Skip to main content
Glama

Cut your MCP client's token usage by ~98% on cached reads, with millisecond responses.

Semantic Cache MCP is a Model Context Protocol server that puts every file operation behind one cache. Re-reading a file you already hold costs a few tokens instead of the whole file, and search and grep run over that same corpus rather than the disk.

Thirteen tools share the layer: read, read_image, batch_read, write, edit, edit_preview, batch_edit, search, grep, glob, delete, clear, stats.


Why this exists

Reads stop costing tokens. The first read hands back a content_hash. Send it back — known_hash on read, a known_hashes entry on batch_read — and the server replies unchanged without resending. A modified file returns a diff with changed line numbers; an oversized one collapses to a structure-preserving summary rather than a blind cut at a byte offset.

That echoed hash is the whole contract, and it is the only evidence the server has that a file is still in your context. A warm cache proves the server holds the file, never that you do — the store is on disk and outlives the process, the session, and your context window. A read without a matching hash always sends the file, so forgetting is safe: after a compaction, omit the hashes and get your files back in full.

Search and grep run on the cache, not the disk. BM25 keyword search, glob, and grep all read the corpus that read and batch_read populate. An in-session result LRU collapses repeated queries to sub-millisecond hits.

Mutations are bounded by default. write, edit, and batch_edit enforce size and match limits, can run formatters, and refresh the cache atomically. A dry_run writes nothing and says so — the status becomes would_create / would_update / would_edit — so a preview is never mistaken for a completed write.


Related MCP server: Ambiance MCP Server

Installation

Add to Claude Code settings (~/.claude.json).

Option 1: uvx, always runs the latest version:

{
  "mcpServers": {
    "semantic-cache": {
      "command": "uvx",
      "args": ["semantic-cache-mcp"]
    }
  }
}

Option 2: uv tool install:

uv tool install semantic-cache-mcp
{
  "mcpServers": {
    "semantic-cache": {
      "command": "semantic-cache-mcp"
    }
  }
}

Restart Claude Code.

Disable the client's built-in file tools so all file I/O routes through semantic-cache.

Claude Code~/.claude/settings.json:

{
  "permissions": {
    "deny": ["Read", "Edit", "Write"]
  }
}

OpenCode~/.config/opencode/opencode.json:

{
  "$schema": "https://opencode.ai/config.json",
  "permission": {
    "read": "deny",
    "edit": "deny",
    "write": "deny"
  }
}

CLAUDE.md Configuration

Add to ~/.claude/CLAUDE.md to enforce semantic-cache globally:

## Tools

- MUST use `semantic-cache-mcp` instead of native I/O tools (98% token savings on cached reads)

Tools

Core

Tool

Description

read

Cache-aware single-file read: full content plus a content_hash on the first read, unchanged for a matching known_hash, a diff for a changed file. offset/limit recover exact line ranges. A partial or summarized read reports file_hash (prefixed partial:) — it identifies the file but is never proof you hold it. A ranged read also returns a signed coverage_token for the lines delivered: echo it back and a window you hold answers unchanged; windows covering the whole file mint a claimable content_hash.

read_image

Image pass-through. Returns an MCP image content block (base64 + mime) so vision models see the pixels; sidecar metadata carries size and mime. Format verified by magic bytes (PNG, JPEG, GIF, TIFF, BMP, WebP), not extension. Bypasses the cache. Capped at 5 MiB (SCMCP_MAX_IMAGE_BYTES).

write

Full-file create or replace with cache refresh. Returns creation status or an overwrite diff; supports append=true and formatters. A full write hands back a claimable content_hash; an append needs known_hash to earn one.

edit

Exact edit against cached content, with scoped and line-range modes plus dry_run=true. Pass known_hash to get a claimable content_hash back and skip the read afterwards. For several edits to one file, use batch_edit.

batch_edit

Many exact edits to one file, applied atomically, with per-edit success reporting. Takes known_hash on the same terms as edit. An ambiguous anchor, an anchor inside another edit's line range, and two overlapping ranges are each rejected rather than silently resolved; every reported success is verified against the text it produced.

edit_preview

Read-only probe returning match count, line numbers, and context snippets for a candidate old_string. Confirms anchor uniqueness before a costly edit.

delete

Single-path delete for a file or symlink, with cache eviction and dry_run=true. No globs, no recursion, no directory delete.

