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Changelog

Source: NEWS.md

codeagent (development version)

  • Concurrent sub-agents (opt-in via settings$async_subagents, default OFF): the Agent tool can run asynchronously so multiple sub-agent delegations requested in a single turn execute concurrently (via ellmer’s tool_mode = "concurrent") on the async streaming paths (CLI REPL / Shiny app). Sync one-shot codeagent() transparently falls back to sequential sub-agents, since async (promise-returning) tools are invalid under Chat$chat(). Also adopts ellmer 0.4.2 (set_model(), chat_posit()).

  • Background sub-agents (opt-in via settings$background_agents, default OFF; requires mirai): a new BackgroundAgent tool delegates a task to a fire-and-forget sub-agent running in a mirai daemon and returns immediately (non-blocking). Its result is polled and surfaced back to the model on a later turn via the system reminder, mirroring Claude Code’s async agents. Users can also spawn and inspect background agents directly with the /bg <task> and /bgstatus slash commands (REPL and Shiny).

codeagent 0.1.0

First public release. codeagent is an R-native reimplementation of a command-line coding agent, built on ellmer and btw. It provides the agent harness (loop, tools, permissions, compaction, hooks, skills) plus a CLI REPL and a shiny user interface.

Model tier env var rename — breaking changes

Three environment variables have been renamed to remove vendor-specific names. Update your .Renviron / settings.json env block accordingly:

Old New Meaning
CODEAGENT_DEFAULT_SONNET_MODEL CODEAGENT_MODEL Everyday main model
CODEAGENT_DEFAULT_OPUS_MODEL CODEAGENT_HEAVY_MODEL High-capability model
CODEAGENT_SMALL_FAST_MODEL CODEAGENT_FAST_MODEL Cheap/fast model

Tier aliases used in /model and codeagent.md also changed: "sonnet" → "main", "opus" → "heavy", "haiku" → "fast".

CODEAGENT_MODEL now serves dual purpose: it sets both the default model and the "main" tier alias (previously CODEAGENT_MODEL and CODEAGENT_DEFAULT_SONNET_MODEL were separate; they are now merged).

CLI/ink unified entry point — breaking changes (plan #20)

  • Default permission mode is now "default" across all entry points (CLI, Shiny, ink). Previously all CLI subcommands defaulted to "bypass". Write operations (file edits, shell commands) now prompt for approval unless you explicitly opt into bypass mode.

  • -y / --yolo — new global flag for the CLI that enables bypass mode (skips all permission prompts). Equivalent to Claude Code’s --dangerously-skip-permissions. Short-hand: -y.

    codeagent -y           # bypass REPL
codeagent app -y       # bypass Shiny app
codeagent run "q" -y   # bypass one-shot query

  • codeagent without a subcommand now starts the interactive REPL directly (equivalent to codeagent chat). Previously a subcommand was required.

  • -p / --print-mode — new flag for one-shot non-interactive output. codeagent "query" or codeagent -p "query" runs a single query and exits.

  • -m now means --model (breaking). The old -m/--mode alias has been removed. Use -y/--yolo for bypass mode instead.

  • ink_ui() gains yolo = FALSE parameter. When TRUE, sets INK_YOLO=1 so the codeagent backend runs in bypass mode. The inkai terminal command also accepts -y/--yolo.

    ink_ui("codeagent", yolo = TRUE)   # bypass
# or from terminal:
inkai codeagent -y                 # bypass

  • INK_YOLO env var — set to "1" to enable bypass mode in ink when launching the inkai command directly: INK_YOLO=1 inkai codeagent.

  • codeagent_app(permission_mode = "default") unchanged — Shiny was already correct; pass permission_mode = "bypass" explicitly when needed.

  • R/cli_dispatch.R — new internal helpers .ca_resolve_mode() and .ca_dispatch() expose CLI dispatch logic as testable pure functions.

