Agent Breaking Changes_

← Hermes Agent

Hermes Agent Hermes Agent v0.15.0 (2026.5.28) — The Velocity Release

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2026-05-28 · official notes

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# Hermes Agent v0.15.0 (v2026.5.28)

**Release Date:** May 28, 2026
**Since v0.14.0:** 1,302 commits · 747 merged PRs · 1,746 files changed · 282,712 insertions · 36,699 deletions · 560+ issues closed (15 P0, 65 P1, 19 security-tagged) · 321 community contributors (including co-authors)

> **The Velocity Release.** Hermes gets dramatically faster — to start, to run, to ship work, and to grow. The 16,083-line `run_agent.py` collapses to 3,821 (-76%) across 14 cohesive `agent/*` modules. Kanban grew into a real multi-agent platform across 104 PRs — orchestrator auto-decomposition, swarm topology, scheduled tasks, worktree-per-task, per-task model overrides. The cold-start perf wave keeps going: another second shaved off launch, 47% fewer per-conversation function calls, `hermes --version` flipping the head-to-head benchmark against Codex CLI. `session_search` is 4,500× faster and free now. Promptware defense lands against Brainworm-class attacks. Bitwarden Secrets Manager replaces N per-provider API keys with one bootstrap token. Skill bundles let one slash command load a whole workflow. The Ink TUI gets a multi-session orchestrator. Two new image_gen providers (Krea 2 Medium + Large, FAL ported to plugin), the Nous-approved MCP catalog with an interactive picker, an OpenHands orchestration skill, ntfy as the 23rd messaging platform, and a deep xAI integration round (Web Search plugin, xai-oauth `hermes proxy` upstream, retired-May-15 model detection + `hermes migrate xai`, natural TTS speech-tag pauses, base_url leak guard, OpenAI-style execution guidance for Grok). 15 P0 + 65 P1 closures alongside.

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## ✨ Highlights

- **The Big Refactor — `run_agent.py` is no longer 16,000 lines** — The file at the heart of Hermes — the agent conversation loop — has been reduced from 16,083 lines to 3,821 (-76%), with the extracted code redistributed across 14 cohesive modules under `agent/`. Behavior is unchanged: every extraction keeps a thin forwarder on `AIAgent`, every test patch path still works, every external caller is compatible. The reason you care: future Hermes development moves faster, plugin authors can finally grep the codebase, and the file that took 90 seconds to load in your editor opens in a blink. ([#27248](https://github.com/NousResearch/hermes-agent/pull/27248))

- **Kanban grew into a real multi-agent platform — 104 PRs end to end** — Triage auto-decomposes one task into a tree of sub-tasks. `hermes kanban swarm` creates a full Swarm v1 graph in one command — root, parallel workers, gated verifier, gated synthesizer, shared blackboard. Tasks support per-task model overrides (cheap models for boilerplate, expensive ones for hard sub-tasks), board-level default workdirs, per-task worktree paths and branches, scheduled start times, configurable claim TTL, retry fingerprinting, stale-task detection, respawn guards, and a drag-to-delete trash zone. Workers report through `/workers/active`, `/runs/{id}`, and `/inspect` endpoints. ([#27572](https://github.com/NousResearch/hermes-agent/pull/27572), [#28443](https://github.com/NousResearch/hermes-agent/pull/28443), [#28364](https://github.com/NousResearch/hermes-agent/pull/28364), [#28394](https://github.com/NousResearch/hermes-agent/pull/28394), [#28462](https://github.com/NousResearch/hermes-agent/pull/28462), [#28384](https://github.com/NousResearch/hermes-agent/pull/28384), [#28467](https://github.com/NousResearch/hermes-agent/pull/28467), [#28455](https://github.com/NousResearch/hermes-agent/pull/28455), [#28452](https://github.com/NousResearch/hermes-agent/pull/28452), [#28432](https://github.com/NousResearch/hermes-agent/pull/28432), [#28468](https://github.com/NousResearch/hermes-agent/pull/28468), [#28420](https://github.com/NousResearch/hermes-agent/pull/28420))

