Using Rocky: agentic-assisted programming value report
Same feature, same model: about 255k to 89k tokens (about 65%), discovery down 89%, Sonnet about $1.62 to $0.85. Side-by-side without vs with Rocky MCP on a real production React monorepo.
For engineers and leads using Cursor or Claude on real repos, solo or on a team.
Connecting Rocky (handbook plus devkit gateway) changes agentic-assisted work: implement a feature, add tests, pass review, open a PR. You do not need a private team server. The public handbook applies to your repo.
Full source doc: using-mcp-devkit-report.md. Product intro: I shipped Rocky.
Side-by-side
Same kind of task everywhere: implement or fix something in the user's repo, then get it review-ready.
| Without Rocky MCP | With Rocky MCP | |
|---|---|---|
| What the AI can use | Search, read files, terminal only | Same, plus handbook (devkit://handbook/...) and devkit actions |
| Conventions | Whatever the model guesses or old chat memory | Shared agents and rules (hexagonal React, tests, PR gate, ...) |
| Discovery | Many greps and 10-20+ file reads | codebase-discovery plus graphify summary |
| What to test | Manual hunt | test_gap_finder gives a short gap list |
| Blast radius | Guess from the diff | change_scope_analyzer on a changed path |
| Run tests | Often the full suite every time | repo_test / scoped commands when the repo allows |
| Lint feedback | Paste long yarn lint output | repo_lint summary |
| Before PR | Hope CI catches issues | pre_pr_quality_gate returns ready / not_ready |
| Handbook tokens (disciplined) | N/A | About 4k-6k for how-it-works, discovery, and 2 reads |
| Typical session tokens (estimate) | About 150k-300k on a medium feature | About 70k-150k (about 40-50% less, directional) |
| Solo without "the team"? | You still need conventions somewhere | Connect hosted Rocky. No org repo required. |
| CI on merge | Your pipeline | Same. MCP does not replace CI. |
Token ranges are directional estimates for a medium feature. Log two comparable sessions in your org if finance needs proof.
Same five phases
| Phase | Without MCP | With Rocky MCP |
|---|---|---|
| 1. Discover | Grep and read many files | codebase-discovery, graphify skim, optional change_scope_analyzer |
| 2. Implement | You still write code in the editor | Same. MCP does not write for you. |
| 3. Test | Full suite or guess which files | test_gap_finder plus targeted repo_test |
| 4. Lint / style | Terminal spam in chat | repo_lint plus handbook rules |
| 5. Before PR | Subjective "looks fine" | pre_pr_quality_gate plus pr-quality-gate agent |
Measured example (same MCP workflow)
Numbers from a real session on a large client project (production React monorepo): add Vitest and Playwright for table filters, with vs without MCP connected.
| Task | Expand automated tests for table filters / status tracking |
|---|---|
| Repo | Large client app (321 unit tests in the full suite) |
| Typical day | Discover, write tests, validate 8 times, lint, optional e2e |
Executive numbers
| Metric | Without MCP | With MCP | Notes |
|---|---|---|---|
| Vitest per check | About 29 s (321 tests) | About 10 s (3 scoped files) | Measured |
| Vitest across 8 loops | About 232 s (about 3.9 min) | About 77 s (about 1.3 min) | From measured single runs |
| Tokens per feature | About 150k-330k | About 70k-170k | About 40-55% lower (estimated) |
| Discovery file reads | About 10-18 files | About 0-3 plus tool JSON | |
| OpenRouter Sonnet 4.6 per feature | About $1.62 | About $0.85 | Same model, fewer tokens |
Tokens by phase (midpoints)
| Phase | Without MCP (thousands) | With MCP (thousands) | Reduction |
|---|---|---|---|
| Discovery | 125 | 14 | About 89% |
| Write tests | 70 | 48 | About 31% |
| Validate x8 | 21 | 12 | About 43% |
| graphify read | 17 | 4 | About 76% |
| E2e / lint | 22 | 11 | About 50% |
| Total (midpoint) | About 255k | About 89k | About 65% |
Discovery 125 vs 14 is the story: a briefing instead of walking every room.
