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+---
+title: Hermes Runtime & Multi-Provider Dispatch
+description: Hermes is Molecule AI's built-in inference router. Route tasks to Anthropic, Gemini, or any OpenAI-compatible model through native dispatch paths — with correct multi-turn history on all three.
+---
+
+import { Callout } from 'fumadocs-ui/components/callout';
+
+# Hermes Runtime & Multi-Provider Dispatch
+
+Hermes is Molecule AI's built-in inference router powering `runtime: hermes` workspaces. It supports three dispatch paths — a native Anthropic Messages API path, a native Gemini `generateContent` path, and an OpenAI-compatible shim for 13+ other providers — keyed automatically by which API secret is present on the workspace.
+
+Phases 2a, 2b, and 2c are fully merged to `main`:
+
+- **Phase 2a** (PR #240) — native Anthropic dispatch
+- **Phase 2b** (PR #255) — native Gemini dispatch with correct `role: "model"` + `parts` wire format
+- **Phase 2c** (PR #267) — correct multi-turn history preserved as turns (not flattened) on all three paths
+
+<Callout type="info">
+  **Phase 2d (roadmap):** tool_use / tool_result blocks, vision content, system instructions, and streaming on the native paths are scoped for a future release. See the [capability table](#capability-table) below.
+</Callout>
+
+---
+
+## Dispatch table
+
+Hermes selects an inference path based on which API key is set on the workspace. Keys are resolved in priority order:
+
+> `HERMES_API_KEY` → `OPENROUTER_API_KEY` → `ANTHROPIC_API_KEY` → `GEMINI_API_KEY`
+
+The first key found wins. Don't set `HERMES_API_KEY` if you want native Anthropic or Gemini dispatch — it takes priority and routes through the OpenAI-compat shim.
+
+| Key present | Dispatch path | Provider | Wire format |
+|---|---|---|---|
+| `ANTHROPIC_API_KEY` | Native Anthropic | Anthropic | Messages API — `{role, content}` |
+| `GEMINI_API_KEY` | Native Gemini | Google | `generateContent` — `{role: "model", parts: [{text}]}` |
+| `OPENROUTER_API_KEY` / `HERMES_API_KEY` / other | OpenAI-compat shim | 13+ providers | OpenAI Chat Completions |
+| None | Error | — | — |
+
+**Fail-loud semantics:** if `ANTHROPIC_API_KEY` is set but the `anthropic` Python package is not installed in the workspace image, Hermes raises a `RuntimeError` immediately — before any inference attempt. Same for `google-genai`. Silent fallback to the compat shim would mask format errors; Hermes fails loudly instead.
+
+---
+
+## Secrets
+
+Set provider keys as global or workspace-level secrets:
+
+```bash
+# Native Anthropic dispatch
+curl -X PUT http://localhost:8080/settings/secrets \
+  -H "Content-Type: application/json" \
+  -d '{"key":"ANTHROPIC_API_KEY","value":"sk-ant-..."}'
+
+# Native Gemini dispatch
+curl -X PUT http://localhost:8080/settings/secrets \
+  -H "Content-Type: application/json" \
+  -d '{"key":"GEMINI_API_KEY","value":"YOUR-GEMINI-KEY"}'
+
+# OpenAI-compat shim (OpenRouter, Groq, Mistral, etc.)
+curl -X PUT http://localhost:8080/settings/secrets \
+  -H "Content-Type: application/json" \
+  -d '{"key":"OPENROUTER_API_KEY","value":"sk-or-..."}'
+```
+
+To force a specific workspace to use Gemini dispatch when a global `ANTHROPIC_API_KEY` is set, clear the key at the workspace level:
+
+```bash
+curl -X PUT http://localhost:8080/workspaces/$GEMINI_WS/secrets \
+  -H "Content-Type: application/json" \
+  -d '{"key":"ANTHROPIC_API_KEY","value":""}'
+```
+
+---
+
+## Quickstart
+
+### Native Anthropic dispatch
+
+```bash
+export MOLECULE_API=http://localhost:8080
+
+# 1. Store your Anthropic key
+curl -s -X PUT $MOLECULE_API/settings/secrets \
+  -H "Content-Type: application/json" \
+  -d '{"key":"ANTHROPIC_API_KEY","value":"sk-ant-YOUR-KEY"}' | jq .
