agentpace

Stop estimating agent work in human weeks. agentpace answers "how long will this take?" from measured agent runs: a P50/P80/P90 range, with the human part (review, testing, decisions) stated on its own line and never derived from agent time.

Try it

With uv, this needs no install, no clone and no history of your own:

uvx agentpace estimate --example

<!-- claim:example_output -->
Plan total on the session clock: P50 2.4 h, P80 5.9 h, P90 9.0 h
The session clock counts agent runs and the gaps between them, each gap up to the idle cap (900 s by default), so waiting on you between runs sits inside the total up to that cap.
Human part (review, testing, decisions, waiting between agent turns): not measured. No allowance for it is added to the total above. State it separately; do not derive it from the agent time.

task          P50        P80        P90  critical  cell (n)
schema     30 min     85 min      2.5 h     100%  feature x normal x claude-opus-5-5 (n=205)
api        30 min     87 min      2.5 h      53%  feature x normal x claude-opus-5-5 (n=205)
ui         30 min     86 min      2.6 h      47%  feature x normal x claude-opus-5-5 (n=205)
docs         72 s      6 min     13 min      18%  docs x normal x claude-opus-5-5 (n=0)
review      3 min      8 min     13 min      82%  review x low x claude-opus-5-5 (n=1255)

Critical path: schema -> ui -> review (longest in 47% of simulations)
Effective parallelism at cap 3: 0.90 (from 29 sessions). Throughput set the total in 76% of simulations.
Method: shrunk. 3383 runs, 47 not completed so excluded. 20000 simulations, seed 20261107.
Not completed, by harness: claude-code 13 of 3219 (0.4%; 3 failed, 10 unknown), codex 34 of 211 (16.1%; 33 failed, 1 unknown). These are recorded harness outcomes, not task acceptance, and they are left out of the fit.

Warnings:
  - cell docs x normal x claude-opus-5-5: n=0. No recorded run has kind docs at risk normal with model claude-opus-5-5. Mean from docs x normal (n=21); residuals pooled from all; interval widened by the spread between models. Recorded models under docs x normal: claude-sonnet-5-5 (21).
<!-- /claim -->

The plan it estimated is examples/plan.json, where each task is one agent run:

{
  "agent_cap": 3,
  "model": "claude-opus-5-5",
  "tasks": [
    { "id": "schema", "kind": "feature", "risk": "normal" },
    { "id": "api", "kind": "feature", "risk": "normal", "depends_on": ["schema"] },
    { "id": "ui", "kind": "feature", "risk": "normal", "depends_on": ["schema"] },
    { "id": "docs", "kind": "docs", "risk": "normal", "depends_on": ["api"] },
    { "id": "review", "kind": "review", "risk": "low", "depends_on": ["api", "ui"] }
  ]
}

To estimate your own, write a plan like it and run agentpace estimate plan.json, or pass - to read it from stdin. In a plan, depends_on and model are optional, and risk can be left out: it defaults to the risk the rows record for the task's kind, because in the data risk is the agent's role, not a rating of the work.

Reading the output

• The plan total is a range, not one number, because agent run times have a long tail and any single number misses most of the time. P50 is a coin flip. P80 is the forecast's 80th percentile, the one to plan on, not a promise: the backtest shows how often it held.
• The session clock counts agent runs and the gaps between them, each gap up to the idle cap, so a short wait on you sits inside the total and a longer one is clipped at the cap. When your own rows or --data take part, an Idle cap: line under the total names the cap they were clipped at and says when they do not share one.
• The human part (review, testing, decisions, waiting between agent turns) is not measured, and no allowance for it is added. It stays on its own line, and agentpace never derives it from agent time.
• cell (n) is the group of recorded runs a task falls in, by kind, risk and model, and how many runs it holds. critical is the share of simulations in which the task was on the longest chain of dependent tasks.
• Effective parallelism is work divided by elapsed time, learned from recorded sessions at the plan's agent cap. It can be below 1, because a session's clock includes the time between runs.
• Warnings are part of the answer. When a task's cell has no or few recorded runs, one says so, what the range could not use (the kind, the risk level or the model) and where it leaned instead.

In your agent

npx skills add mohamedzhioua/agentpace

or, in Claude Code 2.1.275 or later, as a plugin:

/plugin install agentpace --marketplace mohamedzhioua/agentpace

Either way, install the CLI first (Install). npx skills add gives /pace-estimate, /pace-log and /pace-share; the plugin namespaces them as /agentpace:pace-estimate, /agentpace:pace-log and /agentpace:pace-share. The agentpace skill triggers by itself in both. Install one route, not both, or each skill loads twice.

Then ask your agent "How long will the billing feature take?": the skill calls the CLI.

This is the beginning of the README. Read the rest at the original. Read the full README ↗