TermAl

Agent Integration Comparison

Cross-agent reference for TermAl adapter design.

Capability details in this document were last verified on 2026-08-13. Agent products and ACP are evolving independently, so implementation decisions must be based on the capability advertised by the connected runtime rather than on the agent name alone.

Protocol and transport

	Claude Code	Codex	Gemini CLI	Cursor CLI
Wire protocol	NDJSON (custom)	JSON-RPC 2.0	stream-json stdout or ACP (experimental)	ACP (JSON-RPC 2.0)
Transport	stdin/stdout only	stdin/stdout or WebSocket	Spawned CLI stdout or stdio (ACP)	stdin/stdout only
Bidirectional	Yes	Yes	No (stream-json) / Yes (ACP)	Yes
Server mode	No	codex app-server	--experimental-acp	cursor agent acp
Best TermAl integration	Spawn child and speak NDJSON over stdio	Spawn shared app-server and speak JSON-RPC over stdio (fire-and-forget writer, resilient reader)	Spawn CLI in ACP mode over stdio	Spawn agent acp and speak JSON-RPC over stdio

Session persistence

	Claude Code	Codex	Gemini CLI	Cursor CLI
Storage format	Append-only .jsonl	JSONL rollout plus SQLite cache	Single .json per session	Managed by Cursor
Location	.claude/sessions/{id}.jsonl	~/.codex/sessions/YYYY/MM/DD/rollout-{id}.jsonl	~/.gemini/tmp/<project>/chats/session-{ts}-{id}.json	Managed internally
Resume mechanism	--resume <session-id>	thread/resume	--resume <index\|latest> (CLI) or session/load (ACP)	session/load
Session discovery	Scan .claude/sessions/	Query SQLite threads table	Scan chats/ directory	Via ACP session management
Cross-session memory	File-based CLAUDE.md	SQLite-backed memory pipeline	save_memory writes to GEMINI.md	.cursor/rules

Context and instructions

	Claude Code	Codex	Gemini CLI	Cursor CLI
Instructions file	CLAUDE.md	AGENTS.md	GEMINI.md	.cursor/rules
Hierarchy	Global plus Project	Global plus Project plus Subdirectory	Global plus Extension plus Project	Global plus Project
Memory file	~/.claude/memory.md	N/A	~/.gemini/memory.md	N/A
Ignore file	.claudeignore	N/A	.geminiignore	.cursorignore
JIT subdirectory discovery	No	No	Yes	No

Approval and permissions

	Claude Code	Codex	Gemini CLI	Cursor CLI
Mechanism	control_request and control_response	JSON-RPC server requests	Policy engine and confirmation bus	session/request_permission
TermAl can intercept	Yes	Yes	No (stream-json) / Yes (ACP)	Yes
Authenticated structured reviewer submit	Yes, qualified injected MCP tool identity	Yes, MCP-server-authenticated elicitation	No over ACP v1	No over ACP v1
Persist decisions	Settings file	N/A	auto-saved.toml	Via allow-always option
Safety checkers	Built-in	Sandbox model	Pluggable	Built-in

ACP v1 permission requests identify a tool call by toolCallId and a human-readable title, but do not carry a portable authenticated MCP server/tool identity. Current runtimes also diverge in their extensions: Cursor has emitted a flat toolName, Gemini emits the standard nested tool call without a name, and OpenCode uses its permission category as the title. TermAl therefore does not infer control-plane authority from any of those presentation fields. mode: reviewer is accepted only for Claude and Codex; Cursor, Gemini, and OpenCode can still use mode: explorer where their write policy is supported. This is a fail-fast protocol boundary, not an agent-name workaround: ACP reviewers can be enabled together when ACP exposes an authenticated tool-origin contract.

Advanced features

	Claude Code	Codex	Gemini CLI	Cursor CLI
Thread forking	CLI fork at the current head; Agent SDK supports up_to_message_id	thread/fork, optionally through lastTurnId	Saved restore points can branch earlier history	“Duplicate Chat” from a selected message in Cursor UI; not exposed by TermAl’s ACP path
Compaction	Auto summarization	thread/compact/start	Two-pass summarization	Managed internally
Rollback	/rewind can restore conversation, code, or both	thread/rollback exists but is deprecated	/rewind can restore conversation, code, or both	No documented rollback method in TermAl’s ACP path
Archival	No	thread/archive and thread/unarchive	No	No
Loop detection	Repetition detection	No	Multi-stage detection	Built-in
Hooks	Pre-commit style	No	11 lifecycle events	Session start/end, prompt, stop
Sub-agents	Via tools	Single agent	Local plus remote via A2A	cursor/task sub-agent
Checkpointing	Per-prompt conversation and edit checkpoints	Persisted thread turns and Git	Conversation snapshots plus shadow Git repo	Managed internally
Mid-turn interrupt	control_request interrupt	Yes via JSON-RPC	No IPC path (stream-json)	session/cancel
Agent modes	N/A	N/A	N/A	agent, plan, ask
Cloud handoff	No	No	No	Yes (push to cloud via & prefix)

Point-in-time conversation branching and rewind

TermAl must distinguish two operations that can look similar in the UI:

• Branch from here creates a new session containing history only through a selected completed turn. The source session remains untouched. This is the preferred, non-destructive operation.
• Rewind this conversation removes later turns from the current provider session. This is destructive and should only be offered when the provider has an explicit native primitive.

Truncating only TermAl’s local message list is not a conversation rewind. The provider would still retain the removed turns in model-visible context, leaving the transcript and the live agent state inconsistent.

