MCP Servers Plugins Webhooks Tools

MCP Servers / Plugins / Webhooks / Tools

Four sidebar items that all extend what Hermes can do. Grouped here because the workflows are similar.

MCP Servers

Manage Model Context Protocol servers Hermes connects to. Two ways to add:

• Curated presets — Filesystem, GitHub, Postgres, Slack, Linear, Sentry, Notion, Stripe, Puppeteer, Memory, Fetch, and more. Picking a preset fills in the command, args, and the env keys it needs.
• Custom — stdio (command + args) or HTTP (URL + optional bearer auth).

Per-server detail view:

• Enable / disable toggle.
• Environment variable + header editor — written through HermesEnvService so existing comments and blanks are preserved.
• Tool include / exclude filters (whitelist / blacklist what the server exposes).
• Resources / prompts toggles.
• Request and connect timeouts.
• OAuth token detection and clearing.
• Test Connection runs hermes mcp test and surfaces the discovered tool list inline.

A gateway-restart banner appears after config changes that require a reload.

MCP servers are stored in config.yaml under the mcp_servers key; the model is HermesMCPServer.

mTLS client certificates (v2.10.0+, Hermes v0.15+)

HTTP and SSE MCP servers gain a mutual-TLS section in the server editor: a client certificate path (client_cert), a private-key path (client_key), and an SSL-verify control (ssl_verify) with an optional custom CA-bundle path. The verify toggle and the CA-bundle path are independent — turning verification off doesn't wipe a typed CA path. Gated on HermesCapabilities.hasMCPClientCerts.

MCP catalog browse (v2.10.0+, Hermes v0.15+)

A read-only Browse catalog sheet renders hermes mcp catalog output (the Nous-curated MCP registry) so you can see what's available before adding a server. Browse-only — picking an entry doesn't auto-install. Gated on HermesCapabilities.hasMCPCatalog.

Plugins

Hermes plugins are git-cloned into ~/.hermes/plugins/. Scarf reads the directory directly for reliable state.

Operations:

• Install via Git URL or owner/repo shorthand.
• Update (pulls latest).
• Remove.
• Enable / disable.

Webhooks

Create, list, test-fire, and remove webhook subscriptions:

• Endpoint URL, event filter, optional secret.
• Test fire sends a synthetic event so you can verify the receiver before going live.
• Detects the "platform not enabled" state and links to the gateway setup.

Tools

Enable / disable Hermes toolsets per platform.

• Each platform (Telegram, Discord, Slack, etc.) gets its own toolset list.
• Connectivity-aware platform menu: green / orange / grey / red dots match the gateway's reported state.
• Toggling calls hermes tools enable/disable via context.runHermes.

Fixed in 1.6: all 13 platforms now appear here (was previously stuck on CLI only).

Credential Pools

(Same Configure section, related concept.) Per-provider credential rotation:

• API key + OAuth flow handling. The OAuth flow does URL extraction → browser open → code paste; --type api-key is correctly inferred for direct API keys.
• API keys are never stored in UI state — only the last 4 chars are previewed.
• Strategy picker: fill_first / round_robin / least_used / random.

Related pages

• Gateway / Cron / Health / Logs — the gateway is what actually consumes platform / tool config.
• Hermes Paths — ~/.hermes/plugins/, config.yaml mcp_servers key.

---

Last updated: 2026-05-28 — Scarf v2.10.0 (MCP mTLS client certs for HTTP + SSE servers + read-only hermes mcp catalog browse sheet)