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Author SHA1 Message Date
patriceckhart
99c9ba8062 feat(ext): phase 4 - full-event interception, arg rewrites, /reload-ext
Clears every deferred extension todo in one push:

1) Interception expands to three events: tool_call (already shipped),
   turn_start (gate the turn before the model call, e.g. rate-limit /
   business-hour), and assistant_message (suppress or rewrite the
   user-visible text while keeping the model's original output in
   the transcript).

2) Tool-call args can now be rewritten mid-flight. An interceptor
   returning modified_args replaces the JSON the tool actually
   receives, without the model seeing the rewrite. Chains: each
   subscriber sees the previous one's output, letting guards
   successively redact / patch / augment. Invalid JSON is dropped
   safely.

3) /reload-ext hot-reloads every extension without restarting zot.
   The manager gracefully shuts down all running subprocesses,
   re-reads extension.json from disk, respawns (including --ext
   paths remembered from startup), and the host rebuilds the agent's
   tool registry in-place so freshly-registered tools are callable
   immediately.

Wire-format changes (extproto):
- EventInterceptResponseFromExt gains modified_args and replace_text
  fields (both optional, ignored when block=true).
- EventInterceptFromHost gains Step (for turn_start) and Text (for
  assistant_message) alongside the existing tool_call payload.

Core agent changes:
- BeforeToolExecute signature now returns (allowed, reason,
  modifiedArgs json.RawMessage). Non-nil+valid JSON args replace
  tc.Arguments before Tool.Execute runs.
- New BeforeTurn hook, invoked in runLoop before oneTurn. Blocking
  cancels the turn with an EvTurnEnd{StopError} carrying the reason.
- New BeforeAssistantMessage hook, invoked after finalMsg is
  assembled but before the EvAssistantMessage emit. Supports
  suppress (block=true) and text rewrite (replace_text). Transcript
  always gets the original; UI gets the rewritten text.
- New SetTools(reg) so /reload-ext can swap the registry on the
  live agent under the agent mutex.

Manager changes:
- InterceptToolCall now returns InterceptResult (Block, Reason,
  ModifiedArgs, ReplaceText), with a chain that folds rewrites.
- New InterceptTurnStart and InterceptAssistantMessage.
- New Reload(ctx, grace) tears down and respawns everything,
  returning ReloadStats{Stopped, Loaded, Ready, Errors}.
- New SetOnReload(fn) callback the host uses to rebuild the agent
  tool registry after a reload.
- LoadExplicit remembers --ext paths so Reload respawns them.
- subscribe accepts "tool_call", "turn_start", "assistant_message"
  under "intercept".

SDK (pkg/zotext):
- New handler types: ToolCallHandler, TurnStartHandler,
  AssistantMessageHandler, and their decision structs
  (ToolCallDecision with ModifiedArgs, AssistantMessageDecision
  with ReplaceText).
- New registration methods: InterceptToolCallX (rich variant of
  the existing InterceptToolCall), InterceptTurnStart,
  InterceptAssistantMessage.
- dispatchIntercept routes per-event with panic recovery and
  always emits exactly one event_intercept_response.

TUI:
- /reload-ext slash command registered in slashCatalog and
  runSlash. Added to slashCancelsTurn so it waits for idle like
  /compact does.
- runReloadExt shows a "reloading extensions..." status, runs the
  Manager.Reload on a goroutine, and reports the resulting stats.

Tests:
- internal/core/intercept_test.go: verifies args are actually
  rewritten on the way to Tool.Execute, malformed JSON is ignored,
  and block surfaces the reason as an error ToolResult.
- internal/agent/extensions/intercept_test.go: end-to-end with a
  bash extension subprocess that blocks rm -rf, rewrites other bash
  args to "echo GUARDED:", passes through read calls, allows
  turn_start, and redacts SECRET in assistant messages. Second test
  verifies Reload respawns the subprocess, re-registers its command,
  and fires the onReload callback.