Migration guide

Old New
codeagent chat codeagent
codeagent chat -m bypass codeagent -y
codeagent -m bypass codeagent -y
ink_ui("codeagent") (was bypass) ink_ui("codeagent", yolo = TRUE) for bypass
inkai codeagent (was bypass) inkai codeagent -y for bypass

Unified agent streaming API (plan #19)

  • codeagent_stream_async() — new exported function. Streams one agent turn asynchronously (coro::async promise). Runs the full turn pipeline (compaction, system-reminder injection, session save, cost tracking via get_cost(include="last")). Fires typed callbacks: on_delta, on_thinking, on_tool_request (pre-gate, from stream chunk), on_tool_result (with typed display contract from .adapt_tool_result()), on_error, on_usage. Supports stream_controller for cancellation and tool_mode for concurrent tool execution.

  • codeagent_stream() — synchronous wrapper around codeagent_stream_async() using later::run_now() to pump the event loop. Handles Ctrl+C gracefully (cancels the stream via stream_controller, does not re-throw the interrupt condition). Intended for CLI and ink frontends.

  • Turn pipeline helpers (R/turn_pipeline.R, internal): .turn_setup() consolidates compaction + resource replacement + system-reminder injection into one call. .turn_teardown() consolidates session save + usage + cost_last. Both are now shared by console, Shiny, and ink.

  • Shiny system-reminder injection fixed. server_chat.R’s stream_task now injects the <system-reminder> block (date/iteration/cwd/memory) on every turn, matching the behaviour of the console REPL and agent_loop().

  • Console Ctrl+C repair. codeagent_console() now creates a stream_controller per turn and catches interrupt conditions, cancelling the stream gracefully. Previously Ctrl+C could corrupt the chat state.

  • Callback deduplication. .register_repl_tool_callbacks() is now guarded by .chat_once() to prevent stacking display callbacks if codeagent_console() is called more than once on the same chat object.

  • .patch_interrupted_chat() retired. Removed from all call sites. ellmer 0.4.0+ (#840) and 0.4.1+ (#643) handle orphaned tool requests and AssistantPartialTurn automatically.

  • inkAssistantUI tool cards upgraded. ink_reply_stream() now calls codeagent_stream() when available (full turn pipeline + display contract). on_tool_result receives a rich display field (title/kind/payload) instead of a plain string. The ink_server() initialises per-session CompactionController / ContentReplacementState / session_id so turns are properly managed.

Multi-agent teams (post-0.1.0 additions)

  • Task DAG. team_coordinate() gains blocked_by — task dependencies given by 1-based index. A task is only claimed once all its blockers are done, so workers respect ordering while still parallelising independent tasks. Cyclic graphs are rejected up front. The shared board’s claim is now dependency-aware and atomic (BEGIN IMMEDIATE).
  • Worktree isolation + crash recovery. worktree = TRUE runs each worker in its own git worktree; board_reclaim_stale() (wired into the worker loop) resets a crashed worker’s timed-out task back to pending so its dependents are never blocked forever.
  • Event-driven board. board_watch() (built on the watcher package) reacts to board changes without polling, powering an event-driven coordinator / live board view (falls back to polling when watcher is unavailable).
  • LLM-lead coordinator. team_lead(goal, max_rounds =) faithfully ports Claude Code’s COORDINATOR_MODE: a lead model decomposes the goal into a task DAG, the work-stealing team runs it, then the lead reviews results and either finishes or adds a follow-up round (bounded loop; decompose/review/coordinate steps are injectable for testing).
  • Live dashboard. team_dashboard(db_path) is a standalone Shiny app that monitors a running team’s board in real time — task table (coloured by status), a progress bar, and the inter-agent message log.

Shiny app UX (post-0.1.0 additions)

  • Instant startup. The UI shell now renders immediately; the slower tool + skill registration runs in the background behind a prominent “Initializing codeagent…” overlay, with the chat input gated until it completes. Pass a bare ellmer::Chat to codeagent_app() for this lazy path.