Discovery

Tool

Description

batch_read

Multi-file cache-aware read. Handles globs, priorities, token budgets, and diff/full routing. Returns each file's content_hash; pass them back as known_hashes to suppress the ones you still hold.

search

Cache-only BM25 ranking of cached files. Terms join with OR, so a word your corpus lacks narrows the ranking instead of emptying the results. Seed likely files with batch_read first.

grep

Cache-only exact search — regex or literal, with line numbers and optional context. Best for symbols and exact strings. An invalid, over-long, or catastrophically backtracking pattern is an error, never an empty result; use fixed_string=true for literal text. Responses state whether the scan completed, so a capped result is never read as a total.

glob

File discovery plus cache coverage. Find candidates, then pass the paths to batch_read.

Management

Tool

Description

stats

Cache metrics, session usage (tokens saved, tool calls), and lifetime aggregates.

clear

Reset all cache entries.


Tool Reference

The table above is the authoritative map; these are the common call shapes.

read path="/src/app.py"                        # automatic: full, unchanged, or diff
read path="/src/app.py" offset=120 limit=80    # lines 120 to 199 only

State

Response

Token cost

First read

Full content plus a content_hash

Normal

Unchanged

unchanged: true, when you pass back a matching known_hash

A few tokens

Modified

Unified diff only

5 to 20% of original

write path="/src/new.py" content="..."
write path="/src/new.py" content="..." auto_format=true
write path="/src/large.py" content="...chunk1..." append=false   # first chunk
write path="/src/large.py" content="...chunk2..." append=true    # subsequent chunks
# Mode A: find/replace, searches the entire file
edit path="/src/app.py" old_string="def foo():" new_string="def foo(x: int):"
edit path="/src/app.py" old_string="..." new_string="..." replace_all=true auto_format=true

# Mode B: scoped find/replace, searches only within the line range (a shorter old_string works)
edit path="/src/app.py" old_string="pass" new_string="return x" start_line=42 end_line=42

# Mode C: line replace, swaps the whole range with no old_string needed (most token savings)
edit path="/src/app.py" new_string="    return result\n" start_line=80 end_line=83

Mode

Parameters

Best for

Find/replace

old_string + new_string

Unique strings, no line numbers known

Scoped

old_string + new_string + start_line/end_line

Shorter context when read gave you line numbers

Line replace

new_string + start_line/end_line

Maximum token savings when line numbers are known

# Mode A: find/replace, [old, new]
batch_edit path="/src/app.py" edits='[["old1","new1"],["old2","new2"]]'

# Mode B: scoped, [old, new, start_line, end_line]
batch_edit path="/src/app.py" edits='[["pass","return x",42,42]]'

# Mode C: line replace, [null, new, start_line, end_line]
batch_edit path="/src/app.py" edits='[[null,"    return result\n",80,83]]'

# Mixed modes in one call (object syntax also supported)
batch_edit path="/src/app.py" edits='[
  ["old1", "new1"],
  {"old": "pass", "new": "return x", "start_line": 42, "end_line": 42},
  {"old": null, "new": "    return result\n", "start_line": 80, "end_line": 83}
]' auto_format=true
batch_read paths="/src/a.py,/src/b.py" max_total_tokens=50000
batch_read paths='["/src/a.py","/src/b.py"]' priority="/src/main.py"
batch_read paths="/src/*.py" max_total_tokens=30000
batch_read paths="/src/a.py,/src/b.py" known_hashes='{"/src/a.py":"8f3c..."}'

Expands simple globs, honors priority, enforces max_total_tokens, and reports skipped paths with recovery hints. Every file is returned in full unless you prove you still hold it: echo the delivered content_hash values back as known_hashes and the ones you hold collapse into an unchanged count.

search query="authentication middleware logic" k=5
glob pattern="**/*.py" directory="./src" cached_only=true
grep pattern="class Cache" path="src/**/*.py"

Configuration

Environment Variables

Variable

Default

Description

LOG_LEVEL

INFO

Logging verbosity (DEBUG, INFO, WARNING, ERROR)

TOOL_OUTPUT_MODE

compact

Response detail (compact, normal, debug)

TOOL_MAX_RESPONSE_TOKENS

0

Global response token cap (0 = disabled)

TOOL_TIMEOUT

30

Seconds before a tool call times out (auto-resets executor)

MAX_CONTENT_SIZE

100000

Max bytes returned by read operations

MAX_CACHE_ENTRIES

10000

Max cache entries before W-TinyLFU eviction

SEMANTIC_CACHE_DIR

(platform)

Override cache/database directory path

A malformed value falls back to the default and logs a warning naming the variable. See docs/env_variables.md for detail.

