feat: add Hermes Agent as a third-party harness

[jcrabapple]

Summary

Adds Hermes Agent (by Nous Research) as a first-class third-party harness alongside Claude Code and Gemini CLI.

Hermes Agent is an open-source, provider-agnostic AI agent framework that runs in terminals and on messaging platforms. It supports 20+ LLM providers (OpenRouter, Anthropic, OpenAI, DeepSeek, local models, etc.), persistent cross-session memory, 200+ skills, and a multi-platform gateway (Telegram, Discord, Slack, Signal, Email, and more).

Changes

New files:

• app/src/ai/agent_sdk/driver/harness/hermes.rs — ThirdPartyHarness impl with HermesHarness and HermesHarnessRunner
• app/src/ai/agent_sdk/driver/harness/hermes_tests.rs — Unit tests
• app/assets/bundled/svg/hermes.svg — Brand icon

Modified files (18):

• crates/warp_cli/src/agent.rs — Add Harness::Hermes variant
• crates/warp_core/src/ui/icons.rs — Add HermesLogo icon variant
• app/src/terminal/cli_agent.rs — Add CLIAgent::Hermes with detection, display name, brand color (#00B4D8 teal)
• app/src/ai/agent_sdk/driver/harness/mod.rs — Wire into harness_kind() factory
• app/src/ai/harness_display.rs — Display metadata (name, icon, color)
• app/src/terminal/view/ambient_agent/harness_selector.rs — Add to harness dropdown
• app/src/terminal/view/ambient_agent/view_impl.rs — Harness detection
• app/src/ai/agent_sdk/mod.rs — Orchestration label
• app/src/ai/ambient_agents/task.rs — Harness name parsing
• app/src/ai/agent_management/view.rs — Agent management list
• app/src/ai/agent/conversation.rs — AIAgentHarness::Hermes variant
• app/src/ai/blocklist/history_model/conversation_loader.rs — Conversation loading
• app/src/pane_group/mod.rs — Pane group harness mapping
• app/src/pane_group/pane/local_harness_launch.rs — Local child launch support
• app/src/server/telemetry/events.rs — CLIAgentType::Hermes telemetry
• app/src/terminal/cli_agent_sessions/listener/mod.rs — Session listener
• app/src/terminal/cli_agent_sessions/plugin_manager/mod.rs — Plugin manager
• app/src/terminal/view/use_agent_footer/mod.rs — Rich input strategy

Design Decisions

• One-shot mode: Uses hermes chat -q (non-interactive query mode) with --yolo for auto-approving tool calls, matching how Claude Code uses --dangerously-skip-permissions. This avoids PTY/prompt_toolkit compatibility issues.
• Prompt via temp file: Prompt content is written to a temp file and read via $(cat ...) to avoid shell-quoting issues with complex content (skill instructions, code blocks, etc.).
• Session handler: Uses the DefaultSessionListener (same as Claude, OpenCode, Gemini, Auggie) since Hermes does not yet emit structured OSC events.
• No resume support yet: Like Gemini, Hermes does not support conversation resume. The fetch_resume_payload default returns Ok(None).
• Local child harness: Supported via hermes chat -q <prompt> --yolo, added to parse_local_child_harness.

Testing

• cargo check -p warp_cli — passes
• cargo check -p warp — passes (full app crate)
• Unit tests in hermes_tests.rs cover harness variant, CLI agent, install docs URL, command generation, and harness_kind dispatch

Related

• Hermes Agent repo
• Hermes Agent docs
• Similar to Support Kiro CLI Agent Integration in Warp #9066 (Kiro CLI integration request) — same pattern, same trait
• @oss-maintainers

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[oz-for-oss]

Overview

This PR adds Hermes Agent as a third-party harness across CLI parsing, UI metadata, session detection, local child launch, telemetry, and a new ThirdPartyHarness runner.

Concerns

• Server-loaded conversation metadata still cannot deserialize Hermes: app/src/server/server_api/ai.rs converts only Oz, Claude Code, and Gemini from warp_graphql::ai::AgentHarness, while crates/graphql/src/api/ai.rs also lacks a Hermes variant. As a result, Hermes conversations created by this runner will come back as AIAgentHarness::Unknown, so the new Hermes restore/display branches will not be reached.

Security

• The Hermes runner expands the staged prompt into the hermes process argv, which can expose prompt contents through process listings; prefer stdin or a CLI-supported prompt-file option if available.

Verdict

Found: 0 critical, 1 important, 1 suggestions

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[oz-for-oss]

💡 [SUGGESTION] [SECURITY] This expands the full prompt into the hermes process argv, so prompt contents can be exposed via process listings; prefer stdin or a Hermes prompt-file flag if available.