fix(config): allow Sisyphus-Junior agent customization via oh-my-opencode.json (#648)

* fix(config): allow Sisyphus-Junior agent customization via oh-my-opencode.json

Allow users to configure Sisyphus-Junior agent via agents["Sisyphus-Junior"]
in oh-my-opencode.json, removing hardcoded defaults while preserving safety
constraints.
Closes #623
Changes:
- Add "Sisyphus-Junior" to AgentOverridesSchema and OverridableAgentNameSchema
- Create createSisyphusJuniorAgentWithOverrides() helper with guardrails
- Update config-handler to use override helper instead of hardcoded values
- Fix README category wording (runtime presets, not separate agents)
Honored override fields:
- model, temperature, top_p, tools, permission, description, color, prompt_append
Safety guardrails enforced post-merge:
- mode forced to "subagent" (cannot change)
- prompt is append-only (base discipline text preserved)
- blocked tools (task, sisyphus_task, call_omo_agent) always denied
- disable: true ignores override block, uses defaults
Category interaction:
- sisyphus_task(category=...) runs use the base Sisyphus-Junior agent config
- Category model/temperature overrides take precedence at request time
- To change model for a category, set categories.<cat>.model (not agent override)
- Categories are runtime presets applied to Sisyphus-Junior, not separate agents
Tests: 15 new tests in sisyphus-junior.test.ts, 3 new schema tests

Co-Authored-By: Sisyphus <sisyphus@mengmota.com>

* test(sisyphus-junior): add guard assertion for prompt anchor text

Add validation that baseEndIndex is not -1 before using it for ordering
assertion. Previously, if "Dense > verbose." text changed in the base
prompt, indexOf would return -1 and any positive appendIndex would pass.

Co-Authored-By: Sisyphus <sisyphus@mengmota.com>

---------

Co-authored-by: Sisyphus <sisyphus@mengmota.com>

README.md

@@ -1058,7 +1058,7 @@ Configure concurrency limits for background agent tasks. This controls how many
 
 ### Categories
 
-Categories enable domain-specific task delegation via the `sisyphus_task` tool. Each category pre-configures a specialized `Sisyphus-Junior-{category}` agent with optimized model settings and prompts.
+Categories enable domain-specific task delegation via the `sisyphus_task` tool. Each category applies runtime presets (model, temperature, prompt additions) when calling the `Sisyphus-Junior` agent.
 
 **Default Categories:**
 

assets/oh-my-opencode.schema.json

@@ -465,6 +465,129 @@
             }
           }
         },
+        "Sisyphus-Junior": {
+          "type": "object",
+          "properties": {
+            "model": {
+              "type": "string"
+            },
+            "category": {
+              "type": "string"
+            },
+            "skills": {
+              "type": "array",
+              "items": {
+                "type": "string"
+              }
+            },
+            "temperature": {
+              "type": "number",
+              "minimum": 0,
+              "maximum": 2
+            },
+            "top_p": {
+              "type": "number",
+              "minimum": 0,
+              "maximum": 1
+            },
+            "prompt": {
+              "type": "string"
+            },
+            "prompt_append": {
+              "type": "string"
+            },
+            "tools": {
+              "type": "object",
+              "propertyNames": {
+                "type": "string"
+              },
+              "additionalProperties": {
+                "type": "boolean"
+              }
+            },
+            "disable": {
+              "type": "boolean"
+            },
+            "description": {
+              "type": "string"
+            },
+            "mode": {
+              "type": "string",
+              "enum": [
+                "subagent",
+                "primary",
+                "all"
+              ]
+            },
+            "color": {
+              "type": "string",
+              "pattern": "^#[0-9A-Fa-f]{6}$"
+            },
+            "permission": {
+              "type": "object",
+              "properties": {
+                "edit": {
+                  "type": "string",
+                  "enum": [
+                    "ask",
+                    "allow",
+                    "deny"
+                  ]
+                },
+                "bash": {
+                  "anyOf": [
+                    {
+                      "type": "string",
+                      "enum": [
+                        "ask",
+                        "allow",
+                        "deny"
+                      ]
+                    },
+                    {
+                      "type": "object",
+                      "propertyNames": {
+                        "type": "string"
+                      },
+                      "additionalProperties": {
+                        "type": "string",
+                        "enum": [
+                          "ask",
+                          "allow",
+                          "deny"
+                        ]
+                      }
+                    }
+                  ]
+                },
+                "webfetch": {
+                  "type": "string",
+                  "enum": [
+                    "ask",
+                    "allow",
+                    "deny"
+                  ]
+                },
+                "doom_loop": {
+                  "type": "string",
+                  "enum": [
+                    "ask",
+                    "allow",
+                    "deny"
+                  ]
+                },
+                "external_directory": {
+                  "type": "string",
+                  "enum": [
+                    "ask",
+                    "allow",
+                    "deny"
+                  ]
+                }
+              }
+            }
+          }
+        },
         "OpenCode-Builder": {
           "type": "object",
           "properties": {