+
+# 2. Create a Hermes workspace
+ANTHROPIC_WS=$(curl -s -X POST $MOLECULE_API/workspaces \
+  -H "Content-Type: application/json" \
+  -d '{
+    "name": "hermes-anthropic",
+    "role": "Inference worker — native Anthropic path",
+    "runtime": "hermes",
+    "model": "anthropic:claude-sonnet-4-5"
+  }' | jq -r '.id')
+
+# 3. Wait for ready
+until curl -s $MOLECULE_API/workspaces/$ANTHROPIC_WS \
+    | jq -r '.status' | grep -q ready; do sleep 5; done
+
+# 4. Confirm dispatch path
+curl -s -X POST $MOLECULE_API/workspaces/$ANTHROPIC_WS/a2a \
+  -H "Content-Type: application/json" \
+  -d '{
+    "jsonrpc":"2.0","id":"probe-1","method":"message/send",
+    "params":{"message":{"role":"user","parts":[{"kind":"text",
+    "text":"Which provider API are you calling to generate this response?"}]}}
+  }' | jq '.result.parts[0].text'
+# Expected: confirms Anthropic Messages API — no OpenAI-compat translation layer
+```
+
+### Native Gemini dispatch
+
+```bash
+# 1. Store your Gemini key
+curl -s -X PUT $MOLECULE_API/settings/secrets \
+  -H "Content-Type: application/json" \
+  -d '{"key":"GEMINI_API_KEY","value":"YOUR-GEMINI-KEY"}' | jq .
+
+# 2. Create a Gemini workspace
+GEMINI_WS=$(curl -s -X POST $MOLECULE_API/workspaces \
+  -H "Content-Type: application/json" \
+  -d '{
+    "name": "hermes-gemini",
+    "role": "Inference worker — native Gemini path",
+    "runtime": "hermes",
+    "model": "gemini:gemini-2.0-flash"
+  }' | jq -r '.id')
+
+# 3. Wait for ready
+until curl -s $MOLECULE_API/workspaces/$GEMINI_WS \
+    | jq -r '.status' | grep -q ready; do sleep 5; done
+
+# 4. Confirm dispatch path
+curl -s -X POST $MOLECULE_API/workspaces/$GEMINI_WS/a2a \
+  -H "Content-Type: application/json" \
+  -d '{
+    "jsonrpc":"2.0","id":"probe-2","method":"message/send",
+    "params":{"message":{"role":"user","parts":[{"kind":"text",
+    "text":"Which provider API are you calling?"}]}}
+  }' | jq '.result.parts[0].text'
+# Expected: confirms Google generateContent — role: "model" + parts[] wrapper used correctly
+```
+
+### Multi-turn history (Phase 2c)
+
+```bash
+# Turn 1
+curl -s -X POST $MOLECULE_API/workspaces/$ANTHROPIC_WS/a2a \
+  -H "Content-Type: application/json" \
+  -d '{
+    "jsonrpc":"2.0","id":"turn-1","method":"message/send",
+    "params":{"message":{"role":"user","parts":[{"kind":"text",
+    "text":"My name is Alice. Remember that."}]}}
+  }' | jq '.result.parts[0].text'
+
+# Turn 2 — history is threaded as turns, not flattened into a single blob
+curl -s -X POST $MOLECULE_API/workspaces/$ANTHROPIC_WS/a2a \
+  -H "Content-Type: application/json" \
+  -d '{
+    "jsonrpc":"2.0","id":"turn-2","method":"message/send",
+    "params":{"message":{"role":"user","parts":[{"kind":"text",
+    "text":"What is my name?"}]}}
+  }' | jq '.result.parts[0].text'
+# Expected: "Alice" — role attribution is preserved across turns
+```
+
+Before Phase 2c, multi-turn history was flattened into a single user blob. The model could often recover context from the text but lost clean role attribution, which caused failures on structured prompts. Phase 2c passes turns as turns: OpenAI and Anthropic use `{role, content}`; Gemini uses `{role: "model", parts: [{text}]}`.
