feat(setup): pass SIM_AGENT_API_URL through, and warn on a half-set mothership

Sim devs testing against a non-prod mothership export SIM_CLI_AUTH_ORIGIN so the Chat key is minted there, but nothing carried the matching backend URL into the install — the app kept defaulting to prod copilot, which rejects a staging key with 'Invalid API key'.

Persist SIM_AGENT_API_URL when it is exported, so later docker compose up / dev runs stay on that backend instead of reverting to prod once the shell is gone:

  SIM_CLI_AUTH_ORIGIN=https://www.staging.sim.ai \
  SIM_AGENT_API_URL=https://www.staging.copilot.sim.ai \
  bun run setup

Setting only the auth origin is the trap, so that combination warns. Neither set is the self-hoster default and stays silent — no prompts, no flags.

Author: TheodoreSpeaks

scripts/setup/modes/compose.ts

@@ -8,6 +8,7 @@ import { httpHealth, waitFor } from '../probes.ts'
 import * as p from '../prompter.ts'
 import {
   collectSecrets,
+  mothershipOverride,
   promptCopilotKey,
   promptEmail,
   promptLlmKeys,
@@ -60,6 +61,7 @@ export async function runComposeMode(detection: Detection, quick: boolean): Prom
   const copilotKey = await promptCopilotKey(root.vars.get('COPILOT_API_KEY'))
   if (copilotKey) values.COPILOT_API_KEY = copilotKey
   Object.assign(values, await promptLlmKeys(detection, !quick))
+  Object.assign(values, mothershipOverride())
   if (!quick) {
     const storage = await promptStorage(root.vars, true)
     if (storage) Object.assign(values, storage)

scripts/setup/modes/dev.ts

@@ -10,6 +10,7 @@ import * as p from '../prompter.ts'
 import { ensureRedis, resolveRedis } from '../redis.ts'
 import {
   collectSecrets,
+  mothershipOverride,
   promptCopilotKey,
   promptEmail,
   promptLlmKeys,
@@ -120,6 +121,7 @@ export async function runDevMode(
   const copilotKey = await promptCopilotKey(simAfter.vars.get('COPILOT_API_KEY'))
   if (copilotKey) values.COPILOT_API_KEY = copilotKey
   Object.assign(values, await promptLlmKeys(detection, !quick))
+  Object.assign(values, mothershipOverride())
 
   // Redis is set up in every mode, quick included. Storage falls back to
   // PostgreSQL without it, but the pub/sub channels (live Chat task-status,

scripts/setup/steps.ts

@@ -65,6 +65,32 @@ export async function promptCopilotKey(existing?: string): Promise<string | null
   return key
 }
 
+/**
+ * Escape hatch for Sim devs pointing an install at a non-prod mothership:
+ *
+ *   SIM_CLI_AUTH_ORIGIN=https://www.staging.sim.ai \
+ *   SIM_AGENT_API_URL=https://www.staging.copilot.sim.ai \
+ *   bun run setup
+ *
+ * The two belong together — SIM_CLI_AUTH_ORIGIN decides where the Chat key is
+ * minted, SIM_AGENT_API_URL decides which backend validates it, and a key from
+ * one environment is rejected by the other. Persisting the URL keeps later
+ * `docker compose up` / dev runs on the same backend instead of silently
+ * reverting to prod once the shell that exported it is gone.
+ */
+export function mothershipOverride(): Record<string, string> {
+  const agentUrl = process.env.SIM_AGENT_API_URL
+  const authOrigin = process.env.SIM_CLI_AUTH_ORIGIN
+  if (authOrigin && !agentUrl) {
+    p.log.warn(
+      `SIM_CLI_AUTH_ORIGIN points the Chat key handoff at ${authOrigin}, but SIM_AGENT_API_URL is unset — the app will validate that key against production and reject it. Set both, or neither.`
+    )
+  }
+  if (!agentUrl) return {}
+  p.log.step(`Using mothership ${agentUrl} (SIM_AGENT_API_URL)`)
+  return { SIM_AGENT_API_URL: agentUrl }
+}
+
 export async function promptLlmKeys(
   detection: Detection,
   custom: boolean