scry-mcp 0.2.0

Marker-indexed SQL cache MCP server

scry

Marker-indexed SQL cache MCP server. Scry indexes in-file @scry.* markers into a SQLite database that agents query via read-only SQL, providing structured project knowledge without LLM reasoning.

Install

uv pip install scry-mcp
# or:
pip install scry-mcp

The PyPI distribution is scry-mcp (the bare name scry was already taken on PyPI). The import name and the installed console command are both scry.

Quickstart

# In your project root:
scry init                # scaffolds agent/ + driver dirs, updates .gitignore

Then add it to your MCP client config:

{
  "mcpServers": {
    "scry": {
      "command": "scry"
    }
  }
}

The MCP client inherits cwd from wherever it's launched, and scry walks up from there looking for an agent/ directory — so the same config works for any project. Bare scry (no subcommand) starts the MCP server over stdio — that's what Claude calls. Other subcommands:

Command	Purpose
scry	Run the MCP server (default).
scry init [path]	Create agent/ + agent/drivers/@local/scry/{data,runtime,scripts}/ and a local .gitignore inside the driver dir. Idempotent — safe to run inside an ACP project.
scry surface [--force]	One-shot batch reindex without booting the server.
scry version	Print the package version.

The server walks up from cwd until it finds an agent/ directory; that becomes the project root. The cache lives at agent/drivers/@<namespace>/scry/data/project.db and is gitignored.

Markers

Scry recognizes five marker kinds. Block markers carry a YAML body between open/close tokens; line markers are single-line @scry.<kind> <id> <ref>.

<!-- @scry.doc
id: design.auth-flow~a1b2c3d4
kind: design
summary: >
  JWT auth middleware, token validation, refresh flow
status: active
weight: 0.85
tags: ["scope:auth", "topic:security"]
rationale: >
  Missing this causes auth bypass bugs
applies: modifying auth, adding protected endpoints
seeded_questions:
  - How does token refresh work?
@scry.doc.end -->

<!-- @scry.file
id: file.auth-middleware~e5f6a7b8
kind: middleware
summary: Express middleware that validates JWT on every request
status: active
weight: 0.7
@scry.file.end -->

<!-- @scry.anchor auth-check~f1e2d3c4
description: JWT validation point for protected routes
@scry.anchor.end -->

# @scry.impl validate-jwt~a1b2c3d4 spec.auth~xyz89012#FR3
# @scry.test jwt-expiry~b2c3d4e5 spec.auth~xyz89012#UT1

Block markers can be embedded in any host-language comment style (HTML, Python, JS, JSDoc, Rust, bare YAML). Comment prefixes are inferred from the YAML body — there is no per-language config.

MCP tools

Tool	Purpose
scry_sql(query)	Read-only SQL gateway. Rejects mutator keywords. Returns {results, row_count} JSON.
scry_mint(kind, prefix)	Generate a collision-free ID and the marker schema.
scry_surface(force=false)	Batch reindex from disk. force=true hard-deletes records whose source file no longer exists.
scry_scrub()	Create a <branch>--clean git branch with all @scry.* markers stripped and agent/ removed.
scry_script(action, script?, params?)	Discover and run validation scripts from src/scry/scripts/ and agent/drivers/@<ns>/scry/scripts/.

Database schema

Five marker-backed tables (scry__doc, scry__file, scry__anchor, scry__impl, scry__test) plus doc_relationship (with cycle detection) and migration. FTS5 is maintained via triggers on the source tables — no manual rebuild step.

The cache is fully reconstructable from disk via scry_surface. The DB is gitignored; after git pull, agents call scry_surface to rebuild.

Watcher

A daemon thread runs alongside the MCP server, watching the project tree with a 150 ms debounce window. A lock file at agent/drivers/@<ns>/scry/runtime/lock performs PID-based primary election so multiple sessions don't race writes. The primary instance runs a cold scan on startup; secondaries observe and wait.

On file deletion: docs and files are soft-deleted (missing_since set); anchors, impls, and tests are hard-deleted.

Tests

uv pip install -e ".[dev]"
pytest

43 unit tests cover the parser, SQL gateway, mint, surface, watcher plumbing, script discovery, and relationship cycle detection.

License

MIT — see LICENSE.