src/agents/sisyphus-junior.test.ts

@@ -0,0 +1,230 @@
+import { describe, expect, test } from "bun:test"
+import { createSisyphusJuniorAgentWithOverrides, SISYPHUS_JUNIOR_DEFAULTS } from "./sisyphus-junior"
+
+describe("createSisyphusJuniorAgentWithOverrides", () => {
+  describe("honored fields", () => {
+    test("applies model override", () => {
+      // #given
+      const override = { model: "openai/gpt-5.2" }
+
+      // #when
+      const result = createSisyphusJuniorAgentWithOverrides(override)
+
+      // #then
+      expect(result.model).toBe("openai/gpt-5.2")
+    })
+
+    test("applies temperature override", () => {
+      // #given
+      const override = { temperature: 0.5 }
+
+      // #when
+      const result = createSisyphusJuniorAgentWithOverrides(override)
+
+      // #then
+      expect(result.temperature).toBe(0.5)
+    })
+
+    test("applies top_p override", () => {
+      // #given
+      const override = { top_p: 0.9 }
+
+      // #when
+      const result = createSisyphusJuniorAgentWithOverrides(override)
+
+      // #then
+      expect(result.top_p).toBe(0.9)
+    })
+
+    test("applies description override", () => {
+      // #given
+      const override = { description: "Custom description" }
+
+      // #when
+      const result = createSisyphusJuniorAgentWithOverrides(override)
+
+      // #then
+      expect(result.description).toBe("Custom description")
+    })
+
+    test("applies color override", () => {
+      // #given
+      const override = { color: "#FF0000" }
+
+      // #when
+      const result = createSisyphusJuniorAgentWithOverrides(override)
+
+      // #then
+      expect(result.color).toBe("#FF0000")
+    })
+
+    test("appends prompt_append to base prompt", () => {
+      // #given
+      const override = { prompt_append: "Extra instructions here" }
+
+      // #when
+      const result = createSisyphusJuniorAgentWithOverrides(override)
+
+      // #then
+      expect(result.prompt).toContain("You work ALONE")
+      expect(result.prompt).toContain("Extra instructions here")
+    })
+  })
+
+  describe("defaults", () => {
+    test("uses default model when no override", () => {
+      // #given
+      const override = {}
+
+      // #when
+      const result = createSisyphusJuniorAgentWithOverrides(override)
+
+      // #then
+      expect(result.model).toBe(SISYPHUS_JUNIOR_DEFAULTS.model)
+    })
+
+    test("uses default temperature when no override", () => {
+      // #given
+      const override = {}
+
+      // #when
+      const result = createSisyphusJuniorAgentWithOverrides(override)
+
+      // #then
+      expect(result.temperature).toBe(SISYPHUS_JUNIOR_DEFAULTS.temperature)
+    })
+  })
+
+  describe("disable semantics", () => {
+    test("disable: true causes override block to be ignored", () => {
+      // #given
+      const override = {
+        disable: true,
+        model: "openai/gpt-5.2",
+        temperature: 0.9,
+      }
+
+      // #when
+      const result = createSisyphusJuniorAgentWithOverrides(override)
+
+      // #then - defaults should be used, not the overrides
+      expect(result.model).toBe(SISYPHUS_JUNIOR_DEFAULTS.model)
+      expect(result.temperature).toBe(SISYPHUS_JUNIOR_DEFAULTS.temperature)
+    })
+  })
+
+  describe("constrained fields", () => {
+    test("mode is forced to subagent", () => {
+      // #given
+      const override = { mode: "primary" as const }
+
+      // #when
+      const result = createSisyphusJuniorAgentWithOverrides(override)
+
+      // #then
+      expect(result.mode).toBe("subagent")
