diff --git a/host/skills/corral-api/SKILL.md b/host/skills/corral-api/SKILL.md
index 01eed76..9974438 100644
--- a/host/skills/corral-api/SKILL.md
+++ b/host/skills/corral-api/SKILL.md
@@ -73,6 +73,43 @@ break the ask into tasks, kick off a worker per task, and keep going.
   running it inline.
 - Put ALL context the worker needs in `prompt` (it starts fresh in a neutral dir).
 - Give a short, human `title` — it's the worker's tab label.
+
+### CODE TASKS RUN IN A SANDBOX — the worker creates a project, it does NOT edit code on the host
+
+The architecture is **Conductor → Worker → Sandbox project** (which has its own
+Claude). A worker runs **on the host and is NOT sandboxed** — so a worker must
+**never write, run, or test a repo's code directly**. That would touch the
+operator's real checkout with no isolation. Instead, a worker whose task is code
+work is an *orchestrator*: it **creates a sandbox project and hands the actual
+work to that project's own Claude** via the auto-submitted `prompt`.
+
+**If the task is a code task** — implement a feature, fix a bug, work a GitHub
+issue, write/run/debug tests, get an app running, anything that edits or executes
+a repo's code — the worker's job is to spin up the sandbox, not to do the coding:
+
+```
+# The worker (or you, when kicking one off) creates the sandbox and passes the
+# real task as the sandbox's first prompt — that sandbox's Claude does the work.
+corral api POST /projects/create -d '{
+  "repoId": "<repoId>",           # from GET /repos (or "repos":[…] for multi-repo)
+  "branch": "<branch>",           # optional; defaults to the repo default branch
+  "prompt": "<the full coding task, with all context the sandbox Claude needs>"
+}'
+# → { "id": "<projectId>", ... }  — a sandbox is now running Claude on the task
+```
+
+So the usual shape for a code request is: **conductor** spawns a **worker** whose
+prompt says "create a sandbox project for repo X on this task and drive it to
+done"; the **worker** calls `POST /projects/create` (with the coding task as the
+project `prompt`); the **sandbox project's Claude** does the isolated code work.
+The worker then supervises — polls `GET /status` for that project, reads its
+conversation (`GET /api/conversations?origin=sandbox&project=<id>`), steers or
+restarts it if needed — but the edits/builds/tests happen **inside the sandbox**.
+
+**Only skip the sandbox for NON-code work** — inspecting Corral state, reading
+logs/PRs, running flows, triage/analysis, orchestration. Those are fine to do on
+the host (in the worker or inline). When in doubt about whether a task will touch
+a repo's code: route it through a sandbox project.
 - Workers, like merge jobs, are listed by `GET /merge-jobs`, streamed at
   `/merge-jobs/<id>/ws`, and removed with `DELETE /merge-jobs/<id>`.
 - Workers run on the HOST and are **not sandboxed**; they use the operator's
diff --git a/internal/dashboard/conductor_workers.go b/internal/dashboard/conductor_workers.go
index 6783eff..e0697d1 100644
--- a/internal/dashboard/conductor_workers.go
+++ b/internal/dashboard/conductor_workers.go
@@ -45,6 +45,17 @@ func workerContractPreamble(jobID string) string {
 		"no human at you to answer one. Use ONLY your granted tools: Read/Grep/Glob, plus Bash and " +
 		"Monitor when you have act capability. Those cover waiting/polling; do not reach for an " +
 		"ungranted tool, which would block on approval and strand you.\n" +
+		"CODE WORK GOES IN A SANDBOX, NOT ON THE HOST: if your task involves writing, running, " +
+		"building, or testing a repo's code (implementing a feature, fixing a bug, working an issue, " +
+		"getting an app running, or exploring code to plan such a change), do NOT edit or run that code " +
+		"here on the host. Instead CREATE A SANDBOX PROJECT and hand the actual work to its own Claude: " +
+		"`corral api POST /projects/create -d '{\"repoId\":\"<id>\",\"prompt\":\"<the full coding task>\"}'` " +
+		"(the project `prompt` is auto-submitted to the sandbox's Claude). Then supervise it — poll " +
+		"`corral api GET /status` and read its conversation " +
+		"(`corral api GET \"/api/conversations?origin=sandbox&project=<id>\"`), steering or restarting if " +
+		"needed. You are the orchestrator; the edits/builds/tests happen inside the sandbox. Only pure " +
+		"host/orchestration work (inspecting Corral state, reading logs/PRs, running flows, analysis) " +
+		"stays on the host.\n" +
 		"Two valid ways to handle a long step (image pull/transfer, build, install):\n" +
 		"  (a) BLOCK on it in-turn — run it in the foreground, or poll with Bash " +
 		"(`until …; do sleep N; done`) / Monitor, then proceed once it's done.\n" +