Best code context tools for agents (2026)

1. 1.CodeGraphMIT local AST code knowledge graph for coding agents

   Free / OSS · OSS/MIT · 74.4k GitHub stars

   VerdictMIT local code graph for agents. Free forever; packers are the text cousins.

   CatchIndex cost and residual context occupancy are real. Not a hosted SaaS brain. Distinct from Repomix/Gitingest (pack text) and Aider (edit loop).

2. 2.RepomixMIT pack entire repo into one AI-friendly file

   Free / OSS · OSS/MIT · 28.9k GitHub stars

   VerdictMIT repo packer. Free forever.

   CatchStill a dump - huge monorepos blow context. Distinct from CodeGraph and Gitingest.

3. 3.GitingestMIT turn any GitHub URL into prompt-ready ingest

   Free / OSS · OSS/MIT · 15.9k GitHub stars

   VerdictMIT GitHub ingest. Free forever.

   CatchPublic-URL convenience, not a private monorepo indexer. Distinct from Repomix local pack and CodeGraph graph.

4. 4.SerenaMIT MCP toolkit: symbol-level retrieve/edit via free LSP

   Free / OSS · OSS/MIT · 30.4k GitHub stars

   VerdictMIT symbol MCP for agents. Free LSP core; JetBrains plugin is optional paid.

   CatchComplements agents; it is not a turnkey SWE loop. JetBrains plugin backend is paid optional (free trial) — LSP path stays free. Symbol quality tracks whatever language server you wire.

5. 5.MarkItDownMIT office/PDF/media→Markdown converter for RAG pipelines

   Free / OSS · OSS/MIT · 191k GitHub stars

   VerdictMIT document converter. Free forever; use when agents need to read Office and PDF, not just code.

   CatchVs files-to-prompt/Repomix/Gitingest (code-context tools): MarkItDown is the *document converter*, not a codebase packer. Heavy formats (PDF, images, audio) need optional dependencies (pdfminer, speechrecognition, Azure services). Quality varies by source format — complex PDFs may need the vision/Azure path.

6. 6.RTKApache-2.0 Rust CLI proxy — fewer agent shell tokens

   Free / OSS · Apache-2.0 · 83.9k GitHub stars

   VerdictApache-2.0 agent shell thrift. Cut tokens under agents; it is not the agent.

   CatchVs the coding agent itself (Claude Code, Codex, Aider): RTK is a token-thrift layer under agents — output compression/proxy, not an agent, not a model router. You must wire it into the shell path the agent actually uses; over-aggressive filtering can hide the error you needed.

7. 7.HisterPrivate local search over visited pages and files

   Free / OSS · AGPL-3.0 · 6.1k GitHub stars

   VerdictAGPL-3.0 local privacy search. Useful personal context for agents; the network-copyleft Catch is loud.

   CatchVs Gitingest and Repomix (package repositories for model context) and Agent Reach (agent-facing public-web access): Hister searches your local history/files, not a repo snapshot or the open web. AGPL-3.0 carries network copyleft if you modify Hister and offer it as a service; keep that boundary in your deployment review.

8. 8.Context ModeElastic-2.0 MCP sandbox for tool output and session continuity

   Free / OSS · Elastic-2.0 · 30.8k GitHub stars

   VerdictElastic-2.0 source-available context middleware. Useful SQLite/FTS MCP sandbox; no hosted/managed offering without a careful license review.

   CatchElastic License 2.0 is source-available, not OSI open-source; do not treat the `open-source` label as MIT/Apache freedom. ELv2 restricts offering the software as a hosted or managed service, so review the license before embedding or commercializing a managed Context Mode deployment. Vs a plain MCP server: this is output/context infrastructure, not another domain tool.

9. 9.Codebase Memory MCPMIT persistent code knowledge graph MCP — static binary, no LLM key

   Free / OSS · OSS/MIT · 46.9k GitHub stars

   VerdictMIT local code-graph MCP when agents need structural queries without a server-side model key; audit the install path and treat the ★ spike as a signal, not proof.

   CatchVs CodeGraph, Serena, and Supermemory: this is a persistent local code-graph MCP from a static binary, not an AST/MCP peer alone, an LSP-symbol MCP alone, or a general memory API. Default install is curl|bash; Microsoft Defender has false-positived release binaries (Wacatac-family); star velocity is extreme (~45k, repo created 2026-02) — verify checksums/VirusTotal links before trusting the pipeline.

10. 10.Code-Graph-RAGMIT Tree-sitter→Memgraph structural RAG for monorepos

    Free / OSS · OSS/MIT · 5.3k GitHub stars

    VerdictMIT structural graph RAG when monorepo English query/edit needs Memgraph+Tree-sitter — not vector-only RAG and not a thin MCP graph.

    CatchVs LAIN (thin ★9 MCP graph): not an MCP coordinator. Vs plain vector RAG: this is structural graph+Memgraph, not chunk embeddings alone. Enterprise support upsell on the site is optional — OSS path stands alone.

Also reviewed (2)

• files-to-prompt — Apache-2.0 concatenate a directory into one LLM prompt
• Context7 — MIT MCP client for live library docs; free anon / free key