shiro-neko/ROADMAP.md

Roadmap

What is built, what is next, and what has been deliberately declined. Reordered when evidence says the order is wrong.

Nothing here is a date. Items move to TODO.md when they are next up.

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Shipped

Session-feature batch (post-1.0)

/changes — diff the last turn's file snapshot: added / modified / deleted, per absolute path. The file side of /undo without undoing; bash effects are still out of reach of either.

System-prompt memoization — version counters (notebook, memory, skills, plugins, tools, workspace) gate a cached system prompt, so the string built on every step becomes one build plus hits. The provider-side win it unlocks — splitting the stable prefix for cache_control — is the remaining half of the old "Prompt caching" entry.

web_search — DuckDuckGo Lite, no API key, five results with title/URL/snippet, re-checked through the same private-address filter as web_fetch, all inside the opt-in net set.

/search <query> — full-text across saved sessions, matching transcript strings and tool-input JSON. Deliberately no index: a session store fits in a grep.

Workspace list refresh — the boot-injected file list re-walks at a turn boundary when that turn wrote files, so a path created mid-session shows up in the next prompt without a restart.

Per-turn spend cap (maxSpendPerTurn) — a deep turn that runs away is stopped at a step boundary by its own budget, complementing the session ceiling.

/fork — clone the session at the last turn boundary into a new saved session; trying a different approach no longer costs the original.

Project-driven workflow — when a repo tracks its own progress (TODO.md, ROADMAP.md, docs/), the agent carries a workflow policy in its system prompt: read the task list first and keep it current, spec-first for non-trivial work, complete unit tests, verify before done. TODO.md/ROADMAP.md ride along as Project tracker instruction blocks. A soft once-per-session nudge reminds an agent that edited files without updating the task list. /workflow shows the state; workflow.enabled / workflow.docsDir configure it. See docs/workflow.md.

0.1.0-beta.1

Core loop — streamText with tool approvals suspended and resumed through the SDK's toolApproval, so a denied tool provably never executes. Endpoint fallback for OpenAI reasoning models that reject function tools on /v1/chat/completions. Retry with backoff for transient failures.

Tools — read_file write_file edit_file glob grep bash, all path-jailed to the workspace. ripgrep bridge with a JavaScript fallback. .gitignore and .shiroignore aware walking. Binary rejection. Live-streaming bash output.

Interface — Ink TUI with markdown rendering, slash command menu, readline input with per-project prompt history, coloured diffs in approval prompts, and panels for tasks, subagents, command output, questions, and command results.

Agents — five variants crossing thinking level with tool restrictions. plan and review withhold mutating tools from the model rather than discouraging them.

Skills — frontmatter markdown, catalogue in the prompt and body on demand. Four bundled, overridable per user and per project.

Plugins — tool contribution, auto-approval, beforeToolCall blocking, afterTurn hooks, prompt appendices. guard refuses irreversible shell commands ahead of any approval, including under --yolo.

Memory and state — durable per-project memory with hit-counted recall and model-driven compaction. Session task lists with four states. Session persistence with resume. Context compaction that repairs the provider-item dependencies pruning breaks.

Subagents — read-only task with explore and review flavours, progress streamed to a panel.

Asking — the ask tool, withheld in headless runs rather than left to hang.

MCP — stdio and HTTP servers, tools namespaced mcp__<server>__<tool>, a failing server reported rather than fatal.

Distribution — five-platform cross-compiled binaries, checksums, install scripts, CI on three operating systems, tag-driven releases.

0.1.0-beta.3

Fourteen built-in tools, up from six, with sets so the schema cost stays controllable.

v0.1.0-beta.2 was tagged and never published: bun build --compile --target=bun-windows-x64 rejects --windows-title unless the host is Windows, and CI releases every target from one Ubuntu runner. It passed locally and failed on the last of five builds. The version was burned rather than moving a published tag.

Visible process — reasoning streams to a collapsed panel with an estimated token count, ctrl-r expands it, and it leaves with the turn since it is progress rather than the answer. The tool in flight is named from tool-input-start, before its arguments have finished streaming, and cleared on its result.

Message queue — the input stays mounted while the model works. A prompt typed mid-turn queues, the panel counts what is waiting, and the queue drains in order when the turn ends. esc clears the queue as well as aborting. Queued slash commands replay as if typed.