Sonnet 4.6 cost by phase (example)
OpenRouter list rates in the source doc (May 2026): $3/M input, $15/M output on Claude Sonnet 4.6.
| Phase | Without $ | With MCP $ |
|---|---|---|
| Discovery | About $0.50 | About $0.08 |
| Write tests | About $0.81 | About $0.59 |
| Validate x8 | About $0.12 | About $0.08 |
| graphify read | About $0.05 | About $0.01 |
| E2e + lint | About $0.14 | About $0.09 |
| Total | About $1.62 | About $0.85 |
What it was like (from the AI agent)
MCP in ~/.cursor/mcp.json is not the same as connected and green in Cursor. Config is not connection.
Without Rocky: semantic search and grep across the repo, conventions inferred from random files, full suite on repeat, no structured ready / not_ready. You can finish. It is slower, noisier, and more expensive in tokens.
With Rocky: devkit-start-task, then the router, then 2-3 handbook reads. codebase-discovery and graphify policy. Scoped repo_test / repo_lint. test_gap_finder. pre_pr_quality_gate. Same outcome, less thrashing. Context goes to your code, not to reinventing process.
For managers
Does MCP change the app or CI? No. Does it change how the AI works? Yes: shared conventions, targeted checks, less context waste. Do you need a team deployment? No for the handbook. Connect public Rocky. Repo tools need path access to your clone.
One line: same model, about 40-50% fewer tokens on a typical feature when Rocky is connected and the model follows the router (estimate).
For engineers
- Connect
devkitin Cursor. Confirm it is green. - Start with
devkit-start-task. - Read
codebase-discoveryonce per repo. Pick one router row. Do not read every agent. - Use
repo_test/ scoped tests, not the full suite every message. - Run
pre_pr_quality_gatebefore opening a PR.
Install notes: docs/INSTALL.md.
Plain English for managers (2 minutes)
Problem: Developers use AI to ship faster. Without shared tooling, each session rediscovers the repo, re-guesses standards, and re-runs huge test and lint cycles. That burns time and tokens. Review still catches style issues late.
Solution in one sentence: Rocky gives the AI a team-grade handbook and small, safe repo actions (test gaps, lint summary, pre-PR gate), even for a solo developer on a public server.
| Without MCP | With Rocky MCP | |
|---|---|---|
| AI context on process | Ad hoc | Shared playbook |
| Test/lint feedback | Heavy logs | Targeted actions |
| Review surprises | More common | pre_pr_quality_gate first |
| Tokens per feature | Higher band (about 150k-300k) | Lower band (about 70k-150k) |
How to work day to day
- Connect Rocky /
devkitMCP. devkit-start-task, thencodebase-discovery, then 1 agent and 1-2 rules.- Edit the user repo.
repo_test/repo_lint.pre_pr_quality_gateuntilverdict: "ready".
Call list_handbook only when you need a URI you do not know. Load skills when you need templates, not by default. Run graphify in the terminal. Read summary sections, not the full wiki in chat.
Token breakdown (one table)
| Bucket | Without MCP (typical) | With Rocky MCP (typical) |
|---|---|---|
| Repo discovery (reads + grep) | About 40k-80k | About 15k-30k |
| Handbook / process | 0 (ad hoc prompts) | About 4k-6k (disciplined) |
| Test + lint logs in chat | About 30k-60k | About 10k-25k |
| Implementation turns | About 80k-160k | About 40k-90k |
| Session total (mid) | About 150k-300k | About 70k-150k |
What saves tokens: router (2-3 handbook files), gateway JSON instead of pasted terminals, scoped tests, graphify summary-first.
What does not: reading every agent after list_handbook, loading all skills, pasting graphify-out/ wholesale into chat.
Solo vs team
| Myth | Reality |
|---|---|
| "Rocky is only for our org's private server." | Public handbook works for any repo you open in Cursor. |
| "I need the team's repo checked in." | Handbook is server-side. Your code stays local. |
| "Without a team I don't need conventions." | Solo devs benefit more. You are your own reviewer. |
