claude-webcache

Persistent cross-session WebFetch cache for Claude Code. 5-15× fewer WebFetch calls on repeated URLs.

Claude Code's built-in cache lasts 15 minutes, within one session. Every new session re-fetches from scratch. claude-webcache persists results across sessions in a local SQLite database — instant cache hits, zero network cost.

Session 1  →  WebFetch("docs.example.com")  →  fetched, stored
Session 2  →  cached_fetch("docs.example.com")  →  instant hit, no network call
Session 7  →  cached_fetch("docs.example.com")  →  still instant, 7-day TTL

Install

claude plugin marketplace add theYahia/claude-webcache && claude plugin install claude-webcache@theyahia

Works in: Claude Code CLI · Desktop (Mac/Windows) · VS Code extension · JetBrains plugin — same command everywhere.

Then add the usage pattern to ~/.claude/CLAUDE.md (20 seconds).

Plugin TUI not working? There's an open Claude Code bug (#41653) where /plugin install rejects third-party sources with "source type not supported." Use the CLI command above — it bypasses the TUI and works fine.

Fallback (no marketplace):

git clone https://github.com/theYahia/claude-webcache && claude --plugin-dir ./claude-webcache/plugin

Option 2 — npm global

npm i -g @theyahia/claude-webcache

Requires Node.js 22.5+ (uses built-in node:sqlite — no native deps, no install step).

Then register in ~/.claude/settings.json (replace path with output of npm root -g):

{
  "mcpServers": {
    "claude-webcache": {
      "command": "node",
      "args": ["/path/from/npm-root-g/claude-webcache/scripts/mcp-server.cjs"]
    }
  },
  "hooks": {
    "SessionStart": [
      {
        "matcher": "startup|clear|compact",
        "hooks": [
          { "type": "command", "command": "node /path/from/npm-root-g/claude-webcache/scripts/hook-stats.cjs" }
        ]
      }
    ]
  }
}

Option 3 — clone (contributors)

See CONTRIBUTING.md.

Usage pattern

Add this to ~/.claude/CLAUDE.md:

## WebFetch caching (claude-webcache)

Before calling WebFetch, call `cached_fetch(url, prompt)` first.
- If it returns text → use that, do NOT call WebFetch.
- If it returns `[CACHE_MISS] <url>` → call WebFetch as normal, then call `cache_store(url, prompt, output)` with the result.

That's it. Same URL + same prompt in any future session = instant hit.

Tools (MCP)

| Tool | Args | Returns | |---|---|---| | cached_fetch | url, prompt | cached text, or [CACHE_MISS] <url> | | cache_store | url, prompt, output | stored | | cache_stats | — | { total, hits, last } | | cache_list | limit? | recent URLs (most recent first) |

SessionStart hook

Every new session injects a one-liner so Claude knows the cache exists:

webcache: 142 pages cached, 38 hits, last fetch 3h ago

No output if cache is empty.

Storage

SQLite at ~/.webcache/cache.db (WAL mode, concurrent-safe).
Cache key = SHA256(url + "|" + prompt). Default TTL: unlimited (set WEBCACHE_TTL_DAYS=N for N-day expiry).

| Field | Type | |---|---| | key | TEXT PRIMARY KEY | | url | TEXT | | prompt_hash | TEXT | | output | TEXT | | cached_at | INTEGER (ms epoch) | | hit_count | INTEGER | | last_hit_at | INTEGER |

Limits

• Cache key includes the prompt — use consistent prompts to maximize hit rate.
• Output is whatever WebFetch returns (already summarized). No re-processing.
• No semantic search. Exact (url, prompt) match only.

Related

• claude-mem — persistent memory across sessions (complements claude-webcache: memory vs. web cache)
• WWmcp — catalog of 120+ MCP servers for non-Western APIs

License

MIT — see LICENSE.