More tools — multi_edit applies several edits to one file atomically, validating every edit in memory first so a late failure cannot leave the file half-written. list_dir gives an ignore-aware depth-limited tree. Five read-only git tools, spawned with a fixed argv rather than a shell string, which is what makes them safe to auto-approve.

activeTools gating — toolSets in config: core always on, edit-plus and git optional. A disabled set reaches neither the wire nor the system prompt. /tools names the set each live tool came from.

Pruning correctness — a tool result whose tool call the pruner discarded is now dropped with it. Message-counted pruning cut between an assistant tool-call and the tool message answering it, and the OpenAI responses API rejects the result on its own with 400 "No tool call found for function call output with call_id ...".

Batch reads — read_many_files takes up to twenty paths, each with its own window, and runs them concurrently. An unreadable path is reported in its own block rather than throwing, so one wrong guess costs a line instead of the call.

@file completion — @ opens a picker fed by the ignore-aware walker, narrowing as you type. Prefix matches rank above substring matches, so @src/ means "under src/" rather than "anything containing src/". Tab inserts a plain relative path. The walk happens on the first @ rather than at startup.

Interruptible commands — ctrl-c kills the command in flight and keeps the turn: the call fails with a message saying the command did not finish and its effects are unknown, and the model takes its next step from there. The kill takes the whole process tree, because killing cmd /c alone leaves the real command holding both pipes open and the read never returns.

0.1.0-beta.4

Compaction no longer stops the loop. The beta.2 repair dropped any assistant part whose reasoning item pruning had removed. On a reasoning model that is every tool call, so past the threshold the model could no longer see what it had already run — and re-ran it until the step limit ended the turn. The fix strips the provider itemId rather than the part: without one the same content is serialised inline instead of as an item_reference, so the dependency on the pruned reasoning item disappears while the history survives. Compaction may shorten the history; it must not blank it.

Bounded compaction. The fixed three-message tool window collapsed long transcripts to a handful of messages — a 405-message run kept two of 202 tool calls. Pruning now drops reasoning first and keeps the widest recent tool tail that fits a ladder, and the SDK's step-to-step message carry-over does the rest: the model keeps its record of what it ran. The turn reports one compaction event rather than one per step.

External registry. /registry browses, searches, installs, and removes skills and plugins from an index over https. The two kinds are treated differently on purpose: a skill is prompt text and is shown in full before it joins your system prompt, while a plugin is a validated manifest of deny rules that the compiled guard evaluates. Loading code from a URL is declined outright — a plugin that could block tool calls could otherwise lie about blocking them.

Interface. Context shown as a percentage of the compaction threshold, amber from two thirds and red at 90, so a turn about to lose history says so first. Aligned command menu and registry tables, and /skills and /plugins name the origin of every entry. Tool calls show their load-bearing arguments — the paths a batch read is about to pull in, the files a patch touches — and each result line carries an outcome summary.

Permission rules. Approval moved from a list of tool names to rules matched against the call's subject: the command for bash, the path for a file tool. bash used to be a single yes/no covering git status and rm -rf, so a user pressing a once during a batch removed the gate for both — the check was strongest when it mattered least. Rules let git * run while everything else asks, always grants the pattern rather than the tool, .env and .pem are refused on read outright, and a call repeated identically three times in one turn asks even when allowed. --yolo folds ask into allow and still cannot reach a deny rule or the guard.

Surveyed Claude Code, Codex, opencode, and phi before writing it. Three of the four had already moved to per-pattern rules; the shape here is closest to opencode's, with the credential deny and the repeat guard taken from it directly.

apply_patch. One atomic patch across files — add, update, move, delete — validated in full before anything is written, so a failure on the fourth file leaves the first three untouched. Permission rules match every path the patch touches, so denying src/generated/* catches a patch that includes one among five files.

web_fetch. URL to markdown, size-capped, in a net tool set that is off unless asked for — it is the one tool that leaves the machine. HTTPS is required for public hosts, private and loopback addresses are refused, and redirects are re-checked one hop at a time so a public URL cannot redirect into the cloud metadata endpoint.

Writable worker subagents. task gains a worker kind that holds the write tools and routes every write and command through the parent's approval gate — the same rules, the same prompt, the same session grants as a direct call. Without an approval channel the worker kind is not offered at all rather than silently downgraded to read-only. explore and review stay structurally read-only, and no subagent holds web_fetch.

