Hermes Agent v0.15.0 “Velocity” Boosts Core Speed 4500× and Fixes Prompt Injection Vulnerability

Release Overview

Nous Research released open‑source AI‑agent framework Hermes Agent v0.15.0, code‑named “Velocity”. The update merged 747 pull requests, 1 302 commits, and contributions from 321 developers.

Basic Experience Optimizations

OpenRouter added session_id sticky routing, keeping long sessions on the same upstream provider to avoid context loss.

Update workflow added syntax validation; code is checked before pulling and failures trigger automatic rollback, preventing half‑finished updates.

Retry and rollback statuses are shown only on final failure, removing noisy retry logs during execution.

New hermes send command pushes any script output to any messaging platform, enabling one‑line notifications after scheduled tasks or script results.

Performance Refactor

Core agent loop trimmed from 16 083 lines to 14 modules totaling 3 821 lines; behavior unchanged and all tests pass, simplifying plugin development.

Kanban upgraded to a true multi‑agent platform that automatically splits task trees; a single command can assemble a full agent cluster (root, workers, gate validators, gate synthesizers, shared blackboard) with customizable model coverage, workspace paths, and schedule start times.

Cold‑start time on Termux dropped from 2.9 s to 0.8 s; hermes --version runs 63 % faster; dialogue function calls decreased from 399 k to 213 k.

Session search rebuilt: searches incur no extra cost, completing in about 20 ms per run without result confusion.

Security Upgrades

Defenses against Brainworm‑style prompt‑injection attacks added at three bottlenecks: tool output, memory reclamation, and skill storage.

New hermes audit command enables on‑demand supply‑chain auditing, powered by OSU.dev; control‑plane file‑write permissions disabled by default.

Integration with Bitwarden password manager replaces all plaintext API keys with bootstrap tokens; rotating credentials in Bitwarden’s web UI takes effect instantly, supporting EU cloud services and self‑hosted deployments.

New Features

Deliverable mode allows agents to send files directly (instead of links) with native support for Slack, Discord, Telegram, Teams, and email.

MCP directory provides curated MCP servers with an interactive selector and one‑click installation that prompts for credentials automatically.

TUI session orchestrator lets users manage multiple live sessions in a single terminal window, supporting switch, refresh, close, and dispatch without leaving the UI.

Skill packs enable bundling multiple skills; invoking /writing-day simultaneously activates content polishing, creative generation, Obsidian sync, and YouTube content creation; additional packs for code‑wiki, OpenHands, and web‑pentest are available.

Image generation now includes Krea 2 medium and large size support; the FAL backend is a plugin, and adding new image providers requires only a single file.

OpenHands orchestration routes coding tasks to OpenHands, Claude Code, Codex, or OpenCode, selecting the lowest‑cost model capable of fulfilling each sub‑task.

Deep xAI integration adds xAI web search as a plugin with SuperGrok OAuth; after the May 15 model retirement the system automatically switches to xAI, and TTS voice pause is optional, closing a credential‑leak vector.

ntfy becomes the 23rd messaging platform; no account registration is needed—just a topic URL—to push messages to phones, watches, desktops, or labs.

Developer API

Added session control API ( /api/sessions/*) supporting external session management, forking, and SSE streaming, facilitating secondary development based on Hermes.

Run hermes update to upgrade to the latest version. Full changelog: https://github.com/NousResearch/hermes-agent/releases/tag/v2026.5.28