Capability matrix

Agent or protocol	Native capability	Current TermAl support
Codex	Exact non-destructive fork through thread/fork(lastTurnId). The destructive thread/rollback method is deprecated.	Partial: TermAl can fork only from the current thread head and exposes rollback by trailing turn count. It does not yet persist the Codex turn ID needed to fork from a selected visible turn.
Claude Code	/rewind can restore conversation, code, or both. The Claude Agent SDK can create an exact fork with fork_session(..., up_to_message_id=...).	Not exposed. TermAl’s persistent stream-json bridge retains the Claude session ID but does not persist native message UUIDs for visible TermAl messages.
Gemini CLI	/rewind can restore conversation, code, or both. Named saved restore points can be resumed as a separate history branch.	Not exposed. TermAl runs Gemini through ACP, which does not expose Gemini’s interactive rewind workflow.
OpenCode	The native TUI supports /undo and /redo; the CLI can fork a resumed session, and the native SDK/API has message revert/unrevert operations.	Not exposed. OpenCode documents /undo and /redo as unsupported in ACP mode, which is the transport TermAl uses.
Cursor	Cursor UI can duplicate a chat from any selected message while preserving the original.	Not exposed by Cursor’s TermAl ACP connection. Cursor CLI documents resume, but no stable point-specific fork or rewind method available through this path.
Generic ACP	session/fork exists as an unstable, capability-negotiated method. Point-specific fork by message ID is a future extension, not a stable cross-agent contract.	TermAl currently records only ACP session/load and session/resume capabilities and does not dispatch session/fork.

TermAl implementation constraints

An exact action needs a durable mapping from a TermAl turn boundary to the provider’s native anchor:

Provider path	Required anchor
Codex App Server	turnId passed as lastTurnId
Claude Code / Agent SDK	Claude transcript message UUID passed as up_to_message_id
ACP	Stable messageId plus an advertised point-fork capability; a generic ACP message ID alone is insufficient
Provider-specific fallback	The provider’s documented checkpoint or revert identifier

Message array indices and “remove the last N messages” are not safe anchors. History paging, bounded-window trimming, transcript repair, tool cards, and multiple assistant items inside one provider turn can all change the number and position of visible TermAl messages. In particular, codex_thread_messages_from_json currently allocates fresh TermAl message IDs and does not retain the enclosing Codex turn ID.

Conversation state and workspace state must also remain separate. The default action should preserve files exactly as they are. A distinct Also restore files choice may be offered only when the provider can describe what it will restore and after TermAl accounts for concurrent sessions and manual changes. Provider checkpoints generally do not cover arbitrary shell commands, remote side effects, or edits made by another process.

An approximate fallback may create a fresh session and replay the visible transcript prefix, but it must be labelled approximate. Visible messages do not fully reproduce hidden tool results, hooks, provider compaction state, system context, approvals, or provider-specific reasoning items.

Recommended delivery order

1. Add Branch from here for completed Codex turns using thread/fork(lastTurnId), while preserving the source TermAl session.
2. Retire or clearly mark the Codex rollback-by-count UI as legacy because the upstream thread/rollback method is deprecated.
3. Persist Claude native message UUIDs and add exact Claude branching through the supported Agent SDK session-fork primitive.
4. Extend ACP capability capture to include session/fork, but expose it only when the connected runtime advertises support. Treat point-specific fork as unavailable until the runtime explicitly advertises that stronger contract.
5. Add provider-specific Gemini, OpenCode, and Cursor actions only through their documented programmatic surfaces; do not synthesize destructive rewind by editing the local transcript.

Primary references:

• Codex App Server protocol
• Claude Code checkpointing
• Claude Agent SDK session forking
• Gemini CLI rewind
• Gemini CLI session management
• OpenCode ACP limitations
• Cursor duplicate chat
• ACP session/fork proposal

Pricing

	Claude Code	Codex	Gemini CLI	Cursor CLI
Model	Subscription plan	Per-token API key	Per-token API key or OAuth	Cursor subscription

VS Code extension

	Claude Code	Codex	Gemini CLI	Cursor CLI
Extension	anthropic.claude-code	No official extension	vscode-ide-companion	Native (Cursor is the editor)
Connects via	Spawns CLI and speaks NDJSON	N/A	HTTP plus MCP	Built-in
Context sync	File context via tools	N/A	Active file, cursor, selection, open files	Full editor context
Auth	Same process	N/A	Bearer token via env var	Same process

ACP protocol convergence

Both Cursor CLI and Gemini CLI (experimental) implement the Agent Client Protocol (ACP), a JSON-RPC 2.0 over stdio standard originally developed between Zed and Google. This means a shared ACP adapter in TermAl could serve both agents, with differences isolated to:

Concern	Cursor CLI	Gemini CLI (ACP)
Executable	cursor	gemini
Subcommand	agent acp	--experimental-acp
Auth methods	cursor agent login, --api-key, --auth-token	OAuth, GEMINI_API_KEY, Vertex AI
Extended methods	cursor/ask_question, cursor/create_plan, cursor/update_todos	TBD
Stability	Stable	Experimental, but already used by TermAl

See individual feature briefs for full protocol details:

• cursor-cli-integration.md
• gemini-cli-integration.md

Future candidate: Kimi CLI

Kimi is not currently a supported TermAl agent, but it is a strong future-work candidate because Kimi CLI now documents ACP support through kimi --acp. The preferred path is to extend the shared ACP adapter with AcpAgent::Kimi rather than adding a separate OpenAI-compatible chat runtime.

Concern	Kimi CLI
Status in TermAl	Future work
Executable	kimi
Subcommand	--acp
Protocol	ACP over stdio
Default model candidate	kimi-k2.6
Auth/API key	Moonshot/Kimi API key, usually MOONSHOT_API_KEY
Platform caveat	Kimi CLI is currently documented for macOS and Linux only
Main risk	Technical-preview CLI and provider-specific ACP behavior

See kimi-cli-integration.md for the future-work brief.