Safety Limits

Limit

Value

Protects against

MAX_WRITE_SIZE

10 MB

Memory exhaustion via large writes

MAX_EDIT_SIZE

10 MB

Memory exhaustion via large file edits, in edit and batch_edit alike

MAX_MATCHES

10,000

CPU exhaustion via unbounded replace_all

GREP_MAX_PATTERN_LEN

1,000 chars

Oversized grep regex source

Regex shape check

Catastrophic backtracking (details)

MCP Server Config

{
  "mcpServers": {
    "semantic-cache": {
      "command": "uvx",
      "args": ["semantic-cache-mcp"],
      "env": {
        "LOG_LEVEL": "INFO",
        "TOOL_OUTPUT_MODE": "compact",
        "MAX_CONTENT_SIZE": "100000"
      }
    }
  }
}

Cache location: ~/.cache/semantic-cache-mcp/ (Linux), ~/Library/Caches/semantic-cache-mcp/ (macOS), %LOCALAPPDATA%\semantic-cache-mcp\ (Windows). Override with SEMANTIC_CACHE_DIR.


How It Works

┌──────────┐     ┌────────────┐     ┌──────────────────────────┐
│  Claude  │────▶│ smart_read │────▶│ stat() + cache lookup    │
│   Code   │     │            │     │ (BEFORE any disk read)   │
└──────────┘     └────────────┘     └──────────────────────────┘
                        │
       ┌────────────────┼─────────────────┬──────────────────┐
       ▼                ▼                 ▼                  ▼
 ┌──────────┐    ┌──────────┐      ┌──────────┐      ┌────────────┐
 │ mtime    │    │ mtime    │      │ Changed  │      │ New /      │
 │ match    │    │ drift,   │      │ content  │      │ Large      │
 │ FAST     │    │ hash     │      │ → diff   │      │ → summary  │
 │ PATH     │    │ match    │      │ (80-95%) │      │  or full   │
 │ ~5 tok   │    │ ~5 tok   │      └──────────┘      └────────────┘
 │ (99%)    │    │ (99%)    │
 │ ~1 ms    │    │ ~1 ms    │
 │ no I/O   │    │ +update  │
 └──────────┘    └──────────┘

search is cached on the same principle. An in-session LRU keyed on (query, k, directory) returns warm hits in ~10 µs, and misses fall through to BM25. Every cache mutation (put, clear, delete_path, update_mtime) bumps the LRU, so callers never see a result that predates a write.


Performance

Measured on this project's 41 source files (212,499 tokens), i9-13900K, ext4 on NVMe, corpus held fixed across phases. Every phase models a caller that keeps its hashes and echoes them back — that is what earns the savings.

Token savings: 98.9% overall (phases 2 to 6)

Phase

Scenario

Savings

Overall (cached, phases 2 to 6)

Aggregate token reduction

98.9%

Unchanged re-read

mtime match, fast path skips disk I/O

99.3%

Content hash

mtime drifted, BLAKE3 still matches

99.3%

Batch read

All files via batch_read, 200K budget

99.3%

Search previews

5 queries × k=5, previews vs full reads

98.6%

Small edits

Real ~5% line changes in 30% of files

98.1%

Cold read

First read, no cache; one file exceeds MAX_CONTENT_SIZE and returns summarised, which is not a cache saving

5.9%

Latency: unchanged reads ~1 ms; repeat searches < 0.01 ms

Operation

p50

Notes

Single unchanged read (fast path)

1.1 ms

mtime + cache hit, no disk I/O

Single diff read (changed file)

0.7 ms

hash check + unified diff

Search k=5 (cache hit)