  • Skill metadata disk cache. list_skills_meta() now caches parsed skill metadata on disk (<config>/cache/skills/, keyed by cwd + a SKILL.md mtime/count signature), so the slash typeahead and skill tool are near-instant on every launch after the first (a disk hit skips the ~20s directory scan). The cache self-invalidates when any SKILL.md changes or a skill is added/removed.

  • Single-file viewer. Clicking a file in the Files tree now opens it in one static, scrollable “File” tab (code / Markdown / image / CSV) with a filename header and close button, replacing the old per-file tabs that could overflow and cover the tab strip.

Security & testing improvements (post-0.1.0 additions)

  • keyring integration (R/keyring.R): Optional API key storage via the OS credential store (keyring package). setup.R offers the keyring as an alternative to ~/.Renviron when the backend is available. Includes .keyring_available() (session-cached probe), .keyring_store_key() with graceful fallback to ~/.Renviron, and .keyring_get_key(). On headless/server environments the keyring backend probe returns FALSE and all functions degrade silently to the existing ~/.Renviron path.

  • webfakes agent integration tests (tests/testthat/test-webfakes-agent.R): 12 tests that mock the LLM API endpoint with webfakes, exercising the full agent loop — tool dispatch (Read, Write, Bash), permission gate (bypass vs plan), error recovery (HTTP 500), and skill invocation — without hitting a real LLM.

  • Explicit tool names: bash_tool(), read_tool(), write_tool(), edit_tool(), multi_edit_tool(), glob_tool(), grep_tool(), ls_tool() now pass name= to ellmer::tool() so the model can refer to tools by their canonical names (Bash, Read, Write, Edit, MultiEdit, Glob, Grep, LS).

Agent harness

  • Agentic loop (agent_loop()) with max-turns, token budget, verification, and error recovery (prompt-too-long, rate-limit, network, and auth handling).
  • Seven-mode permission system: default, plan, accept_edits, bypass, dont_ask, auto, and bubble (sub-agent decisions bubble to the parent). Fine-grained rules match on tool arguments (e.g. Bash(npm run test *)).
  • Twelve-event hook system covering tool, permission, message, and lifecycle events, configurable declaratively from settings.json.
  • Five-level context compaction (snip, session memory, full summary, prompt fallback, context collapse).
  • System prompt with tone, task, convention, tool-use, and R-specific guidance.

Tools

  • Core tools: Bash, Read, Write, Edit, MultiEdit, Glob, Grep, LS.
  • RunR executes R code behind the permission gate; with sandboxing enabled it runs in an isolated callr subprocess with a scrubbed environment (secrets hidden), no .Renviron reload, and a wall-clock timeout.
  • btw tool groups (docs, git, pkg, env, etc.), web fetch and search, notebook tools, task and persistent-todo tools.
  • Optional codebase retrieval via ragnar (vector + keyword search).

Coordination

  • Sub-agents via agent_tool(), with optional git-worktree isolation and persistent “sidechain” sessions.
  • Parallel teams: team_run() (fixed fan-out) and team_coordinate() (work-stealing over a shared SQLite board with inter-agent messaging), both capped to the container’s CPU quota via parallelly.
  • Plan-mode tools let the model enter and exit read-only planning mid-turn.

State and configuration

  • Sessions saved as JSONL with lossless tool-call preservation; fork, rename, tag, resume, and rewind (truncate_chat_turns() / /rewind).
  • Auto-memory persisted across sessions, with relevance selection by a small fast model.
  • settings.json configuration mirroring command-line agents: env block, model tiers, permissions, hooks, MCP servers, sandbox, effort level, and more.
  • Model switching mid-conversation (switch_model()), lossless where possible.

Interfaces

  • CLI: codeagent executable with run, chat/repl, app, skills, mcp, and info sub-commands; the REPL streams output, shows tool activity, and renders reasoning blocks.
  • shiny app (codeagent_app()) with tool cards, session management, and theme options.
  • MCP server (codeagent_mcp_server(), stdio and HTTP) and MCP client (register_mcp_client(), stdio) for external tool interoperability.