refactor(core): remove core.lua and adopt services as shared primitives

lua/opencode/commands/handlers/AGENTS.md

@@ -1,27 +1,49 @@
 # AGENTS.md (handlers)
 
-This directory owns domain actions and command definitions.
+This directory owns command-facing action adapters and command definitions.
+
+One-line positioning:
+- `handlers/` = **command-entry adapters**
+- `services/` = **cross-entry reusable business primitives**
 
 ## Scope
 
-- `M.actions`: domain operations
+- `M.actions`: command-facing action adapters
 - `M.command_defs`: command-facing definitions (desc/completions/execute)
 - No command pipeline logic here
 
+## Relation with services
+
+- Handlers should call `services/*` when logic is shared by command/UI/quick_chat entries.
+- Handlers should not become the only place for reusable business logic.
+- If an action is needed outside command entry paths, move/keep it in `services/`.
+
 ## Hard Invariants
 
 - Handlers do not call `dispatch.execute` directly
 - Handlers do not parse command text
 - Handlers do not decide hook routing
 - Keep action behavior identical across entry points
 - Handlers must not introduce any new bind/execute entry symbols (`*.run`, `bind_*`, or dispatch wrappers)
+- Prefer `services/*` over direct new `opencode.session` / `opencode.api` requires in handlers
 
 ## Structure Guidance
 
 - Keep `actions` and `command_defs` aligned by domain
 - Keep keymap compatibility aliases explicit and grouped
 - Avoid duplicating command validation already guaranteed by parse schema
 
+## Current boundary debt (file-level TODO)
+
+The following handler files still directly require `opencode.session` and should be routed via services APIs.
+
+- [ ] `lua/opencode/commands/handlers/diff.lua` -> `opencode.session`
+- [ ] `lua/opencode/commands/handlers/session.lua` -> `opencode.session`
+
+Sync rule:
+- keep this list aligned with `lua/opencode/services/AGENTS.md`
+- remove an item only after code + tests pass
+
 ## Editing Rules
 
 - Prefer consolidation over introducing new layers
@@ -46,12 +68,14 @@ This directory owns domain actions and command definitions.
 - Is `command_defs` declarative and minimal?
 - Are aliases grouped and obvious?
 - Did we avoid reintroducing duplicate argument validation paths?
+- Did we add any new direct `session/api` requires in handlers?
 
 ## Reject Conditions
 
 - Any direct call to `dispatch.execute` from handlers
 - Any parse/hook routing logic added to handlers
 - Any new entry-style wrapper added in handlers
+- Any new direct `require('opencode.session')` or `require('opencode.api')` in handlers without exception note
 
 ## Minimal Regression Commands
 
@@ -63,6 +87,6 @@ This directory owns domain actions and command definitions.
 ## Entry Notes For New Agents
 
 - Start from the domain file you are touching (`window/session/diff/workflow/surface/agent/permission`), then verify invariants against `commands/dispatch.lua`.
-- Treat handlers as **domain behavior + command definition only**.
+- Treat handlers as **command adaptation + command definition only**.
 - If you feel the need to touch parse/dispatch from handlers, stop and move that change to the command infrastructure layer.
 - Keep compatibility aliases explicit, local, and justified inline.

lua/opencode/commands/handlers/agent.lua

@@ -1,9 +1,9 @@
-local core = require('opencode.core')
 local config_file = require('opencode.config_file')
 ---@type OpencodeState
 local state = require('opencode.state')
 local util = require('opencode.util')
 local Promise = require('opencode.promise')
+local agent_model = require('opencode.services.agent_model')
 
 local M = {
   actions = {},
@@ -18,23 +18,23 @@ local function invalid_arguments(message)
 end
 
 function M.actions.configure_provider()
-  core.configure_provider()
+  agent_model.configure_provider()
 end
 
 function M.actions.configure_variant()
-  core.configure_variant()
+  agent_model.configure_variant()
 end
 
 function M.actions.cycle_variant()
-  core.cycle_variant()
+  agent_model.cycle_variant()
 end
 
 function M.actions.agent_plan()
-  core.switch_to_mode('plan')
+  agent_model.switch_to_mode('plan')
 end
 
 function M.actions.agent_build()
-  core.switch_to_mode('build')
+  agent_model.switch_to_mode('build')
 end
 