Docs:
- docs/extensions.md: rewrote the intercept section to cover all
  three events, added a table of event_intercept_response fields,
  documented the /reload-ext hot-reload command, expanded the SDK
  section with examples of every handler, moved the old "future"
  items into a shipped Phase 4.
- README.md: extensions summary mentions intercept beyond tool_call,
  /reload-ext added to the slash-commands table and to the
  turn-cancel list in "Queued messages".
2026-04-19 17:02:04 +02:00
patriceckhart
83ae236571 feat(extensions): phase 3 — event subscriptions + tool-call interception
Two new capabilities, both ride on the existing subprocess
protocol with a couple of new frame types.

Event subscriptions (one-way notifications):

  ext  -> host: subscribe {events: [...], intercept: [...]}
  host -> ext:  event {event, ...payload}

  Recognised events: session_start, turn_start, turn_end,
  tool_call, assistant_message. Subscribers get fire-and-forget
  notifications on each. Useful for telemetry, audit logs, custom
  state widgets that follow live agent activity.

Tool-call interception (round-trip, can refuse):

  host -> ext:  event_intercept {id, event:"tool_call", tool_name, tool_args}
  ext  -> host: event_intercept_response {id, block?, reason?}

  When at least one extension subscribed to "tool_call" intercept,
  zot asks each one in turn before running every tool call. First
  blocker wins; reason becomes the tool-result error text the model
  sees. Per-extension 5s timeout treats unresponsive interceptors
  as "allow" so a wedged extension never stalls the agent.

Wire format additions (internal/extproto):
  ext -> host: SubscribeFromExt, EventInterceptResponseFromExt
  host -> ext: EventFromHost, EventInterceptFromHost

Manager (internal/agent/extensions):
  - per-extension eventSubs / interceptSubs sets, populated by the
    subscribe frame
  - EmitEvent fans out to every subscribed extension on its own
    goroutine (won't block the agent on slow stdin writes)
  - InterceptToolCall walks subscribers serially, returning the
    first refusal; 5s timeout per subscriber (allow on timeout)
  - readLoop handles event_intercept_response correlations the
    same way it handles command/tool responses

Core (internal/core/agent.go):
  - Agent.BeforeToolExecute hook called from runOneTool right
    before tool.Execute. Returning (allowed=false, reason)
    short-circuits with an IsError tool result containing reason.
  - Agent.OnEvent observer fires for every emitted AgentEvent;
    composed transparently with the per-Prompt sink via wrapSink
    so neither the existing TUI nor the rpc loop need changes.

Wiring (internal/agent/cli.go, rpc.go):
  - wireAgentExt sets BeforeToolExecute -> InterceptToolCall and
    OnEvent -> fanoutAgentEvent for every freshly-built agent
    (initial, login rebuild, model swap)
  - fanoutAgentEvent translates core AgentEvent kinds into
    extproto.EventFromHost. Internal-only events (text_delta,
    tool_progress) are dropped to keep the per-extension stream
    sane.
  - session_start emitted once after extensions come up

SDK (pkg/zotext):
  - On(name, EventHandler) registers per-event observers
  - InterceptToolCall(InterceptHandler) registers a single
    intercept callback
  - Run() now also sends a subscribe frame before the ready
    sentinel, with the union of subscribed events + intercept
  - Frame loop handles "event" and "event_intercept" frames,
    runs the handlers (intercepts on a goroutine to avoid
    head-of-line blocking)
  - Capabilities advertised: commands + tools + events

Example (examples/extensions/guard):
  - subscribes to session_start / turn_start / tool_call / turn_end
    and writes one-line audit entries
  - intercepts every bash call; refuses commands matching
    rm -rf, sudo, dd of=/, mkfs, the fork bomb, chmod -R 777
  - end-to-end verified live: agent -> bash("rm -rf /tmp/foo")
    -> guard refuses -> model sees the refusal text and surfaces
    it in its reply ("the guard blocked it, as expected — the
    pattern \brm\s+-rf\b matched")

Docs/extensions.md updated with all five new frame types and the
guard example.
2026-04-19 14:57:03 +02:00
patriceckhart
74709a0bd9 feat(extensions): phase 2 — extension-defined tools
Extensions can now register tools the LLM calls directly. The model
sees them in its tool list alongside the built-ins (read, write,
edit, bash, skill); when it invokes one, zot routes the tool_call
to the owning extension subprocess and feeds the tool_result back.

