return Effect.void
+            return normalizeImages(
+              (update.content ?? []).map((part) =>
                 part.type === "text"
                   ? { type: "text" as const, text: part.text }
                   : {
@@ -97,7 +133,8 @@ const registryLayer = Layer.effect(
                       name: part.name,
                     },
               ),
-            }) ?? Effect.void,
+            ).pipe(Effect.flatMap((content) => progress({ structured: update.structured, content })))
+          },
         },
       ).pipe(
         Effect.map((output) => ({ output })),
@@ -115,7 +152,7 @@ const registryLayer = Layer.effect(
         const bounded = yield* resources.bound({
           sessionID: input.sessionID,
           callID: input.call.id,
-          output: pending.output,
+          output: { structured: pending.output.structured, content: yield* normalizeImages(pending.output.content) },
         })
         const result = ToolOutput.toResultValue(bounded.output)
         settlement =
@@ -232,11 +269,11 @@ function whollyDisabled(action: string, rules: PermissionV2.Ruleset) {
 export const node = makeLocationNode({
   service: Service,
   layer,
-  deps: [ToolOutputStore.node, ToolHooks.node],
+  deps: [ToolOutputStore.node, ToolHooks.node, Image.node],
 })
 
 export const toolsNode = makeLocationNode({
   service: Tools.Service,
   layer,
-  deps: [ToolOutputStore.node, ToolHooks.node],
+  deps: [ToolOutputStore.node, ToolHooks.node, Image.node],
 })

packages/core/test/lib/image.ts

@@ -0,0 +1,7 @@
+import { Image } from "@opencode-ai/core/image"
+import { Effect, Layer } from "effect"
+
+/** Passthrough resizer for tests that build ToolRegistry.node without a Location. */
+export const imagePassthrough = Layer.mock(Image.Service, {
+  normalize: (_resource, content) => Effect.succeed(content),
+})

packages/core/test/mcp.test.ts

@@ -29,7 +29,9 @@ import { McpTool } from "@opencode-ai/core/tool/mcp"
 import { ToolRegistry } from "@opencode-ai/core/tool/registry"
 import { ToolOutputStore } from "@opencode-ai/core/tool-output-store"
 import { Deferred, Effect, Exit, Fiber, Layer, Schema, Stream } from "effect"
+import { Image } from "@opencode-ai/core/image"
 import { testEffect } from "./lib/effect"
+import { imagePassthrough } from "./lib/image"
 import { location } from "./fixture/location"
 import { settleTool, toolDefinitions, toolIdentity, waitForTool } from "./lib/tool"
 
@@ -250,6 +252,7 @@ const it = testEffect(
     [PermissionV2.node, permissions],
     [EventV2.node, events],
     [ToolOutputStore.node, ToolOutputStore.nodeWithoutConfig],
+    [Image.node, imagePassthrough],
   ]),
 )
 

packages/core/test/session-prompt.test.ts

@@ -1,5 +1,5 @@
 import { describe, expect } from "bun:test"
-import { DateTime, Effect, Fiber, Layer, Schema, Stream } from "effect"
+import { DateTime, Effect, Fiber, Layer, LayerMap, Schema, Stream } from "effect"
 import { mkdtemp, rm } from "fs/promises"
 import { tmpdir } from "os"
 import path from "path"
@@ -24,7 +24,10 @@ import { SessionExecution } from "@opencode-ai/core/session/execution"
 import { SessionPending } from "@opencode-ai/core/session/pending"
 import { SessionPendingTable, SessionMessageTable, SessionTable } from "@opencode-ai/core/session/sql"
 import { SessionStore } from "@opencode-ai/core/session/store"
+import { LocationServiceMap } from "@opencode-ai/core/location-service-map"
+import type { LocationServices } from "@opencode-ai/core/location-services"
 import { testEffect } from "./lib/effect"
+import { imagePassthrough } from "./lib/image"
 
 const executionCalls: SessionV2.ID[] = []
 const interruptCalls: SessionV2.ID[] = []
@@ -49,10 +52,22 @@ const execution = Layer.succeed(
     awaitIdle: () => Effect.void,
   }),
 )
+const locations = Layer.effect(
+  LocationServiceMap.Service,
+  LayerMap.make(
+    () =>
+      // Attachment admission only needs the location-scoped Image service.
+      // oxlint-disable-next-line typescript-eslint/no-unsafe-type-assertion
+      imagePassthrough as unknown as Layer.Layer<LocationServices>,
+  ),
+)
 const it = testEffect(
   AppNodeBuilder.build(
     LayerNode.group([Database.node, EventV2.node, SessionProjector.node, SessionStore.node, SessionV2.node]),
-    [[SessionExecution.node, execution]],
+    [
+      [SessionExecution.node, execution],
+      [LocationServiceMap.node, locations],
+    ],
   ),
 )
 const sessionID = SessionV2.ID.make("ses_prompt_test")