misterdev

Autonomous LLM build orchestrator: plans a goal into tasks, edits code with anchored SEARCH/REPLACE, and verifies every change through build/test/lint/typecheck gates before reporting done. Runs as a CLI or MCP server.

Install · What it does · CLI · Extending · Configuration · Development · License

Point misterdev at a repository and a goal. It reads the codebase as a symbol graph, decomposes the goal into concrete tasks, and works each one in a try-edit-verify loop: it emits an anchored SEARCH/REPLACE edit, applies it against the file on disk, and runs the change through a sequence of correctness gates — build, tests, lint, typecheck, and any optional gates you enable. A gate that fails RED blocks the change; a gate that has nothing to check SKIPs and never blocks. When a change regresses the suite, misterdev reverts it through git. Nothing merges unless it stays green.

$ misterdev build . "add rate limiting to the public API"

  planning   goal → 3 tasks  (model: anthropic/claude-sonnet-4-6, budget $100.00)
  task 1/3   middleware: token-bucket limiter          api/limiter.py
    edit     1 hunk applied · syntax ok
    gates    build GREEN · tests GREEN (142 passed) · lint GREEN · typecheck GREEN
  task 2/3   wire limiter into request pipeline         api/app.py
    edit     2 hunks applied
    gates    build GREEN · tests RED (1 failed) → rolling back, regenerating
    edit     2 hunks applied (attempt 2)
    gates    build GREEN · tests GREEN (145 passed) · lint GREEN · typecheck GREEN
  task 3/3   docs + config surface                      README.md, config.py
    gates    all GREEN

  done       3/3 tasks · 145 tests green · $0.38 over 11 calls

Because misterdev only trusts its gates, the loop is honest: "the model said it's done" is never the finish line — the build, the tests, and the diff are.

Install

pip install misterdev
# or
uv pip install misterdev

Python 3.10 – 3.13. Optional extras add capability without bloating the core install:

pip install 'misterdev[local-embeddings]'   # offline semantic context ranking (fastembed, no API key)
pip install 'misterdev[lsp]'                 # LSP semantic-diagnostics gate
pip install 'misterdev[web]'                 # headless-browser web verification gate (+ playwright install chromium)
pip install 'misterdev[mcp]'                 # Model Context Protocol tool-host substrate

Extras are all opt-in and timeout-bounded. When an extra's runtime dependency is absent, the gate it powers SKIPs rather than failing.

What it does

Autonomous build loop

Give misterdev a goal and it drives the whole cycle: analyze the project, plan tasks, edit, and validate — repeating until the goal is met or the budget is spent. Edits are anchored SEARCH/REPLACE hunks: the model emits only the changed regions, which are applied against the on-disk file, so a 5,000-line module is edited without reprinting it and without hitting the output-token ceiling. Matching tries exact first, then tolerates whitespace and indentation drift, always requiring a single unique anchor so a partial file is never written.

Polyglot symbol-graph context

A tree-sitter symbol graph gives misterdev structural understanding of Python, Rust, TypeScript/JavaScript, Go, Java, C/C++, C#, Swift, and Kotlin. Per-file outlines plus a whole-project structural map feed planning and editing, and large files are sent as a symbol outline plus verbatim windows of the task-relevant symbols — so context and cost scale with the edit, not with the file.

Correctness gates

Every change runs through an ordered gate sequence: build → lint → tests → typecheck, with optional gates layered on top — an adversarial critic (an independent second model that reviews each diff before it is applied), goal-check, claim-verifier, mutation scoring, runtime-smoke, web, and vision verification. A gate that fails RED blocks the change; a gate with nothing to check SKIPs and never blocks. Regressions are reverted via git, so a working tree only ever moves forward.

Dynamic model selection

misterdev keeps a per-model performance ledger and pairs it with a cost-aware selector that picks for quality-per-dollar across the full breadth of OpenRouter — routing each task up a capability ladder (harvested free / cheap → a strong mid-tier → a frontier tier) and escalating to a stronger model only when a cheaper one can't clear the gates. The strongest tier is reserved for the final attempt, so frontier spend is the rare safety net, not the default; a hard task that a mid model stalls on is finished by a frontier model, while easy tasks resolve on free/cheap ones. Quality never drops because a weak model that writes bad code fails the gate and the policy climbs. It runs against OpenRouter or Anthropic with automatic failover, caches responses to avoid paying twice, and token budgeting keeps spend inside the ceiling you set.

Parallel worktrees

Disjoint tasks run concurrently, each in its own isolated git worktree, so independent work doesn't contend for the tree. An integration gate re-checks each wave against the full suite and reverts any task that regresses it — parallelism without cross-contamination.

Self-improving

misterdev keeps a durable, fingerprinted stream of its own real failures and runs an AlphaEvolve-style keep-if-better loop over its own source: it attributes what breaks, classifies why (harness artifact vs observation gap vs capability), proposes a targeted structural self-edit, and promotes it only when it beats the champion on a held-out task set it never optimized against — with zero regressions. A reward-hacking guardrail walls off the tests and benchmark. The result is a loop that removes whole failure classes over time without overfitting to any one benchmark. See docs/path-to-100.md.

Run it with misterdev evolve --benchmark <polyglot-benchmark checkout> --workdir <scratch dir> (dry-run by default; add --live to actually apply/gate/promote, --from-failures to target the real-build failure stream instead of the benchmark's worst niche). evolution.benchmark_dir/evolution.noise_band in project.yaml set the defaults so a caller can omit the matching flags; both are opt-in and unset by default. An evolve_async MCP tool runs the same pass in the background (poll with job_status). A nightly --scheduled --live --from-failures pass also runs via .github/workflows/evolve.yml once the repo secret OPENROUTER_API_KEY is configured — gated by the same exclusive lock + circuit breaker, so an overlapping or repeatedly-failing trigger is a clean no-op.

On the correctness side, misterdev works reproduction-first: for an issue-driven task it synthesizes a failing test from the acceptance criteria, validates that the test actually fails on the clean tree (a test that reproduces nothing is discarded rather than trusted), then drives the fix to turn it green — so the model edits toward a concrete, verified target instead of a description.