Wire format additions (internal/extproto):
  ext -> host:
    register_tool {name, description, schema}
    ready                                       # all initial regs flushed
    tool_result {id, content[], is_error}       # reply to a tool_call
  host -> ext:
    tool_call {id, name, args}                  # raw json args from the model

Manager (internal/agent/extensions):
  - tracks per-extension RegisterToolFromExt frames
  - validates schemas parse as JSON before registering (bad schema
    skipped + logged, doesn't crash zot)
  - toolIndex map for O(1) lookup
  - WaitForReady(grace): blocks per extension on its readyCh until
    a ready frame arrives or the grace expires; called once after
    Discover so the agent's tool registry is built against the
    final set
  - Tools() / HasTool() / InvokeTool() public surface
  - readLoop closes readyCh on stdout EOF so a wedged extension
    doesn't permanently block WaitForReady

extensionTool (internal/agent/extensions/tool.go):
  implements core.Tool. Execute() round-trips through
  Manager.InvokeTool with a 60s default timeout, decodes
  base64 image blocks, surfaces extension+tool name in
  ToolResult.Details for the renderer.

internal/agent/build.go:
  - new ExtensionToolSource interface (declared here to avoid the
    build->extensions->core import cycle) + ExtensionToolInfo
    mirror of extensions.ToolInfo
  - Resolved.MergeExtensionTools(): folds extension tools into
    ToolRegistry, re-renders the system prompt's tool summary
    with both built-in and extension tools listed
  - Resolved gains private bookkeeping fields so the rebuild
    works without re-running Resolve

internal/agent/cli.go:
  extension manager built BEFORE the agent in interactive mode
  so MergeExtensionTools can fire before NewAgent. Same in
  buildAgent + buildAgentFor closures so login / model-switch
  rebuilds also include extension tools. extToolAdapter bridges
  *extensions.Manager to ExtensionToolSource.

internal/agent/rpc.go:
  extension lifecycle now also runs in `zot rpc` mode. Notify and
  Display from extensions surface as `ext_notify` / `ext_display`
  events on the rpc stream so any consumer can react.

pkg/zotext (Go SDK):
  - ToolHandler, ToolResult, ToolContent types
  - Tool(name, desc, schema, fn) registration method
  - TextResult / TextErrorResult / Image / ImageBytes constructors
  - Run() now also flushes register_tool frames + a final ready
    sentinel after the last registration

examples/extensions/weather: working Go example registering one
tool. Deterministic fake weather (sha1 of city -> temp + cond) so
the demo is repeatable. Plus README explaining how to install.

Tests:
  internal/agent/extensions/tool_test.go: spawns a mock /bin/sh
  extension that registers a tool, sends ready, and echoes tool
  calls. Verifies registration timing, lookup via HasTool/Tools,
  invoke roundtrip via InvokeTool.

End-to-end verified against live anthropic backend:
  prompt: "What is the weather in Berlin?"
  -> [tool_call] weather({"city":"Berlin"})
  -> [tool_result] Berlin: 16°C, fog (deterministic fake)
  -> reply: "Berlin is 16°C."

Docs/extensions.md updated with phase 2 wire format, the new SDK
tool API, and the weather example.
2026-04-19 14:46:32 +02:00
patriceckhart
0c92d6e914 feat: extension system (subprocess + json-rpc, any language)
Phase 1: extensions can register slash commands and push chat
notifications. Tools and event subscriptions land in later phases.

Architecture: each extension is its own subprocess. Zot launches
it on startup, completes a hello/hello_ack handshake over its
stdin/stdout, then routes slash commands the extension registered.
Crash isolation, language agnostic, works with any executable
that can read/write json lines.

What lands here:

- internal/extproto: shared wire-format types (Frame, HelloFromExt,
  RegisterCommandFromExt, CommandResponseFromExt, NotifyFromExt,
  HelloAckFromHost, CommandInvokedFromHost, ShutdownFromHost...).
  Both the host and the SDK marshal/unmarshal the same types.

