16 pages for onblock.

Beta Claude Developer Platform · in the page api/beta …che control breakpoint at this content block. - `BetaCompactionBlockParam object` A compaction block containing summary of previous context. Users should round-trip thes… Messages Claude Developer Platform · in the page api/beta/messages …che control breakpoint at this content block. - `BetaCompactionBlockParam object` A compaction block containing summary of previous context. Users should round-trip thes… Batches Claude Developer Platform · in the page api/beta/messages/batches …control breakpoint at this content block. - `BetaCompactionBlockParam object` A compaction block containing summary of previous context. Users should round-t… Create a Message Batch Claude Developer Platform · in the page api/beta/messages/batches/create …control breakpoint at this content block. - `BetaCompactionBlockParam object` A compaction block containing summary of previous context. Users should round-t… Retrieve Message Batch results Claude Developer Platform · in the page api/beta/messages/batches/results …ner_upload - `file_id: string` - `BetaCompactionBlock object` A compaction block returned when autocompact is triggered. When content is None, it indi… Count tokens in a Message Claude Developer Platform · in the page api/beta/messages/count_tokens …che control breakpoint at this content block. - `BetaCompactionBlockParam object` A compaction block containing summary of previous context. Users should round-trip thes… Create a Message Claude Developer Platform · in the page api/beta/messages/create …che control breakpoint at this content block. - `BetaCompactionBlockParam object` A compaction block containing summary of previous context. Users should round-trip thes… sent_count = len(messages sent in the compaction request) Claude Developer Platform · in the page build-with-claude/compaction …tVariant.ContentBlock.AsAny().(type) { case anthropic.BetaCompactionBlock: fmt.Println("Compaction started...") case anthropic.BetaTextBlock: fmt.Println("Text response started...")… compaction-threshold Claude Developer Platform · in the page build-with-claude/compaction-threshold …tVariant.ContentBlock.AsAny().(type) { case anthropic.BetaCompactionBlock: fmt.Println("Compaction started...") case anthropic.BetaTextBlock: fmt.Println("Text response started...")… mid-conversation-system-messages Claude Developer Platform · in the page build-with-claude/mid-conversation-system-messages …ent = new( [ new BetaRequestToolAdditionBlock { Tool = new BetaToolChangeToolDefinitionParam {… Connect to external tools with MCP Claude Code CLI · in the page agent-sdk/mcp …it, before Claude Code sends the init message: * **[`MCP_CONNECTION_NONBLOCKING`](https://code.claude.com/docs/en/env-vars) set to `0`**: startup waits for the whole connection batch, up to 5 seconds… Agent SDK reference - TypeScript Claude Code CLI · in the page agent-sdk/typescript …tps://code.claude.com/docs/en/hooks#response-schema) without `continueOnBlock: true`, Claude Code stops the message instead of dropping it. The message waits for its own turn, you get a result for it,… Environment variables Claude Code CLI · in the page env-vars …| | `CLAUDE_CODE_NONBLOCKING_STDOUT` | Set to `1` to write terminal output through a second non-blocking file descriptor, so… Automate actions with hooks Claude Code CLI · in the page hooks-guide …the deny `reason` appears in the chat as a warning line. Set `continueOnBlock: true` on the hook to instead return the `reason` to Claude as the tool error, so it can adjust and continue * `PostTool… Connect Claude Code to tools via MCP Claude Code CLI · in the page mcp …r servers connect in the background by default; set [`MCP_CONNECTION_NONBLOCKING=0`](https://code.claude.com/docs/en/env-vars) to make startup wait for them too. ### Defer a server's tools To keep a… Customize sessions in self-hosted environments Claude Code CLI · in the page self-hosted-environments-configuration …ver-from-deferral), or for all servers when you set [`MCP_CONNECTION_NONBLOCKING=0`](https://code.claude.com/docs/en/env-vars) in the runner's environment. HTTP and SSE servers otherwise connect in th…