Bloom vs firstmate

Bloom and firstmate are both large language models tracked by AIDiveForge. Below is a side-by-side comparison of pricing, capabilities, platforms, and ownership — sourced from each tool's live website and verified before publishing.

Bloom

Bloom generates targeted evaluation suites for arbitrary behavioral traits.

firstmate

firstmate puts a single orchestrating agent — the 'first mate' — in front of you, while it spawns a crew of autonomous coding agents behind the scenes, each isolated in its own git worktree. You describe what needs doing; the crew splits the work in parallel and keeps collisions out of your main branch. The visible session backend means you can watch what each agent is doing without switching tabs. The architecture works cleanly for investigation tasks, parallel fixes, or supervised PR generation — the constraint is that there is no API surface, so anything requiring programmatic integration into an existing CI pipeline has to wire around the tool manually.

Attribute	Bloom	firstmate
Pricing	Free	Free
Free trial	No	No
Open source	No	Yes
Has API	Yes	No
Self-hosted option	Yes	Yes
Platforms	Python; integrates with Anthropic and OpenAI models via LiteLLM; supports Weights & Biases	—
Languages	Python	—
Released	2025-12-20	—
Pros	Reproducible and targeted evaluations that quantify frequency and severity across automatically generated scenarios Evaluations correlate strongly with hand-labelled judgments and reliably separate baseline models from intentionally misaligned ones Researchers can extensively configure Bloom's behavior, through choosing models for each stage, adjusting interactions' length and modality Using Bloom evaluations took only a few days to conceptualize, refine and generate Integrates with Weights & Biases for experiments at scale and exports Inspect-compatible transcripts	Crew-based parallel dispatch, so three investigation or fix tasks run simultaneously instead of sequentially — cutting the wall-clock time you'd spend babysitting separate agent sessions. Per-agent git worktree isolation, which means parallel agents working on adjacent code do not produce mid-run merge conflicts that you have to untangle before any output is usable. Visible session backend for the whole crew, so you can monitor what each agent is doing without switching terminals or losing track of which session held the failing test. Self-hosted under MIT license with no paid features gated behind a tier, so teams with data-residency or audit requirements can deploy it without a vendor conversation. Supervised agent loops with PR or report output as the end state, which means you review finished work rather than raw agent traces — keeping you in the loop at the decision point that matters.
Cons	Bloom is only as robust as the seeds and judging logic that power it; teams should treat seeds as living governance artifacts, and for ambiguous or highly contextual behaviors, periodic manual review is still necessary Bloom's evaluation suite is unlikely to match the precise distribution of scenarios found in existing benchmarks, and since model behavior can be sensitive to context and prompt variations, direct comparisons are unreliable	No API surface exists in the architecture, so teams that need to trigger agent crews from a CI system or external scheduler have to build shell-level integrations against a tool not designed for that pattern — and maintain that glue code themselves. The crew model requires a human interacting with the first mate agent as the starting point; fully unattended, scheduled agent runs with no human in the dispatch loop are not a supported workflow, which is the condition under which teams move to an orchestration framework that exposes a programmatic entry point. Community support through GitHub issues is the primary support channel — with 29 open issues noted on the repo — so teams encountering edge-case failures in production have no escalation path beyond the open-source community.

Bottom line

Firstmate is open source; only Bloom exposes a public API. Choose based on which difference matters most for your workflow.

Frequently asked questions

What is the difference between Bloom and firstmate?

Bloom is Free, while firstmate is Free and open source. Compare pricing, free trial, API, platforms, and pros/cons in the table above on AIDiveForge.

Is Bloom better than firstmate?

It depends on your workflow. Use the side-by-side attributes (pricing, open source, API, self-hosted, platforms) to decide. AIDiveForge does not rank a universal winner — we publish verified facts so you can choose.