567519184b
- Re-validate redirect targets through validateFetchUrl before following, so a same-origin Location carrying credentials (or a non-http(s)/over-long URL) cannot bypass the transport hygiene a direct request enforces. - Treat only DROPPED bytes as truncation: a body exactly at maxResponseBytes is no longer falsely flagged truncated (which emitted a spurious footer). - Honor the declared response charset: parse the Content-Type charset and decode with it (rejecting unsupported labels as WEB_UNSUPPORTED_CONTENT_TYPE) instead of always assuming UTF-8 and returning replacement characters. - Catalog the web seam vocabulary in docs/core-data-structures/web.md with type-equiv blocks + manifest entries, per the core-data-structures rule.
@deepseek-ai/dsh-web-fetch-local
An anonymous public HTTP(S) WebFetchProvider for the harness web capability seam (ctx.web). It retrieves a concrete URL and returns a status code plus bounded decoded content.
This is an implementation package: it registers a provider into ctx.web, it does not own the key and it does not register a model-facing tool. It is a function/namespace plugin (inject: ['web']).
Responsibility split
The provider owns safe resource retrieval: URL validation, HTTP transport, redirect policy, timeout, abort propagation, byte caps, charset decoding, content-type classification, and binary rejection. @deepseek-ai/dsh-tool-web owns presentation (HTML→markdown, truncation formatting). A non-2xx HTTP response is a result (status code + decoded body), not an error; WebError is reserved for failures to safely retrieve or represent the resource.
Transport hygiene
- Accepts only
http:andhttps:URLs; rejects credentials in URLs (WEB_BLOCKED_URL) and over-long/malformed URLs (WEB_INVALID_URL). - Enforces a max URL length, response byte cap (
WEB_FETCH_TOO_LARGE), decoded body character cap, timeout (WEB_FETCH_TIMEOUT), and redirect hop cap. - Propagates the caller's abort signal (
WEB_ABORTED) into the network request and the streaming read. - Follows only same-origin redirects; a cross-origin redirect fails with
WEB_REDIRECT_BLOCKED, requiring a fresh tool call (the model of Claude Code's WebFetch). - Sends an explicit product
User-Agent, never a browser disguise. - Rejects unsupported (e.g. binary) content types with
WEB_UNSUPPORTED_CONTENT_TYPE.
Config
| Key | Default | Meaning |
|---|---|---|
maxUrlLength |
2048 |
Maximum accepted request URL length. |
maxResponseBytes |
5_000_000 |
Maximum response body size in bytes. |
maxBodyChars |
100_000 |
Maximum decoded body length in characters. |
timeoutMs |
30_000 |
Default fetch timeout. |
maxTimeoutMs |
120_000 |
Upper bound for a per-request timeout override. |
maxRedirects |
5 |
Maximum same-origin redirect hops. |
userAgent |
deepseek-harness/… |
User-Agent header. |
Security note
SSRF / private-network protection (blocking private, loopback, link-local, multicast, and otherwise non-public destinations, with DNS-resolve-then-validate and per-hop re-validation) is deferred — see the web capability seam RFC. Until it lands, this provider is an SSRF primitive and must not be enabled in a deployment that can reach sensitive internal network targets.