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0.1.0-beta.5

A dead provider item no longer ends the turn. An item_reference resolves only while the provider still stores that item, so a resumed session — or one that fell back to /v1/responses mid-turn — could fail with 404 "Item with id 'msg_...' not found" on every attempt, since every retry sent the same reference. Compaction now strips every provider itemId from what it sends, and a 404 naming a missing item rewrites the session's history inline and runs the request again, once per turn and only before any output has been delivered.

Interface. Context shows the elapsed working time and a compaction warning as the threshold approaches, diff lines are numbered, markdown task lists render, the prompt edits by word and ctrl-d deletes to the end of line, and a farewell tells you how to resume the session.

More tools. git_commit_message writes a commit message from the staged diff and the repository's own recent subjects, in one nested model call — it never commits, so it needs no approval. move_file and delete_file fill the gap that made every rename a write-then-delete pair: both are gated, move_file matches permission rules at both ends, and delete_file refuses a directory because removing a tree is what the guard blocks in bash. git_branch lists branches with the current one marked.

More plugins. protect refuses writes to .git, lockfiles, node_modules, vendored code, and build output — files a tool owns rather than a person, where an edit leaves a repository that looks fine and behaves wrongly. It ships on, alongside guard and secrets, and every path-based guard now shares one helper that understands where each write tool keeps its paths.

More skills. security (trust boundaries, then injection, authorisation, traversal, SSRF), perf (measure, locate, one change, stop at a target), and migrate (changelog first, every call site before one edit, never hand-merge a lockfile) join the bundled set.

The MCP panel. /mcp add walks through a local or remote server — kind, name, command and arguments or URL and headers — validating the name against the mcp__<server>__<tool> namespace as it is typed rather than failing at connect. /mcp lists what is configured with each server's live tool count or its connection error, and /mcp remove takes one out. All three write config.json directly; a new server connects on the next start, because connecting mid-turn would change the tool list under a running request.

1.0.0

The first stable release. The beta line's architecture held; this release rounds out cost control, extensibility, and the interface, and hardens the test suite to match.

Cost control. Two halves of one problem, both shipped. A spend ceiling (maxSpendUsd) checks before each turn: past the limit the model is never called, the turn is refused naming the ceiling, headless exits non-zero, and it warns once at 80%. A cheaper subagent model (subagentModel) runs explore — which is search, not reasoning — on a less expensive model while review and worker keep the parent's; /cost reports subagent spend as its own line, priced against the subagent's model id.

Tools: 41 built-in. Twenty new tools in four families, all path-jailed and ignore-aware, in a new extra tool set: precise line edits (insert_lines, delete_lines, replace_lines, append_file, prepend_file, count_lines), filesystem navigation (tree, file_info, find_files, recent_files, changed_files), read-only git extensions (git_log_file, git_diff_commits, git_show_file, git_current_branch, git_changed_in_ref), and code and environment reads (find_symbol, json_query, outline, read_symbol, env_info, count_tokens). Every git call still spawns the binary with a fixed argv, never a shell.

Skills: 29 bundled, as Markdown. The catalogue grew from nine to twenty-nine and every skill moved to a single source of truth: a Markdown file in src/skills-md/, frontmatter and body, embedded into the compiled binary by Bun text imports. A format test enforces that each one parses and carries a real body.

Plugins: 10 more, all data. Six narrow safety refusals (force push, pipe-to-shell, root elevation, env credential writes, main-branch commits, git config changes) and three advisory plugins (conventional commits, tests-first, small diffs) plus a delete guard for ambiguous paths. The safety refusals are on by default for the same reason the guard is; the opinionated ones are opt-in.

Custom slash commands. A Markdown file in .shiro/commands/ or ~/.shiro-neko/commands/ becomes a slash command, with frontmatter description/agent, $ARGUMENTS and $1 positionals, and !`cmd` substitution passed through the guard. A custom command can never shadow a built-in.

Auto-loaded extensions. External skills, tools, and plugins load from ~/.shiro-neko/<kind>/ and .shiro/<kind>/ — all data, never code. An external tool is a bounded manifest (a shell template through the guard, an HTTPS fetch, or a workspace file read); an external plugin is a refusal manifest. A malformed file is reported and skipped, never fatal.

Interface. The welcome screen is a structured dashboard — a session banner, a grouped environment panel with attention-worthy facts lifted out of the quiet layer, and a meta bar — replacing a wall of dim text. The input sits in an OpenCode-style two-tone box with the agent·model row inside it and a split footer beneath.

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What the other agents have

Surveyed opencode, Claude Code, Codex CLI, and phi against this tool's feature set. The point of the table is to record what is worth copying and what is worth declining, not to chase parity: each of these four spent effort here deliberately, and several of their choices are load-bearing for a reason that applies to us.

