feat(oxide-code): add Anthropic streaming client and async REPL by hakula139 · Pull Request #2 · hakula139/oxide-code

hakula139 · 2026-04-01T09:22:02Z

Summary

Add the Anthropic Messages API streaming client, conversation types, and an async REPL — the foundation for an interactive AI coding assistant. Includes OAuth token refresh with proactive renewal, so sessions don't break when tokens expire.

Add config.rs with dual auth: ANTHROPIC_API_KEY env var or Claude Code OAuth credentials from ~/.claude/.credentials.json
Add config/oauth.rs with proactive token refresh (5-minute buffer before expiry), directory-based file locking compatible with Claude Code's proper-lockfile, and credential write-back preserving unknown JSON fields
Add message.rs with conversation types: Role, ContentBlock (Text / ToolUse / ToolResult), and Message
Add client/anthropic.rs with Anthropic Messages API streaming client — manual SSE parser, typed StreamEvent deserialization, channel-based streaming
Wire up main.rs as an async REPL: read stdin → call API → stream response to stdout
Default model set to claude-opus-4-6 with 1M context beta header
Add documentation index and Anthropic API authentication research notes

Key Findings

OAuth tokens require a system prompt prefix ("You are Claude Code, Anthropic's official CLI for Claude.") and the claude-code-20250219 beta header for the API to apply correct rate limits on non-Haiku models. Without these, Opus and Sonnet requests return 429.
Token refresh endpoint is platform.claude.com/v1/oauth/token (JSON POST with grant_type, refresh_token, client_id, scope).
See docs/research/anthropic-api.md for full details.

Changes

File	Description
`crates/oxide-code/src/client.rs`	Client module root
`crates/oxide-code/src/client/anthropic.rs`	Anthropic Messages API streaming client with SSE parser
`crates/oxide-code/src/config.rs`	Configuration loading (env vars, model, base URL, auth dispatch)
`crates/oxide-code/src/config/oauth.rs`	OAuth credential loading, proactive token refresh, file locking
`crates/oxide-code/src/message.rs`	Conversation message types (Role, ContentBlock, Message)
`crates/oxide-code/src/main.rs`	Async REPL: stdin → API → streamed stdout
`crates/oxide-code/Cargo.toml`	Crate dependencies
`Cargo.toml`	Workspace dependency versions
`CLAUDE.md`	Crate structure diagram and coding conventions
`docs/research/anthropic-api.md`	Anthropic API authentication research notes
`docs/README.md`	Documentation index
`docs/roadmap.md`	Roadmap updates for current working features
`.github/pull_request_template.md`	PR template with Changes table
`.markdownlint.json`	Markdownlint configuration
`pyproject.toml`	Python (uv) environment for dev scripts

Test plan

cargo build compiles cleanly
cargo clippy --all-targets -- -D warnings — zero warnings
cargo test — 23 tests pass (55.8% line coverage)
Smoke test: Opus 4.6 responds successfully via OAuth token
Empty ANTHROPIC_API_KEY correctly falls through to OAuth
Smoke test: token refresh triggers when token is near-expiry

anyhow, dirs, futures, reqwest (json + rustls-tls + stream), serde, serde_json, tokio, tracing, tracing-subscriber.

Auth priority: ANTHROPIC_API_KEY env var > Claude Code OAuth credentials at ~/.claude/.credentials.json.

Role, ContentBlock (Text / ToolUse / ToolResult), and Message with convenience constructors.

SSE parser with typed StreamEvent deserialization. Supports both API key and OAuth token auth via x-api-key header. Channel-based streaming for non-blocking event consumption.

Simple stdin REPL that sends user input to the Anthropic API and streams the response character-by-character to stdout.

OAuth tokens require `Authorization: Bearer` + `anthropic-beta: oauth-2025-04-20`, not `x-api-key`. Also clean up dead_code expect reasons that referenced internal plan labels.

The API model ID is always `claude-opus-4-6` — the 1M context window is activated by sending `anthropic-beta: context-1m-2025-08-07`. Beta headers are now accumulated in a vec and joined, so OAuth (`oauth-2025-04-20`) and 1M context compose cleanly.