< 0.01 ms

in-session LRU

Search k=5 (cache miss)

1.4 ms

BM25 keyword search

Edit (scoped find/replace)

3.1 ms

cached content, plus the atomic write's fsync

Grep (literal def )

1.5 ms

FTS5 over cached corpus

Grep (regex)

3.4 ms

compiled once

Batch read (41 files, diff mode)

45.6 ms

chunk + tokenize changed files; one summarises each full pass

Unchanged re-read (41 files)

19.5 ms

whole-corpus pass

Cold read (41 files, total)

100 ms

single unrepeated pass: I/O, tokenisation, one summarisation

Write (200-line file)

2.7 ms

creates + caches, durable before it returns

Run them yourself. Pin TMPDIR to a real disk — the default /tmp is usually tmpfs, which discards fsync and reports write latency ~40% low:

TMPDIR="$HOME/.cache/scmcp-bench" \
  uv run python benchmarks/benchmark_performance.py    # operation latency
uv run python benchmarks/benchmark_token_savings.py    # token savings

See docs/performance.md for full methodology.


Documentation

Guide

Description

Architecture

Component design, algorithms, data flow

Performance

Benchmarks, methodology, cache footprint

Security

Threat model, input validation, size limits

Advanced Usage

Programmatic API, custom storage backends

Troubleshooting

Common issues, debug logging

Environment Variables

All env vars with defaults and examples


Contributing

git clone https://github.com/CoderDayton/semantic-cache-mcp.git
cd semantic-cache-mcp
uv sync
uv run pytest

See CONTRIBUTING.md for commit conventions, pre-commit hooks, and code standards.


License

MIT License. Use it freely in personal and commercial projects.


Credits

Built with FastMCP 3.2+ and:

  • SQLite with FTS5 for keyword (BM25) full-text search, vendored as a small built-in store

  • Semantic summarization based on TCRA-LLM (arXiv:2310.15556)

  • BLAKE3 cryptographic hashing for content freshness

  • W-TinyLFU frequency-aware cache eviction

Install Server
A
license - permissive license
A
quality
A
maintenance

Maintenance

Maintainers
Response time
1wRelease cycle
23Releases (12mo)
Commit activity

Resources

Unclaimed servers have limited discoverability.

Looking for Admin?

If you are the server author, to access and configure the admin panel.

Related MCP Servers

  • A
    license
    A
    quality
    C
    maintenance
    Provides AI coding assistants with context optimization tools including targeted file analysis, intelligent terminal command execution with LLM-powered output extraction, and web research capabilities. Helps reduce token usage by extracting only relevant information instead of processing entire files and command outputs.
    Last updated
    5
    38
    62
    TypeScript
    MIT
  • A
    license
    A
    quality
    D
    maintenance
    Provides intelligent code context and analysis through semantic compression, AST parsing, and multi-language support. Offers 60-80% token reduction while enabling AI assistants to understand codebases through local analysis, OpenAI-enhanced insights, and GitHub repository integration.
    Last updated
    6
    48
    3
    MIT
  • A
    license
    -
    quality
    D
    maintenance
    Provides LLM-optimized tools for advanced code analysis, repository complexity evaluation, and call graph generation. It enables users to visualize directory structures, detect code patterns, and build semantic context with significant token savings.
    Last updated
    18
    MIT
  • A
    license
    -
    quality
    C
    maintenance
    Provides file caching and diff tracking for AI coding agents, reducing token usage by returning changes or confirming no changes instead of full file contents on repeated reads.
    Last updated
    98
    216
    MIT

View all related MCP servers

Related MCP Connectors

  • Provide your AI coding tools with token-efficient access to up-to-date technical documentation for…

  • SaaS intelligence for AI agents. 5 unified tools cover 1,000+ services with 91-96% token savings.

  • Shared distillation cache for AI agents — every fetch ~73-89% fewer tokens via a shared cache.

View all MCP Connectors

Latest Blog Posts

MCP directory API

We provide all the information about MCP servers via our MCP API.

curl -X GET 'https://glama.ai/api/mcp/v1/servers/CoderDayton/semantic-cache-mcp'

If you have feedback or need assistance with the MCP directory API, please join our Discord server