Field noteNov 3, 20266 min read1 source

Meituan released LongCat-2.5, its new multimodal model with 1.6T total parameters and 49B active.

In one minute

Meituan’s LongCat site presents LongCat-2.5 as a natively multimodal mixture-of-experts model for coding agents, complex codebases and visual work. It matters to AI builders because Meituan says it can work across familiar agent harnesses, although the supplied primary material provides neither benchmarks nor commercial operating details.

What happened

Meituan’s LongCat website describes LongCat-2.5 as a natively multimodal model intended for agent tasks. The page says the model has 1.6 trillion parameters and calls it a mixture-of-experts, or MoE, model in the linked release description. It frames the update around large-scale long-context training and long-horizon reinforcement learning. The supplied official text does not specify an active parameter count, despite an unverified discovery excerpt making such a claim.

The company positions the model for complex engineering development and visual programming. On the product page, LongCat-2.5 is described as supporting visual coding, creative design and 3D tasks. Those labels indicate that Meituan wants the model used beyond text-only code generation, but the page does not define the visual inputs, output formats, supported tools or task boundaries for those workloads. It also does not provide demonstrations or independently measured performance for them.

For software work, Meituan says LongCat-2.5 handles complex codebases and full-project builds using multi-step reasoning and tool use. This is a product claim about agentic operation rather than a documented workflow specification. The supplied material does not say which tools the model can call, how an agent is configured, what permissions it needs, or how a team should assess completion and correctness on a repository-level task. It also offers no task-success rates, reliability data, or evidence about long-running work.

The page lists compatibility with Claude Code, Codex, Hermes and other agent harnesses. For teams already using one of those environments, that could make an evaluation less disruptive than adopting a wholly separate interface. However, Meituan does not explain the integration mechanism, whether compatibility is native or adapter-based, which capabilities work in each harness, or whether behavior differs between them. Compatibility should therefore be read as a claim to investigate rather than proof of interchangeable deployment.

The homepage links to an “API & Token Pack” page and to a LongCat-2.5 article dated 2026-11-01, “LongCat-2.5: Native Multimodal Model for Agent Tasks.” The supplied source does not include pricing, quotas, availability, account eligibility, API documentation, context-window size, or rate limits. It also displays an earlier LongCat-2.0 article dated 2026-06-29, described as a 1.6 trillion-parameter MoE model with 1M long context. That earlier model’s context figure cannot be assigned to LongCat-2.5 from the material provided here.

What the archive adds

An earlier LongCat-2.5 Field Note covered the 2.5-Preview. The current official page is a fuller release announcement with claims about harness compatibility and multimodal tasks, so this is a new fact on a known story rather than a wholly new thread.

Trend signal

This release weakly supports harness architecture outlives model choice. Meituan foregrounds claimed compatibility with Claude Code, Codex and Hermes instead of requiring a single proprietary harness. That is directionally consistent with models competing inside established workflows, but the source does not establish integration quality, feature parity, switching cost, or whether a team can move between models without engineering work.

Why now

The official page lists the LongCat-2.5 article as dated 2026-11-01, after the LongCat-2.0 article dated 2026-06-29. The archive also identifies an earlier 2.5-Preview. Together, those facts support treating this as a fuller 2.5 release, but neither the source nor archive explains Meituan’s timing or a specific market trigger.

Connections to other events

The direct connection is the earlier LongCat-2.5 Field Note, which covered the preview version. The present source adds a public product-page framing around multimodal tasks and cross-harness use. It does not provide enough detail to compare LongCat-2.5 substantively with other multimodal releases in the archive.

Why it matters

The practical question for builders is not the headline parameter count alone. If the stated harness compatibility holds, a team could test LongCat-2.5 within an existing coding-agent workflow rather than first rebuilding its orchestration around a vendor-specific application. Its claimed visual capabilities may also make it a candidate for workflows that combine repositories with design, visual-programming, or 3D artifacts.

None of that establishes adoption value yet. The source gives no independent evaluation, completed-task metric, pricing, service limits, or evidence that the model reduces retries or review effort. A model that can be selected in a familiar harness may be easier to trial, but it still needs to earn a place through controlled evaluation on the team’s own tasks. Treat this release as an evaluation option, not as proof of a quality, cost, or productivity advantage. Earlier coverage: Meituan releases LongCat-2.5, a 1.6T-parameter native multimodal MoE for long-horizon agentic coding.

What happens next

  • Meituan publishes fuller operational details for LongCat-2.5, such as access terms, API limits, or technical evaluation material. (3 months, 65%). Watch for: updates to the linked API & Token Pack page or the LongCat-2.5 article.
  • Builders test whether the listed harness compatibility provides usable tool-driven coding workflows rather than nominal model access. (6 months, 55%). Watch for: documented setup guidance and capability-specific integration notes.

Limits and uncertainty

The supplied official-page material does not establish LongCat-2.5’s active parameter count, context-window length, benchmark performance, inference cost, API terms, or general availability. It lists harnesses but does not say whether the connections are native integrations, adapters, or compatibility claims with limitations. The page’s statements about complex engineering, full-project builds, and long-horizon agency are vendor characterizations, not independently verified results. A discovery excerpt mentions API availability and comparisons with named models, but the official page excerpt supplied here does not substantiate those details. The linked API page and technical article may contain more information, but they are outside the supplied evidence.

Skill to build now

Create a small, repeatable evaluation pack before trialing any newly announced coding model: select a representative repository task, define tool permissions, preserve the same harness configuration, and record completion quality, retries, elapsed time, and reviewer corrections. That makes a claimed cross-harness integration testable on the work your team actually performs. Do not infer model quality from parameter totals or compatibility labels alone.

Reader takeaway

LongCat-2.5 is Meituan’s newly presented multimodal MoE for agentic coding and visual tasks, with claimed support for common agent harnesses. That makes it potentially convenient to evaluate, but the supplied release material leaves the decisive adoption questions unresolved: access, cost, integration depth, reliability, and performance on completed work.

Open question

What active-parameter count, API access terms, evaluation results, and harness-specific integration details will Meituan publish for LongCat-2.5?

Evidence / sources

  1. 1longcat.ai
All Field Notes

Next reads

Read next

Open the graph
  1. 01topicClaudeExplore the claude topic hub.
  2. 02topicClaude CodeExplore the claude-code topic hub.
  3. 03topicCodexExplore the codex topic hub.
  4. 04archiveField NotesOpen the latest editorial analysis.
  5. 05sourcesSourcesSee the original sources this archive cites.
Who read this page?Machine requests, hidden until opened

Loading the privacy-safe route aggregate...

Open the JSON contract