+
+---
+
+## Multi-provider teams
+
+An orchestrator can fan tasks to Anthropic and Gemini workers simultaneously, each routed through its native path — no application-level provider switching required:
+
+```bash
+# Fan out — both workers fire via delegate_task_async
+curl -s -X POST $MOLECULE_API/workspaces/$ORCH_ID/a2a \
+  -H "Content-Type: application/json" \
+  -d "{
+    \"jsonrpc\":\"2.0\",\"id\":\"fan-1\",\"method\":\"message/send\",
+    \"params\":{\"message\":{\"role\":\"user\",\"parts\":[{\"kind\":\"text\",
+    \"text\":\"delegate_task_async $ANTHROPIC_WS 'Draft release notes for v2.1' AND delegate_task_async $GEMINI_WS 'Summarise the last 30 days of support tickets'\"}]}}
+  }" | jq .
+```
+
+Both workers receive correctly formatted messages through their native paths. No LiteLLM proxy layer. No format translation overhead on every request.
+
+---
+
+## Capability table
+
+### Shipped (Phases 2a + 2b + 2c — all merged to main)
+
+| Capability | OpenAI-compat shim | Anthropic native | Gemini native |
+|---|---|---|---|
+| Plain text, single-turn | ✅ | ✅ | ✅ |
+| Multi-turn history | ⚠️ flattened into one user blob | ✅ role-attributed turns | ✅ `role: "model"` + `parts` wrapper |
+| Correct Gemini wire format | ❌ wrong role, missing parts | — | ✅ |
+| No compat-shim translation overhead | ❌ every request translated | ✅ | ✅ |
+
+### Roadmap — Phase 2d (not yet shipped)
+
+| Capability | Anthropic native | Gemini native |
+|---|---|---|
+| `tool_use` / `tool_result` blocks | 📋 Phase 2d | 📋 Phase 2d |
+| Vision content blocks | 📋 Phase 2d | 📋 Phase 2d |
+| System instructions | 📋 Phase 2d | 📋 Phase 2d |
+| Extended thinking | 📋 Phase 2d | — |
+| Streaming | 📋 Phase 2d | 📋 Phase 2d |
+
+---
+
+## Troubleshooting
+
+### `RuntimeError: anthropic is not installed`
+
+The `anthropic` Python package is missing from the workspace image. Add `anthropic` to `requirements.txt` in your custom image and rebuild, or use the standard `molecule-ai-workspace-template-hermes` image.
+
+### Gemini workspace getting Anthropic dispatch instead
+
+A global `ANTHROPIC_API_KEY` is taking priority. Clear it at the workspace level:
+```bash
+curl -X PUT $MOLECULE_API/workspaces/$GEMINI_WS/secrets \
+  -d '{"key":"ANTHROPIC_API_KEY","value":""}'
+```
+
+### Multi-turn context lost between calls
+
+Each workspace maintains its own history buffer. Ensure you are sending all turns of a conversation to the same workspace. A2A `context_id` scopes history within the workspace.
+
+### OpenAI-compat shim returns garbled Gemini output
+
+If you are routing a Gemini model through a key that triggers the compat shim (e.g. `OPENROUTER_API_KEY`), you will see the old role/format translation issues. Switch to `GEMINI_API_KEY` for native dispatch.
+
+---
+
+## See also
+
+- [Concepts — Workspaces](/docs/concepts#workspaces)
+- [API Reference — POST /workspaces](/docs/api-reference#post-workspaces)
+- [Google ADK Runtime](/docs/google-adk) — Gemini-native alternative to Hermes for ADK-first workflows
+- PR #240: [Phase 2a — native Anthropic dispatch](https://github.com/Molecule-AI/molecule-core/pull/240)
+- PR #255: [Phase 2b — native Gemini dispatch](https://github.com/Molecule-AI/molecule-core/pull/255)
+- PR #267: [Phase 2c — multi-turn history on all paths](https://github.com/Molecule-AI/molecule-core/pull/267)
+- Issue [#513](https://github.com/Molecule-AI/molecule-core/issues/513)
diff --git a/content/docs/meta.json b/content/docs/meta.json
index 7157fa9..ebafd13 100644
--- a/content/docs/meta.json
+++ b/content/docs/meta.json
@@ -17,6 +17,7 @@
     "observability",
     "troubleshooting",
     "---Runtimes---",
-    "google-adk"
+    "google-adk",
+    "hermes"
   ]
 }