fix(opencode): resolve MCP resource content

packages/opencode/src/session/message-v2.ts

@@ -219,8 +219,13 @@ export const toModelMessagesEffect = Effect.fnUntraced(function* (
             type: "text",
             text: part.text,
           })
-        // text/plain and directory files are converted into text parts, ignore them
-        if (part.type === "file" && part.mime !== "text/plain" && part.mime !== "application/x-directory") {
+        // Text, directories, and MCP references are resolved before provider conversion.
+        if (
+          part.type === "file" &&
+          part.mime !== "text/plain" &&
+          part.mime !== "application/x-directory" &&
+          part.source?.type !== "resource"
+        ) {
           if (options?.stripMedia && isMedia(part.mime)) {
             userMessage.parts.push({
               type: "text",

packages/opencode/src/session/prompt.ts

@@ -728,7 +728,16 @@ export const layer = Layer.effect(
             const exit = yield* mcp.readResource(clientName, uri).pipe(Effect.exit)
             if (Exit.isSuccess(exit)) {
               const content = exit.value
-              if (!content) throw new Error(`Resource not found: ${clientName}/${uri}`)
+              if (!content) {
+                pieces.push({
+                  messageID: info.id,
+                  sessionID: input.sessionID,
+                  type: "text",
+                  synthetic: true,
+                  text: `Failed to read MCP resource ${part.filename}: resource not found or could not be read`,
+                })
+                return pieces
+              }
               const items = Array.isArray(content.contents) ? content.contents : [content.contents]
               for (const c of items) {
                 if ("text" in c && c.text) {
@@ -740,13 +749,14 @@ export const layer = Layer.effect(
                     text: c.text,
                   })
                 } else if ("blob" in c && c.blob) {
-                  const mime = "mimeType" in c ? c.mimeType : part.mime
+                  const mime = ("mimeType" in c ? c.mimeType : undefined) ?? part.mime
                   pieces.push({
                     messageID: info.id,
                     sessionID: input.sessionID,
-                    type: "text",
-                    synthetic: true,
-                    text: `[Binary content: ${mime}]`,
+                    type: "file",
+                    mime,
+                    filename: part.filename,
+                    url: `data:${mime};base64,${c.blob}`,
                   })
                 }
               }
@@ -992,7 +1002,7 @@ export const layer = Layer.effect(
       )
 
       const parts = yield* Effect.forEach(resolvedParts, (part) =>
-        part.type === "file" && part.mime.startsWith("image/")
+        part.type === "file" && part.source?.type !== "resource" && part.mime.startsWith("image/")
           ? image.normalize(part).pipe(
               Effect.catchIf(
                 (error) => error instanceof Image.ResizerUnavailableError,