The four are not the same shape. Claude Code and Codex are first-party CLIs tied to one vendor's models; opencode and phi are open-source and provider-agnostic, and opencode in particular is the closest thing to a peer here. Where a feature exists, the notes say what it costs — several are cheap to copy, and three are not.

Where the four agree

Six features have converged across all or nearly all of them. Convergence is the strongest signal available that a feature is not a fad — and the gaps in the table are as informative as the checks, because they show which features are genuinely optional and which are table stakes.

Feature	opencode	Claude Code	Codex	phi	Here
Per-pattern permission rules	permission.bash globs	settings.json allow/deny/ask	approval_policy + rules	Gate + permissions.mode	shipped
Subagents with fresh context	mode: subagent	agents/*.md	—	sub-agents	shipped
Markdown-defined agents	agents/, commands/	agents/, skills/	AGENTS.md	.phi/	shipped
Session resume	--session, --continue	--resume, --continue	resume + rollout files	sessions	shipped
Compaction	auto + /compact	/compact, /rewind summarize	compact prompt file	—	shipped
Undo / rewind	/undo, /redo (via git)	/rewind (snapshots)	—	—	missing

Two of the six are outright missing from one or more tools, and undoing is missing from two of the four — so it is a real feature, not table stakes, and the two that have it disagree about how. The permission model here is not behind: it already carries the per-pattern rules, the credential deny, and the repeat guard the others arrived at, and doom_loop (below) is the one refinement worth taking. Undo is the single converged feature genuinely absent, which is why it leads Next.

Detail worth having, by tool

opencode — the closest peer, and the source of the permission shape already adapted here. /undo and /redo revert file changes through git, so they require the project to be a git repository; this is a real limitation, not an implementation detail, and it means an undo is only as good as the working tree's state. Agents are primary (build, plan) or subagent (general, explore, scout), switchable with Tab or @-mention, configured in opencode.json or Markdown frontmatter. A subagent runs in a child session with its own navigation keybinds (session_child_first, session_parent), and subagent_depth (default 1) caps nesting. Notable: doom_loop is a first-class permission key that fires when the same tool call repeats three times with identical input — the repeat guard here is an approval rule; theirs is a named primitive with its own recovery prompts. Sessions share over a URL (/share), which is a hosted product decision, not a local one.

Claude Code — the most complete implementation of undo, and worth reading before building one. Checkpointing snapshots before every user prompt, keeps the 100 most recent checkpoints, and stores them with the conversation so /rewind survives a resume. The rewind menu offers five distinct actions, and the split is the interesting part: restore code, restore conversation, restore both, summarize from here, summarize up to here. That is undo and compaction sharing one control surface. The honest limits are documented rather than hidden: only Write/Edit/ NotebookEdit are tracked, bash side effects are not, subagent edits are not captured unless the skill ran in the foreground with context: fork, and symlinked or hard-linked files are skipped with an explicit warning. Their hook surface is the largest of the four — see External hooks under Later, which is where that capability belongs here.

Codex — the sandbox is the differentiator, and it is genuinely hard to copy. Apple Seatbelt on macOS, Landlock + seccomp on Linux, and a restricted-token/AppContainer mechanism on Windows, with workspace-write the default and network off unless sandbox_workspace_write.network_access is set. approval_policy is now on-request | never | { granular = {...} } — untrusted was retired and can prevent the client from starting. Also shipped and worth knowing: approvals_reviewer = "auto_review" routes an approval prompt through a reviewer subagent rather than the user. AGENTS.md resolves global → project root → cwd, one file per directory, AGENTS.override.md winning, capped by project_doc_max_bytes (32 KiB default).

phi — small (Go, ~12 MB), and the two ideas most worth stealing. First, MCP without context death: server tool schemas never enter the prompt; the system prompt lists only server names, and the model uses three meta-tools — mcp_list, mcp_inspect, mcp_call — with subprocesses starting lazily on first use. This is the concrete design behind MCP without the schema tax under Next. Second, the hook contract is the cleanest of the four: pre_tool runs before the permission gate and can allow, deny, or modify the input; post_tool can append model-facing context or rewrite output. Exit code 2 is a hard deny; fail_closed decides crash behaviour; in readonly mode only fail_closed hooks run, so a slow audit hook cannot stall exploration.

