feat(models,devin-acp): add swe-2 + route Devin Local-only models through ACP

.env.example

@@ -134,6 +134,9 @@ LS_PORT=42100
 # be used before enabling these in production.
 # DEVIN_CLI_ALLOW_CLIENT_TOOLS=0
 # DEVIN_CLI_ALLOW_MEDIA=0
+# ACP initialize clientInfo.name. Default is WindsurfAPI. Set windsurf only when
+# the CLI rejects a custom client name (team-settings 403 on enterprise).
+# DEVIN_ACP_CLIENT_NAME=windsurf
 # After configuring Devin CLI/ACP, validate the route with:
 # API_KEY=... BASE_URL=http://127.0.0.1:3003 npm run smoke:special-agent
 

src/backend-router.js

@@ -41,6 +41,21 @@ function isSpecialAgentInfo(modelInfo) {
   return modelInfo?.backend === 'special_agent';
 }
 
+function specialAgentEnabled(env = process.env) {
+  if (getBackendSwitch('devinOnly', env)) return true;
+  const backend = String(env?.WINDSURFAPI_SPECIAL_AGENT_BACKEND || '').trim().toLowerCase();
+  return backend === 'devin-cli' || env?.DEVIN_CLI_ENABLED === '1';
+}
+
+// Observed gpt-5.6 SKUs Cascade rejects with "This model is only in Devin Local".
+// Anchored to luna/sol/terra (+ effort / -priority). Do not prefix-match gpt-5.60.
+// swe-2* is catalogued as backend: 'special_agent' and is handled by that branch.
+const GPT56_LOCAL_SKU = /^(?:gpt-5[.-]6|gpt5[.-]6)-(luna|sol|terra)(?:-(none|low|medium|high|xhigh|max)(?:-priority)?)?$/;
+
+function isDevinLocalOnlyModel(modelInfo) {
+  return [modelInfo?.name, modelInfo?.modelUid].some((k) => GPT56_LOCAL_SKU.test(String(k || '').trim().toLowerCase()));
+}
+
 /**
  * Resolve the Devin CLI sub-mode (acp vs print). Defaults to print — the same
  * conservative default special-agent.js uses.
@@ -125,6 +140,14 @@ export function selectBackend({ modelInfo = null, env = process.env } = {}) {
     };
   }
 
+  if (specialAgentEnabled(env) && isDevinLocalOnlyModel(modelInfo)) {
+    return {
+      backend: devinCliMode(env),
+      reason: 'devin_local_only',
+      flow: 'special_agent',
+    };
+  }
+
   const modelEnum = modelInfo?.enumValue || 0;
   const modelUid = modelInfo?.modelUid || null;
   if (modelUid || modelEnum) {

src/data/devin-catalog-snapshot.json

@@ -1,7 +1,7 @@
 {
   "_comment": "DEVIN_CONNECT catalog whitelist. Refreshed from live GetCascadeModelConfigs 2026-07-08. Live dash-form + enum selectors; MODEL_PRIVATE_* excluded EXCEPT those referenced by SELECTOR_MAP; swe-1-6-slow free-tier fallback preserved. Extended 2026-08-11 from docs.devin.ai modelCostData (gpt-5-6-luna-*, claude-opus-5-*) — NOT yet frame-verified; selector form follows the 4-8/fable family convention.",
   "_calibratedAt": "2026-07-08",
-  "_count": 120,
+  "_count": 123,
   "models": [
     {
       "selector": "claude-opus-4-8-medium",
@@ -41,6 +41,19 @@
       "selector": "swe-1-7-lightning",
       "provider": "cognition"
     },
+    {
+      "selector": "swe-2-medium",
+      "provider": "cognition",
+      "alias": "swe-2"
+    },
+    {
+      "selector": "swe-2-high",
+      "provider": "cognition"
+    },
+    {
+      "selector": "swe-2-max",
+      "provider": "cognition"
+    },
     {
       "selector": "claude-opus-4-7-medium",
       "provider": "anthropic",

src/devin-acp.js

@@ -524,6 +524,12 @@ export async function runDevinAcpProcess(prompt, { modelKey = '', apiKey = '', a
   const command = process.env.DEVIN_CLI_PATH || 'devin';
   const env = { ...process.env };
   const args = parseAcpArgs();
+  // One channel only: `devin acp --model` (do not also set DEVIN_MODEL — the
+  // two can disagree). Leave DEVIN_PERMISSION_MODE to the operator; do not
+  // default it to auto.
+  if (modelKey && !args.includes('--model')) {
+    args.push('--model', modelKey);
+  }
   const client = makeAcpClient({
     command,
     args,
@@ -541,7 +547,7 @@ export async function runDevinAcpProcess(prompt, { modelKey = '', apiKey = '', a
         fs: { readTextFile: false, writeTextFile: false },
         terminal: false,
       },
-      clientInfo: { name: 'WindsurfAPI', version: VERSION },
+      clientInfo: { name: process.env.DEVIN_ACP_CLIENT_NAME || 'WindsurfAPI', version: VERSION },
     }, 30_000);
     if (init.error) throw errorFromRpcResponse(init, 'Devin ACP initialize failed');
 