 M.actions.select_agent = Promise.async(function()
@@ -47,7 +47,7 @@ M.actions.select_agent = Promise.async(function()
       return
     end
 
-    core.switch_to_mode(selection)
+    agent_model.switch_to_mode(selection)
   end)
 end)
 
@@ -60,11 +60,11 @@ M.actions.switch_mode = Promise.async(function()
   end
 
   local next_index = (current_index % #modes) + 1
-  core.switch_to_mode(modes[next_index])
+  agent_model.switch_to_mode(modes[next_index])
 end)
 
 M.actions.current_model = Promise.async(function()
-  return core.initialize_current_model()
+  return agent_model.initialize_current_model()
 end)
 
 local agent_subcommands = { 'plan', 'build', 'select' }

lua/opencode/commands/handlers/diff.lua

@@ -1,8 +1,8 @@
-local core = require('opencode.core')
 local git_review = require('opencode.git_review')
 local session_store = require('opencode.session')
 ---@type OpencodeState
 local state = require('opencode.state')
+local session_runtime = require('opencode.services.session_runtime')
 
 local M = {
   actions = {},
@@ -11,7 +11,7 @@ local M = {
 local diff_subcommands = { 'open', 'next', 'prev', 'close' }
 
 local function with_output_open(callback, open_if_closed)
-  local open_fn = open_if_closed and core.open_if_closed or core.open
+  local open_fn = open_if_closed and session_runtime.open_if_closed or session_runtime.open
   return function(...)
     local args = { ... }
     open_fn({ new_session = false, focus = 'output' }):and_then(function()

lua/opencode/commands/handlers/session.lua

@@ -1,9 +1,10 @@
-local core = require('opencode.core')
 ---@type OpencodeState
 local state = require('opencode.state')
 local session_store = require('opencode.session')
 local Promise = require('opencode.promise')
 local window_actions = require('opencode.commands.handlers.window').actions
+local session_runtime = require('opencode.services.session_runtime')
+local agent_model = require('opencode.services.agent_model')
 
 local M = {
   actions = {},
@@ -77,13 +78,13 @@ local function run_api_action_with_checktime(request_promise, error_prefix)
 end
 
 function M.actions.open_input_new_session()
-  return core.open({ new_session = true, focus = 'input', start_insert = true })
+  return session_runtime.open({ new_session = true, focus = 'input', start_insert = true })
 end
 
 ---@param title string
 function M.actions.open_input_new_session_with_title(title)
   return Promise.async(function(session_title)
-    local new_session = core.create_new_session(session_title):await()
+    local new_session = session_runtime.create_new_session(session_title):await()
     if not new_session then
       vim.notify('Failed to create new session', vim.log.levels.ERROR)
       return
@@ -96,12 +97,12 @@ end
 
 ---@param parent_id? string
 function M.actions.select_session(parent_id)
-  core.select_session(parent_id)
+  session_runtime.select_session(parent_id)
 end
 
 function M.actions.select_child_session()
   local active = state.active_session
-  core.select_session(active and active.id or nil)
+  session_runtime.select_session(active and active.id or nil)
 end
 
 ---@param current_session? Session
@@ -162,15 +163,14 @@ function M.actions.initialize()
   return Promise.async(function()
     local id = require('opencode.id')
     local state_obj = state
-    local core_obj = core
 
-    local new_session = core_obj.create_new_session('AGENTS.md Initialization'):await()
+    local new_session = session_runtime.create_new_session('AGENTS.md Initialization'):await()
     if not new_session then
       vim.notify('Failed to create new session', vim.log.levels.ERROR)
       return
     end
 