+    })
+
+    test("prompt override is ignored (discipline text preserved)", () => {
+      // #given
+      const override = { prompt: "Completely new prompt that replaces everything" }
+
+      // #when
+      const result = createSisyphusJuniorAgentWithOverrides(override)
+
+      // #then
+      expect(result.prompt).toContain("You work ALONE")
+      expect(result.prompt).not.toBe("Completely new prompt that replaces everything")
+    })
+  })
+
+  describe("tool safety (blocked tools enforcement)", () => {
+    test("blocked tools remain blocked even if override tries to enable them via tools format", () => {
+      // #given
+      const override = {
+        tools: {
+          task: true,
+          sisyphus_task: true,
+          call_omo_agent: true,
+          read: true,
+        },
+      }
+
+      // #when
+      const result = createSisyphusJuniorAgentWithOverrides(override)
+
+      // #then
+      const tools = result.tools as Record<string, boolean> | undefined
+      const permission = result.permission as Record<string, string> | undefined
+      if (tools) {
+        expect(tools.task).toBe(false)
+        expect(tools.sisyphus_task).toBe(false)
+        expect(tools.call_omo_agent).toBe(false)
+        expect(tools.read).toBe(true)
+      }
+      if (permission) {
+        expect(permission.task).toBe("deny")
+        expect(permission.sisyphus_task).toBe("deny")
+        expect(permission.call_omo_agent).toBe("deny")
+      }
+    })
+
+    test("blocked tools remain blocked when using permission format override", () => {
+      // #given
+      const override = {
+        permission: {
+          task: "allow",
+          sisyphus_task: "allow",
+          call_omo_agent: "allow",
+          read: "allow",
+        },
+      } as { permission: Record<string, string> }
+
+      // #when
+      const result = createSisyphusJuniorAgentWithOverrides(override as Parameters<typeof createSisyphusJuniorAgentWithOverrides>[0])
+
+      // #then - blocked tools should be denied regardless
+      const tools = result.tools as Record<string, boolean> | undefined
+      const permission = result.permission as Record<string, string> | undefined
+      if (tools) {
+        expect(tools.task).toBe(false)
+        expect(tools.sisyphus_task).toBe(false)
+        expect(tools.call_omo_agent).toBe(false)
+      }
+      if (permission) {
+        expect(permission.task).toBe("deny")
+        expect(permission.sisyphus_task).toBe("deny")
+        expect(permission.call_omo_agent).toBe("deny")
+      }
+    })
+  })
+
+  describe("prompt composition", () => {
+    test("base prompt contains discipline constraints", () => {
+      // #given
+      const override = {}
+
+      // #when
+      const result = createSisyphusJuniorAgentWithOverrides(override)
+
+      // #then
+      expect(result.prompt).toContain("Sisyphus-Junior")
+      expect(result.prompt).toContain("You work ALONE")
+      expect(result.prompt).toContain("BLOCKED ACTIONS")
+    })
+
+    test("prompt_append is added after base prompt", () => {
+      // #given
+      const override = { prompt_append: "CUSTOM_MARKER_FOR_TEST" }
+
+      // #when
+      const result = createSisyphusJuniorAgentWithOverrides(override)
+
+      // #then
+      const baseEndIndex = result.prompt!.indexOf("Dense > verbose.")
+      const appendIndex = result.prompt!.indexOf("CUSTOM_MARKER_FOR_TEST")
+      expect(baseEndIndex).not.toBe(-1) // Guard: anchor text must exist in base prompt
+      expect(appendIndex).toBeGreaterThan(baseEndIndex)
+    })
+  })
+})