Empty strings like `ANTHROPIC_API_KEY=""` were treated as valid values, bypassing the OAuth fallback and causing auth failures.

The Anthropic API requires a specific system prompt prefix to identify requests as Claude Code clients and apply correct rate limits for OAuth tokens. Without it, non-Haiku models return 429. Also add claude-code-20250219 and interleaved-thinking beta headers that claude-code always sends, and the x-app: cli header.

Documents the OAuth authentication flow, required beta headers, system prompt prefix requirement, and model ID conventions discovered by reverse-engineering claude-code.

- Drop _returns_none / _returns_error test naming convention (not idiomatic Rust — use scenario-based names instead) - Drop indoc! requirement - Add visibility convention (prefer minimal: private → pub(crate) → pub) - Add import ordering convention (std → external → internal) - Add expect reason accuracy rule (describe current state, not future) - Add unwrap/expect guidance (avoid in production, require invariant comment) - Clarify pub use guidance (consistency over prohibition) - Simplify helper ordering wording - Simplify code review section (remove implementation-specific tooling)

- Fix #[expect(dead_code)] reasons: "consumed by agent loop" → "defined for full SSE protocol coverage" (no agent loop exists yet) - Fix system prompt comment: clarify it's always sent, not OAuth-only - Remove dead skip_serializing_if on system field (always Some) - Rename tests to scenario-based names per revised CLAUDE.md - Reorder tests: happy path → variants → edge cases - Convert escaped test strings to raw strings

Move credentials_path below load_claude_oauth per CLAUDE.md convention that helper functions follow their caller.

Group always-sent beta headers together before conditional OAuth header, matching the vec initialization order in Client::new.

Add indoc as a dev dependency and convert SSE frame test literals to use indoc! macro, keeping test data properly indented with the surrounding code. Add convention to CLAUDE.md.

- Fix claude-code version (v2.1.87 → v2.1.88) and link to fork - Remove subscription-specific fields from credential example - Expand "1P" to "first-party only" in beta header table - Reorder beta headers by adoption priority - Update token refresh URL to platform.claude.com - Document oxide-code's refresh implementation and add source refs

- Extract OAuth logic from config.rs into config/oauth.rs - Refresh tokens proactively with a 5-minute buffer before expiry - Use directory-based locking (~/.claude.lock) compatible with Claude Code's proper-lockfile for cross-process safety - Double-check credentials after acquiring lock (another process may have already refreshed) - Graceful degradation: if refresh fails but token is still valid, warn and use existing token - Write back refreshed credentials preserving unknown JSON fields - Set 0o600 permissions on credentials file after write - Make Config::load() async to support the refresh HTTP call

- Replace Follow-ups section with per-file Changes table in PR template - Add prose intro guidance and markdownlint suppression - Reorganize git conventions into Commits / Branches / Pull Requests - Narrow commit scope guidance to module-level (not crate-level)

…oken Destructure creds.claude_ai_oauth into a local `oauth` binding and add OAuthCredential::expires_at_ms() to avoid repeating the u64 conversion.

Import Client, Delta, and StreamEvent all from client::anthropic instead of mixing re-exported and direct paths.

Also: replace .expect() with .context()? in stream_message, add doc comment on write_refreshed_credentials lock precondition, document clock skew assumption on expiresAt, and sort OAUTH_SCOPES alphabetically.

Decision #4 in the design section claimed `truncated_total` would become the single structural signal; the PR ended up splitting into `truncated_total` (view-shape) + `truncated_bytes` (byte cap) after review caught a unit-conflation hazard. Notes now describe the split and the rationale. Source-line list also updated: the bash and read self-cap references are gone with the code; remaining entries point at the constants and helpers without brittle line ranges. Test-name references in decision #2 follow the rename from `truncate_output_*` to `cap_output_*`.

hakula139 added 7 commits April 1, 2026 16:37

chore(oxide-code): add dependencies for Anthropic client

1e4a4c4

anyhow, dirs, futures, reqwest (json + rustls-tls + stream), serde, serde_json, tokio, tracing, tracing-subscriber.

feat(oxide-code): add config with API key and OAuth auth

05f2eb4

Auth priority: ANTHROPIC_API_KEY env var > Claude Code OAuth credentials at ~/.claude/.credentials.json.

