feat(plugins): share native session handoff and soften memory search

integrations/agent-plugin-core/build/build.py

@@ -41,6 +41,7 @@ TEMPLATE_TOKENS = {
     "COMMAND_PREFIX",
     "HARNESS_ID",
     "HARNESS_NAME",
+    "HANDOFF_INSTRUCTIONS",
 }
 
 
@@ -81,6 +82,30 @@ def replace_output(staged: Path, output: Path) -> Path:
     return output
 
 
+def handoff_instructions(host: str, plugin_root: str) -> str:
+    command = f'python3 "{plugin_root}/core/session_handoff.py"'
+    if host == "claude-code":
+        return (
+            "The transfer command has already run before model invocation:\n\n"
+            f'!`{command} --source claude-code --session "${{CLAUDE_SESSION_ID}}" --target codex --create --command-output`\n\n'
+            "Return the command output exactly. Do not retry the transfer or do any other work."
+        )
+    source = host if host != "coding-agent" else "SOURCE_HOST"
+    return (
+        f"The source is {host}. Ask for a completed native transcript path or a neutral handoff bundle "
+        "if none was supplied. Never guess the latest session. Do not create a summary from memory. "
+        "For the portable plugin, replace SOURCE_HOST with the actual supported native host.\n\n"
+        f'```bash\n{command} --source {source} --session "NATIVE_TRANSCRIPT_PATH" --target codex --create --command-output\n```\n\n'
+        "Quote the supplied path as one shell argument. Cursor and Antigravity transcripts need "
+        "`--cwd` with their source project directory; `--title` preserves a title absent from the export. "
+        "For a neutral bundle use `--bundle PATH` instead of `--source` and `--session`.\n\n"
+        "A still-running source or this skill's own shell call may leave an unfinished tool call. "
+        "In that case, return the error and show the same command for running from a terminal after "
+        "the source turn finishes. Never trim pending calls, automatically retry, or claim that a "
+        "partial memory capture is the complete conversation. Return the command output."
+    )
+
+
 def _bundle_python(
     staged: Path,
     host: str,
@@ -103,17 +128,21 @@ def _bundle_python(
         "COMMAND_PREFIX": "mem0",
         "HARNESS_ID": host,
         "HARNESS_NAME": host.replace("-", " ").title(),
+        "HANDOFF_INSTRUCTIONS": handoff_instructions(host, plugin_root),
     }
     for source in sorted(SHARED_SKILLS.glob("*/SKILL.md.tmpl")):
         target = staged / "skills" / source.parent.name / "SKILL.md"
         target.parent.mkdir(parents=True)
         rendered = render_template(source.read_text(encoding="utf-8"), values)
         if portable:
-            rendered = "\n".join(
-                line
-                for line in rendered.splitlines()
-                if not line.startswith(("argument-hint:", "disable-model-invocation:"))
-            ) + "\n"
+            rendered = (
+                "\n".join(
+                    line
+                    for line in rendered.splitlines()
+                    if not line.startswith(("argument-hint:", "disable-model-invocation:"))
+                )
+                + "\n"
+            )
         target.write_text(rendered, encoding="utf-8")
 
 
@@ -196,11 +225,7 @@ def bundle_drift(host: str, kind: str) -> list[str]:
         generated = build(host, kind, Path(temporary) / "bundle")
         errors: list[str] = []
         for directory in ("core", "skills"):
-            expected = {
-                path.relative_to(generated)
-                for path in (generated / directory).rglob("*")
-                if path.is_file()
-            }
+            expected = {path.relative_to(generated) for path in (generated / directory).rglob("*") if path.is_file()}
             actual = {
                 path.relative_to(target)
                 for path in (target / directory).rglob("*")

integrations/agent-plugin-core/build/handoff-runtime.json

@@ -0,0 +1,5 @@
+[
+  "claude_to_codex.py",
+  "session_handoff.py",
+  "handoff_sources.py"
+]

integrations/agent-plugin-core/build/package_handoff.mjs

@@ -0,0 +1,15 @@
+import { copyFile, mkdir, readFile } from "node:fs/promises";
+import { resolve } from "node:path";
+import { fileURLToPath } from "node:url";
+
+export async function packageHandoff(output = "dist") {
+  const files = JSON.parse(await readFile(new URL("./handoff-runtime.json", import.meta.url), "utf8"));
+  await mkdir(output, { recursive: true });
+  for (const name of files) {
+    await copyFile(new URL(`../python/${name}`, import.meta.url), resolve(output, name));
+  }
+}
+
+if (process.argv[1] && resolve(process.argv[1]) === fileURLToPath(import.meta.url)) {
+  await packageHandoff(process.argv[2]);
+}