A skill is trusted instruction text — optionally with its own tool manifest — that WebBrain loads into a run only when it is relevant. Manage them under Settings → Skills, where you can import skill text or a URL, or remove any bundled skill.
Mid and Full runs receive a small catalog of eligible skills: ID, name, summary,
and optional canonical semantic intents. Full instructions are appended to the
system prompt only after the skill is activated for the current run, via
load_skill. Compact tier disables skills entirely — no loader, no skill
prompt, no skill tools.
Imported skills are copied into browser local storage.
An optional fenced webbrain-skill JSON block can declare:
| Field | Meaning |
|---|---|
summary |
Maximum 200 characters |
modes |
ask, act, and/or dev |
intents |
Up to six canonical intents such as verification_code or public_media_download |
Intents are cross-language meaning hints for the LLM, not literal keyword matching. Skills without metadata infer the first prose paragraph as their summary, have no inferred intents, and default to Act/Dev.
WebBrain also recognizes the required name and description YAML frontmatter
from an imported Agent Skills SKILL.md.
The name and description populate the routing catalog, and the frontmatter is
removed before the Markdown body is loaded. A name entered in Settings and a
webbrain-skill block still take precedence.
This is instruction-only compatibility. WebBrain imports one text document; it
does not fetch bundled scripts/, references/, or assets/, execute skill
code, or treat the Agent Skills allowed-tools field as a WebBrain permission
or tool manifest. Use webbrain-tools for WebBrain HTTP tools. WebBrain
recognizes webbrain-skill and webbrain-tools fences only in the Markdown
body after valid frontmatter; fence-like text inside frontmatter cannot grant
routing eligibility or register tools.
A skill can expose read-only HTTP tools, or short-lived download-job tools, with
a fenced webbrain-tools JSON manifest.
Importing a skill is the trust boundary for its declared HTTPS endpoint.
Download-job skill tools still run in Act mode and use the normal Downloads
permission gate before saving files. Tool results derived from third-party
content should be marked resultPolicy: "untrusted" so they are wrapped as
data, not instructions.
Skill HTTP tools reject redirects (including opaque browser redirects), so manifests must use a final HTTPS host that does not 3xx.
Skill tools are not part of the static tool matrix: before a skill is loaded, or after it is removed, its tools are absent.
Packaged skill markdown lives under skills/ and is registered in
PACKAGED_SKILL_SOURCES (agent/skills.js). Settings → Skills lists every
packaged skill; only the defaults below are seeded enabled.
Both can be removed from Settings → Skills. A removed default is not silently restored.
Can expose read_youtube_transcript, fetch_nytimes_article,
resolve_public_media, and download_public_media through its skill manifest.
On NYTimes / The Athletic tabs it is preactivated for the current run so a
structured blocking pageGate can route directly to the credentialless article
fallback.
Loads only for relevant requests and declares no network tool. On the active run tab it prefers selected text or a bounded accessibility-tree subtree, matches the newest relevant service code, excludes SMS/native-app access, and honors Strict secret handling.
When used, the scoped page content and the code are included in the normal request to your configured LLM provider. If Record traces is enabled, raw tool results and model responses are also stored locally until those traces are deleted.
These ship in the extension and appear under Settings → Skills as available to enable. They are not seeded on by default.
| Skill | Modes | Network tools |
|---|---|---|
| Disposable email (Mail.tm) | Act, Dev | Mail.tm HTTPS API |
| Temporary file share (Litterbox) | Act, Dev | Uses browser upload tools; short-lived public link |
| Open-Meteo weather | Ask, Act, Dev | Geocoding + forecast HTTPS |
| Open Library | Ask, Act, Dev | Open Library search HTTPS |
| Wikipedia | Ask, Act, Dev | Wikipedia REST search + Action API summary HTTPS |
Enable a skill only when you want its tools and instructions available for
load_skill on eligible runs.
- Agent tools — tiers, modes, and the full tool matrix
- Privacy and data flow
- Architecture — skills and dynamic tool exposure in the turn flow