src/devin-connect-models.js

@@ -121,6 +121,16 @@ const SELECTOR_MAP = new Map(Object.entries({
   'swe-1.7': 'swe-1-7',
   'swe-1-7-lightning': 'swe-1-7-lightning',
   'swe-1.7-lightning': 'swe-1-7-lightning',
+  'swe-2': 'swe-2-medium',
+  'swe-2.0': 'swe-2-medium',
+  'swe-2-0': 'swe-2-medium',
+  'swe2': 'swe-2-medium',
+  'swe-2-medium': 'swe-2-medium',
+  'swe-2-high': 'swe-2-high',
+  'swe-2-max': 'swe-2-max',
+  'swe-2.0-medium': 'swe-2-medium',
+  'swe-2.0-high': 'swe-2-high',
+  'swe-2.0-max': 'swe-2-max',
   'deepseek-v4': 'deepseek-v4',
 
   // GPT-5.6 family (live catalog 2026-07-09, docs.devin.ai price table). Luna is

src/models.js

@@ -280,6 +280,13 @@ export const MODELS = {
   // (dash-form modelUid, no special_agent backend — resolved via catalog, not LS).
   'swe-1-7':                        { name: 'swe-1-7',                        provider: 'windsurf', enumValue: 0, modelUid: 'swe-1-7', credit: 0.5 },
   'swe-1-7-lightning':              { name: 'swe-1-7-lightning',              provider: 'windsurf', enumValue: 0, modelUid: 'swe-1-7-lightning', credit: 0.5 },
+  // SWE-2 — Cognition 2026-09-10 (docs.devin.ai: swe-2-medium/high/max).
+  // DEVIN_CONNECT=1 uses the snapshot selectors. Cascade has no UID, so the
+  // LS path marks them special_agent (same as swe-1.6) for an opted-in CLI.
+  'swe-2':                          { name: 'swe-2',                          provider: 'windsurf', enumValue: 0, modelUid: 'swe-2-medium', credit: 6, backend: 'special_agent' },
+  'swe-2-medium':                   { name: 'swe-2-medium',                   provider: 'windsurf', enumValue: 0, modelUid: 'swe-2-medium', credit: 6, backend: 'special_agent' },
+  'swe-2-high':                     { name: 'swe-2-high',                     provider: 'windsurf', enumValue: 0, modelUid: 'swe-2-high', credit: 9, backend: 'special_agent' },
+  'swe-2-max':                      { name: 'swe-2-max',                      provider: 'windsurf', enumValue: 0, modelUid: 'swe-2-max', credit: 12, backend: 'special_agent' },
 
   // ── Adaptive (Windsurf 2026-04-06 changelog) ────────────
   // Adaptive Model Router + Arena models live in the cloud catalog but their
@@ -385,6 +392,12 @@ _lookup.set('gpt-5-3-codex-xhigh-priority', 'gpt-5.3-codex-xhigh-fast');
 // Cloud-format aliases for existing dotted names
 _lookup.set('swe-1-6', 'swe-1.6');
 _lookup.set('swe-1-6-fast', 'swe-1.6-fast');
+_lookup.set('swe-2.0', 'swe-2');
+_lookup.set('swe-2-0', 'swe-2');
+_lookup.set('swe2', 'swe-2');
+_lookup.set('swe-2.0-medium', 'swe-2-medium');
+_lookup.set('swe-2.0-high', 'swe-2-high');
+_lookup.set('swe-2.0-max', 'swe-2-max');
 _lookup.set('minimax-m2-5', 'minimax-m2.5');
 _lookup.set('kimi-k2-5', 'kimi-k2.5');
 _lookup.set('kimi-k2.6', 'kimi-k2-6');

test/backend-router.test.js

@@ -33,6 +33,68 @@ describe('backend-router selectBackend — behaviour parity with legacy', () =>
     assert.ok(usesCascadeFlow(sel));
   });
 
