fix: default agent config, timestamps display, and tests

CONTEXT/PLAN-255-default-agent-not-applied-2026-01-03.md

@@ -0,0 +1,262 @@
+# Plan: Fix Default Agent Not Applied in Shuvcode (Issue #255)
+
+**Issue:** [#255 - Default agent does not apply in shuvcode](https://github.com/Latitudes-Dev/shuvcode/issues/255)  
+**Created:** 2026-01-03  
+**Author:** iamhenry  
+**Priority:** High (Bug)
+
+---
+
+## Problem Statement
+
+The `default_agent` configuration option is not respected in the shuvcode TUI. When a user sets a custom default agent (e.g., `"orchestrator"`) in their config, the TUI always starts with the first agent in the list (typically `"build"`) instead of the configured default.
+
+### User Report
+
+> In my config I have the `orchestrator` custom agent set as my default and it works as expected in opencode. However in shuvcode it always starts with the `build` agent and doesnt respect the config.
+
+```json
+"default_agent": "orchestrator"
+```
+
+---
+
+## Root Cause Analysis
+
+### The Bug
+
+The TUI's local context initializes the current agent using the first agent in the list rather than checking for the `default` property that's set by the Agent module based on the user's `default_agent` configuration.
+
+**Location:** `packages/opencode/src/cli/cmd/tui/context/local.tsx:42`
+
+**Current (Buggy) Code:**
+```typescript
+const [agentStore, setAgentStore] = createStore<{
+  current: string
+}>({
+  current: agents()[0].name,  // <-- Always uses first agent
+})
+```
+
+### How It Should Work
+
+1. User sets `default_agent: "orchestrator"` in their `opencode.json`
+2. The `Agent.state()` function in `packages/opencode/src/agent/agent.ts:269-279` marks the configured agent with `default: true`
+3. The TUI should look for an agent with `default: true` and use that as the initial selection
+4. If no default is found, fall back to the first agent
+
+### Upstream Fix
+
+This issue was fixed in upstream opencode in commit `8f6c8844d` (PR #5843):
+
+**Fixed Code:**
+```typescript
+const [agentStore, setAgentStore] = createStore<{
+  current: string
+}>({
+  current: agents().find((x) => x.default)?.name ?? agents()[0].name,
+})
+```
+
+---
+
+## Technical Context
+
+### Agent Default Property Flow
+
+1. **Config Schema** (`packages/opencode/src/config/config.ts:722-727`):
+   ```typescript
+   default_agent: z
+     .string()
+     .optional()
+     .describe(
+       "Default agent to use when none is specified. Must be a primary agent. Falls back to 'build' if not set or if the specified agent is invalid.",
+     ),
+   ```
+
+2. **Agent State Processing** (`packages/opencode/src/agent/agent.ts:269-279`):
+   ```typescript
+   // Mark the default agent
+   const defaultName = cfg.default_agent ?? "build"
+   const defaultCandidate = result[defaultName]
+   if (defaultCandidate && defaultCandidate.mode !== "subagent") {
+     defaultCandidate.default = true
+   } else {
+     // Fall back to "build" if configured default is invalid
+     if (result["build"]) {
+       result["build"].default = true
+     }
+   }
+   ```
+
+3. **Server-side Default Agent** (`packages/opencode/src/agent/agent.ts:300-304`):
+   ```typescript
+   export async function defaultAgent(): Promise<string> {
+     const agents = await state()
+     const defaultCandidate = Object.values(agents).find((a) => a.default)
+     return defaultCandidate?.name ?? "build"
+   }
+   ```
+
+### Agent Info Type
+
+The `Agent.Info` type includes a `default?: boolean` property that gets set when the agent matches the configured `default_agent`.
+
+---
+
+## Implementation Plan
+
+### Task 1: Apply the TUI Fix
+
+- [ ] **1.1** Modify `packages/opencode/src/cli/cmd/tui/context/local.tsx` line 42
+  - Change: `current: agents()[0].name,`
+  - To: `current: agents().find((x) => x.default)?.name ?? agents()[0].name,`
+
+### Task 2: Add Unit Tests
+
+- [ ] **2.1** Create new test file or extend `packages/opencode/test/agent/agent.test.ts`
+  - Add test: "default_agent config sets default property on specified agent"
+  - Add test: "default_agent falls back to build when invalid agent specified"
+  - Add test: "defaultAgent() returns configured default agent name"
+
+- [ ] **2.2** Example test cases:
+  ```typescript
+  test("default_agent config sets default property on specified agent", async () => {
+    await using tmp = await tmpdir({
+      init: async (dir) => {