- **Cold-start perf wave keeps going — another second saved, 47% fewer per-turn function calls** — Three new optimization rounds: defer `openai._base_client` import (-240ms / -17MB on every CLI invocation), hot-path optimizations cut 47% of per-conversation function calls (399k → 213k for 31-turn chat), defer compression-feasibility check (-170 to -290ms on every agent construction), adaptive subprocess polling (-195ms per tool call, 1+ second per turn). Termux cold start drops from 2.9s to 0.8s. `hermes --version` cold drops 63% (701ms → 258ms), flipping the head-to-head benchmark against Codex CLI from 5/11 wins to 6/11. ([#28864](https://github.com/NousResearch/hermes-agent/pull/28864), [#28866](https://github.com/NousResearch/hermes-agent/pull/28866), [#28957](https://github.com/NousResearch/hermes-agent/pull/28957), [#29006](https://github.com/NousResearch/hermes-agent/pull/29006), [#29419](https://github.com/NousResearch/hermes-agent/pull/29419), [#30121](https://github.com/NousResearch/hermes-agent/pull/30121), [#30609](https://github.com/NousResearch/hermes-agent/pull/30609), [#31968](https://github.com/NousResearch/hermes-agent/pull/31968))

- **`session_search` rebuilt — no LLM, no cost, 4,500× faster** — The old `session_search` was an aux-LLM-powered tool that cost ~$0.30/call and took ~30 seconds to summarize three sessions, sometimes confabulating when the right session wasn't even in the FTS5 hit list. The new shape is one tool with three modes (discovery, scroll, browse) inferred from which args are set — no `mode` parameter, no aux-LLM, no config knob, no companion skill. Discovery is ~20ms instead of ~90s; scroll is ~1ms. Searching your past sessions for context is now free and instant. ([#27590](https://github.com/NousResearch/hermes-agent/pull/27590))

- **Promptware defense — Brainworm-class attacks blocked at three chokepoints** — Inspired by recent Brainworm / Promptware Kill Chain research (Origin HQ, arxiv 2601.09625), Hermes now defends the context window against prompt-injection attacks that try to hijack the agent via tool output, recalled memory, or stored skills. Single source of truth (`tools/threat_patterns.py`) with ~15 new Brainworm/C2 patterns; recalled memory is scanned at load time; tool results get delimiter markers so a malicious file or remote service can't impersonate Hermes' own system content. Paired with a new `security-guidance` plugin that pattern-matches dangerous code writes. ([#32269](https://github.com/NousResearch/hermes-agent/pull/32269), [#33131](https://github.com/NousResearch/hermes-agent/pull/33131), [#9151](https://github.com/NousResearch/hermes-agent/pull/9151))

- **Bitwarden Secrets Manager — one bootstrap token replaces every per-provider API key** — Stop keeping plaintext API keys in `~/.hermes/.env`. Install Bitwarden Secrets Manager (`bws` auto-installs lazily on first use), point Hermes at it with one bootstrap token (`BWS_ACCESS_TOKEN`), and every credential you need comes from Bitwarden at startup. Rotate a key in the Bitwarden web app and the rotation actually takes effect — Bitwarden defaults to source-of-truth so its values overwrite matching env vars on startup. Flip `secrets.bitwarden.override_existing: false` to invert. EU Cloud and self-hosted Bitwarden server URLs supported. Detected credentials are now labeled with their source so you can see at a glance which keys came from Bitwarden vs. the local env. ([#30035](https://github.com/NousResearch/hermes-agent/pull/30035), [#31378](https://github.com/NousResearch/hermes-agent/pull/31378), [#30364](https://github.com/NousResearch/hermes-agent/pull/30364))

- **ntfy as the 23rd messaging platform — push notifications without an account** — ntfy is the self-hostable push-notification service with no signup, no API key, just a topic URL. Hermes now adapts to it as a platform plugin (zero edits to core), so your agent can send you push notifications from any cron job, kanban task completion, or chat `send_message` — to your phone, your watch, your desktop, your homelab. (salvages [#30625](https://github.com/NousResearch/hermes-agent/pull/30625) → originally [#4043](https://github.com/NousResearch/hermes-agent/pull/4043)) ([#30867](https://github.com/NousResearch/hermes-agent/pull/30867))