Corrections to what this file said before

Two claims previously written here were incomplete, and the research fixes them:

• Input-rewriting hooks are not phi's alone. Codex ships it too: PreToolUse returns permissionDecision: "allow" with updatedInput to rewrite a call, verified in their docs and in codex-rs/.../mcp.rs (with_updated_hook_input). Two independent implementations make this the standard shape rather than one project's quirk — which raises its priority, and means the compiled plugin interface here is now the odd one out.
• Codex's hook trust is exactly as described, and the mechanism is now known. Non-managed hooks cannot run until reviewed: Codex persists a trusted_hash in config.toml, records trust against the hook's current hash, and marks new or changed hooks for review in /hooks. --dangerously-bypass-hook-trust skips it for one invocation. The known hole is instructive: a reviewer on their PR noted that replacing the script a hook points at does not reset trust, because only the config is hashed. A trust story that hashes the declaration but not the artefact is a partial one — worth designing past rather than copying.

What is worth declining

Three of their features are deliberate here, and the survey confirms the reasoning:

• A client/server split (opencode's OpenAPI server + TUI-as-client + IDE/web clients) exists to serve second clients. No second client is wanted here.
• LSP integration — the quote already cited in Declined is accurate and now verified in full: opencode's own LSP page says it "is useful in some projects, but it is not always a net positive," that servers "can get out of sync, use significant memory, vary by version or project, and slow down agent workflows," and that "in many projects it is better to have the agent run lint, typecheck, or other diagnostic CLI tools directly." They ship 30+ built-in servers and still say this. That is the strongest possible endorsement of the position in Declined.
• Session sharing over a URL (opencode /share) is a hosted-service feature and brings a privacy surface this tool has no reason to take on.

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Next

Prompt caching

The system prompt is now memoized client-side, so the string is byte-identical across steps when nothing volatile changed. The remaining half is provider-side: Anthropic cache_control and OpenAI automatic prefix caching already reward that stable prefix, and splitting the stable prefix from the volatile suffix (notebook/memory) would make the cache unmissable even when a todo_write happens mid-turn.

MCP without the schema tax

Every MCP tool's schema is in the prompt on every request, and toolSets does not gate them: a twenty-tool server costs roughly 2,750 tokens a turn whether the model touches it or not. phi's answer is three meta-tools — mcp_list, mcp_inspect, mcp_call — with the prompt naming only the servers, so a hundred servers cost almost nothing until one is called. Worth keeping direct registration as an option: for a two-tool server the indirection is the more expensive of the two.

Undo a turn

Every comparable CLI has this: opencode /undo and /redo, Claude Code /rewind with checkpoints. There is /resume here, which restores a session, and nothing that walks one back. Claude Code's implementation is the one to read first, because it has already worked out the seams: it snapshots before every user prompt, keeps the 100 most recent, stores snapshots with the conversation so a rewind survives a resume, and splits one menu into restore code, restore conversation, restore both, and summarize from here / up to here — undo and compaction on one control surface. opencode's version is simpler and takes a different position: it reverts through git, so it needs a repository and inherits whatever the working tree already contained.

Both document the same hard limit, and so must this: a bash command's effects cannot be snapshotted. Claude Code tracks only its own file-edit tools, explicitly does not cover bash side effects, and does not capture subagent edits unless the fork ran in the foreground. The honest version here covers file-tool edits, says so in the command's own output, and reports what it skipped rather than pretending the tree is clean — the same shape used for an interrupted command, whose effects are already reported as unknown.

Lossless-enough compaction

Compaction keeps the model's memory of a turn now, but it still says nothing about the messages it discarded, so the model can contradict its own earlier decision with confidence. A summary of the discarded span costs one cheap call and removes the whole class of problem.

Derived tool metadata

TOOL_SETS and MUTATING_TOOLS are hand-maintained lists of tool names. A tool added to one and forgotten in the other is a silently ungated write. Marking each tool where it is defined, and checking the coverage in the suite, removes the failure mode rather than documenting it.

Registry trust

An index is trusted for its contents, not its authorship: registryUrl is the whole trust decision, and there are no signatures. Publisher keys and a pinned digest per entry would make "install this skill" a decision about a specific artifact rather than about a URL.

Auto-review an approval

Codex ships approvals_reviewer = "auto_review": an eligible approval prompt is routed through a reviewer subagent instead of surfacing to the user, using the same sandbox boundary. explore and review already exist and are read-only, so the piece to build is a reviewer persona that decides an approval request and a policy that says which prompts are eligible — a batch of three identical git status calls should not each interrupt, but a first rm should. The failure mode to design against is a reviewer that waves through exactly what the user would have stopped, so it must be opt-in, name itself when it approves, and never override a deny rule.