src/agents/sisyphus-junior.ts

@@ -1,9 +1,10 @@
 import type { AgentConfig } from "@opencode-ai/sdk"
 import { isGptModel } from "./types"
-import type { CategoryConfig } from "../config/schema"
+import type { AgentOverrideConfig, CategoryConfig } from "../config/schema"
 import {
   createAgentToolRestrictions,
   migrateAgentConfig,
+  supportsNewPermissionSystem,
 } from "../shared/permission-compat"
 
 const SISYPHUS_JUNIOR_PROMPT = `<Role>
@@ -77,6 +78,71 @@ function buildSisyphusJuniorPrompt(promptAppend?: string): string {
 // Core tools that Sisyphus-Junior must NEVER have access to
 const BLOCKED_TOOLS = ["task", "sisyphus_task", "call_omo_agent"]
 
+export const SISYPHUS_JUNIOR_DEFAULTS = {
+  model: "anthropic/claude-sonnet-4-5",
+  temperature: 0.1,
+} as const
+
+export function createSisyphusJuniorAgentWithOverrides(
+  override: AgentOverrideConfig | undefined
+): AgentConfig {
+  if (override?.disable) {
+    override = undefined
+  }
+
+  const model = override?.model ?? SISYPHUS_JUNIOR_DEFAULTS.model
+  const temperature = override?.temperature ?? SISYPHUS_JUNIOR_DEFAULTS.temperature
+
+  const promptAppend = override?.prompt_append
+  const prompt = buildSisyphusJuniorPrompt(promptAppend)
+
+  const baseRestrictions = createAgentToolRestrictions(BLOCKED_TOOLS)
+
+  let toolsConfig: Record<string, unknown> = {}
+  if (supportsNewPermissionSystem()) {
+    const userPermission = (override?.permission ?? {}) as Record<string, string>
+    const basePermission = (baseRestrictions as { permission: Record<string, string> }).permission
+    const merged: Record<string, string> = { ...userPermission }
+    for (const tool of BLOCKED_TOOLS) {
+      merged[tool] = "deny"
+    }
+    toolsConfig = { permission: { ...merged, ...basePermission } }
+  } else {
+    const userTools = override?.tools ?? {}
+    const baseTools = (baseRestrictions as { tools: Record<string, boolean> }).tools
+    const merged: Record<string, boolean> = { ...userTools }
+    for (const tool of BLOCKED_TOOLS) {
+      merged[tool] = false
+    }
+    toolsConfig = { tools: { ...merged, ...baseTools } }
+  }
+
+  const base: AgentConfig = {
+    description: override?.description ??
+      "Sisyphus-Junior - Focused task executor. Same discipline, no delegation.",
+    mode: "subagent" as const,
+    model,
+    temperature,
+    maxTokens: 64000,
+    prompt,
+    color: override?.color ?? "#20B2AA",
+    ...toolsConfig,
+  }
+
+  if (override?.top_p !== undefined) {
+    base.top_p = override.top_p
+  }
+
+  if (isGptModel(model)) {
+    return { ...base, reasoningEffort: "medium" } as AgentConfig
+  }
+
+  return {
+    ...base,
+    thinking: { type: "enabled", budgetTokens: 32000 },
+  } as AgentConfig
+}
+
 export function createSisyphusJuniorAgent(
   categoryConfig: CategoryConfig,
   promptAppend?: string