- **Skill bundles — `/<name>` loads multiple skills at once** — A skill bundle is a named group of skills that loads them all together with one slash command. Set up your "writing day" bundle (humanizer + ideation + obsidian + youtube-content) and `/writing-day` activates all four for the session. Skills Hub now has health checks, a freshness badge, and a watchdog cron. Three new optional skills land: `code-wiki` (Karpathy's LLM-Wiki, persistent indexed dev wiki), `openhands` (delegate to OpenHands for parallel coding agents), and `web-pentest` (OWASP-style web pentest recipes). ([#28373](https://github.com/NousResearch/hermes-agent/pull/28373), [#32345](https://github.com/NousResearch/hermes-agent/pull/32345), [#32240](https://github.com/NousResearch/hermes-agent/pull/32240), [#32261](https://github.com/NousResearch/hermes-agent/pull/32261), [#32265](https://github.com/NousResearch/hermes-agent/pull/32265))

- **TUI session orchestrator — multiple live sessions in one TUI window** — The Ink TUI gained an active-session switcher overlay. List, switch between, refresh, and close multiple live process-local sessions without leaving the TUI; dispatch a new session with a session-scoped model picker. Plus a wave of TUI polish — mouse-tracking DEC mode presets, scrollback preservation across branches and termux, slash-dropdown fixes, x.com link rendering, and CJK / IME input rendering improvements. (salvages [#27642](https://github.com/NousResearch/hermes-agent/pull/27642)) ([#32980](https://github.com/NousResearch/hermes-agent/pull/32980), [#30084](https://github.com/NousResearch/hermes-agent/pull/30084))

- **Two new image_gen providers — Krea 2 Medium + Large, FAL ported to plugin** — Krea joins the image_gen lineup as a built-in plugin: `Krea 2 Medium` ($0.03) and `Krea 2 Large` ($0.06), auto-discovered, selectable via `hermes tools` → Image Generation → Krea. Available through both the native Krea plugin and the FAL.ai catalog. The FAL.ai backend got pulled out of the monolithic image-generation tool into `plugins/image_gen/fal/`, completing the four-way architectural parity already established by web, browser, and video_gen — new image providers are now one file, not a fork. ([#33236](https://github.com/NousResearch/hermes-agent/pull/33236), [#30380](https://github.com/NousResearch/hermes-agent/pull/30380), [#33506](https://github.com/NousResearch/hermes-agent/pull/33506))

- **Nous-approved MCP catalog with interactive picker** — A curated catalog of Nous-vetted MCP servers, mirroring the optional-skills shape. Run `hermes mcp` and you get an interactive picker; install with one keystroke, credentials prompted at install time and written to `~/.hermes/.env`. Ships with the n8n manifest first. Closes the discovery gap that left users hunting GitHub for trusted MCP servers. ([#30870](https://github.com/NousResearch/hermes-agent/pull/30870))

- **OpenHands orchestration skill** — A new optional skill under `optional-skills/autonomous-ai-agents/openhands/` lets the agent delegate coding tasks to the OpenHands CLI alongside `claude-code`, `codex`, and `opencode`. OpenHands is the model-agnostic member of that family — any LiteLLM-supported provider works (OpenAI, Anthropic, OpenRouter, your own), so you can route a sub-task to the cheapest model that can finish it. Drop-in worker for kanban swarms and `/delegate` flows. (closes [#477](https://github.com/NousResearch/hermes-agent/issues/477)) ([#32261](https://github.com/NousResearch/hermes-agent/pull/32261))

