# Context Window Manager

> Context Window Manager is a paid API for AI agents from context-window-manager.johntaylor1online.workers.dev, paid per call via x402, $0.15/call, status unknown (last checked 2026-10-11).

Manages and optimizes AI context windows by trimming, summarizing, or restructuring conversation history to fit within token limits

## Facts

- Endpoint: POST https://context-window-manager.johntaylor1online.workers.dev/manage?utm_source=zero.xyz
- Price: $0.15/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-11
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/context-window-manager-31e3beca
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_b-9tXxaPWm-URgZ6ZzauP

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability context-window-manager-31e3beca -d '<json body>'
```

Example prompt: My conversation history is getting too long and I'm hitting token limits — can you use the Context Window Manager to trim and optimize it so it fits within the available context window while preserving the most important information?

## When to prefer this

Choose this endpoint when an AI agent or application is encountering context window overflow, needs to compress long conversation histories before passing them to an LLM, or requires automated management of token budgets without manually implementing trimming logic. It is especially useful for long-running agent sessions or multi-turn chatbot applications.

## Known failure modes

- Missing required 'input' or 'output' fields returns a validation error
- Malformed JSON body causes a 400 Bad Request
- Oversized payload that cannot be meaningfully reduced may return an error or partial result
- Service unavailability returns 5xx errors
- Payment not provided or invalid x402 payment header results in 402 Payment Required

## How this service works

Context Window Manager

## Output

Returns a processed context object with the managed/optimized conversation history, potentially including trimmed messages, summaries, or restructured content designed to fit within a specified token budget while retaining the most relevant information.

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/context-window-manager-31e3beca/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from context-window-manager.johntaylor1online.workers.dev](https://www.zero.xyz/host/context-window-manager.johntaylor1online.workers.dev/llms.txt)