mcp-injector for Devin AI
Give Devin's autonomous agent a structurally compressed view of your codebase. 41–89% fewer tokens. Deterministic. Always-on.
41–89% Token Reduction
AST body-folding removes function implementations while preserving every signature, type, import, and interface. Devin sees the architecture without the noise.
No Secrets in Context
Shannon entropy filtering runs locally before any context reaches the model. API keys, JWTs, and private key headers are automatically redacted.
Always Current
The daemon watches your filesystem in real-time. Every file save triggers an incremental index update. Devin always reads from a current snapshot.
Prompt Cache Hits
Output is byte-identical across calls — alphabetically sorted, timestamps stripped. Anthropic's KV cache fires on every request after the first load.
Configuration for Devin Desktop
Devin Desktop supports the Model Context Protocol natively. Add mcp-injector to your Devin MCP configuration file:
{
"mcpServers": {
"mcp-injector": {
"command": "/usr/local/bin/mcp-injector",
"env": {
"MCP_WORKSPACE": "/path/to/your/repo"
}
}
}
}
Replace /path/to/your/repo with your repository root. Devin will automatically start the daemon when it initializes a session. Full installation instructions at foldwork.dev/docs.
What Devin sees with mcp-injector
Instead of loading raw source files — which can exhaust context in minutes on a large codebase — Devin calls get_project_map and receives a structurally compressed snapshot. Function bodies are replaced with fold markers. Signatures, types, and imports are always intact. When Devin needs to edit a specific file, it calls injector_retrieve for the full uncompressed source.
Benchmark reductions on real codebases
Full methodology and raw token counts at foldwork.dev/benchmarks.
Free for codebases under 50,000 lines
Install mcp-injector and use all 12 MCP tools — including get_project_map, injector_search, injector_diagram, injector_blast_radius, and more — at no cost for repositories under 50,000 lines. No account, no credit card, no sign-up. The Pro tier ($12/month) unlocks unlimited repository size for large monorepos.