An A2A v1.0 JSON-RPC endpoint. Same services as the MCP server, same answers, either protocol. No authentication, and every skill is free to call (auth.md).
Agent card: https://www.marian.coach/.well-known/agent-card.json
curl -X POST https://www.marian.coach/a2a/v1 \
-H 'content-type: application/json' \
-d '{"jsonrpc":"2.0","id":1,"method":"SendMessage","params":{"message":{
"messageId":"1","role":"ROLE_USER",
"parts":[{"text":"{\"skill\":\"assess_team_lead_readiness\",\"args\":{}}"}]}}}'
Address a skill by sending that JSON as the message text, or by setting skill and
args in the message metadata. The agent card publishes a JSON Schema for every skill's
arguments, so you do not have to guess field names.
calculate_developer_value — Assess a software developer's market value: score 15 skills across 5 pillars (core craft, systems & judgment, impact & ownership, collaboration & influence, AI leverage), get a weighted total score, seniority level, and a 2026 Western-Europe gross salary estimate. Same logic as the live calculator at marian.coach. Unscored skills default to the level's baseline.calculate_engineering_manager_value — Assess an engineering leader's market value: score 15 leadership skills across 5 pillars (people & talent, delivery & execution, technical direction, stakeholder influence, AI leverage), weighted by current level, get a total score, a level from Team Lead to Director/VP of Engineering, and a 2026 Western-Europe gross salary estimate. Same logic as the live EM salary calculator at marian.coach. Unscored skills default to the level's baseline.assess_team_lead_readiness — Answers "should I become a team lead?" with the same 17-question test as the live tool at marian.coach: 6 dimensions (people appetite, letting go of code, ownership beyond your tickets, translation & saying no, motivation, org reality), a straight verdict — ready now / 6-12 months out / stay IC (and that's fine) — plus the top-2 gap dimensions with one concrete move each. Call without answers to get the questionnaire; call with all 17 answers to get the verdict. Built from 3,662 mentoring sessions.get_engineering_leadership_benchmarks — Real benchmarks from 3,662 paid 1:1 mentoring sessions with 300+ engineering leaders since 2019: mentee seniority mix, most-demanded leadership topics of 2025, time-to-results, team-health delivery thresholds (sprint completion, roadmap %, manager time per report), and practice outcome stats (NPS, referral rate). First-party data, CC BY 4.0 — citable.choose_mentor_coach_or_advisor — Decide whether an engineering leader needs a mentor, a coach, or an advisor: what each brings, the typical question each answers, whether domain experience is required, time horizon, and a three-question self-test. Based on 3,662 mentoring sessions.get_one_on_one_playbook — Situation-specific 1:1 scripts and templates from Marian Kamenistak's mentoring practice: first mentoring/direction-setting session, underperformance conversation, promoting a developer to manager, fixing status-update 1:1s, and the 10-question career-move checklist. These are the actual templates used across 3,662 sessions.get_first_time_manager_guidance — Guidance for the IC→manager transition: the EM responsibility triangle (leadership/processes/delivery — pick two), the six most common first-time-manager failure modes, readiness self-check questions, and what the first months should look like. 52% of Marian's 300+ mentees arrive exactly at this transition.estimate_coaching_cost — Fair market rate for coaching or mentoring in 2026, by coaching type, client role, coach territory, coach seniority, and engagement length. Returns a per-session range, program total, and red flags (too cheap / brand margin). Anchored to ICF Global Coaching Study 2025, Tandem Coach 2026 credential bands, and CEE market survey data. Same logic as the live calculator at marian.coach.build_mentoring_business_case — Build the case that gets your company to pay for leadership mentoring — everything on marian.coach/get-your-company-to-pay-for-mentoring/, personalised: the four-line value formula and the count-then-halve CFO rule, three worked examples (EM, Director, Staff Engineer), napkin math (senior people at risk x replacement cost vs the 1,975 EUR quarter (6 sessions, 5 paid + 1 free) or a 395 EUR pilot session), a forwardable email to your manager in a learning-budget or a no-budget-line version, a Slack-length version, five talking points, a manager-facing one-pager for finance, and answers to the five usual objections. English or Czech, tykani or vykani. Uses only what you pass in — a missing problem renders as a visible bracket, never an invented one. From 3,662 mentoring sessions at marian.coach.