src/config/schema.test.ts

@@ -315,3 +315,76 @@ describe("BuiltinCategoryNameSchema", () => {
     }
   })
 })
+
+describe("Sisyphus-Junior agent override", () => {
+  test("schema accepts agents['Sisyphus-Junior'] and retains the key after parsing", () => {
+    // #given
+    const config = {
+      agents: {
+        "Sisyphus-Junior": {
+          model: "openai/gpt-5.2",
+          temperature: 0.2,
+        },
+      },
+    }
+
+    // #when
+    const result = OhMyOpenCodeConfigSchema.safeParse(config)
+
+    // #then
+    expect(result.success).toBe(true)
+    if (result.success) {
+      expect(result.data.agents?.["Sisyphus-Junior"]).toBeDefined()
+      expect(result.data.agents?.["Sisyphus-Junior"]?.model).toBe("openai/gpt-5.2")
+      expect(result.data.agents?.["Sisyphus-Junior"]?.temperature).toBe(0.2)
+    }
+  })
+
+  test("schema accepts Sisyphus-Junior with prompt_append", () => {
+    // #given
+    const config = {
+      agents: {
+        "Sisyphus-Junior": {
+          prompt_append: "Additional instructions for Sisyphus-Junior",
+        },
+      },
+    }
+
+    // #when
+    const result = OhMyOpenCodeConfigSchema.safeParse(config)
+
+    // #then
+    expect(result.success).toBe(true)
+    if (result.success) {
+      expect(result.data.agents?.["Sisyphus-Junior"]?.prompt_append).toBe(
+        "Additional instructions for Sisyphus-Junior"
+      )
+    }
+  })
+
+  test("schema accepts Sisyphus-Junior with tools override", () => {
+    // #given
+    const config = {
+      agents: {
+        "Sisyphus-Junior": {
+          tools: {
+            read: true,
+            write: false,
+          },
+        },
+      },
+    }
+
+    // #when
+    const result = OhMyOpenCodeConfigSchema.safeParse(config)
+
+    // #then
+    expect(result.success).toBe(true)
+    if (result.success) {
+      expect(result.data.agents?.["Sisyphus-Junior"]?.tools).toEqual({
+        read: true,
+        write: false,
+      })
+    }
+  })
+})

src/config/schema.ts

@@ -39,6 +39,7 @@ export const OverridableAgentNameSchema = z.enum([
   "build",
   "plan",
   "Sisyphus",
+  "Sisyphus-Junior",
   "OpenCode-Builder",
   "Prometheus (Planner)",
   "Metis (Plan Consultant)",
@@ -119,6 +120,7 @@ export const AgentOverridesSchema = z.object({
   build: AgentOverrideConfigSchema.optional(),
   plan: AgentOverrideConfigSchema.optional(),
   Sisyphus: AgentOverrideConfigSchema.optional(),
+  "Sisyphus-Junior": AgentOverrideConfigSchema.optional(),
   "OpenCode-Builder": AgentOverrideConfigSchema.optional(),
   "Prometheus (Planner)": AgentOverrideConfigSchema.optional(),
   "Metis (Plan Consultant)": AgentOverrideConfigSchema.optional(),

src/plugin-handlers/config-handler.ts

@@ -1,5 +1,5 @@
 import { createBuiltinAgents } from "../agents";
-import { createSisyphusJuniorAgent } from "../agents/sisyphus-junior";
+import { createSisyphusJuniorAgentWithOverrides } from "../agents/sisyphus-junior";
 import {
   loadUserCommands,
   loadProjectCommands,
@@ -152,10 +152,9 @@ export function createConfigHandler(deps: ConfigHandlerDeps) {
         Sisyphus: builtinAgents.Sisyphus,
       };
 
-      agentConfig["Sisyphus-Junior"] = createSisyphusJuniorAgent({
-        model: "anthropic/claude-sonnet-4-5",
-        temperature: 0.1,
-      });
+      agentConfig["Sisyphus-Junior"] = createSisyphusJuniorAgentWithOverrides(
+        pluginConfig.agents?.["Sisyphus-Junior"]
+      );
 
       if (builderEnabled) {
         const { name: _buildName, ...buildConfigWithoutName } =

src/shared/permission-compat.ts

@@ -1,5 +1,7 @@
 import { supportsNewPermissionSystem } from "./opencode-version"
 
+export { supportsNewPermissionSystem }
+
 export type PermissionValue = "ask" | "allow" | "deny"
 
 export interface LegacyToolsFormat {