Name the repeat guard

opencode has doom_loop as a first-class permission key: it fires when the same tool call repeats three times with identical input, carries its own recovery prompts, and is configurable per agent. The equivalent here is a rule inside the permission layer — the call repeated identically three times in one turn asks even when allowed — which works but is unnamed, unconfigurable, and invisible in /tools. Promoting it to a named primitive makes it inspectable and lets an agent tighten or loosen it, and the recovery prompt is the part genuinely missing: a loop is better interrupted with advice than with silence.

web_fetch

Shipped in beta.4 — see above. What remains declined: wrappers around a single bash line with no added guarantee. run_tests, typecheck, lint, build are five tools of pure schema tax when the real commands are already in AGENTS.md.

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Later

Structured diff review. Approve or reject individual hunks of an edit_file call rather than the whole thing.

Plugin code from disk. Declarative manifests ship in beta.4, and that is the whole of it for now. Loading .shiro/plugins/*.ts needs a sandbox story first — a plugin that can block tool calls can also lie about blocking them, and one that can execute can read whatever the agent can read.

Prompt caching. Anthropic and OpenAI both support it. The system prompt is rebuilt every step for task-list freshness, which defeats a naive cache; splitting the stable prefix from the volatile suffix would fix that.

External hooks. Every one of the four surveyed except here lets a script sit in the tool loop: a directory with a manifest and an executable, one JSON object in on stdin, one out. Both phi and Codex let a PreToolUse hook rewrite a tool's input, not merely allow or deny it — phi returns {"action":"modify","input":{...}}, Codex returns permissionDecision: "allow" with updatedInput — and that is the exact capability the compiled plugin interface here cannot express. Two independent implementations make it the expected shape rather than one project's quirk. What blocks it is the trust story, not the mechanism.

The trust story has a known shape and a known hole. Codex will not run a non-managed hook until it has been reviewed: it persists a trusted_hash in config.toml, records trust against the hook's current hash, and lists new or changed hooks for review under /hooks; --dangerously-bypass-hook-trust overrides for one invocation. The hole is that only the declaration is hashed — replacing the script the hook points at does not reset trust, as a reviewer on their own PR pointed out. Hashing the declaration and the artefact is the minimum worth doing here, and it is why this is work rather than a weekend.

OS-level sandboxing. The strongest thing in this class, and Codex is the one that has it: Seatbelt on macOS, Landlock and seccomp on Linux, a restricted-token/AppContainer mechanism on Windows, with network off by default under workspace-write. Permission rules gate the call; a sandbox governs what the process can then reach. Note that even Codex's sandbox is not a complete boundary — their own hook docs say "hooks are guardrails, but they are not a complete enforcement boundary for every shell or tool path." Three platform-specific implementations, and OpenAI moved Codex to Rust partly for this. A half-built sandbox is worse than none, because people would trust it.

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Declined

A web UI. This is a terminal tool. A browser front end doubles the surface area and serves a different product.

Model-agnostic prompt tuning. Per-model prompt variants are a maintenance treadmill for gains that evaporate on the next model release.

Auto-commit. The agent should never write git history without being asked. Commits are the user's record of their own work.

Vector search over the codebase. ripgrep answers a scoped question in 135 ms with no index to build, invalidate, or ship. An embedding store is a large amount of machinery for a worse answer on a codebase that fits in a grep.

Tool call retries on model error. A model that produced a malformed call will usually produce it again. Surfacing the error teaches it more than a silent retry.

A client/server split. opencode runs a server and treats its TUI as one client of an OpenAPI endpoint, which is what lets IDE extensions and a web client exist. It is the right architecture for that product. Here it would add a protocol, a port, and an auth story to serve a second client nobody has asked for.

LSP integration. opencode ships 30+ built-in language servers and its own documentation still says the honest thing: LSP "is useful in some projects, but it is not always a net positive," servers "can get out of sync, use significant memory, vary by version or project, and slow down agent workflows," and "in many projects it is better to have the agent run lint, typecheck, or other diagnostic CLI tools directly." That is the strongest available endorsement of declining it: the project with the most invested says it is often the wrong trade. bash bun run typecheck puts the same errors in front of the model with none of that, and AGENTS.md is where the command belongs.