+        const opencodeDir = path.join(dir, ".opencode")
+        await fs.mkdir(opencodeDir, { recursive: true })
+        const agentDir = path.join(opencodeDir, "agent")
+        await fs.mkdir(agentDir, { recursive: true })
+
+        // Create custom agent
+        await Bun.write(
+          path.join(agentDir, "orchestrator.md"),
+          `---
+  model: test/model
+  mode: primary
+  ---
+  Orchestrator agent prompt`,
+        )
+
+        // Set as default
+        await Bun.write(
+          path.join(dir, "opencode.json"),
+          JSON.stringify({
+            $schema: "https://opencode.ai/config.json",
+            default_agent: "orchestrator",
+          }),
+        )
+      },
+    })
+    await Instance.provide({
+      directory: tmp.path,
+      fn: async () => {
+        const agents = await Agent.list()
+        const orchestrator = agents.find((a) => a.name === "orchestrator")
+        expect(orchestrator?.default).toBe(true)
+
+        const build = agents.find((a) => a.name === "build")
+        expect(build?.default).toBeFalsy()
+
+        const defaultName = await Agent.defaultAgent()
+        expect(defaultName).toBe("orchestrator")
+      },
+    })
+  })
+  ```
+
+### Task 3: Verify Related Code Paths
+
+- [ ] **3.1** Review other locations where agent initialization happens:
+  - `packages/opencode/src/cli/cmd/run.ts` - CLI run command
+  - `packages/opencode/src/cli/cmd/github.ts` - GitHub integration
+  - `packages/opencode/src/session/prompt.ts` - Session prompts
+  - `packages/opencode/src/acp/agent.ts` - ACP agent handling
+
+- [ ] **3.2** Ensure all paths use `Agent.defaultAgent()` or check the `default` property
+
+### Task 4: Testing & Validation
+
+- [ ] **4.1** Run type checking: `bun turbo typecheck`
+- [ ] **4.2** Run test suite: `bun test` in `packages/opencode`
+- [ ] **4.3** Manual testing:
+  - Create a custom agent file in `.opencode/agent/`
+  - Set `default_agent` in `opencode.json`
+  - Launch TUI with `bun dev`
+  - Verify the configured agent is selected on startup
+  - Verify agent cycling (`tab`/`shift+tab`) works correctly
+
+---
+
+## File References
+
+### Internal Files to Modify
+
+| File | Line(s) | Change Description |
+|------|---------|-------------------|
+| `packages/opencode/src/cli/cmd/tui/context/local.tsx` | 42 | Fix initial agent selection |
+| `packages/opencode/test/agent/agent.test.ts` | New | Add default_agent tests |
+
+### Internal Files for Reference (No Changes)
+
+| File | Purpose |
+|------|---------|
+| `packages/opencode/src/agent/agent.ts:269-304` | Agent default marking & defaultAgent() function |
+| `packages/opencode/src/config/config.ts:722-727` | default_agent config schema |
+| `packages/opencode/src/session/prompt.ts:730,1374,1536` | Uses Agent.defaultAgent() |
+| `packages/opencode/src/server/server.ts:503-504,1154,1158` | Uses Agent.defaultAgent() |
+| `packages/opencode/src/acp/agent.ts:709-710,812` | Uses Agent.defaultAgent() |
+
+### External References
+
+| URL | Description |
+|-----|-------------|
+| https://github.com/sst/opencode/commit/8f6c8844d | Upstream fix commit |
+| https://github.com/sst/opencode/pull/5843 | Upstream PR with full context |
+
+---
+
+## Validation Criteria
+
+### Definition of Done
+
+1. **TUI respects `default_agent` config** - When launching the TUI, the configured default agent should be selected
+2. **Fallback works** - If `default_agent` is not set or invalid, the first agent should be selected
+3. **Tests pass** - All existing tests continue to pass
+4. **New tests added** - Tests cover the default_agent configuration and TUI initialization
+5. **Type check passes** - No TypeScript errors introduced
+
+### Test Commands
+
+```bash
+# Type check
+cd packages/opencode && bun run typecheck
+
+# Unit tests  
+cd packages/opencode && bun test
+
+# Full turbo test
+bun turbo test
+
+# Manual TUI test
+cd packages/opencode && bun dev
+```
+
+---
+
+## Rollback Plan
+
+If the fix introduces regressions:
+
+1. Revert the single line change in `local.tsx`
+2. Return to: `current: agents()[0].name,`
+
+---
+
+## Notes
+
+- This is a straightforward one-line fix from upstream
+- The server-side `Agent.defaultAgent()` function already works correctly
+- The bug is specifically in the TUI's client-side agent initialization
+- The fix aligns with how other parts of the codebase respect the default agent setting

