diff --git a/.changeset/api-pin-and-next-steps.md b/.changeset/api-pin-and-next-steps.md
new file mode 100644
index 0000000..ee95ded
--- /dev/null
+++ b/.changeset/api-pin-and-next-steps.md
@@ -0,0 +1,5 @@
+---
+"seamless-cli": patch
+---
+
+Scaffold the auth server at v0.18.0, whose OTP and magic-link send routes are POST, as the Go, Rust and Python adapters and the current `@seamless-auth/client` send them. v0.18.0 still serves the deprecated GET routes, so projects on the Express and Fastify starters keep working. The next steps after `seamless init` now give each api starter its own command (`go run .`, `cargo run`, `uv run uvicorn ...`) instead of `npm install && npm run dev`.
diff --git a/src/core/images.ts b/src/core/images.ts
index 45f142c..80018be 100644
--- a/src/core/images.ts
+++ b/src/core/images.ts
@@ -3,7 +3,7 @@
 // scaffolded with, and never has its data directory pulled out from under it.
 export const POSTGRES_IMAGE = "postgres:18";
 
-export const SEAMLESS_AUTH_API_VERSION = "v0.17.0";
+export const SEAMLESS_AUTH_API_VERSION = "v0.18.0";
 
 export const SEAMLESS_AUTH_API_IMAGE = `ghcr.io/fells-code/seamless-auth-api:${SEAMLESS_AUTH_API_VERSION}`;
 
diff --git a/src/core/output.test.ts b/src/core/output.test.ts
index 281a8da..72c71e0 100644
--- a/src/core/output.test.ts
+++ b/src/core/output.test.ts
@@ -1,5 +1,6 @@
 import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
 import {
+  apiDevCommand,
   maskDatabaseUrl,
   printManagedSuccessOutput,
   printSuccessOutput,
@@ -351,3 +352,31 @@ describe("output for a full-stack web app", () => {
     expect(out).not.toContain("# Database");
   });
 });
+
+describe("apiDevCommand", () => {
+  it("starts each api starter with its own toolchain", () => {
+    expect(apiDevCommand("express")).toBe("cd api && npm install && npm run dev");
+    expect(apiDevCommand("fastify")).toBe("cd api && npm install && npm run dev");
+    expect(apiDevCommand("gin")).toBe("cd api && go run .");
+    expect(apiDevCommand("axum")).toBe("cd api && cargo run");
+    expect(apiDevCommand("fastapi")).toBe(
+      "cd api && uv run uvicorn app.main:build --factory --reload --port 3000",
+    );
+  });
+
+  it("prints the api starter's own command in the managed next steps", () => {
+    printManagedSuccessOutput({
+      projectName: "my-app",
+      webFramework: "react",
+      apiFramework: "axum",
+      authServerUrl: "https://auth.example.com",
+      appName: "Acme App",
+    });
+
+    const out = allLogs();
+    expect(out).toContain("(Axum)");
+    expect(out).toContain("cd api && cargo run");
+    expect(out).not.toContain("cd api && npm install");
+  });
+});
+
diff --git a/src/core/output.ts b/src/core/output.ts
index d98b53f..9a02e3e 100644
--- a/src/core/output.ts
+++ b/src/core/output.ts
@@ -283,7 +283,7 @@ export function printManagedSuccessOutput(config: {
 
   if (apiFramework) {
     console.log(kleur.dim("  # API server"));
-    console.log("  cd api && npm install && npm run dev\n");
+    console.log(`  ${apiDevCommand(apiFramework)}\n`);
   }
   if (webFramework) {
     console.log(kleur.dim("  # Web app"));
@@ -329,6 +329,21 @@ export function maskDatabaseUrl(url: string): string {
   return url.replace(/\/\/[^@/]*@/, "//****:****@");
 }
 
+// The Go, Rust and Python api starters are not npm projects; each README gives
+// the same command for running it on the host.
+export function apiDevCommand(framework: string): string {
+  switch (framework) {
+    case "gin":
+      return "cd api && go run .";
+    case "axum":
+      return "cd api && cargo run";
+    case "fastapi":
+      return "cd api && uv run uvicorn app.main:build --factory --reload --port 3000";
+    default:
+      return "cd api && npm install && npm run dev";
+  }
+}
+
 function formatFramework(name: string) {
   const map: Record<string, string> = {
     react: "React",
@@ -338,6 +353,8 @@ function formatFramework(name: string) {
     nextjs: "Next.js",
     fastapi: "FastAPI",
     fastify: "Fastify",
+    gin: "Gin",
+    axum: "Axum",
     vue: "Vue",
     expo: "Expo",
   };