- internal/agent/extensions: discovery + lifecycle manager.
  - Discover() walks $ZOT_HOME/extensions and ./.zot/extensions
    (project-local first, global second; first wins for duplicates)
  - Spawns each enabled extension, captures stderr to
    $ZOT_HOME/logs/ext-<name>.log
  - Reads frames in a goroutine, dispatches register_command and
    notify, correlates command_response by id
  - Stop() sends shutdown, waits 2s, then SIGTERM/SIGKILL
  - HostHooks abstracts the tui callbacks (Notify/Submit/Insert/Display)

- Interactive bridge: extensions slot into the slash dispatcher
  *after* the built-in catalog, so built-ins always win on conflict.
  Extension-registered commands also flow into the autocomplete
  popup and /help via slashSuggester.SetExtra. NotifyFromExt frames
  render as muted [ext-name] notes above the editor.

- internal/agent/extcmd: `zot ext` CLI.
    list / install <path|git-url> / remove / enable / disable / logs

- pkg/zotext: public Go SDK. Construct an Extension, register
  Command(name, desc, fn), call Run(). Fn returns a Response built
  with Prompt(), Insert(), Display(), Noop(), or Errorf(). Stderr
  via Logf() so stdout stays clean for the protocol.

- examples/extensions/hello: working Go example registering /hello
  and /summon, plus README + extension.json.

- docs/extensions.md: full protocol reference, including a
  ~30-line raw-Python example for users who don't want the SDK.

Tests: internal/agent/extensions/manager_test.go spawns a mock
extension via /bin/sh and exercises the full handshake -> register
-> invoke -> response cycle. Verifies the hello frame ordering,
correlation-by-id, and graceful shutdown.

Verified manually: built and installed the example, drove it via
stdin pipes, confirmed clean handshake + correct frame ordering
and shutdown_ack. Builds vet-clean on darwin / linux / windows.

Editor.Insert exported (was Editor.insert) so the extension hooks
can drop text into the input.
2026-04-19 14:09:43 +02:00
patriceckhart
a670442c9e feat: zotcore SDK + zot rpc subprocess protocol
two new ways to embed the zot agent runtime in third-party apps:

1. pkg/zotcore - public Go SDK
   - Runtime type: New(Config), Prompt(ctx,text,imgs)->chan Event,
     Cancel, Compact, SetModel, State, Messages, Cost, ListModels,
     Close. Concurrent-safe; one prompt at a time per Runtime,
     ErrBusy if you try to overlap. Spawn multiple Runtimes for
     multiple projects.
   - Public types mirror the JSON-RPC wire schema 1:1 so consumers
     can share parsing code with the out-of-process clients.
   - Internal core/agent/provider stay internal; SDK is a thin
     facade that exposes only what's stable.

2. zot rpc subcommand - newline-delimited JSON on stdin/stdout
   - 'zot rpc' (or 'zot --rpc') turns the agent runtime into a
     subprocess that any language can drive via pipes.
   - Commands: hello, prompt, abort, compact, get_state,
     get_messages, clear, set_model, get_models, ping. Each
     optionally carries an id; the matching response echoes it.
   - Stream notifications: turn_start, user_message,
     assistant_start, text_delta, tool_call, tool_progress,
     tool_result, assistant_message, usage, turn_end, done,
     error, compact_done. Same shape as the existing --json mode
     events (modes.EventToJSON / ContentToJSON were exported
     for reuse).
   - Auth: optional ZOTCORE_RPC_TOKEN env var; first command
     must be hello {token: ...} when set. Without the env var
     the spawning process is implicitly trusted.
   - Concurrency: one prompt or compact at a time per process,
     enforced by a turnMu mutex. abort fires immediately
     regardless. Stdin close exits the process.

3. docs/rpc.md - full schema reference
4. examples/rpc/{python,node,shell,go} - reference clients
5. examples/sdk - in-process Go embedding example
6. README updated with a new modes entry and an embedding section
2026-04-19 12:26:48 +02:00