- **Deep xAI integration round — Web Search plugin, OAuth proxy upstream, May 15 retirement detection, natural TTS, security hardening** — Six interlocking xAI improvements:
    - **xAI Web Search** lands as a `plugins/web/xai/` provider, slots alongside Brave / Tavily / Exa / SearXNG / DDGS / Firecrawl — reuses your existing Grok OAuth or `XAI_API_KEY` credentials, no new env vars. ([#29042](https://github.com/NousResearch/hermes-agent/pull/29042))
    - **`hermes proxy` gains an xAI upstream** — your local OpenAI-compatible endpoint can now be backed by SuperGrok OAuth, no PKCE-refresh code to write in your client. ([#28356](https://github.com/NousResearch/hermes-agent/pull/28356))
    - **May 15 model retirement detection** — `grok-4`, `grok-4-fast{,-reasoning,-non-reasoning}`, `grok-3`, `grok-code-fast-1`, `grok-imagine-image-pro` etc. are detected in doctor and chat startup, with `hermes migrate xai` to one-shot config migration to the supported model. No more silent 404s after the retirement date. ([#29277](https://github.com/NousResearch/hermes-agent/pull/29277))
    - **Opt-in `auto_speech_tags`** for xAI TTS — inserts light `[pause]` tags between paragraphs and sentences for more natural-sounding voice replies. Default OFF. ([#29376](https://github.com/NousResearch/hermes-agent/pull/29376))
    - **`xai-oauth` `base_url` pinned to `x.ai` origin** — closes a silent credential-leak vector where `XAI_BASE_URL` could repoint OAuth-authenticated inference to an attacker-controlled host. ([#28952](https://github.com/NousResearch/hermes-agent/pull/28952))
    - **OpenAI-style execution guidance applied to Grok models** — Grok and xai-oauth now get the same family-specific execution discipline block GPT/Codex have, so the model stops claiming completion without tool calls and stops suggesting workarounds instead of using existing tools. ([#27797](https://github.com/NousResearch/hermes-agent/pull/27797))
    - Plus `x_search` degraded-results surfacing, tier-gated 403 with API-key fallback, PKCE `code_challenge` round-trip fix, dead-token quarantine on terminal refresh failure, MiniMax-style short-token refresh on per-request, and `WKE=unauthenticated` honor at both classifier sites. ([#29484](https://github.com/NousResearch/hermes-agent/pull/29484), [#28351](https://github.com/NousResearch/hermes-agent/pull/28351), [#27560](https://github.com/NousResearch/hermes-agent/pull/27560), [#28116](https://github.com/NousResearch/hermes-agent/pull/28116), [#30619](https://github.com/NousResearch/hermes-agent/pull/30619), [#30872](https://github.com/NousResearch/hermes-agent/pull/30872))

---

## 🏗️ Core Agent & Architecture

### The Big Refactor — `run_agent.py` 16k → 3.8k

- `run_agent.py` from 16,083 → 3,821 lines (-76%), extracted into 14 cohesive `agent/*` modules. `run_conversation` alone was 3,877 lines before the refactor. Every extraction keeps a thin forwarder on `AIAgent`, every test-patch path is preserved, every external caller stays compatible. ([#27248](https://github.com/NousResearch/hermes-agent/pull/27248))

### Agent loop & conversation

- Auxiliary task layered fallback (primary → chain → main agent → graceful fail) on capacity errors (402/429/connection). (salvages [#26811](https://github.com/NousResearch/hermes-agent/pull/26811) + [#26998](https://github.com/NousResearch/hermes-agent/pull/26998)) ([#27625](https://github.com/NousResearch/hermes-agent/pull/27625))
- Buffer retry/fallback status; surface only on terminal failure (no more noisy "retrying..." spam in mid-run output). ([#33816](https://github.com/NousResearch/hermes-agent/pull/33816))
- Host contract for external context engines — condenses 5 prior PRs into one extension surface. ([#33750](https://github.com/NousResearch/hermes-agent/pull/33750))
- Fallback immediately on provider content-policy blocks. ([#33883](https://github.com/NousResearch/hermes-agent/pull/33883))
- Re-pad `reasoning_content` on cross-provider fallback to require-side providers. (salvage [#33784](https://github.com/NousResearch/hermes-agent/pull/33784)) ([#33795](https://github.com/NousResearch/hermes-agent/pull/33795))
- Per-turn tool-outcome verifier — patch tool gets indent preservation, CRLF preservation, per-file failure escalation. ([#32273](https://github.com/NousResearch/hermes-agent/pull/32273))
- Single-knob native vision for custom-provider models. ([#29679](https://github.com/NousResearch/hermes-agent/pull/29679))
- Background review fork isolated from external memory plugins. ([#27190](https://github.com/NousResearch/hermes-agent/pull/27190))
- Background review inherits parent toolset config for `tools[]` cache parity. ([#29704](https://github.com/NousResearch/hermes-agent/pull/29704))
- Recover from providers returning list-type tool content. ([#30259](https://github.com/NousResearch/hermes-agent/pull/30259))
- Treat partial-stream stub responses as length truncation rather than clean stop. ([#30998](https://github.com/NousResearch/hermes-agent/pull/30998))
- OpenAI execution guidance applied to xAI Grok / xai-oauth. ([#27797](https://github.com/NousResearch/hermes-agent/pull/27797))
- ContextVars propagate to concurrent tool worker threads.
- Preload `jiter` native parser. ([#33692](https://github.com/NousResearch/hermes-agent/pull/33692))
- Expose context engine tools with saved toolsets. (salvage of [#31194](https://github.com/NousResearch/hermes-agent/pull/31194)) ([#33719](https://github.com/NousResearch/hermes-agent/pull/33719))

