
Hermai Cli
io.github.hermai-aiPublished by GitHub account hermai-aiv0.3.0Updated Oct 28, 2026
Hermai MCP server — look up, submit, and classify website API schemas from any MCP client.
Overview
Hermai CLI exposes the Hermai registry of website API schemas, letting an assistant look up, submit and call site endpoints from an MCP client.
- What you can do
- Look up and pull website API schemas from the Hermai registry, list the catalog, and summarize or show cached schemas for a URL
- Submit new schemas to the registry and run discovery helpers that classify a site's platform, anti-bot setup, well-known files, embedded data and GraphQL schemas
- Call read endpoints directly, or run authenticated write actions with session handling and per-request signing, with a dry-run mode to inspect the signed request first
- Import cookies from an installed browser for a single named domain, or bootstrap a fresh session, to reach login-gated endpoints
- Capture XHR traffic from a headful browser and replay captured requests to document write flows
- When to use it
- Useful when an assistant needs structured access to a website's API rather than scraping pages, or when you want to document a site's endpoints and contribute the schema to a community catalog. Also suited to agents that must perform login-gated writes such as posting, saving drafts or adding to cart.
- Requirements
- Runs as a local process; installable via npm (Node.js), Homebrew, Go, or prebuilt binaries. A Hermai registry account with GitHub sign-in is needed for an API key to pull schemas. Browser cookie import requires OS-level authorization (Keychain, DPAPI, libsecret) and installed browsers for capture.
Installation
In SourceWeft
- Open Hermai Cli in the dashboard and add it to a workspace.
- Enable the server for the chats that should use its tools.
Desktop only via STDIO. STDIO servers start a local process, so they need the SourceWeft desktop host.
Other MCP clients
Follow the launch instructions in the repository.
README
hermai-cli
Discover, contribute, and call structured website APIs from your terminal.
hermai is the open-source CLI for the Hermai registry — a community catalog of website API schemas for AI agents. Probe a site to document its endpoints, push the schema to the catalog, or pull an existing schema and call it — including authenticated writes with per-request signing.
Install
Already installed? Upgrade in place without re-running any of the above:
Agent skill
Running in Claude Code, Codex, Cursor, or another agent? Install the Hermai skill so the agent knows how to use this CLI:
One skill covers both audiences. When a user asks for data from a site, the agent pulls the schema and calls it. When a user wants to add a new site, the skill's contributor references (loaded on demand via progressive disclosure) walk the agent through discovery, schema authoring, and push.
Repo: hermai-ai/hermai-skills.
Call a site as an API
hermai action loads the schema, resolves the user's session (cookies from disk, or pulled from an installed browser on first run), runs any schema-declared bootstrap JS to compute per-session state, runs any per-request signer JS, fires via a Chrome-TLS fingerprinted HTTP client, and rotates Set-Cookie back on 2xx responses. Works against sites that require per-request signing (X's x-client-transaction-id, TikTok's X-Bogus) without opening a browser.
Useful flags:
--dry-run— print the fully-signed request, don't hit the network--schema <file>— use a local schema JSON instead of the registry cache--arg key=value— repeatable, fills{{var}}placeholders in the schema's URL/body templates
Registry
Discovery toolkit
Deterministic subcommands for composing a new schema. No LLM key — each prints JSON the next step can consume.
Capturing authenticated write endpoints
Most interesting APIs are gated behind cookies. To capture a write flow (add-to-cart, save-draft, submit-review) without logging in a second time, combine headful intercept with session injection:
The request body goes straight into your schema's body_template with {{var}} placeholders for user-varying fields. Capture, don't guess — inventing body fields is the #1 cause of rejected write schemas.
hermai introspect takes --header name=value (repeatable) for auth-gated GraphQL endpoints like Shopify Storefront or Estée Lauder's Stardust.
Import your existing browser session
When a schema requires login (post a tweet, add to cart, RSVP), you can use the session you already have in Chrome, Firefox, Safari, Edge, or Brave — no need to log in again:
The first run surfaces an OS-level authorization prompt (macOS Keychain, Windows DPAPI, Linux libsecret) — Hermai can't read your cookies without your explicit consent at the OS level. Reads are always scoped to the single domain you name; we never touch cookies for other sites.
Use --dry-run to see the cookie names without writing values to disk:
Local cache
hermai --help for the full command list.
Docs
- Concepts + schema spec — docs.hermai.ai
- Hosted registry + dashboard — hermai.ai
- Skill reference:
hermai-ai/hermai-skills— architecture, runtime, CLI, contributing
License
AGPL-3.0. Running a modified version as a hosted service requires publishing your changes.
Source: README.md at commit 7419a24
Tools
0Version history
1- v0.3.0LatestSep 16, 2026
Score
50% of the applicable checks met
How complete this listing is, computed from the registry entry, the endpoint and public sources. Not a rating of the server and not a statement that it is safe or working today: reachability is a dated check, and no installs or reviews go into the score.
- Reached in the last 30 days25 pts
Keep the endpoint answering the MCP handshake; SourceWeft probes it every 30 days.
- Auth declared10 pts
Declare the credential headers in the registry entry, or keep the endpoint answering the probe so its auth can be classified.
- Tools listed15 pts
Answer tools/list without a credential, or ship a package that starts in a sandbox without one.
- DescriptionRequired15 pts
- Logo10 pts
- Documentation15 pts
- License10 pts