Files
hermes-agent/website/docs/user-guide/features/context-references.md
Teknium ebcb81b649 docs: document 9 previously undocumented features
New documentation for features that existed in code but had no docs:

New page:
- context-references.md: Full docs for @-syntax inline context
  injection (@file:, @folder:, @diff, @staged, @git:, @url:) with
  line ranges, CLI autocomplete, size limits, sensitive path blocking,
  and error handling

configuration.md additions:
- Environment variable substitution: ${VAR_NAME} syntax in config.yaml
  with expansion, fallback, and multi-reference support
- Gateway streaming: Progressive token delivery on messaging platforms
  via message editing (StreamingConfig: enabled, transport, edit_interval,
  buffer_threshold, cursor) with platform support matrix
- Web search backends: Three providers (Firecrawl, Parallel, Tavily)
  with web.backend config key, capability matrix, auto-detection from
  API keys, self-hosted Firecrawl, and Parallel search modes

security.md additions:
- SSRF protection: Always-on URL validation blocking private networks,
  loopback, link-local, CGNAT, cloud metadata hostnames, with
  fail-closed DNS and redirect chain re-validation
- Tirith pre-exec security scanning: Content-level command scanning
  for homograph URLs, pipe-to-interpreter, terminal injection with
  auto-install, SHA-256/cosign verification, config options, and
  fail-open/fail-closed modes

sessions.md addition:
- Auto-generated session titles: Background LLM-powered title
  generation after first exchange

creating-skills.md additions:
- Conditional skill activation: requires_toolsets, requires_tools,
  fallback_for_toolsets, fallback_for_tools frontmatter fields with
  matching logic and use cases
- Environment variable requirements: required_environment_variables
  frontmatter for automatic env passthrough to sandboxed execution,
  plus terminal.env_passthrough user config
2026-03-24 08:56:21 -07:00

3.9 KiB

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9 Context References Inline @-syntax for attaching files, folders, git diffs, and URLs directly into your messages

Context References

Type @ followed by a reference to inject content directly into your message. Hermes expands the reference inline and appends the content under an --- Attached Context --- section.

Supported References

Syntax Description
@file:path/to/file.py Inject file contents
@file:path/to/file.py:10-25 Inject specific line range (1-indexed, inclusive)
@folder:path/to/dir Inject directory tree listing with file metadata
@diff Inject git diff (unstaged working tree changes)
@staged Inject git diff --staged (staged changes)
@git:5 Inject last N commits with patches (max 10)
@url:https://example.com Fetch and inject web page content

Usage Examples

Review @file:src/main.py and suggest improvements

What changed? @diff

Compare @file:old_config.yaml and @file:new_config.yaml

What's in @folder:src/components?

Summarize this article @url:https://arxiv.org/abs/2301.00001

Multiple references work in a single message:

Check @file:main.py, and also @file:test.py.

Trailing punctuation (,, ., ;, !, ?) is automatically stripped from reference values.

CLI Tab Completion

In the interactive CLI, typing @ triggers autocomplete:

  • @ shows all reference types (@diff, @staged, @file:, @folder:, @git:, @url:)
  • @file: and @folder: trigger filesystem path completion with file size metadata
  • Bare @ followed by partial text shows matching files and folders from the current directory

Line Ranges

The @file: reference supports line ranges for precise content injection:

@file:src/main.py:42        # Single line 42
@file:src/main.py:10-25     # Lines 10 through 25 (inclusive)

Lines are 1-indexed. Invalid ranges are silently ignored (full file is returned).

Size Limits

Context references are bounded to prevent overwhelming the model's context window:

Threshold Value Behavior
Soft limit 25% of context length Warning appended, expansion proceeds
Hard limit 50% of context length Expansion refused, original message returned unchanged
Folder entries 200 files max Excess entries replaced with - ...
Git commits 10 max @git:N clamped to range [1, 10]

Security

Sensitive Path Blocking

These paths are always blocked from @file: references to prevent credential exposure:

  • SSH keys and config: ~/.ssh/id_rsa, ~/.ssh/id_ed25519, ~/.ssh/authorized_keys, ~/.ssh/config
  • Shell profiles: ~/.bashrc, ~/.zshrc, ~/.profile, ~/.bash_profile, ~/.zprofile
  • Credential files: ~/.netrc, ~/.pgpass, ~/.npmrc, ~/.pypirc
  • Hermes env: $HERMES_HOME/.env

These directories are fully blocked (any file inside):

  • ~/.ssh/, ~/.aws/, ~/.gnupg/, ~/.kube/, $HERMES_HOME/skills/.hub/

Path Traversal Protection

All paths are resolved relative to the working directory. References that resolve outside the allowed workspace root are rejected.

Binary File Detection

Binary files are detected via MIME type and null-byte scanning. Known text extensions (.py, .md, .json, .yaml, .toml, .js, .ts, etc.) bypass MIME-based detection. Binary files are rejected with a warning.

Error Handling

Invalid references produce inline warnings rather than failures:

Condition Behavior
File not found Warning: "file not found"
Binary file Warning: "binary files are not supported"
Folder not found Warning: "folder not found"
Git command fails Warning with git stderr
URL returns no content Warning: "no content extracted"
Sensitive path Warning: "path is a sensitive credential file"
Path outside workspace Warning: "path is outside the allowed workspace"