### Sessions & memory

- `session_search` rebuilt — single-shape (discovery + scroll + browse), no aux-LLM, ~20ms vs. ~90s. ([#27590](https://github.com/NousResearch/hermes-agent/pull/27590))
- Salvage [#29182](https://github.com/NousResearch/hermes-agent/pull/29182) — opt-in JSON snapshot writer for sessions. ([#29278](https://github.com/NousResearch/hermes-agent/pull/29278))
- Persist `platform_message_id` for recall across gateway restarts. ([#29449](https://github.com/NousResearch/hermes-agent/pull/29449))
- Inline memory-context mentions stay visible in conversation. ([#28132](https://github.com/NousResearch/hermes-agent/pull/28132))
- Recalled memory labeled informational, not authoritative. ([#28583](https://github.com/NousResearch/hermes-agent/pull/28583))
- Memory + context-engine tool injection gated on `enabled_toolsets`. ([#30177](https://github.com/NousResearch/hermes-agent/pull/30177))
- Guard against external drift in `MEMORY.md` / `USER.md`. ([#30877](https://github.com/NousResearch/hermes-agent/pull/30877))
- Honcho runtime peer mapping — correctness follow-ups + setup wizard + docs. ([#30077](https://github.com/NousResearch/hermes-agent/pull/30077))
- Periodic memory logging for leak detection. (salvage of [#17667](https://github.com/NousResearch/hermes-agent/pull/17667)) ([#27102](https://github.com/NousResearch/hermes-agent/pull/27102))

### Codex / Responses-API maturation

- TTFB watchdog for stalled Codex Responses streams. ([#32042](https://github.com/NousResearch/hermes-agent/pull/32042))
- Actionable hint when stale-call detector fires on known silent-reject pattern. ([#32016](https://github.com/NousResearch/hermes-agent/pull/32016), [#33133](https://github.com/NousResearch/hermes-agent/pull/33133))
- Drop SDK `responses.stream()` helper; consume events directly. ([#33042](https://github.com/NousResearch/hermes-agent/pull/33042))
- Gracefully recover from `invalid_encrypted_content`. (salvage of [#10144](https://github.com/NousResearch/hermes-agent/pull/10144)) ([#33035](https://github.com/NousResearch/hermes-agent/pull/33035))
- Recover Codex Responses streams with null output. ([#32963](https://github.com/NousResearch/hermes-agent/pull/32963), [#33390](https://github.com/NousResearch/hermes-agent/pull/33390))
- Drop foreign-issuer reasoning and transient `rs_tmp` reasoning replay state. ([#33156](https://github.com/NousResearch/hermes-agent/pull/33156), [#33146](https://github.com/NousResearch/hermes-agent/pull/33146))
- Codex 429 quota classified as rate-limit, not missing credentials. ([#33168](https://github.com/NousResearch/hermes-agent/pull/33168))
- Codex chat path falls back to credential_pool when singleton is empty. ([#33189](https://github.com/NousResearch/hermes-agent/pull/33189))
- Codex re-auth syncs credential_pool. ([#33164](https://github.com/NousResearch/hermes-agent/pull/33164))
- Omit `tools` key whe
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