-    if not core_obj.initialize_current_model():await() or not state_obj.current_model then
+    if not agent_model.initialize_current_model():await() or not state_obj.current_model then
       vim.notify('No model selected', vim.log.levels.ERROR)
       return
     end
@@ -369,7 +369,7 @@ function M.actions.fork_session(message_id)
         vim.schedule(function()
           if response and response.id then
             vim.notify('Session forked successfully. New session ID: ' .. response.id, vim.log.levels.INFO)
-            core.switch_session(response.id)
+            session_runtime.switch_session(response.id)
           else
             vim.notify('Session forked but no new session ID received', vim.log.levels.WARN)
           end

lua/opencode/commands/handlers/window.lua

@@ -1,10 +1,10 @@
-local core = require('opencode.core')
 ---@type OpencodeState
 local state = require('opencode.state')
 local ui = require('opencode.ui.ui')
 local config = require('opencode.config')
 local Promise = require('opencode.promise')
 local input_window = require('opencode.ui.input_window')
+local session_runtime = require('opencode.services.session_runtime')
 
 local M = {
   actions = {},
@@ -19,11 +19,11 @@ local function invalid_arguments(message)
 end
 
 function M.actions.open_input()
-  return core.open({ new_session = false, focus = 'input', start_insert = true })
+  return session_runtime.open({ new_session = false, focus = 'input', start_insert = true })
 end
 
 function M.actions.open_output()
-  return core.open({ new_session = false, focus = 'output' })
+  return session_runtime.open({ new_session = false, focus = 'output' })
 end
 
 function M.actions.close()
@@ -47,7 +47,7 @@ function M.actions.get_window_state()
 end
 
 function M.actions.cancel()
-  core.cancel()
+  session_runtime.cancel()
 end
 
 ---@param hidden OpencodeHiddenBuffers|nil
@@ -90,8 +90,8 @@ M.actions.toggle = Promise.async(function(new_session)
 
   local function open_windows(restore_hidden)
     local ctx = build_toggle_open_context(restore_hidden == true)
-    return core
-      .open({
+      return session_runtime
+        .open({
         new_session = is_new_session,
         focus = ctx.focus,
         start_insert = false,
@@ -132,7 +132,7 @@ end)
 function M.actions.toggle_focus(new_session)
   if not ui.is_opencode_focused() then
     local focus = state.last_focused_opencode_window or 'input' ---@cast focus 'input' | 'output'
-    core.open({ new_session = new_session == true, focus = focus })
+      session_runtime.open({ new_session = new_session == true, focus = focus })
   else
     ui.return_to_last_code_win()
   end

lua/opencode/commands/handlers/workflow.lua

@@ -1,4 +1,3 @@
-local core = require('opencode.core')
 local util = require('opencode.util')
 local config_file = require('opencode.config_file')
 ---@type OpencodeState
@@ -11,6 +10,7 @@ local Promise = require('opencode.promise')
 local input_window = require('opencode.ui.input_window')
 local ui = require('opencode.ui.ui')
 local nvim = vim['api']
+local session_runtime = require('opencode.services.session_runtime')
 
 local M = {
   actions = {},
@@ -49,8 +49,8 @@ end
 ---@param prompt string
 ---@param opts SendMessageOpts
 local function run_with_opts(prompt, opts)
-  return core.open(opts):and_then(function()
-    return core.send_message(prompt, opts)
+  return session_runtime.open(opts):and_then(function()
+    return require('opencode.services.messaging').send_message(prompt, opts)
   end)
 end
 
@@ -189,7 +189,7 @@ for _, action_name in ipairs({ 'debug_output', 'debug_message', 'debug_session'
 end
 
 function M.actions.paste_image()
-  core.paste_image_from_clipboard()
+  session_runtime.paste_image_from_clipboard()
 end
 
 M.actions.submit_input_prompt = Promise.async(function()
@@ -301,12 +301,12 @@ function M.actions.toggle_max_messages()
 end
 
 M.actions.review = Promise.async(function(args)
-  local new_session = core.create_new_session('Code review checklist for diffs and PRs'):await()
+  local new_session = session_runtime.create_new_session('Code review checklist for diffs and PRs'):await()
   if not new_session then
     vim.notify('Failed to create new session', vim.log.levels.ERROR)
     return
   end
-  if not core.initialize_current_model():await() or not state.current_model then
+  if not require('opencode.services.agent_model').initialize_current_model():await() or not state.current_model then
     vim.notify('No model selected', vim.log.levels.ERROR)
     return
   end