feat(oxide-code): add conversation message types

e0e4e96

Role, ContentBlock (Text / ToolUse / ToolResult), and Message with convenience constructors.

feat(oxide-code): add Anthropic Messages API streaming client

75d4063

SSE parser with typed StreamEvent deserialization. Supports both API key and OAuth token auth via x-api-key header. Channel-based streaming for non-blocking event consumption.

feat(oxide-code): wire up async REPL with streaming responses

66d965a

Simple stdin REPL that sends user input to the Anthropic API and streams the response character-by-character to stdout.

docs: update crate structure diagram and cspell dictionary

cf31dc8

refactor(oxide-code): rename binary from oxide-code to ox

213260f

hakula139 self-assigned this Apr 1, 2026

hakula139 added enhancement New feature or request labels Apr 1, 2026

hakula139 added 14 commits April 2, 2026 10:44

fix(oxide-code): change default model to claude-opus-4-6

d4baad0

fix(oxide-code): use correct auth headers for OAuth tokens

006ddce

OAuth tokens require `Authorization: Bearer` + `anthropic-beta: oauth-2025-04-20`, not `x-api-key`. Also clean up dead_code expect reasons that referenced internal plan labels.

docs: standardize section dividers to box-drawing style (── xxx ──)

fe48c1b

chore: add missing words to cspell dictionary

f1eadac

fix(oxide-code): treat empty env vars as unset in config loading

25dade3

Empty strings like `ANTHROPIC_API_KEY=""` were treated as valid values, bypassing the OAuth fallback and causing auth failures.

docs: add Anthropic API authentication research notes

fe1e1c0

Documents the OAuth authentication flow, required beta headers, system prompt prefix requirement, and model ID conventions discovered by reverse-engineering claude-code.

docs: update roadmap with current working features

17d6736

docs: add documentation index

3926ecf

chore: add markdownlint configuration

1c64fce

chore: add Python environment (uv) for development scripts

d42ff04

chore: add missing words to cspell dictionary

8736261

style: fix table alignment in docs index

f0e9804

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hakula139 added 5 commits April 2, 2026 11:40

refactor(oxide-code): reorder helpers after their callers

286347a

Move credentials_path below load_claude_oauth per CLAUDE.md convention that helper functions follow their caller.

style(oxide-code): reorder beta header constants by usage

9b75352

Group always-sent beta headers together before conditional OAuth header, matching the vec initialization order in Client::new.

test(oxide-code): use indoc for multi-line test strings

8cf339d

Add indoc as a dev dependency and convert SSE frame test literals to use indoc! macro, keeping test data properly indented with the surrounding code. Add convention to CLAUDE.md.

hakula139 added 9 commits April 2, 2026 11:53

chore: update Cargo.lock for indoc dependency

616c699

style(research): sort source references alphabetically by path

0607730

refactor(oauth): extract expires_at_ms() and reduce nesting in load_t…

15ab134

…oken Destructure creds.claude_ai_oauth into a local `oauth` binding and add OAuthCredential::expires_at_ms() to avoid repeating the u64 conversion.

refactor(client): remove Client re-export, use consistent import path

5e5c324

Import Client, Delta, and StreamEvent all from client::anthropic instead of mixing re-exported and direct paths.

fix(oauth): add #[serde(default)] for missing refresh_token field

605549d

Also: replace .expect() with .context()? in stream_message, add doc comment on write_refreshed_credentials lock precondition, document clock skew assumption on expiresAt, and sort OAUTH_SCOPES alphabetically.

test(message): add tests for Message::user and Message::assistant

cac7ea6

hakula139 merged commit 8ec6f56 into main Apr 2, 2026
1 check passed

hakula139 deleted the feat/anthropic-client branch April 2, 2026 08:02

hakula139 mentioned this pull request Apr 19, 2026

chore(deps): bump rustls-webpki and rand for Dependabot alerts #17

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feat(oxide-code): add Anthropic streaming client and async REPL - #2

feat(oxide-code): add Anthropic streaming client and async REPL#2
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hakula139 commented Apr 1, 2026 •

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Summary

Key Findings

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Test plan

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hakula139 commented Apr 1, 2026 •

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