+  it('gpt-5.6 stays on cascade unless Devin CLI special-agent is enabled', () => {
+    const sel = selectBackend({
+      modelInfo: { name: 'gpt-5.6-luna', modelUid: 'gpt-5-6-luna-medium' },
+      env: {},
+    });
+    assert.equal(sel.flow, 'cascade');
+  });
+
+  it('gpt-5.6-luna → ACP when DEVIN_CLI_ENABLED=1 and DEVIN_CLI_MODE=acp', () => {
+    const sel = selectBackend({
+      modelInfo: { name: 'gpt-5.6-luna', modelUid: 'gpt-5-6-luna-medium' },
+      env: { DEVIN_CLI_ENABLED: '1', DEVIN_CLI_MODE: 'acp' },
+    });
+    assert.equal(sel.backend, BACKEND.DEVIN_ACP);
+    assert.equal(sel.flow, 'special_agent');
+    assert.equal(sel.reason, 'devin_local_only');
+  });
+
+  it('gpt-5.6-luna → print when CLI is on but mode is not acp', () => {
+    const sel = selectBackend({
+      modelInfo: { name: 'gpt-5.6-luna', modelUid: 'gpt-5-6-luna-medium' },
+      env: { DEVIN_CLI_ENABLED: '1' },
+    });
+    assert.equal(sel.backend, BACKEND.DEVIN_PRINT);
+    assert.equal(sel.reason, 'devin_local_only');
+  });
+
+  it('does not treat gpt-5.60 as a Devin Local gpt-5.6 SKU', () => {
+    const env = { DEVIN_CLI_ENABLED: '1', DEVIN_CLI_MODE: 'acp' };
+    // No uid: hijack would be special_agent / devin_local_only.
+    const noUid = selectBackend({ modelInfo: { name: 'gpt-5.60' }, env });
+    assert.equal(noUid.flow, 'legacy');
+    assert.notEqual(noUid.reason, 'devin_local_only');
+    // With uid the fall-through is cascade, still not the local-only branch.
+    const withUid = selectBackend({
+      modelInfo: { name: 'gpt-5.60', modelUid: 'gpt-5-60' },
+      env,
+    });
+    assert.equal(withUid.flow, 'cascade');
+    assert.equal(withUid.reason, 'modelUid');
+    assert.notEqual(withUid.reason, 'devin_local_only');
+  });
+
+  it('swe-2 catalog entries use backend=special_agent (not the gpt-5.6 local-only branch)', () => {
+    const sel = selectBackend({
+      modelInfo: { name: 'swe-2-medium', modelUid: 'swe-2-medium', backend: 'special_agent' },
+      env: { DEVIN_CLI_ENABLED: '1', DEVIN_CLI_MODE: 'acp' },
+    });
+    assert.equal(sel.backend, BACKEND.DEVIN_ACP);
+    assert.equal(sel.flow, 'special_agent');
+    assert.equal(sel.reason, 'modelInfo.backend=special_agent');
+  });
+
+  it('DEVIN_CONNECT=1 still wins over swe-2 special_agent', () => {
+    const sel = selectBackend({
+      modelInfo: { name: 'swe-2-medium', modelUid: 'swe-2-medium', backend: 'special_agent' },
+      env: { DEVIN_CONNECT: '1', DEVIN_CLI_ENABLED: '1', DEVIN_CLI_MODE: 'acp' },
+    });
+    assert.equal(sel.backend, BACKEND.DEVIN_CONNECT);
+    assert.equal(sel.reason, 'devin_connect');
+  });
+
   it('enumValue > 0 (no uid) → cascade', () => {
     const sel = selectBackend({ modelInfo: { enumValue: 166 }, env: {} });
     assert.equal(sel.backend, BACKEND.CASCADE);

test/devin-connect-models.test.js

@@ -23,6 +23,26 @@ describe('resolveConnectSelector', () => {
     assert.deepEqual(resolveConnectSelector('swe-1.6-slow'), { selector: 'swe-1-6-slow', mapped: true });
   });
 
+  it('maps swe-2 _lookup aliases onto catalog selectors', () => {
+    // Same names models.js _lookup accepts. Without these SELECTOR_MAP rows,
+    // DEVIN_CONNECT=1 + STRICT_MODEL=1 400s them even though resolveModel succeeds.
+    const cases = [
+      ['swe-2', 'swe-2-medium'],
+      ['swe-2.0', 'swe-2-medium'],
+      ['swe-2-0', 'swe-2-medium'],
+      ['swe2', 'swe-2-medium'],
+      ['swe-2-medium', 'swe-2-medium'],
+      ['swe-2-high', 'swe-2-high'],
+      ['swe-2-max', 'swe-2-max'],
+      ['swe-2.0-medium', 'swe-2-medium'],
+      ['swe-2.0-high', 'swe-2-high'],
+      ['swe-2.0-max', 'swe-2-max'],
+    ];
+    for (const [name, selector] of cases) {
+      assert.deepEqual(resolveConnectSelector(name), { selector, mapped: true }, name);
+    }
+  });
+
   it('maps claude friendly names to their captured upstream selectors', () => {
     assert.equal(resolveConnectSelector('claude-opus-4.8').selector, 'claude-opus-4-8-medium');
     // Dashed bare form is a real catalog selector (base model) → resolves to itself;

test/tool-emulation.test.js

@@ -242,6 +242,8 @@ describe('ToolCallStreamParser', () => {
     assert.equal(pickToolDialect('swe-1-6-slow'), 'openai_json_xml');
     assert.equal(pickToolDialect('swe-1-8'), 'openai_json_xml');
     assert.equal(pickToolDialect('swe-2-0'), 'openai_json_xml');
+    assert.equal(pickToolDialect('swe-2'), 'openai_json_xml');
+    assert.equal(pickToolDialect('swe-2-medium'), 'openai_json_xml');
     assert.equal(pickToolDialect('swe-1-7-future-slow'), 'openai_json_xml');
   });