packages/opencode/src/cli/cmd/tui/context/local.tsx

@@ -39,7 +39,7 @@ export const { use: useLocal, provider: LocalProvider } = createSimpleContext({
       const [agentStore, setAgentStore] = createStore<{
         current: string
       }>({
-        current: agents()[0].name,
+        current: agents().find((x) => x.default)?.name ?? agents()[0].name,
       })
       const { theme } = useTheme()
       const colors = createMemo(() => [

packages/opencode/src/cli/cmd/tui/routes/session/index.tsx

@@ -1904,6 +1904,9 @@ function AssistantMessage(props: { message: AssistantMessage; parts: Part[]; las
               <Show when={duration()}>
                 <span style={{ fg: theme.textMuted }}> · {Locale.duration(duration())}</span>
               </Show>
+              <Show when={ctx.showTimestamps()}>
+                <span style={{ fg: theme.textMuted }}> · {Locale.todayTimeOrDateTime(props.message.time.created)}</span>
+              </Show>
               <Show when={ctx.showTokens() && contextTokens() > 0}>
                 <span style={{ fg: theme.textMuted }}>
                   {" "}

packages/opencode/test/agent/agent.test.ts

@@ -144,3 +144,87 @@ Custom primary agent`,
     },
   })
 })
+
+test("default_agent config sets default property on specified agent", async () => {
+  await using tmp = await tmpdir({
+    init: async (dir) => {
+      const opencodeDir = path.join(dir, ".opencode")
+      await fs.mkdir(opencodeDir, { recursive: true })
+      const agentDir = path.join(opencodeDir, "agent")
+      await fs.mkdir(agentDir, { recursive: true })
+
+      // Create custom agent
+      await Bun.write(
+        path.join(agentDir, "orchestrator.md"),
+        `---
+model: test/model
+mode: primary
+---
+Orchestrator agent prompt`,
+      )
+
+      // Set as default
+      await Bun.write(
+        path.join(dir, "opencode.json"),
+        JSON.stringify({
+          $schema: "https://opencode.ai/config.json",
+          default_agent: "orchestrator",
+        }),
+      )
+    },
+  })
+  await Instance.provide({
+    directory: tmp.path,
+    fn: async () => {
+      const agents = await Agent.list()
+      const orchestrator = agents.find((a) => a.name === "orchestrator")
+      expect(orchestrator?.default).toBe(true)
+
+      const build = agents.find((a) => a.name === "build")
+      expect(build?.default).toBeFalsy()
+
+      const defaultName = await Agent.defaultAgent()
+      expect(defaultName).toBe("orchestrator")
+    },
+  })
+})
+
+test("default_agent falls back to build when invalid agent specified", async () => {
+  await using tmp = await tmpdir({
+    init: async (dir) => {
+      await Bun.write(
+        path.join(dir, "opencode.json"),
+        JSON.stringify({
+          $schema: "https://opencode.ai/config.json",
+          default_agent: "nonexistent-agent",
+        }),
+      )
+    },
+  })
+  await Instance.provide({
+    directory: tmp.path,
+    fn: async () => {
+      const agents = await Agent.list()
+      const build = agents.find((a) => a.name === "build")
+      expect(build?.default).toBe(true)
+
+      const defaultName = await Agent.defaultAgent()
+      expect(defaultName).toBe("build")
+    },
+  })
+})
+
+test("defaultAgent returns build when no default_agent configured", async () => {
+  await using tmp = await tmpdir()
+  await Instance.provide({
+    directory: tmp.path,
+    fn: async () => {
+      const agents = await Agent.list()
+      const build = agents.find((a) => a.name === "build")
+      expect(build?.default).toBe(true)
+
+      const defaultName = await Agent.defaultAgent()
+      expect(defaultName).toBe("build")
+    },
+  })
+})